JIM THEO

As per the tittle, I am thinking of an aftermarket I/C for my WRX03 (full decat, factory STI backbox, PPP ECU) and after some search I decided not to go the STI I/C route as it has fitting issues by hitting the air con lines etc
I am looking for TMICs like APS, Hyperflow, Perrin, Helix etc but how they affect turbo spool up and lag, bear in mind I still have the small factory TD04 turbo and what have been told is they all increase lag, although a friend with MRT TMIC says it has better spool up and overall performance with less boost (!) who to believe?
I am not going to remap my car as the Prodrive ECU compensates very well with all my mods, I'll modify only my air splitter to work with the new I/C.
Thanks in advance
JIM

Neilo

i would ebb towards the second opinion, i have the same car and put on the STI top mount, only trouble bieng that the scoops splitter o nly blows ait on the the original size of the standard one, ive just bought an sti one to improve the situation. They should be correct about obtaining slightly more power from the the same boost level though.

A worthwhile mod if you have the spare cash but dont waste your omney on the APS one or anything like that, most good tuners will recommend that the standard one from an 01+ STI is as good as any i managed to get mine for 140 delivered although i know they go for more than that now....

Neil.

stevebt

iTrader: (8)

i added a larger TMIC to my 99/00 impreza and it increased lag but a remap soon got rid of it

Granby

iTrader: (5)

I've fitted a STi I/C to my 2004 WRX and had no fitting issues, changed the scoop & splitter for STi items to get the most out of the I/C.

JIM THEO

What did you do with air con lines?
I saw many WRXs with STI I/C, in all cases the I/C touches the aircon lines which isn't good for long term use!
JIM

Butty

iTrader: (2)

Jim,
maybe your problems with the AC lines is something to do with different bulkhead layouts between left hand and right hand drive cars?
Perhaps there's some info on NASIOC on how the Yanks get around the problem?
I'm also sure I read about this problem and how to get around it on
www.subaruforester.com/forum/index.php


Nick

JIM THEO

Nick you are correct

this is a RHD WRX and is different from my car!
JIM

Granby

iTrader: (5)

You had me worried there, i had to go out and double check but everythings OK so it must be something to do with LHD, but they do STi's in LHD so there must be a way round it

Neilo

same here!! good old butty, to the rescue!!!

incidentally nick, thanks again for the link to the splitter, its on its way now b

hades

From memory, the APS TMIC drops ~2psi less pressure across the intercooler than the standard WRX TMIC. This means you'll get 2psi more boost for a given "effort" from the turbo. In theory, I'd suggest that means you'll get a little faster spool (you'll make 15psi at the same revs as you used to make 13psi), plus less exhaust back-pressure, i.e. a little more power. Alternatively, allows you to run a little more boost at the manifold from the same turbo.

I doubt the APS TMIC is unique in that lower pressure drop, just happens to be the one I've seen the figure quoted for. And whilst the STi TMIC is capable of handling at least 350bhp, and undoubtedly the best value option if you get it for £150 or similar, I don't believe it is actually as good as the better aftermarket ones.

hades

P.S. having said that, the bigger volume of the I/C should in theory marginally increase lag as it takes longer for the turbo to pressurise the bigger system

Butty

iTrader: (2)

Then If anyone wants an MY03/04 STi splitter - I will have one free next week. I can l also provide a template or make up plates so that the STi one can fit under the WRX scoop whilst feeding the STi IC.



Looking for £70 ono

Nick