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HangerQueen
02-03-2004, 07:54 AM
For those of you like me who may have been wondering what the difference between a supercharger and a turbo charger is, here's a good description.

http://www.howstuffworks.com/question122.htm

This is about car engines, but I guess the principles are the same for prop planes.

"You can try, but it is a difficult and thankless task to compare the combat qualities of aircraft using reference book data. There are simply too many nuances to consider." N. G. Golodnikov

HangerQueen
02-03-2004, 07:54 AM
For those of you like me who may have been wondering what the difference between a supercharger and a turbo charger is, here's a good description.

http://www.howstuffworks.com/question122.htm

This is about car engines, but I guess the principles are the same for prop planes.

"You can try, but it is a difficult and thankless task to compare the combat qualities of aircraft using reference book data. There are simply too many nuances to consider." N. G. Golodnikov

dugong
02-03-2004, 08:05 AM
Too bad you can't really hear the whossh of a turbo in an aircraft. That is a sweet sound. I think my modded turbo VW sounds better than many WWII planes!

Thanks for the link - great read.

BaldieJr
02-03-2004, 08:06 AM
OMFG I want a Type-R P-40 d000dz!!!!!

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Rajvosa
02-03-2004, 08:09 AM
Interesting link!
Too bad they do not answer which one is more efficient. As for cars, I prefer the supercharger (aka blower). It delivers more power at low rpm while every turbo suffers from turbo lag (time until the turbine spinns up) and works best at high rpms. Also, turbos require intercoolers to keep the intake air cool since this gives more power. The heat they generate is immense.
Plus, I can't help but associate turbos with "rice", if you know what I mean http://ubbxforums.ubi.com/images/smiley/16x16_smiley-wink.gif

Golf GTI Edition 2.0 16v (Rest In Pieces!)

michapma
02-03-2004, 08:55 AM
That discussion doesn't consider the effect of altitude on engine performance, understandable for cars.

If you're interested in learning more, have a look at this article:
http://rwebs.net/avhistory/opsman/geturbo/geturbo.htm

In addition, if you go to the Further information (http://people.ee.ethz.ch/~chapman/il2guide/cemguide/furtherinfo.htm) page of the CEM guide, you'll find a link to a rather large PDF file (17.5MB, it consists of jpgs that Loco-S scanned and sent me), called "The Aircraft Engine and its Operation" from the war era. There is a 25-page section dedicated to discussing superchargers, very informative stuff.

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effte
02-03-2004, 09:07 AM
Both will benefit from intercoolers... the air is being compressed in either case.

I'd argue that supercharging is the more effective, as you are bound to have losses in the turbine that you will not have in a more direct transmission. However, a supercharger will not be regulated as readily to provide just the right pressure.

Good to be rid of all the ducting associated with the turbocharger too. Oh well... have both, and get the worst of both worlds... as some aircraft we know of. http://ubbxforums.ubi.com/infopop/emoticons/icon_wink.gif

Cheers,
Fred

michapma
02-03-2004, 09:14 AM
FT, long time no see. http://ubbxforums.ubi.com/images/smiley/16x16_smiley-happy.gif

I think supercharging is lost on a lot of folks around here due to the low-alt nature of Eastern Front operations.

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Platypus_1.JaVA
02-03-2004, 09:22 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by dugong:
Too bad you can't really hear the whossh of a turbo in an aircraft. That is a sweet sound. I think my modded turbo VW sounds better than many WWII planes!

Thanks for the link - great read.<HR></BLOCKQUOTE>

Yeah right, your puny little VW golf sounds better then the Mustang or the P-47 In real life??

Okay, the engine sound in Il-2 is nog great but, you should hear those planes on an airshow sometimes!! After that, you want a merlin in your car also http://ubbxforums.ubi.com/infopop/emoticons/icon_smile.gif

Cheers mate, good luck with your golf. How fast is it?

1 Judge not, that ye be not judged.
2 For with what judgment ye judge,
ye shall be judged: and with what
measure ye mete, it shall be measured
to you again.

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michapma
02-03-2004, 09:44 AM
Did I mention the good old Deakin articles?

http://www.avweb.com/news/columns/182102-1.html

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dugong
02-03-2004, 04:23 PM
[QUOTE]Originally posted by Rajvosa:
Interesting link!
Too bad they do not answer which one is more efficient. As for cars, I prefer the supercharger (aka blower). It delivers more power at low rpm while every turbo suffers from turbo lag (time until the turbine spinns up) and works best at high rpms. Also, turbos require intercoolers to keep the intake air cool since this gives more power. The heat they generate is immense.
Plus, I can't help but associate turbos with "rice", if you know what I mean http://ubbxforums.ubi.com/images/smiley/16x16_smiley-wink.gif

Ack! Associate turbo's with rice? There are very few Japanese cars with stock turbos. They are mostly highly reving redliners.

As for turbo lag, in modern turbos it is not even a factor. Turbos spool up much quicker than the old days. Mine gets going around 1700 RPM's. That will plant you in the back of your seat like a Merlin engine!

dugong
02-03-2004, 04:31 PM
_________________________________________
Yeah right, your puny little VW golf sounds better then the Mustang or the P-47 In real life??
_________________________________________

Nah - maybe I exaggerated a little bit. My car still sounds sweet though.
___________________________________________
Cheers mate, good luck with your golf. How fast is it?
___________________________________________

It's a Jetta! And it is f a s t. Currently, I just have a chip that boosts the turbo output. It'll get to 60 in about 6.4 secs, maybe a little quicker on a cold day. To get techincal, soon I may add a CAI, catback, and performance exhuast - then it will be beast!

And that comment about adding a Merlin engine - that was a great suggetion. I will get back to you and tell you how it worked out....

JR_Greenhorn
02-03-2004, 10:05 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by effte:
I'd argue that supercharging is the more effective, as you are bound to have losses in the turbine that you will not have in a more direct transmission. <HR></BLOCKQUOTE>I would argue that the opposite were true.
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by dugong:
It's a Jetta! And it is f a s t. Currently, I just have a chip that boosts the turbo output. It'll get to 60 in about 6.4 secs, maybe a little quicker on a cold day. To get techincal, soon I may add a CAI, catback, and performance exhuast - then it will be beast!<HR></BLOCKQUOTE> http://ubbxforums.ubi.com/images/smiley/16x16_smiley-indifferent.gif

WhiskeyRiver
02-04-2004, 12:15 AM
Turbocharging is more efficient. Superchargers are driven off the crankshaft. The energy used to turn a blower is energy that could be accelerating the car/aircraft. Turbo's are driven by the heat from exhaust gasses which would normally be wasted. About 1/4 to 1/3 of a piston engine's energy is wasted through the exhaust. Both benefit from intercoolers. You get about 1 horsepower for every 11 degrees F you lower air inlet temperature.

Turbo lag is not much of an issue with aircraft since aircraft engines operate at fairly constant rpms. A parallel to this would be the big diesel engines used in large trucks or boats. Both operate in fairly narrow rpm ranges like aircraft engines. I've never seen a supercharged diesel-only turbos.

