Gt35r Screamer Pipe Or Plumb It Back?

[Turbz RB-25]

Hi fellas,

My build finally finished and the RB25/30 block will be in the car in a few days. I will be running:

1) GT35R 0.86 A/R with Tial 38mm external waste gate

2)256 inlet 264 exhaust cams with adjustable gears,

3) plazmaman plennum,

4) 3.5" turbo back exhaust with high flow cat

5) power FC

+ all the other usual mods I.e. front mount, 040 fuel pump, 555 nismo injectors etc etc.

Anyways, I know that my power output should be around the 350 - 370 rwkw. Now, I know screamer pipes don't make any difference under 250 rwkw if the exhaust is not restricted.

However, with around 360 rwkw, I am begining to think that if I have the screamer plumbed into the exhaust, it will restrict it alot.

I am not in it for the sound, actually, I think it sounds quite shit, but anyway, thats my opinion. However, if I am going to lose power by not having a screamer, I think I will put it on.

I need some opinions from people in this power range or people that have had experience with such things, screamer or no screamer? WIll I lose power if I plumb it back at this power range with a 3.5" straight through exhaust with a high flow cat?????

Cheers fellas!

[R31Nismoid]

Make up an adaptor - its nice and easy for an exhaust shop.

Once the car is fully tuned (with it venting external), put the plumb adaptor back in and see if there is a power/driveability loss.

That will soon tell you if your exhaust is free flowing enough or not and there honestly is no other way to truly tell.

When my adaptor was made (just a pipe with flanges on either end, $80) it was a simple test.

I miss external gate, it gets me hot... no better sound IMO.

[Lithium]

Venting to atmosphere wastegates sound bloody aweful, especially when drowning out a tidy tight RB exhaust note - so thats a good reason to not go for one in the first place. 360kw @ wheels isn't an awefully huge amount of power in the grand scheme of things, there may be a little advantage in venting to atmo but really I doubt its needed. There are heaps of people running twin GT2530s and GT-RSs on their GTRs on here and they're all internally gated, hell one of my mates with an EVO is making >350kw @ wheels on BP98 with full legal exhaust on his 2litre with wastegate plumbed into his exhaust... he's relying on ~28psi of boost to do that power and if anything is going to start feeling the pinch from exhaust pressure he would.

Edited February 28, 2009 by Lithium

[R31Nismoid]

If you have a good A/M manifold and a exhaust with fark all muffler - you can still hear both, i could with mine lol

[2LV8ETR]

After I got pinged for the screamer I went to a divorced downpipe to the cat and didn't see any difference.

That was with a 3" exhaust, with yours having a 3.5" exhaust I'd be surprised if there was a difference.

The reason I went with a divorced pipe to the cat was for minimal vortex disruption near the manifold. The disruption happens at the cat which disrupts the flow anyway.

Hope my experience helps.

Later!

[Turbz RB-25]

Make up an adaptor - its nice and easy for an exhaust shop.

Once the car is fully tuned (with it venting external), put the plumb adaptor back in and see if there is a power/driveability loss.

That will soon tell you if your exhaust is free flowing enough or not and there honestly is no other way to truly tell.

When my adaptor was made (just a pipe with flanges on either end, $80) it was a simple test.

I miss external gate, it gets me hot... no better sound IMO.

Then this is what shall be done.

[NYTSKY]

I have a screamer on mine, sounds absolute horn!

But i will be getting it flanged for plumback aswell.

[l0WRB]

I ran screamer pipe thru a 50mm gate for a few months, sounded ok, but u get over it after awhile haha

fine example haha

[gotRICE?]

Buggered if i can find the thread, but someone on here put a muffler on the screamer pipe. It looked pretty cool. But i dont think there was a sound vid when i read it.

Anyone know what the thread was called??