Thinking of changing OE intercooler on WRX PPP (05 with viper induction kit) to an STI intercooler. Could I expect reasonable gains in torque and BHP? I plan on aiming for 300 as is the revolution wagon in this months jap performance...

Many thanks

 

I did this swap before doing more extensive work and all I found was peak boost came in some 300 rpm earlier and managed to get the injectors to reach 103% idc when loading the engine.
Nothing was really noticeable though when driving or when logging the change on delta dash.

To get air flow over the STi IC, you'll need the STi scoop splitter (tweaked to fit under WRX scoop) or go for larger STi scoop.


Nick

 

The same with Butty here and more over I had some ignition retard (1-1.5 degrees) at 5400-5600rpms with the factory I/C which dissapeared with the STI unit.

 

Hi Jim,
Hows it going?
Tried to send you a PM but your inbox is full.

Nick

 

Cheers - I'll have a think about this one then!!

 

Ooops...
Sorry mate I delete right now some messages from my inbox.
My car has currently according to DD road dyno more than 255ps ATW in "very heavy smoothing" and this IMHO is about 250 "true" ps cause peaks in road dyno curve give the max power which is slightly lower if it was smooth:



I added recently a cated Invidia downpipe (4">3" open neck with splitter) which, believe it or not, performs better than my previous full decat (image above)!
Of course injector duties are very high after 5500rpm and touch 105% sometimes but measured with wide band my mixture is still very rich and EGT's lower than 815C degrees.
Fulll boost now with 4th-5th gear at 2650 rpms and a happy owner, me!
JIM

 

Andy F reccommends the STI Top mount on his on going mods on scoobynet! I got mine for about £250 from flat4 online and bought a samco hose kit to fit it. It certainly helped me get to 283HP on my standard map with a decat and panel filter!!