That said turbo's are much harder to manufacture and maintain due to the heat and high rpm's they encounter. The require exotic materials(P-38's compressor and turbine were tungsten) and precision made high speed bearings. Not to mention balancing, inspection, etc.

Dugong,
The "whoosh" sound your Golf makes is from the blowoff or compressor bypass valve. This valve vents excess bosst pressure to keep the turbo spinning between shifts. Listen to a P-38 at idle. You can definitely hear a high pitch whistling sound over the noise from the exhaust and props. That noise is from the turbo. If you pulled the airbox off of your VW you could hear it also.

To kill me you've got to hit the heart Ramon--Clint F*cking Eastwood

WhiskeyRiver
02-04-2004, 12:26 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by effte:

I'd argue that supercharging is the more effective, as you are bound to have losses in the turbine that you will not have in a more direct transmission. However, a supercharger will not be regulated as readily to provide just the right pressure.
<HR></BLOCKQUOTE>

Yuo've got it backward. The direct connection is what costs you power. Horsepower that would normally go to the prop or wheels instead is used to compress inlet air via the supercharger. Turbo's are driven with energy that would normally be wasted.

Also, some supercharged aircraft engines like the DB series engines in the 109 were hydraulically driven by a torque converter. Boost is easily regulated on these and less horsepower is used to drive the blower. This does cause poor throttle response though. But like I said before, throttle response isn't much of problem on aircraft

To kill me you've got to hit the heart Ramon--Clint F*cking Eastwood

Rajvosa
02-04-2004, 12:46 AM
....Ack! Associate turbo's with rice? There are very few Japanese cars with stock turbos. They are mostly highly reving redliners....


My point exactly! It's what most of those punks will bolt on just to be fast. And blow their engines. And than they'll add A LOT of plastic spoilers (yeah, they spoil their cars), wings and other nonsense. Rice Boys http://ubbxforums.ubi.com/images/smiley/16x16_smiley-tongue.gif.

Having said that, you may notice that my Golf is now resting in pieces (combination of icy roads and overzealous driver). In a few weeks I'll be buying a BMW 325, but in the mean time I got a 1988 Mazda 626 2 l and 16 v. It's not as powerful as the Golf, but it's revvy like heck! I had it past 7000 rpm the other day. Made a helluva burnout. A 16 years old car with 260 000 km on the odo meter! Japanese cars ARE good! http://ubbxforums.ubi.com/images/smiley/icon_twisted.gif

Golf GTI Edition 2.0 16v (Rest In Pieces!)

Tempestate
02-04-2004, 01:38 AM
michapma, a very fine article. njoyed the read.

Although I cannot make head nor tail of the pounds and feet imperial stuff LOL

pourshot
02-04-2004, 04:24 AM
This is the cutting edge for superchargers

Wipple Superchargers (http://www.whipplesuperchargers.com/default.asp)

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Ride It Like Ya Stole It

pourshot
02-04-2004, 04:40 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by WhiskeyRiver:

Turbo lag is not much of an issue with aircraft since aircraft engines operate at fairly constant rpms. A parallel to this would be the big diesel engines used in large trucks or boats. Both operate in fairly narrow rpm ranges like aircraft engines. I've never seen a supercharged diesel-only turbos.
<HR></BLOCKQUOTE>

All the 2 stroke GM diesels were supercharged and later Turbo supercharged,Being a wet sumped 2 stroke meens you must force air into it to run at all.

A normal 2 stroke uses the down cycle of the piston to force air into and out of the chamber (at the same time).

how it works (http://www.marinediesels.info/Basics/uniflow_and_loop_scavenging.htm)

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Ride It Like Ya Stole It

[This message was edited by pourshot on Wed February 04 2004 at 04:22 AM.]

michapma
02-04-2004, 05:18 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Tempestate:
michapma, a very fine article. njoyed the read.

Although I cannot make head nor tail of the pounds and feet imperial stuff LOL<HR></BLOCKQUOTE>

I guess you mean the one at avhistory. My engine gets forty rods to the hogshead, and that's the way I likes it! http://ubbxforums.ubi.com/images/smiley/16x16_smiley-very-happy.gif

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p1ngu666
02-04-2004, 09:32 AM
the turbo's used on rally cars have antilag
basicaly they explode fuel in the exhaust to keep the turbo spiining at high rpm. thats what the pops and bangs are.
im sure dragsters have some badass turbos/supercharges

michapma
02-04-2004, 09:55 AM
Cars, huh? http://ubbxforums.ubi.com/infopop/emoticons/icon_rolleyes.gif

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Seedking1
02-04-2004, 09:57 AM
Supercharging is the more efficeint of the two -both pump more gas/air into the engine - one uses exhaust flow- the other uses direct drive off the crank - supercharging adds 1hp per cubic inch, where as turbo charging is 1/2 that. As for the argument that supercharging uses energy to add energy agst turbo - yes, but the end result is awesome!!!!

WhiskeyRiver
02-04-2004, 12:04 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Seedking1:
Supercharging is the more efficeint of the two -both pump more gas/air into the engine - one uses exhaust flow- the other uses direct drive off the crank - supercharging adds 1hp per cubic inch, where as turbo charging is 1/2 that. As for the argument that supercharging uses energy to add energy agst turbo - yes, but the end result is awesome!!!!<HR></BLOCKQUOTE>

you are incorrect. There is no set rule as to how much horsepower a supercharger or turbocharger will add to an engine. When I added a turbocharger to my car I gained a good amount of horsepower. After porting the exhaust manifold, adding an intercooler w/ water sprayer, an electronic boost controller, larger downpipe, and re-routing the intake piping I suddenly had another 90 horsepower at the same boost level(9 psi) as before. I had definitely gained more than 1/2 horsepower per cubi inch. An excellent book would be the "Bosch Automotive Handbook". It explains with charts, graphs, etc. most aspects of forced induction.

To kill me you've got to hit the heart Ramon--Clint F*cking Eastwood

dugong
02-04-2004, 04:00 PM
Whiskey River -

Sounds like you have mean ride. What exactly is it?

Blottogg
02-04-2004, 06:41 PM
JR, WhiskeyRiver, you beat me to it.

Turbochargers are more efficient than superchargers. Top fuel dragsters use superchargers to generate something on the order of 3000 HP, but at those power levels, the blower alone takes something like 800 HP to run (so the engine is actually making at least 3800 HP.) They use blowers instead of turbos though because when you're running the 1/4 mile in less than 4 seconds, just a little turbo lag makes you uncompetitive (0.1 sec is imperceptible, but is a lifetime in competitive terms.)

That being said, my Miata is supercharged (w/ intercooler), not turbocharged. Blowers are easier to install, and give instant (if inefficient) power gains. If I had to do over again, I'd probably go with an 8 psi turbo instead of an 8 psi blower though. Same power made, without the power loss of driving the blower.

Intercoolers dissipate the heat of compression (PV=nRT), not the heat of the turbine itself.

