Alittle help from some professionals

[85 rat rod]

so a friend of mine sitting next to me in class is in a heated debate in a saturn forum, yes i did not studder, Saturn, these people actually boost these things, anyway, my request is that if i drop a link will a few profssionals briefly review, seperate fact from myth and i will have the guy sitting next to me post a link to the following page...
:!: some of the people on this site are like :banme:

http://www.xtremesaturn.com/phpbb/viewtopic.php?t=21199
:imwithst:

[Speed Racer]

so a friend of mine sitting next to me in class is in a heated debate in a saturn forum, yes i did not studder, Saturn, these people actually boost these things, anyway, my request is that if i drop a link will a few profssionals briefly review, seperate fact from myth and i will have the guy sitting next to me post a link to the following page...
:!: some of the people on this site are like :banme:

http://www.xtremesaturn.com/phpbb/viewtopic.php?t=21199
:imwithst:

Tell them to go to this website: http://www.bellengineering.net/Pages/products_books.html and also buy the book "Maximum Boost" - Corky Bell is THE expert in the area of turbocharging. Everything you'd ever want to know about turbocharging an engine is in that book...I highly recommend it.

Rather than debate what they're saying over in Saturn-land, just give them the tools to educate themselves.

[williamb82]

there are som real dumbasses there. a 2.5in exhaust would be fine for one of those 2liter engines. also, the turbo doesnt force the exhaust out. the exhaust is what spins the turbo. i didnt read past half the first page. there was too much to correct already.

[KesekiSupra]

hah, u dont need any exhaust bigger than the turbo's outlet, say u have a 2.5 outlet on the turbo, u can put a 2.5 and make say 300 hp, and put a 3 inch and still make the same horsepower, the turbo wont push out more than wat can fit in the 2.5 outlet, silly ppl

[4SFED]

Just curious, was that a spelling class that you and your friend were sitting in? :lol:

[Junkie]

Just curious, was that a spelling class that you and your friend were sitting in? :lol:


:greatpos: :rotfl: :rotfl: :rotfl:

[WadeT]

hah, u dont need any exhaust bigger than the turbo's outlet, say u have a 2.5 outlet on the turbo, u can put a 2.5 and make say 300 hp, and put a 3 inch and still make the same horsepower, the turbo wont push out more than what can fit in the 2.5 outlet, silly ppl
Exhaust is everything to a turbo.
Go run a 2.25" exhaust with the crappy stock elbow on a 7mgte then go dyno it. The CT26 exhaust wheel outlet is ~ 2", BTW. Then bolt on a 3" elbow and 3" back setup then dyno it. The car with the 3" spool MUCH faster make more peak power and it will make it's peak power higher in the rpm band. There is no relationship between exhaust diameter and turbine/outlet size.

[dohc82]

there are som real dumbasses there. a 2.5in exhaust would be fine for one of those 2liter engines. also, the turbo doesnt force the exhaust out. the exhaust is what spins the turbo. i didnt read past half the first page. there was too much to correct already.

Yea I was tempeted to stop also...to much teeth grinding :lol: But I pushed on :flex: and finished the thread...eventually someone shows up who has some idea how a turbo works but they have trouble convincing some of the others :roll:

[KesekiSupra]

wats the greatest restriction in on a turbo car? the turbo. u put a pressure gauge at the end of the pipe with a 2 inc exhaust, then do it again with a 3 inch exhaust, its gunna have the same amount flowing out with either one. dont believe me? try it nothing changes if the turbo cant flow it i know a lota smart mkiii turbo buys that leave the stock exhaust on, y? cuz itmakes no difference

[WadeT]

wats the greatest restriction in on a turbo car? the turbo. u put a pressure gauge at the end of the pipe with a 2 inc exhaust, then do it again with a 3 inch exhaust, its gunna have the same amount flowing out with either one. dont believe me? try it nothing changes if the turbo cant flow it i know a lota smart mkiii turbo buys that leave the stock exhaust on, y? cuz itmakes no difference

lol, I'm not really sure what you're talking about...

First, a turbo is a restiction but it's there to grab the exhaust backpressure to spin the turbine. The turbine spins the compressor which sucks in more air creating higher cylinder pressures. Higher cylinder pressures = more exhaust back pressure spining the turbine even faster and boost builds. Everything AFTER the turbo should be as large and restriction free as possible. This is elementary stuff here. Larger than stock exhaust systems have been dyno proven over and over.

