PPP

[mystery machine]

Hi folks,

I'd be very grateful if someone could tell me whether the PPP for a Hawkeye STI removes any of the cats? (this doc suggests not).

I'd like to have the car remapped for some fairly modest gains, really to increase power and response between 4.5K-6.5K rpm - I don't really need peak torque @ around 3.6K rpm to increase much, but 320-ish bhp at 6K rpm would be nice

It seems that - prior to mapping - most folks around here will replace the downpipe cat with a decat pipe or sports cat, as it's the greatest restriction in the exhaust system. Fair enough if you're after big power gains, but the problem I have with this is expense - seems that a sports cat will set me back around £400

I figure that, if the PPP doesn't spec a sports cat or decat downpipe, then a good mapper should be able to map my car to a similar level (i.e. 320-ish bhp) without me being required to fit the same? I should add that I would be willing to replace the lower cat with a decat pipe, as these can be had for only £110 (this in lieu of the PPP backbox - I want to keep the existing backbox). I'd also be willing to fit an uprated fuel pump, if required.

Anyone care to comment? Does this sound feasible, worthwhile and MOT-friendly, or am I being an optimistic skinflint?

Cheers

Edited January 11, 2011 by Mystery Machine

[rig-pig]

the prodrive sports cat is a good one to have on the scoob i dont know if you get them for the 2.5, i know the ppp on the bug/blobeye wrx remove the 2nd cat and leave the one on the up-pipe and the down pipe on the STi im sure they change to a sports cat down pipe and remove the 2nd cat to a de-cat pipe the STi doesn't have a cat-ed up-pipe

Edited January 11, 2011 by rig-pig

[scooby222]

not too sure from your post if you have PPP already or not?

anyways PPP should be sports cat downpipe, then 2nd cat delete pipe and prodrive backbox and walbro fuel pump

ive a feeling Gus the bus had a mate doing sports cat DP's for reasonable price but it should be possible to get 320 with a remap on a panel air filter, fuel pump and straight through centre section (providing your current backbox is fairly free flowing)

[wrx kenny]

jap speed over on scoobynet are always doing group buys on sports cats 100 cel, i and a few others on the site have them fitted no issues so far and i think they were roundabout the £ 200 mark

kenny

[BalliSTIc]

Whaddaya want cats for anyway? *chuckle*

[mystery machine]

Thanks for the replies, folks. OK, sounds like the downpipe cat has to be sports catted. Interesting that the PPP brochures make no mention of this (political correctness?).

Dave - my car doesn't have the PPP.

Kenny, that's interesting - do you know if the Jap Speed cats are the type that also decat the second cat (i.e. one part to replace two)? £200 is probably about as much as I'd want to spend, would rather not pay for a second cat delete pipe on top of that.

BalliSTIc - can't be arsed swapping cats in and out at MOT time, or locating a shifty MOT garage

Edited January 11, 2011 by Mystery Machine

[wrx kenny]

Kenny, that's interesting - do you know if the Jap Speed cats are the type that also decat the second cat (i.e. one part to replace two)? £200 is probably about as much as I'd want to spend, would rather not pay for a second cat delete pipe on top of that.

[scooby222]

good work Stevie - didnt realise the 2.5's didnt get the sports cat downpipe

[mystery machine]

Will give you a wee bit information I found out, My car is a 55 plate hawk sti type uk, Wasnt sure if my car had ppp or not (was sold to me as ppp but had no certificate), but when I took it to andy forrest for a remap he confirmed that it had been remapped 3 times by prodrive (It was a subaru uk car the exact car shown on that prodrive advert BV55 TCO ye its famous lol, so i guess they were wanting it right), My car had the normal cat downpipe,(I was told prodrive didnt replace the downpipes on the 2.5ltr), straight through up pipe and straight through with resonator where the 2nd cat would have been. Before i got a sports cat andy did say he could achieve about 330bhp but the spool up on turbo would be slower due to the restriction or 350-360bhp with a sports/delete cat and early boost. I got a 200cell meerkat sports cat fitted and andy got it to 350bhp and turbo spooling up 500rpm earlier. I also replaced the fuel pump with a walbro but when I went to take the old one out I did noticed someone had wrote ppp on the cover you have to remove. Feel free to ask any more questions hopefully i can answer them.

cheers

Stevie

Thanks for all the info Stevie, very useful

I've just one question for you, if that's OK. You say that the PPP has a "straight through with resonator where the 2nd cat would have been". As I understand it, the standard hawk STI exhaust uses these parts, from turbo back:

[downpipe cat] -> [second cat] -> [resonator pipe] -> [back box]

So are you saying that the PPP modifies this to:

[downpipe cat] -> [resonator pipe] -> [resonator pipe] -> [prodrive back box]

In other words, two resonator pipes?

I ask because I can buy a 'straight through' pipe to replace the second cat for about £110... but I don't think it has any resonator section. Bit concerned I'll end up with more exhaust drone in the cabin (resonator pipes are supposed to reduce cabin noise so that the majority of the exhaust noise comes from the back box).

Cheers again mate!

P.S. Interesting to hear that your very car was the Prodrive pinup!

[mystery machine]

When I got the car it had a 2nd decat but with a small resonator section about the size of the cat itself and had the subaru stamp on the heatshields (I thought it was a cat until I took it off and found it was straight through, possibly standard with the STI), the next section was a funny flat triangle shape section then the prodrive back box.The work I got done was a downpipe and 2nd cat pipe in 1 section including the sports cat where the 2nd cat would have been bought from meerkat exhausts, then got a straight trhough pipe with resonator to replace the triangle shape type bit which i bought from cobra sport, and left the prodrive back box as is as i liked teh burble it made, the noise inside the car is pretty quiet, not any louder than it was before i did the changes. If you want I could meet up and let you hear just what it sounds like.

cheers

stevie

Cheers again for the insights, Stevie.

I wonder if anyone can shed light on the triangle-shape section... whether that's the standard STI reso pipe?

[wrxcook]

Sorry for invading the post but, reading it I was wondering if the wrx pop comes with a sportcat downpipe as I may have replaced it without knowing there fore have it sitting in my shed

[wrxcook]

Sorry for invading the post but, reading it I was wondering if the wrx ppp comes with a sportcat downpipe as I may have replaced it without knowing there fore have it sitting in my shed

[mystery machine]

That's OK - it only counts as a thread invasion if you repeat yourself

[mmcd87]

Sorry for invading the post but, reading it I was wondering if the wrx ppp comes with a sportcat downpipe as I may have replaced it without knowing there fore have it sitting in my shed

As far as I am aware, the newage WRX PPP kit removes one of the centre cats and replaces it with a straight pipe. The other 2 are unchanged from stock.