Blotto

"Speed is life." - Anon
"Sight is life. Speed is merely groovy." - "Junior"

WhiskeyRiver
02-04-2004, 09:23 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by dugong:
Whiskey River -

Sounds like you have mean ride. What exactly is it?<HR></BLOCKQUOTE>

It's a 1997 Honda civic coupe. It's not that mean. I used to have it turbocharged and intercooled with the 1.6L SOHC (single overhead camshaft) engine. That engine blew up at about 150mph on the interstate. The lower coolant hose ruptured and the engine overheated and melted a piston before I could shut it off. It was pretty fast though. I was easily beating Chevy Camaros and Mustangs(5.7L and 4.6/5.0L engines) pretty easily. Since then I've changed engines and now have a 2.0L DOHC engine out of a Honda CR-V. It's not turbocharged yet. I'm probably gonna build up another 2.0L with a turbo and drop it in sometime next year. I figure 400 horsepower is a nice round number.

PS Almost forgot, It's also got some mild suspension modifications. I also stripped out all the sound deadener(about 100 pounds). I plan on removing about another 100 punds of weight from the car. Power steering and A/C have also been removed.

To kill me you've got to hit the heart Ramon--Clint F*cking Eastwood

WhiskeyRiver
02-04-2004, 09:35 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Blottogg:
JR, WhiskeyRiver, you beat me to it.

Turbochargers are more efficient than superchargers. Top fuel dragsters use superchargers to generate something on the order of 3000 HP, but at those power levels, the blower alone takes something like 800 HP to run (so the engine is actually making at least 3800 HP.) They use blowers instead of turbos though because when you're running the 1/4 mile in less than 4 seconds, just a little turbo lag makes you uncompetitive (0.1 sec is imperceptible, but is a lifetime in competitive terms.)

That being said, my Miata is supercharged (w/ intercooler), not turbocharged. Blowers are easier to install, and give instant (if inefficient) power gains. If I had to do over again, I'd probably go with an 8 psi turbo instead of an 8 psi blower though. Same power made, without the power loss of driving the blower.

Intercoolers dissipate the heat of compression (PV=nRT), not the heat of the turbine itself.

Blotto

"Speed is life." - Anon
"Sight is life. Speed is merely groovy." - "Junior"<HR></BLOCKQUOTE>
Top Fuel rules require them to use the "Roots" blowers. Turbo Top Fuel cars were tried in late 60's and early 70's. They proved so powerful that they destroyed their transmissions. Recently a team built an experimental turbocharged and fuel injected "Top Fuel" 4 cylinder. It only displaced 4.8 liters but put down over 3000 horsepower on the dyno. Wait here's the article:
http://www.turbomagazine.com/tech/0202tur_extremeedge/

seems they're making 4000+ hp now

To kill me you've got to hit the heart Ramon--Clint F*cking Eastwood

pourshot
02-04-2004, 10:53 PM
Thats nothing we have a triumph drag bike over here that displaces just over 1400cc and makes over 1600hp , oh and it's supercharged http://ubbxforums.ubi.com/images/smiley/16x16_smiley-surprised.gif

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dugong
02-05-2004, 05:48 PM
WhiskeyRiver -

Sounds pretty mean to me. Surely at least as quick as my car as, probably quicker. What does the turbo and intercooler due to a high reving engine? I would love to drive a turbod Honda/Accura. A friend has and RSX-S, and I love the "revy" feeling. The car feels like it is ready to make war, just hit the gas and all will break loose. It is a nice contrast to mine.

Melted a piston! At 150? I am guessing you had the rev/top speed limiter altered just a bit!

Blottogg
02-05-2004, 08:54 PM
WhiskeyRiver, thanks for the link. I didn't know the Roots type blower was mandated (my Eaton is the same type.)

Do you know if the turbo cars had a slushbox to allow for pre-launch slippage (and enough RPM to spool the turbo up), or were they just dumping the clutch?

Your's sounds like a quick ride. Good luck with the buildup.

Blotto

"Speed is life." - Anon
"Sight is life. Speed is merely groovy." - "Junior"

WhiskeyRiver
02-05-2004, 09:33 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by dugong:
WhiskeyRiver -

Sounds pretty mean to me. Surely at least as quick as my car as, probably quicker. What does the turbo and intercooler due to a high reving engine? I would love to drive a turbod Honda/Accura. A friend has and RSX-S, and I love the "revy" feeling. The car feels like it is ready to make war, just hit the gas and all will break loose. It is a nice contrast to mine.

Melted a piston! At 150? I am guessing you had the rev/top speed limiter altered just a bit!<HR></BLOCKQUOTE>

Turbocharging/intercooling and supercharging(positive displacement aka "Roots" blowers) affect a cars powerband differently. Superchargers tend to exaggerate a engine's powerband i.e. an engine with a wide, flat, torque band will still have a wide, flat torque band just more of it. Turbo's tend to make power up higher in the rpm band and make an engine "peakier". This isn't a hard and fast rule. WRC cars use small turbo's that spool instantly thus giving them tons of midrange power but modest gains up top.
Honda/Acura are equipped with the VTEC system. At full throttle above about 5200 rpm the engine switches over to a higher lift and duration camshaft profile allowing more airflow through the motor. When turbocharged it allows awesome power gains. The plus side is that the engine still gets good gas mileage and excellent driveability at normal rpm's and throttle position.

Actually my car's computer is not modified at all. I use "black" boxes that allow me to alter some parameters and monitor certain sensors. The rev limiter hasn't been altered at all. As far as I know, Honda does not put speed limiters on their cars. Usually you'll run out of power before you run out gears. I was almost at redline when the turbo motor blew up. I was winning the race though http://ubbxforums.ubi.com/infopop/emoticons/icon_smile.gif.

here's a link you can cut and paste to see what different dyno charts for naturally aspirated, turbocharged, and supercharged cars look like:
http://www.hondata.com/dynocharts.html

Blottog: I don't know what type of tranny they were using. My guess would be a Lenco like the other Top Fuel cars at the time. I'll see if I can find out what they used.
Thanks for interest in my ride. A lot of folks talk smack cause it's a 4 cylinder. I look at it like any idiot if given enough money can make a V-8 fast. Making power with only half the number of cylinders and less than half the displacement is a challenge.
I mainly hope that people understand now why supercharged aircraft run out of power before turbocharged ones.

To kill me you've got to hit the heart Ramon--Clint F*cking Eastwood

JR_Greenhorn
02-05-2004, 10:00 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by WhiskeyRiver:
Honda/Acura are equipped with the VTEC system. At full throttle above about 5200 rpm the engine switches over to a higher lift and duration camshaft profile allowing more airflow through the motor. When turbocharged it allows awesome power gains. The plus side is that the engine still gets good gas mileage and excellent driveability at normal rpm's and throttle position.<HR></BLOCKQUOTE>I was under the impression that Honda's VTEC system disabled one of the two intake valves below 5200rpm in oreder to increase low-rpm port velocities. It is accomplished by an electro-hydraulic pin that lets the lifter "float" when disengaged. Is this correct, or am I confusing it with the new VFR Interceptor engine?