This might help you and those MKIII guys better understand this principle:

http://auto.howstuffworks.com/turbo.htm

[Junkie]

Wade,you must remember....your dealing with a DRIFTER on this subject.All logic is lost on them :P

[Speed Racer]

Wade,you must remember....your dealing with a DRIFTER on this subject.All logic is lost on them :P

So true, it must be those random times when they fall out of their cars while drifting with "El Door-o esta Openo" and the resulting brain damage...

I'd be fucked in the head TOO if I fell out of my own car while in a 4 wheel slide and got to watch it take off without me -- sorta like a fighter pilot ejecting from his plane.

[williamb82]

bigger exhaust does help, but for their application 2.5in mandrel should be fine.

[KesekiSupra]

since when am i a drifter? wat the hell?

[KesekiSupra]

btw get a water hose with a 1 inch outlet, and put a small ass water hose .5 inch, and see how much it flows, then try it with a 1 inch hose, then 2 inch hose, does it flow more? tell me

[canadian_psyko]

Put a buncha curves in the hose, and then measure the presure required to flow the same amount out of the end of the pipe.

[WadeT]

btw get a water hose with a 1 inch outlet, and put a small ass water hose .5 inch, and see how much it flows, then try it with a 1 inch hose, then 2 inch hose, does it flow more? tell me

So, I guess Titan Motor Sports should just run a 2.25" exhaust on their 1200HP+ drag car cause, what the hell, 4" won't make any more power?

Sigh, time for brain surgery. :banghead: :pat:

We are not talking about static flows like those from NA engines or garden hoses.

The flow is directly related to how much throttle is given and how many rpms the turbo spins.

You choke up the exhaust and the turbo will not spool or spin as fast when throttle is given. Free up the exhaust and it will spool like crazy. THis is why a stock MKIII turbo makes 232 crank HP and why one with a 3" exhaust will make about 300HP at the same boost level.

Come back next week and we will find out how internal combustion engines work. :suicide:

[BillyM]

I love the "take a straw, and take a paper towel tube, blow through them, air in straw go faster!" comment.

For those of you who side with that comment, think about how long it takes you to expel a lungs-ful of air through both media. The name of the game is getting as much air out of the system as quickly as possible. Yes, the air coming out of the straw will be faster, but how long does it take you to breath all the way out through it? 10seconds? Now the paper towel tube, remember, blow out just as hard as you did with the straw, how long does it take until you are out of breath? 1.5-2sec?

I dont mind when they are dumbasses, I just dont like when they try to tell other people how it works.

a.) keep in mind a gas has a great affinity for lower pressure areas.
b.) once its into the downpipe, the turbo has been spun, no more power from velocity.
c.) heat does not spin a turbo... gas pressures do, heat affects pressures, yes, but not after the turbine, fuck the air after the turbine, its done its job, get it the hell out of the way.

--BillyM

[KesekiSupra]

guess everyone at my school and all the instructors and retired 750 hp motorcycle draggers and 4000 hp draggers have no idea wat they are talking about

[Deanfun]

guess everyone at my school and all the instructors and retired 750 hp motorcycle draggers and 4000 hp draggers have no idea what they are talking abouti can't believe you're arguing this point.

yuo might be confusing flow with velocity. i think. flow is a volume movement per given amount of time. this is the important characteristic.

if a pipe with an area of 1m^2 expels a liquid at 5m / s, that's a flow of 5m^3 / s.

now if that pipe has a cross-sectional area of 2m^2 and the velocity of the liquid is, say, 4m / s, we're now moving 8m^3 / s.

okay, so maybe i don't know exactly where i'm going with this, but literally hundreds of thousands of cars on the road prove the point - stock exhaust piping is a huge restriction on turbo vehicles.

[4SFED]

btw get a water hose with a 1 inch outlet, and put a small ass water hose .5 inch, and see how much it flows, then try it with a 1 inch hose, then 2 inch hose, does it flow more? tell me
that's only part of the equation. Read the pressure, the larger hose has more volume so it can let more flow, dropping the pressure. But if you dont increase the pressure forcing the liquid through your waterhose of course you wont increase flow even though you now have the means with the larger volume vessel.
for instance, the 7m and 5m use basically the same oil pumps but the mk3 will read lower pressure on the gauge because of the high volume/low pressure larger journals used in the 7m.
Or that vein going from your heart to your brain. You used to have more blood flow to your brain but with all that junk you eat, you now have plaque built up inside so the vein is smaller, you still have that same heart in you pumping that same blood but your blood pressure has skyrocketed because the cross-sectional area of the vessels supplying the blood to the brain is so much smaller, squirting that blood at your brain when it used to just flow lazily through your skull.

