What are the advantages of fitting a twin dump dp?, understand they achieve better gas flow, does this inturn give better performance gains?

are they any better than the single type such as a ScoobySport or HKS?

do they sound any different?

or, are there any dis-advantages?

 

Hi there,

This subject has been discussed many times in the past on both the major subaru bbs's. As scoobynet's search system is still non-operational I would suggest you try doing a search on the more technical bbs, bbs.22b.com .

Moray

 

from what ive read on other threads a lot depends on other engine mods and your driving characteristics...

i have a standard MY00 Turbo 2000, will be changing my exhaust system and maybe an induction kit, but thats about it, so will probably only make about 260bhp when done.

i dont mind the noise (louder the better ), although i drive fairly low down the rev range, never go far above 4500rpm.

so will a 3inch dp be too big? as i so far understand that 3inch dp's are best suited to heavily modded cars which require this extra size.

 

Well the PE T75 Twin Dump wastegate pipe joins very close to the top!!??

 

Err, I don't think you'll go much better on either type. You are not running max potential on your current system as the power increases up to at least 5,500 rpm. If you change the downpipe you'll gain spool up a feww hundred rpm lower, but that is about it. If you want more power, consider raising the boost or driving with a few more revs whn you want to go faster.

Duncan

 

has anyone had any experance of PE T75 &/or SS downpipe??

 

David,

If you look at Stephen Dones site (go thhru www.ecutek.co.uk), he's go the low down on the PE system ... it's good reading.

Steve

 

I've recently fitted Power Engineering T75 System to my STI7 UK including downpipe.

Massive improvements to performance and over boost easily fixed with restrictor. I strongly suspect that the PE twin dump downpipe is the reason why I haven't had the same crazy over boost problems as other STI 7 owners with other exhaust systems.

Car dyno'd @ PE on a pretty hot day a few weeks back, 300bhp & 284 lbft, Steve Done did some data logging whilst I was there also to check overboost problem was solved in the workshop & on the road. Prior to restrictor car was dyno'd @ 311bhp & 295lbft, but after restrictor I gained approx 15bhp/15lbft from 4000rpm thro to 6500rpm, and a much smoother and quicker car. All in all, well chuffed!

PE T75 system is absolutely superb quality also!


[Edited by Paul N P - 4/6/2002 8:45:27 PM]

 

If I remember right from the old debate on here, open neck, single dump DPs are reputedly the best.

Apparently, closed necks block off the wastegate completely, thus hampering flow, twin dumps relieve pressure by not blocking the wastegate but can cause turbulence in the exhaust due to two pipes full of hot gas meeting. If you do go for twin dump, you want the join to be quite far along the DP, not near the top.

Open necks give the best flow with less turbulence.

This is just what I remember being the overall conclusion from the last debate and I'm not pretending to be Mr. Downpipe or anything

Cheers
Rich

[Edited by RICH WILD - 4/5/2002 1:57:27 PM]