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by WhiskeyRiver:
A lot of folks talk smack cause it's a 4 cylinder. I look at it like any idiot if given enough money can make a V-8 fast. Making power with only half the number of cylinders and less than half the displacement is a challenge.<HR></BLOCKQUOTE>Easy, you're stepping on toes here. I respect anyone whose not afraid to do motor work to get power out of a 4-cylinder, although I do have personal issues with front-wheel-drive. However, its also a challenge to make a V-8 actually fast on a very tight budget, even with more than twice the displacement.

Can I assume we both dislike those concerned with merely "the appearance of speed," be it a stock-motored Eclipse or a tired 305 Camaro?

WhiskeyRiver
02-05-2004, 11:04 PM
JR, I shouldn't have called V8 guys idiots. I respect anyone who goes fast, turns their own wrenches, and takes an intelligent approach. And yes, I abhor wankers who slap a bunch of silly crap on their ride i.e. huge spoilers, 20 inch wheels, and of course the infamous windshield sprayer lights. The only exterior mods I've done is Civic Si factory tailights, tinted windows and wheels. I'll probably get around to buying a carbon fiber hood and a Civic type-R chin spoiler one of these days. I think Honda did a nice job with the styling on my car so why ruin it with a bunch of expensive parts that don't make it any faster.

In regards to Hondar VTEC system; At cam switchover a third arm which rides on the "High" cam lobe is locked to the 2 regular rocker arms by a sliding pin. Each valve has it's own rocker arm with a third rocker arm between them. Some models only have VTEC on the intake valves while others(Integra Type R, RSX type S and R, late Civic Si, Prelude type S and NSX) have VTEC on both intake and exhaust valves. I believe you're thinking of the VTEC-E system. A horrid thing designed to increase gas mileage at the expense of horsepower. Never ever buy a car equipped with this.
You're right about the front wheel drive. Getting any traction on launch is b*tch.

To kill me you've got to hit the heart Ramon--Clint F*cking Eastwood

JR_Greenhorn
02-05-2004, 11:18 PM
WhiskeyRiver, thank you for that. Its nice when guys of different schools of thought can agree.

I do turn my own wrenchs, but I still haven't learned to paint. My car is starting to look a little rough.

To compensate, I can do some of my own machining. I'm in the process of making fixtures to do some cutting on a modern pair of heads (mine were cast in '63!).

I grew up around big Deisels--now those engines have good turbo systems. Some day I hope to afford to build a proper turbo engine, but until then, I'll scrape by with my old stuff.

What is the crank throw spacing on Honda fours? Is it 90 or 180 degrees?



Admittedly, I drive a Camaro. I can't stand the stigma that projects thanks to so many rednecks everywhere. Those cars tend to become victims to air shocks and spring lifts, noisy inefficeint exhausts, and a multitude of other cheesy "upgrades" that should have died with the '70s.
Mine is externally stock, with the "external ornamentation delete" option (read: no guady stripes).

Its tough to beat the elegance of restraint with a serious engine under the hood.

WhiskeyRiver
02-06-2004, 12:13 AM
Honda crank throws are 180 degrees. The #2 and #3 cylinders are both at Top Dead Center at the same time.

If you've got a fuel injected Camaro it wouldn't be too difficult to turbo. Admittedly a nice turbo setup on anything is pricey.

I also cannot paint. I've found it's easier to learn to like flat black primer than to learn to paint. Ugly fast cars are way more fun than nice fast cars.

A buddy of mine has an 81 Trans Am with the famous "Smokey and the Bandit" Black/Gold color scheme. It's got nice body/paint but the motor is a tired carburated turbo 307. I might buy it and drop in a 400 small block with a homebrew turbo sytem(Mitsu turbo's, F250 turbo diesel intercooler, and water methanol injection). He only paid 1500 bucks for it and hasn't put much money into it. Summit sells a DIY header kit. I figure I can use that to build a set of workable manifolds. 1st generation mitsubishi eclipse blowoff valves are cheap and can handle up to about 20 psi of boost. I drew up plans for a liquid C02 intercooler sprayer maybe I'll build one of those if he sells it to me.

To kill me you've got to hit the heart Ramon--Clint F*cking Eastwood

JR_Greenhorn
02-06-2004, 12:44 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by WhiskeyRiver:
Honda crank throws are 180 degrees. The #2 and #3 cylinders are both at Top Dead Center at the same time.<HR></BLOCKQUOTE>
Sure, just like sportbikes. I had often wondered about that.
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by WhiskeyRiver:
If you've got a fuel injected Camaro it wouldn't be too difficult to turbo. Admittedly a nice turbo setup on anything is pricey.<HR></BLOCKQUOTE>Alas, mine's carbureted. I'll buy fuel injection long before a turbo, but even that costs $3000 to do right. My engine is a 1962 327, and I just love the mechanical fuel injection used on the Corvettes from '63-'65. Maybe someday, but that stuff is impossible to find.
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by WhiskeyRiver:
I also cannot paint. I've found it's easier to learn to like flat black primer than to learn to paint. Ugly fast cars are way more fun than nice fast cars.[/qoute]I couldn't agree more. I've got an old motorcycle fogged flat black to cover the dings--yellow flames even (easier to pull off on a bike because there's less surface area to look shoddy). I have tons of fun with it but it looks like hell!
[QUOTE]Originally posted by WhiskeyRiver:
A buddy of mine has an 81 Trans Am with the famous "Smokey and the Bandit" Black/Gold color scheme. It's got nice body/paint but the motor is a tired carburated turbo 307. I might buy it and drop in a 400 small block with a homebrew turbo sytem(Mitsu turbo's, F250 turbo diesel intercooler, and water methanol injection). He only paid 1500 bucks for it and hasn't put much money into it. Summit sells a DIY header kit. I figure I can use that to build a set of workable manifolds. 1st generation mitsubishi eclipse blowoff valves are cheap and can handle up to about 20 psi of boost. I drew up plans for a liquid C02 intercooler sprayer maybe I'll build one of those if he sells it to me.<HR></BLOCKQUOTE>
Ahh, my area of expertise! You see, my Camaro is also an '81, and I love the second generation F-cars. The beauty of these cars is the ease at which almost any GM V-8, I-6, or early V-6 bolts in. I've got a manual- and an auto-based drivetrain I used to swap back and forth between two cars with ease, and the rear end is the same internally as Chevy's 1/2-ton trucks--with plenty of gearing choices.

IIRC, the Turbo Trans Ams came with T-04 turbos. Aren't they easy to match to an application due to their popularity and scroll avialibilty? (If only you could find another one...)

A nitpick: Turbo Trans Ams came with the junk short-deck 301 Pontiac, the 307 is an Oldsmobile motor. The Olds that the Trans Ams ran was a 403.