[Dave S]

The power generated by the internal combustion engine is directly related to the amount of air that is compressed into the cylinder. In other words, the greater the compression, the greater the output of the engine.
Turbochargers are used to increase engine power by compressing the air that goes into the cylinder. They do not require a mechanical connection between the engine and the pressurizing pump to compress the intake gases. Instead, They rely on the rapid expansion of hot exhaust gases exiting the cylinders. These gases spin the turbine blades of the pump. Because exhaust gases is a waste product, the energy developed by the turbine is said to be free since it Theoretically does not use any of the engine's power it helps to produce.
There are 6 parts to a turbocharge:
1. Turbine or hot wheel.
2. Shaft.
3. Compressor or Cold wheel.
4. Waste gate valve
5. Actuator
6. Center housing and rotating assembly.
The turbine wheel(hot wheel) is attached via a shaft to the intake compressor wheel (cold wheel). Each wheel is encased in it's own spiral-shaped housing that sewrves to control and direct the flow of exhaust and intake gases. The shaft that joins the two wheels rides on bearings.
The air compressing process typically starts when the engine's speed is above 2,000 rpm. The force of the exhaust flow is directed through a nozzle against the side of the turbine wheel. As the gases hit the turbine wheel causing it to spin, the specially curved turbine fins direct the air toward the center of the housing where it exits. This action creates a flow called a vortex. Once the turbine starts to spin, the compressor wheelalso starts to spin. this causes air to be drawn into the center where it is caught by the whirling blades of the compressor and thrownoutward by centrifugal force.
Air is typically drawn into the cylinder by the difference in pressure betweenthe atmosphere and engine vacuum. A turbocharger, however, is capable of pressurizing the intake charge above normal atmospheric pressure.
Turbo boost is a turm used to describe the positive pressure increased by a turbocharger. For example, 10 psi of bost means the air is being fed inot the engine at 24.7 psi (14.7 psi atmospheric plus 10 pounds of boost).
I'll stop there...Hope this answers some questions.

[WadeT]

guess everyone at my school and all the instructors and retired 750 hp motorcycle draggers and 4000 hp draggers have no idea what they are talking about

They are problably old school carb'd V8 people right? Do any of them have experience with turbos? I don't think so.

Arguing about exhaust sizes for turboed cars is really just a waste of time. It has been proven countless of times on all kinds of cars over many decades that larger diameter exhaust systems yield huge performance gains.

[rcpilot]

This doesn't really have anything to do with turbos, but I was down at the Formula SAE competition this weekend and one of the teams had an interesting exhaust setup. They had the normal header tubes coming off of their 600cc motorcycle engine, but those 4 went into a tube that was actually smaller than what was required to keep the same overall area. And then the exhaust after that widened out to a 'normal' size. One of the engine guys on our team ran some simulations and found out that we would gain about 1 or 2 hp (which is a decent amount for a 480 lbs car that makes 54hp at the wheels), but decided it would probably be too much effort to custom fabricate for that small of a gain. (The engine I'm talking about and our engine are both N/A, although some of the teams opt to go with turbochargers and generally produce more hp, but sacrifice having a good torque curve.)

[Supra_devil]

the first mistake i saw was that there turboing Saturns, enough is said by this alone that we should all shake our heads. Saturns are ok in there spot but they are not sports cars, i know people who have gone through engines and cylinder heads on Saturns driving them nicely and doing regular maitenance. So that wouldn't make me want to boost one of them.
i make fun of turbo hondas but the people i see doing it now more than these guys, i have seen turbo hondas w/ 3 inch exhaust, want proof that it helps make power, he beat my supra in all power ranges except off the line, but he wasn't far behind. so obviously big pipe on a small engine tuned properly makes power.
grrrrrr.
i hate people sometimes.

[Speed Racer]

Cars shouldn't be named after planets. I can just see the new line of cars from GM's spin-off company. The Pluto, The Jupiter, The Mars....

"Ooooh....wanna go ride in my 2025 Moon? It's the shit man. 400 amp motor and everything...it's fast man!"

[4SFED]

Cars shouldn't be named after planets. I can just see the new line of cars from GM's spin-off company. The Pluto, The Jupiter, The Mars....

"Ooooh....wanna go ride in my 2025 Moon? It's the shit man. 400 amp motor and everything...it's fast man!"

And who'd want to be seen driving Uranus? :shock:

[dogstar]

saturns are ok... turboing one of them is just like turboing a cavalier...
and when you get right down to it, turboing a cavalier is like turboing a civic.

theyre all front drive shitboxes.... i personally dont understand why people want to sink 5000 bucks into a turbo kit for a grocery getter, but thats just my opinion.

*would rather work at mc donalds to pay for a RC turbo kit and put it on a rusty mkII than drive a stock cavalier/civic/saturn*