Just about to order the de resonated centre section for my newage STI PPP. Does this just replace the resonator section or the CAT aswell? If so, when I replace it will it fail the MOT?
If so, I presume it is just a case of switching the pipes before an MOT?

 

I'm about to do the same thing, my understanding is it just replaces the resonated section and stops short of the cat. If you are talking about a centre section such as scoobyworld or hayward and scott sell.
you can get a seperate decat cat pipe for £100 new.

anyone please correct me if I am wrong

 

yes, from scooby world.

 

yep, just the resonated pipe is replaced - I went for the resonated centre section to keep noise down.

It was a nice fit and very, very shiney

Edit: and no, replacing it shouldn't make you fail your MOT (unless the MOT person is cranky and thinks it's too loud). In fact, you should be able to remove the centre cat also (as long as you've got the PPP downpipe)

 

Assuming your car is pre 06, then the centre has a silencer and NOT a resonator, removing it liberates more noise but almost nothing in the way of power.

Removing any cat is contrary to construction and use regs, and whilst it may pass an MOT its illegal, that's not to say I havn't done it, but just to make you fully aware!

Simon

 

You can just change the centre for the straight pipe as pic below...

 

I want more power but I dont want it to be too loud so would it be worth getting
an aftermarket backbox coupled with the original centre section (to keep noise down) but a decat cat pipe, instead of cat back system?

 

I've got the following:

ppp backbox
afterburner resonated centre section
centre decat
ppp sport cat downpipe
gt spec headers and up-pipe.

I don't think it's too loud at all, my engine makes more noise than the exhaust when "going for it". I've never driven the car with just a ppp backbox, so I can't compare, but the noise at the moment is not at all over the top in my opinion

Edit: obviously it's a bit louder than the standard twin pipe exhaust, but not really louder than the normal PPP WRX's I come across.

 

You've not got a CAT in the centre section of a PPP Exhaust, all you've got is the Prodrive Sports CAT in the downpipe. So by replacing the resonator/silencer with straight through section will give you better sound along with a better throttle response. One of the best Mods i made when i did mine

 

Cool, didn't actually know that the PPP replaced the centre cat on an STI ... I learn something new on here every day

 

Id be interested to see what u guys think after you have done this. Im looking to do the same on my 05 PPP i dont want it too loud like a nova a civic or some chavved up scoobs i just want a tad more volume with out going ott!!

 

Replaced the centre section of my MY05 STI PPP with a Japspeed stainless section and it was well worth doing - gave more burbble but not too loud.Certainly sounds a lot better and deeper than with the standard middle section.

 

Sounds good. Got a link to the place u got it from pls?

 

Check out MySpace.com - Boyd - 97 - Male - Colchester, UK - www.myspace.com/b0dski

Then click on Video, thats my car with a straight through Afterburner centre section & Afterburner backbox, that should give you some sort of idea what the volume is like

 

Thanks for that.

Pretty loud then, lol. I dont think with the PPP it will be quite so much so though?
Im guessing the after burners louder?

 

Why did you replace the standard centre pipe with another resonated one?

 

I like the stainless steel look and I believe the standard diameter on a WRX is 2.25" as opposed to the 2.5" I went for. Doesn't sound like a big increase but it's actually a 23% increase in cross area. Hopefully it will survive longer than a standard section as well, so I can fit it once and forget about it

 

Yeah i had the PPP exhaust on before the Afterburner and yes it is a fair bit louder, but thats not the main reason for having it, the PPP backbox is quite a restrictive one and by having the afterburner i find the turbo spools earlier and seems to pull harder from lower revs

 

Thats interesting and worth thinking about in the future.

Would anyone say its worth getting de-res pipe and still keep the PPP box?

 

yes it's what i have done on my classic and its not loud at all.

 

Except the stock pipe is stainless of coures, low grade so it surface rusts, but it will last pretty much forever!

Simon