If you're accostomed to an engine that revs, you'll want to rethink your engine choice. You see, I just took a small block 400 out of my car, in favour of the "free-er revving" 327. It drives much better now, and seems a shade faster to boot. Of course, running a 350 is a sin, especially in a Pontiac, and any 327 you find you should ship directly to me. http://ubbxforums.ubi.com/images/smiley/16x16_smiley-wink.gif

Finally, don't turbo a Pontiac V-8, 400 or otherwise. Pontiacs have restrictive exhaust ports, not good for a turbo engine. However, they're quite torquey and make great pickup engines.

WhiskeyRiver
02-06-2004, 02:56 AM
301 eh? LOL I have almost no experience with Pontiac stuff. I've swapped some Chevy small blocks into S10's and S10 Blazers but never really messed with Pontiac engines. Those S10 swaps are easy and a blast to drive in dry weather. In the rain you better load about 400 punds of sandbags in the back.

in planning a turbo system for a "V" configuration engine I would just treat each cylinder bank as an 8 valve 4 cylinder. I also try to find the newest pair of turbo's I can. Turbocharger technology has advanced so much especially in reliability.

I was kinda curious about the Chevrolet 302 that came in the 1st gen Z/28's. AS I understand this was a 327 block and heads destroked using a 283 crank. I read it could rev to the moon. I know Chevy won a bunch of races with that engine. I think a pair of Porsche 968 turbo's would be perfect(3.0 and 2.5 liter turbo 4). BTW I looked at a service manual for Porsche's mechanical fuel injection. It looked like a giant fire waiting to happen(about 100 little fuel lines). The fuel maps are determined by a tapered metal cylinder that rotates against a pickup arm on the fuel pump. The cylinder moves in response throttle and rpm. It looks ungodly hard to mess with. I don't know about the Vette's system though. Wasn't it made by Hilborn?

$3000..huh. a guy at work has the Edelbrock on his 76 Camaro. It seems to work well. I think it was about 1500 bucks. BTW stay away from carburated turbo sytems. They have all kinds of problems with rapidly changing throttle and boost.

Actually small ports aren't necessarily bad on a turbo engine. With smaller ports you can get the flow velocity to go supersonic. This helps the turbo spool extremely quickly. Supersonic exhaust ports also scavenge superbly allow the use of a cam with very little overlap(good for turbo motors). Also because the hot exhaust gasses leave the cylinder and port faster less heat is transferred to the head. The engine will run cooler and spool earlier.

check out www.theoldone.com (http://www.theoldone.com)

All kinds of great info. Lot's of smart folks with really neat ideas on their boards.

To kill me you've got to hit the heart Ramon--Clint F*cking Eastwood

Blottogg
02-06-2004, 07:21 PM
WhiskeyRiver, looking at the link you posted again, they talk about spinning the two turbos up at launch with a shot of nitrous/ethanol/gasoline for quick spool-up, then switching over to pure nitromethane for the rest of the run. Quite the piece of kit that motor; dual fuel, solid block, a fairly complex dry sump oil system to scavenge as much of the nitromethane fumes as possible, etc. Didn't see anything on the tranny there, but the fuel approach should do it, regardless. As you've already mentioned, aircraft applications don't need to worry much about spool-up since most combat is with the throttle parked in "student cruise", or full power.

I'm a four cylinder guy myself, though rear wheel drive, so I can either relate to both you and JR, or argue with you I suppose. I've already had more than enough of that in other threads, if it's all the same with you guys. I prefer rear-wheel drive dynamics, but I'm an old guy. Front drivers can handle well too, and even throttle steer if they're set up for it, though the technique is different (and not one I'm familiar with.)

It's kind of neat to see the technology come around again though. Fuel injection, turbos, blowers, intercooling, water and nitrous injection. This stuff has been around for a while. The newer stuff like VTEC probably isn't as useful for aviation, since again aero engines tend to require less flexibility in their torque and power bands. VTEC combined with a turbo would strike me as a very peaky combination, and one dependent on proper gearing to allow the most from the narrow torque and power bands. Geared and driven properly, it would be a fast combination though.

Sorry to interrupt, please continue. I'm still learning new stuff. I'd like to say I'm knowledgeable about carbs, but aside from an aborted attempt to tune the S.U. carbs on my old MGB, I'm pretty clueless on that front.

Blotto

"Speed is life." - Anon
"Sight is life. Speed is merely groovy." - "Junior"

Edit - removed "()"

DaBallz
02-07-2004, 02:41 PM
Man, I have seen more BS and testoserone
spread in this thread than in any 20 before.

First, exahust driven turbosuperchargers of the
WWII era were for altitude compensation only.
No real boost above sea level was wanted.
The "boost" was provided by an engine driven
centrafugal supercharger. No WWII powerplant
used only a turbosupercharger.

Ok, as to the comments on supersonic intake ports.
Cannot be done. That simple. I am in the head
porting business and can tell you that as soon
as any area in the port sets up a shock wave
it's lights out, all HELL breaks loose.
Roughly 600fps is the air speed limit.
When testing a set of heads that were inadvertantly
made too small, you could hear the snap and bang
in the carb throat, along with that came violent
reversion.
Enlarging the ports slightly solved the problem.
It's really more complicated than that, but I
am trying not to be to technical.

Ok, as to the comment about weather a gear/belt
driven supercharger can make more power than a
turbo equiped engine....
The answer is that when pushed to the limit
the turbo will always make more power with
all else being equal.
Roots type positave displacement blowers dominate
drag racing in the top fuel and top alcahol classes
because of responce time. More power may be available
with turbo's, but turbo lag will prevent them from
ever being used. (also the NHRA and IHRA rules ban turbos from all TA and TF classes).

The trade off between the three basic superchargers
is this...

Turbos, advantage, nearly unlimited boost with no crankshaft loading, easy to control.
Disadvantage, heat loading.

Centrifugal gear or belt drive, advantages, Compact, light and reasonable efficent, easy to control.
Disadvantage, great parasitic drag, loss of fuel efficency.

Roots/posative displacment... Advantage, light, rapid responce.
Disadvantage, impossible to control, great parasitic drag, high heat load, bulky installation.

Da

pourshot
02-07-2004, 02:55 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by DaBallz:

No WWII powerplant used only a turbosupercharger.

Da<HR></BLOCKQUOTE>

What about the p38,p47 and b17.

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Ride It Like Ya Stole It

DaBallz
02-07-2004, 03:19 PM
What about the p38,p47 and b17.

All those aircraft used an exhaust driven turbosupercharger
for altitude compensation. On the back of the engines,
Wright GR-1820 in the case of the B-17, P&W R-2800
in the case of the P-47 and Allison V-1710
in the case of the P-38, there is an centrafugal
gear driven supercharger.

The Turbo actc as the second stage in a similar manner
to a two stage Merlin.

That's right, two supercharging methods in use
at the same time on the same engine.

The Turbocharger compressor feeds an intercooler
then feeds a carburator then a mechanical supercharger referred to as the
"engine supercharger" which sends compressed fuel
air mixture to the intake manifold then the intake ports.


