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DIY Turbo Discussion greddy on a 1.8? homebrew kit?

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Old 10-18-2007, 12:40 AM   #41
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Originally Posted by Tesseracter View Post
the 8psi sounds like a decent looking girl who dresses conservatively, but you can talk intellectually to her and she happens to be a nyphomaniac and bi-curious.

i just join the rest of the guys in checking out the hot chick with massive clevage, then turn to my girlfriend and she says "damn i'd like to see her naked"
for the mother ******* WIN
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Old 10-18-2007, 06:48 AM   #42
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Originally Posted by Saml01 View Post
btw, whats the stock exhausts diameter?
Stretch bent 1 7/8"
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Old 10-18-2007, 04:43 PM   #43
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Originally Posted by Atlanta93LE View Post
Stretch bent 1 7/8"
Whats the diameter of the drinking straws they hand out at the movies?
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Old 10-18-2007, 06:34 PM   #44
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I don't think it matters. Hondas make 700+whp with 3" turbo back exhausts. I doubt "turbulent" flow is a concern in their minds when it comes to the exhaust.
That's because the turbine exducer is 3", btw 7-11 degree tapers are thought to be optimum and yes there is proof that this is the case but you can get away with more taper than that. The idea is to keep the transition smooth and yes, it does make a difference on the dyno.

Mark
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Old 10-18-2007, 06:40 PM   #45
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Originally Posted by Saml01 View Post
So whats the verdict? 2.5 inch or 3 inch when the target is 200 - 230 hp?

btw, whats the stock exhausts diameter?
On the dyno I was not able to tell the difference between a really nice 2.5" system and a 3" dump pipe that exited under the car on the dyno. It didn't make a damn bit more power. This was with a GT2860R with an internal wastegate.

It didn't even spool any better to be honest. With that small of a turbine at 240 RWHP, the 2.5" system was plenty adequate and a lot more quiet than the 3" dump pipe. I subsequently made 300 RWHP on that same 2.5" system with a T3/T4 hybrid, but I am pretty sure that it is now an issue compared to a 3" system. 2.5" systems are fine up to about 250 RWHP. (I will concede that on a well designed 3" system with an external wastegate you can see benefits of a 3" system as low as 200 RWHP. YMMV)

Mark
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Old 10-18-2007, 08:40 PM   #46
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Well then, I will have my BEGI DP go into a nice fatty 3" back pipe with the external waste gate dumping to the atmosphere.. By 2008 that is..
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Old 10-19-2007, 02:25 PM   #47
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Originally Posted by Saml01 View Post
So whats the verdict? 2.5 inch or 3 inch when the target is 200 - 230 hp?

btw, whats the stock exhausts diameter?
We've done 250 whp on a stock exhaust before. (2" or 2.25" I think?)
My car has done 243 on a 2 1/2" exhaust.

Now that the 3" dual is on, I think that the power band is much smoother. There is not the sudden sit you back in the seat. But it has not been back to the dyno. The 3" sound is deeper. I wish I had put the 3" on sooner.
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Old 10-19-2007, 02:32 PM   #48
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The best exhaust for a turbo is no exhaust at all. Period.

Probably the pinnacle of turbocharged piston engine technology was WWII era airplanes. They ran no exhaust, turbine housing straight to atmosphere, along with lots of other fun stuff (nitrous, alky injection, cockpit boost controllers/overboost). No exhaust is unrealistic on a car but I'd never suggest smaller is better. I may suggest that smaller is sufficient but you'll always have gains with a bigger exhaust, no matter how minute they may be. Period.

If you have the ability to go 3" all the way from the start, do it. If not, 2.5" will probably be fine for anything under 300hp.
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Old 10-19-2007, 02:53 PM   #49
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^

The pinnacle of turbocharged piston engine technology was the F1 turbo era.Where cars were making 1300+hp in qualifying trim on 1.5 liter 4 cylinder engines.
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Old 10-19-2007, 06:58 PM   #50
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You got me there.

What did they run for exhaust?
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Old 10-19-2007, 08:51 PM   #51
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^ I'm pretty sure it was open header/flame thrower.
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Old 10-19-2007, 09:01 PM   #52
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Quote:
Originally Posted by spike View Post
^

The pinnacle of turbocharged piston engine technology was the F1 turbo era.Where cars were making 1300+hp in qualifying trim on 1.5 liter 4 cylinder engines.
Ahhh skeet skeet skeet
Man i love F1.
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