I've just bought a 2005 Sport Wagon WRX which looks like it has the PPP. It certainly has the Prodrive zorst and a blue Prodrive hose under the IC. When I have more time I'll pull up the carpet and check the ECU.

Assuming it has the PPP fitted and I wanted to do some light upgrades would a larger IC (perhaps from the same vintage STI) and a good induction kit help?

Would I need a further remap to realise any benefit from those changes? Any other suggestions if I'm talking complete nonsense?

And a big "Hi" from me as a new member to the forum too

 

Normally if you do any kind of engine changes you're better getting it mapped to suit.
If you went to that trouble I would probably get change the exhaust - prodrive one has 3 cats from what I can remember, if you change the backbox and middle section I think you can remove two - 'could be wrong, though theres defiantly at least one to be removed by changing middle section and backbox'.

Dont think there would be any need for an induction kit, just a good panel filter.

 

Normally comprises
Back box
Centre section with resonator
Downpipe with 2 cats ( not sure on PPP wrx )
Cat in up pipe.
You'll need a remap for an induction kit so just get a good panel filter. You can out an sti intercooler on but not needed at your power levels. I would go for a custom remap with just one prodrive sports cat and a decent panel filter you'll be circa 280bhp with that and decent drivability. Might as well put on a 3 port boost solenoid from a classic at point of remap as it's cheap enough and good for future power increases.

 

Prodrive only has two cats, one in the downpipe and one in the up pipe. Stick with an uprated panel filter unless your looking over 400bhp. I would keep the prodrive exhaust as they are one of the best flowing systems out there, maybe just change the centre pipe for a non resonated one for more noise.

 

The middle section and backbox have no cats in them.

 

All interesting stuff folks. It sounds like the PPP pack its quite well sorted for the quick and easy mods already and I'm not sure about ditching the resonated mid pipe as its already quite loud... I dont think my neighbours like it.

So I guess the only upgrade would be a good panel filter... I guess even that on its own would ideally need a remap too?

 

No a panel filter wont need a map.

 

Any performance gain or just some noise?

 

Maybe 1 or 2 bhp but you wont notice. Ive tried many over the years, green filter, sti filter, pipercross, k&n. The best ive found is the cosworth filter, its the only one that feels like its making a difference.