Da...

pourshot
02-07-2004, 03:57 PM
Yeah I understand that ,but can you tell me the differance between a Turbo charger and a turbo supercharger I dont understand what must be only a subtle differance.

My understanding was the turbo-charger is a standalone unit while the turbo-supercharger was the compond unit used in ww2 fighters.?

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Ride It Like Ya Stole It

SkyChimp
02-07-2004, 04:08 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by WhiskeyRiver:

Yuo've got it backward. The direct connection is what costs you power. Horsepower that would normally go to the prop or wheels instead is used to compress inlet air via the supercharger. Turbo's are driven with energy that would normally be wasted.

<HR></BLOCKQUOTE>

Not necessarily correct, with regards to aircraft. Exhaust gases used to drive a turbine is exhaust that otherwise could have provided exhaust thrust.

Regards,
SkyChimp
http://members.cox.net/rowlandparks/skychimp.jpg

SkyChimp
02-07-2004, 04:12 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by DaBallz:
What about the p38,p47 and b17.

All those aircraft used an exhaust driven turbosupercharger
for altitude compensation. On the back of the engines,
Wright GR-1820 in the case of the B-17, P&W R-2800
in the case of the P-47 and Allison V-1710
in the case of the P-38, there is an centrafugal
gear driven supercharger.

The Turbo actc as the second stage in a similar manner
to a two stage Merlin.

<HR></BLOCKQUOTE>


The turbo is the 1st stage, not the 2nd stage. The compressor the air enters 1st is the 1st stage, then 2nd and so on. (I say "so on" because Allision actually experiments with a 3 stage superchargin system.)

Regards,
SkyChimp
http://members.cox.net/rowlandparks/skychimp.jpg

SkyChimp
02-07-2004, 04:17 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Blottogg:
JR, WhiskeyRiver, you beat me to it.

Turbochargers are more efficient than superchargers.
<HR></BLOCKQUOTE>

I disagree when it come to WWII aircraft. The turbosupercharger is a better system at high altitudes, I believe. But down low, it's a lot of dead weight. A mechanical two stage supercharger is a lot lighter and less bulky than the same engine with an engine stage supercharger and an auxillery stage turbosupercharger. At altitudes where the auxillery stage is undeeded, it's better to lug around the mechanical unit than the turbosupercharger.

Regards,
SkyChimp
http://members.cox.net/rowlandparks/skychimp.jpg

SkyChimp
02-07-2004, 04:22 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by pourshot:
Yeah I understand that ,but can you tell me the differance between a Turbo charger and a turbo supercharger I dont understand what must be only a subtle differance.

My understanding was the turbo-charger is a standalone unit while the turbo-supercharger was the compond unit used in ww2 fighters.?

http://members.optusnet.com.au/~andycarroll68/mybaby.jpeg.JPG
Ride It Like Ya Stole It<HR></BLOCKQUOTE>

It's all sematics.

A "turbosupercharger" is nothing more than a short way of saying "turbine driven supercharger."

A turbocharger IS a turbosupercharger. Exhaust gasses drive a turbine, the turbine is linked via a shaft to an impellor, that impellor compresses the air/fuel mixture.

Regards,
SkyChimp
http://members.cox.net/rowlandparks/skychimp.jpg

pourshot
02-07-2004, 04:35 PM
I just found this link Skychimp that explains it very well,it's not a bad read actualy.
About Supercharging Aircraft (http://rwebs.net/avhistory/opsman/geturbo/geturbo.htm)

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Ride It Like Ya Stole It

SkyChimp
02-07-2004, 04:48 PM
Here are some schematics for the airflow for the supercharging system on the F4U Corsair and F6F Hellcat:

Corsair
http://members.cox.net/rowlandparks/f4u.jpg

Hellcat
http://members.cox.net/rowlandparks/f6f.jpg

Regards,
SkyChimp
http://members.cox.net/rowlandparks/skychimp.jpg

pourshot
02-07-2004, 04:58 PM
I just got Americas Hundred Thousand but have not had time to read it fully,I will learn it all soon enough I suppose.

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Ride It Like Ya Stole It

DaBallz
02-07-2004, 05:51 PM
I believe in USAAC language it is the engine supercharger and auxilliary stage.
The Aux stage can be one, two or three speeds.
In terms of flow direction the second stage is
the engine supercharger.
So the turbocharger is the aux stage.
I read an early P&W news release on the two stage
R-1830, it referred to the aux stage as a second stage.

Confusing eh?

In terms of specific power consumption a turbocharged
engine will always give better numbers than a
two stage supercharged engine.

As to power to weight the turbo is a looser.
Efficency can be gauged in many ways. I neglected
to clarify my comparison.


Oh, turbochargers today are more compact and
FAR more efficent than any of the previously
mentioned methods of supercharging, by weight, bulk
or by parasitic drag.


Da...

SkyChimp
02-07-2004, 06:13 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by DaBallz:
I believe in USAAC language it is the engine supercharger and auxilliary stage.
The Aux stage can be one, two or three speeds.
In terms of flow direction the second stage is
the engine supercharger.
So the turbocharger is the aux stage.
I read an early P&W news release on the two stage
R-1830, it referred to the aux stage as a second stage.

Confusing eh?

<HR></BLOCKQUOTE>

Yes, it's confusing, and that's the reason for the errors when it comes to mixing the 1st stage and 2nd stage terms.

The first compressor that the air flows through is the 1st stage (the 1st stage of supercharging). That would be the turbosupercharger in the P-38 or P-47. Yes, it's also called the auxillery stage.

The 2nd stage is the main stage compressor (also known as engine stage).

Regards,
SkyChimp
http://members.cox.net/rowlandparks/skychimp.jpg

WhiskeyRiver
02-07-2004, 08:00 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by DaBallz:

Ok, as to the comments on supersonic intake ports.
Cannot be done. That simple. I am in the head
porting business and can tell you that as soon
as any area in the port sets up a shock wave
it's lights out, all HELL breaks loose.
Roughly 600fps is the air speed limit.
When testing a set of heads that were inadvertantly
made too small, you could hear the snap and bang
in the carb throat, along with that came violent
reversion.
Enlarging the ports slightly solved the problem.
It's really more complicated than that, but I
am trying not to be to technical.

Ok, as to the comment about weather a gear/belt
driven supercharger can make more power than a
turbo equiped engine....
The answer is that when pushed to the limit
the turbo will always make more power with
all else being equal.
Roots type positave displacement blowers dominate
drag racing in the top fuel and top alcahol classes
because of responce time. More power may be available
with turbo's, but turbo lag will prevent them from
ever being used. (also the NHRA and IHRA rules ban turbos from all TA and TF classes).


Da<HR></BLOCKQUOTE>

I was talking about supersonic exhaust ports. Supersonic intake ports "wet out" once flow speeds hit supersonic.

In the drag racing classes that allow them turbochargers are the power adders of choice. I think that if they were allowed in Top Fuel they would be used. The fastest cars in NIRA and IHRA drag racing use turbocharged engines.

