Diagram here showing the rear decat....



Tony.

 

decatting will cause boost spikes and should not be done without remapping to take the changes into account - chaning the backbox and centre section are fine.

 

Tony,

Totally agree with what your saying. Here's another diagram on the subject.

http://www.southwestscoobies.org.uk/...xhaust+diagram

Would be interesting to see if it would be much more noiser with the other section removed although mine sounds very much my old 04 WRX PPP

 

The exhaust layout is not as per that diagram on the 06 - the front centre section pipe extends up to the bottom of the downpipe.

With the ceentre resonator removed and replaced with just a straight through pipe it is not noise but gives a nice burble along with backbox chaange (both original cats still in place)

 

Agree... MY06 layout has changed from the diagram, was just to show that it is a 4 piece system and that the resonator section is not changed on the PPP.

My PPP exhaust is still getting louder as the miles go on . My wife now knows when i'm back from work again

Tony.

 

OK .. (from a non techie) - are we saying that my STI PPP (MY06) has not had the resonator taken out?

Mark

 

No, it has the rear cat removed and replaced with a resonated section and a new backbox.... as Mike Wood's quote above.

Tony.

 

Just got my car on the dyno yesterday at an SIDC meet.

MY06 STI UK 9000 miles everything standard

298.5 BHP and 299 lbs Torque

Going to order a new exhaust now

 

wow thats 20 up on expected (I guess within the limits of errors?) - still its the right way and could be even more I suppose.

Mark

 

Very good figures Noki!

What was the general view on the day, were figures up or down?

 

Most figures were bang on what people expected.

3 WRX PPP's all produced 255 bhp with Prodrive stickers reading 261 bhp.
But having 3 identical cars reading the same was good.

The guy at Dastek had an 06 on before and it was 300 bhp. I said its 280 in the manual so anything above. Would be good. Spoke to the salesman at local Scoob garage about it as well and he said every 06 STI he has known to be on rollers have reached 300 BHP Standard

Hit just under 300 in both bhp and torque with 1.0 bar boost so im really happy with that.
All the pre 06 STI's with PPP were hitting 300-305.

 

Very interesting stuff...

I must admit I did not think I would have much fun up to 4000 rpm with a PPP'd STi (MY06). However its rapid from 3000 onwards with much more go than my MY04 WRX PPP. Overall the car at this stage feels much faster than I was expecting - and thats at low revs and tight engine..

Mark

 

Just to add a bit to the MY06s all being up on book figures, before fitting the PPP to my WRX the car got 250bhp, so 20bhp up.....

After fitting PPP figures were pretty much bang on.

Tony.