4" Dp

What are the advantaged that a 4" DP has over a 3" bellmouth? Is it just something for the 'bigger turbo guys' or what?

 

I would assume the less restriction would equal faster spool. But u can only spool a vf39/43 so fast. So it would probly be most advantageous for the bigger turbo guys, yes. Jason is running one on his 18g.

 

Yeah, thats what brought up my question

 

Is there any other 4 inch besides the turbo xs?

 

Yeah its the only one. We call it the fat nasty.

 

Even if you do have a small turbo(td04/vf39/34/16g). Would you see any diffrence in numbers if you go with a 4" dp instead of a 3" one?

 

No. I don't think you'd have any different numbers or spoolup time.

 

really? For a turbo car isn't bigger supposed to be better?

 

It is, to a point...

 

that makes sense. thanks

 

I doubt it would make a noticeable difference on stock-ish turbos but probably would make a bigger difference at higher boost levels.

Bigger is normally better but its always got diminishing returns; going from 2.5" to 3" creates gains across the entire power band. Some people swear that by keeping the 2.5" exhaust piping their car feels torquier but dynos dont seem to back that up. 3.5" exhausts are for the faster end of cars and sacrifice some low end. 4" pipes are reserved for the fastest Supras, etc.

 

hummmm...I have the turbo xs 4'' dp to the 3" race and mid to a 2.5''stromung...I think the low end torque is less but the eventual pull is worth it.

 

Hmm...interesting. I've been planning on going with the standard turboxs exhaust (whenever I finally get around to buying one) for a while now. This doesn't change my plans or anything, but interesting none-the-less

 

This is Turboxs' philosophy.

Quote
"Why is that important? Because, despite what your girlfriend might tell you, size does matter. Turbochargers work best when there is large pressure and temperature differential across the turbine wheel. Having a large, free flowing downpipe is what give you that large pressure and temperature differential."

 

Really, anything larger than 3" on a SUBARU with anything smaller than a GT35 is a waste.

Unless you are making over 600hp...its just more noise.

 

I doubt theres going to be a noticeable difference though... Maybe 2-3hp

 

i bet a 4" dp would work better with a 4" cat

 

and a 4 inch mid pipe...and 4 inch 'muffler'....

 

yeah.. I was actually thinking about getting a random technology 4" cat, as they say that they flow better than the 3" ones...

 

i bet I could make 50 more HP with a 4" TBE....

 

I bet that I could make 50 more hp having SS ride in my trunk, datalogging.

--
Brian

 

No, thats 100hp, and 300tq.

 

damn! did he learn new tricks?

 

I think so. he tunes with Cobb, enginuity, ecutek, AEM, hydra and JDM all at the same time, while using all 3 fuel types at the pump.

Oh, and a big ass meth nozzle.

 

nice! he is a true pimp tuner, and i admire him like a taxi driver

 

Hmm

 

Not sure if this is tension or friendly banter!?

Turboxs' 4 in dp is the nasty, I'd get one, and the philosophy makes sense so...

 

:rofl: my thoughts exacly

 

nah, just joking around. I can't wait to get our car tuned, and will definately get it done by SS.

--
Brian

 

indeed, a good joking time. I'm bored.