To kill me you've got to hit the heart Ramon--Clint F*cking Eastwood

BlindHuck
02-08-2004, 01:49 AM
Being the expert I am (unfortunately, not in forced induction http://ubbxforums.ubi.com/images/smiley/16x16_smiley-sad.gif), I would guess that the volume required for top fuel would require such huge, artificially enhanced turbos that it would be impractical. http://ubbxforums.ubi.com/images/smiley/16x16_smiley-indifferent.gif

I have ruled. http://ubbxforums.ubi.com/images/smiley/16x16_smiley-happy.gif

"I race full real exclusively in IL2:The Forgotten Battles." - Mark Donohue

WhiskeyRiver
02-08-2004, 03:09 AM
if running on gasoline you're right. Nitromethene needs much less air for optimum A/F ratio

How do you "artificially enhance" a turbocharger?

To kill me you've got to hit the heart Ramon--Clint F*cking Eastwood

Blottogg
02-08-2004, 06:53 AM
SkyChimp, good point. I hadn't considered thrust recovery, which the turbo supercharger installation will certainly reduce. Given that the drag calculation I did for Huck in another thread had the 109's exhaust thrust at max speed as only 140 lbf, there is a little wiggle room for turbos (turbo superchargers) still coming out ahead of blowers (mechanical superchargers). I guess it depends upon how much of the 140 lbf would be eaten away by a turbo, versus how much HP (above the 1200 available in Dr. Hoerner's example) would be liberated by replacing the blower with a turbo.

You're also correct about forced induction preserving rather than enhancing engine power in many aero engine applications, though most of the engines in FB benefit from added MP at sea level due to forced induction. Merlins for example can't pull 67" of Hg boost without forced induction (sea level atmospheric pressure being 29.92" Hg, minus the pressure losses from the intake manifold and carb throat.)

DaBallz, I'd seen the comment on supersonic exhaust header flow, and had my doubts, but frankly I don't know enough about the design to say either way. Design for supersonic flow is tricky, especially in a closed environment like a header. A normal shock (one that forms 90 degrees to the relative flow, as in a closed tube or intake) in the header will "choke" the flow (once a shock wave forms across a closed tube like that, you can't increase the flow rate, no matter how hard you push on the "upwind" side of the flow), leading to conditions like you describe. If they flared out the header tubing properly though, it might work. Feeding supersonic flow into the turbine would be seriously bad, however. All the shock waves shed by the blades would definitely choke the flow in the turbine. Much popping, banging (and possibly bursting) would ensue, similar to a jet engine compressor stall, which can be caused by a similar interruption of airflow (though not always due to supersonic flow hitting the compressor blades.) Supersonic flow on the turbine exit side however, might promote increased flow through the turbine itself. WhiskeyRiver mentioned supersonic exhaust ports, which might help scavenge exhaust out of the cylinder, though again you'd want to shape the porting such that the flow went subsonic again before it hit the turbine blades. The necessary shock waves and expansion fans for this exhaust flow would result in pressure losses and additional heat, which might not be bad going into a turbine.

I thought I could avoid reminiscing about compressible fluid flow on this forum. Now I'm going to be thinking about subsonic and supersonic nozzles and diffusers for hours. Argh, I hope you guys are happy.

Blotto

"Speed is life." - Anon
"Sight is life. Speed is merely groovy." - "Junior"

DaBallz
02-08-2004, 07:59 AM
We have limited experiance with turbochared engines.
But we have built a few. One point is that
in the exhaust port it aint air anymore!
It's now mostly Nitrogyn, water vapor, with CO2 CO and
a collection of unburnt hydrocarbons and other
odd compounds.

I would verture a guess that at peak speeds
the exhaust comes close to mach 1.
I got to break out the calculator and do the math.
But if you are hitting 600fps in the intake port
you should see rougly three times that in the ex port.
That's well past supersonic.

Average it out, further down the head pipe and it's well subsonic.

Da...

DaBallz
02-08-2004, 08:05 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by WhiskeyRiver:
if running on gasoline you're right. Nitromethene needs much less air for optimum A/F ratio

How do you "artificially enhance" a turbocharger?

To kill me you've got to hit the heart Ramon--Clint F*cking Eastwood<HR></BLOCKQUOTE>

It is possible to push air and fuel into the turbine inlet
to keep the speed up, but it sounds fishy to me.
In a properly running 4 stroke engine dumping
fuel alone will get you nothing, you need oxygyn
to combine with the fuel!

I have heard of fuel being dumped into the
engine when making a down shift for it's cooling
effects. if anything it should slow the turbine
even more (without air being injected).

Da...

WhiskeyRiver
02-08-2004, 01:19 PM
DaBallz, check www.theoldone.com (http://www.theoldone.com). The main guy there, Larry Widmer, has done a lot of amazing work. That's where I first read about supersonic exhaust ports. He is always happy to answer questions either on the message boards or via email. He help me out a whole lot on an exhaust manifold I ported. With regards to nitro fuels, I was simply saying that a smaller volume of air is needed for optimal A/F ratios when using nitromethane. The smaller the amount of air required the smaller the the turbo you need.

THe exhaust flow speeds are only supersonic inside the port. By the time it reaches the turbine the flow has dropped below supersonic. Supersonic exhaust ports help with cylinder scavenging and combat reversion.

To kill me you've got to hit the heart Ramon--Clint F*cking Eastwood

DaBallz
02-08-2004, 04:05 PM
Yes, there is a great amount of scavenging to be
had with very high exhaust velocity. In a normally
aspirated engine you can wind up with streaming
and a resulting "lumpy" torque curve. We play
with back pressure, port and head pipe diameter
to cure it.
In an aircraft all aspects of port size, cam timing
and head pipe size are designed to run in a very narrow RPM range.

Da...

JR_Greenhorn
02-08-2004, 05:04 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by WhiskeyRiver:
301 eh? LOL I have almost no experience with Pontiac stuff. I've swapped some Chevy small blocks into S10's and S10 Blazers but never really messed with Pontiac engines. Those S10 swaps are easy and a blast to drive in dry weather. In the rain you better load about 400 punds of sandbags in the back.<HR></BLOCKQUOTE>
Personally, I'm not a believer in weighting the rear of any vehicle to "fix" traction problems. I also think it is rather dangerous. I have had to drive one of my 2nd gen F-cars through Minnesota and now Fargo winters several times now, and after learning the hard way at 16, I still do it without weighting. It really improves driving skills as well.
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by WhiskeyRiver:
in planning a turbo system for a "V" configuration engine I would just treat each cylinder bank as an 8 valve 4 cylinder. I also try to find the newest pair of turbo's I can. Turbocharger technology has advanced so much especially in reliability. <HR></BLOCKQUOTE> Agreed, but I got kind of a "budget" vibe from the original description of your build up. Although I have little experience in gasoline turbo applications, I tend to like the VATN-equipped Aerocharger turbos for thier technology and reliability.
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by WhiskeyRiver:
I was kinda curious about the Chevrolet 302 that came in the 1st gen Z/28's. AS I understand this was a 327 block and heads destroked using a 283 crank. I read it could rev to the moon. I know Chevy won a bunch of races with that engine. <HR></BLOCKQUOTE>You are correct. IIRC, the trick was originally dreamed up by a PR-type, not an engineer, but it became an incredible engine for the era either way. Indeed, the combination of the 283's 3.0" stroke crank into the 327's 4.0" bore block produced the 302, that met the 5.0L restriction on the SCCA Trans-Am class. The engine certainly had the best small block parts made to date, including "unobtainium" rods and the Winters-cast cross ram intake of the 1969 DZ 302. They did indeed rev quite well, but the exact numbers escape my memory.

I happen to have a 1967 NOS (New Old Stock: over-the-counter) 302 crank, and it is only slightly different from the 283's. In '68 Chevy increased the journal diameters of small blocks across the board, including the 302, while the 283 was dropped. However, about this time, another engine was made by reversing the formula. The Chevrolet 307 (the Olds 307 is different) had a 327-stroke crank working through a 283-spec bore. This was an uderachieving economy motor, however.

Many have built roll-yer-own 302s using small journal 327 & 283 parts (my cousin built one for a rules-restricted hobbystock racing class), and with the right heads they make a fine motor. The small-journal parts provide for less rotational inertia and friction, but the weak link is the smaller rod bolts. Large journal 302s are the opposite, but are impossible to find at a fair price.

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by WhiskeyRiver:
BTW I looked at a service manual for Porsche's mechanical fuel injection. It looked like a giant fire waiting to happen(about 100 little fuel lines). The fuel maps are determined by a tapered metal cylinder that rotates against a pickup arm on the fuel pump. The cylinder moves in response throttle and rpm. It looks ungodly hard to mess with. I don't know about the Vette's system though. Wasn't it made by Hilborn?<HR></BLOCKQUOTE>Most of those old mechanical FI systems were quite complex in an effort to provide decent drivablility on the street. The racing systems worked well, but they obviously don't need to behave as well when cruising and other light-load conditions.
Hilborn did not make the stock Corvette system, GM's own Rochester did. Like Hilborn, the British firm Lucas is another manufacturer that made racing units, but to my knowledge only the Rochester system saw production use on Detriot V-8s. It can be quite hard to find info on the Rochester system, as even when it was new, it was easer to coax power out of the cheaper carbureted engines. I have read, however, that GM evaluated two systems--the other by the Detriot Desiel Allison division--in the '50s. The Deisel-based system worked much better, but was more costly to produce, and other factors contributed to the choice for the Rochester system.
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by WhiskeyRiver:
$3000..huh. a guy at work has the Edelbrock on his 76 Camaro. It seems to work well. I think it was about 1500 bucks. BTW stay away from carburated turbo sytems. They have all kinds of problems with rapidly changing throttle and boost.<HR></BLOCKQUOTE>I know of these systems, but it is simply a personal preference to wait until I can afford a sequential multi-port system with a dedicated manifold, although I'm sure the others work fine.
Supposedly a pressure box setup with a carb works well enough, but again, I wouldn't mess with it out of personal preference for an EFI-based turbo system.
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by WhiskeyRiver:
Actually small ports aren't necessarily bad on a turbo engine. <HR></BLOCKQUOTE>Yes, but there is a difference between high-velocity ports that are small (like those found on the 3-valve BBC Fueling truck heads), and poorly designed small ports that are just plain restrictive. Pontiac's V-8s and Ford's 351C suffer from the latter on the exhaust side in an attempt to lower the height the exhaust ports' exit from the motor for better packaging across production lines.

DaBallz
02-09-2004, 03:52 PM
First, the small journal 302 Chevy crank is the
same exact crank as the 283 vette crank.
Both are twisted steel forgings but the
302 has nitrided journals.
I have been involved with a few. It's easy
to make 1.75hp per inch in drag race trim.
A horse an inch for the street is also easy.

Mid 60's to early 70's Pontiac heads are very good
and well matched to the bottom end. Few Pontiacs
can turn fast enough to need bigger ports.
The SD455 and early Super Stock 421cid engines
could rev a bit higher but were equipped
with the RA2 for the 421, and the RA4 for the
RA4 400 and DS455. These round port heads were
excellent on both intake and exhaust sides.

Ford Cleveland intakes were too big, and the exhaust
ports really sucked. the only good exhaust ports I
have seen on an iron head Ford V8 was on the
FE block engines. Notably the 427 and 428.
(Fe Block engines were as follows, 332, 352,
360, 390, 406, 427, and 428).


As to pre electronid American fuel injection
systems for the street,,, Rochester did in fact
build the Vette system. They were trouble to
tune and most were swapped for a carb and manifold.
Chrysler offered a FI system on the 392 early Hemi
on the Chrysler 300. It was a total failure, all were
retrofitted with carbs. I am not sure any of them
got to the showroom, they got axed early.
Hillborn never built a street injection setup.

On an un supercharged engine a carb(s) on gasoline
will usually make more peak power. The reason is
the wet manifold carries more mass per volume
and sets up a stronger signal and pressure wave effect.
That's commonly called the ram effect.
injection offers many advantages, runners can be any
length or shape without causing fuel stratification.
So electronic injection will make a broader
power band and will be more drivable.

For an aircraft engine all the above becomes moot.
They run in a very narrow range of rpms and
are supercharged. Dry manifold is preffered
over wet to reduce the chance of fire.

Most WWII aircraft engines were wet manifold.

Da

Rickustyit
02-02-2006, 02:26 AM
I know, I know, it's a 2 years old thread, but I was searching for something to read on Turbo and Supercharged aircrafts/cars.
Interesting thread.

BUMP then!

Whenever I accelerate in my Mini Cooper S and hear that whine from the supercharger (or volumetric compressor as we call it here in Italy) I always love to think I'm sitting in a Spitfire http://forums.ubi.com/groupee_common/emoticons/icon_cool.gif

http://www.n3bcars.co.uk/images/largegallery/coopers_large3.jpg

My car is actually quite the same as above, minus that chrome grill on the front. Sexy.

Cheers,
Rick

Immermann
02-02-2006, 04:32 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Platypus_1.JaVA:
After that, you want a merlin in your car also http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif
</div></BLOCKQUOTE>

http://www.rodshop.com.au/project55.htm

Rickustyit
02-03-2006, 03:36 AM
OMG!

darkhorizon11
02-03-2006, 10:11 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by SkyChimp:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by WhiskeyRiver:

Yuo've got it backward. The direct connection is what costs you power. Horsepower that would normally go to the prop or wheels instead is used to compress inlet air via the supercharger. Turbo's are driven with energy that would normally be wasted.

</div></BLOCKQUOTE>

Not necessarily correct, with regards to aircraft. Exhaust gases used to drive a turbine is exhaust that otherwise could have provided exhaust thrust.

Regards,
SkyChimp
http://members.cox.net/rowlandparks/skychimp.jpg </div></BLOCKQUOTE>

Exhaust thrust? Not on a recip aircraft... your thinking gas turbine...