2004 STI -

APS SR40 Turbo
Motec M800 ECU
uprated fuel pump/injectors
FMIC
APS recirculation valve
air filter
3.5" straight through exhaust with decat

realistically what bhp should i be getting?

 

I would guess around 360bhp

 

what would be needed to get to 400? slightly better turbo? headers?

 

Depends on your injectors, who maps it, how good a condition your engine is in etc.
APS show the turbo is good for upto the 440bhp figure, you should be happy with 400bhp imo

http://www.airpowersystems.com/wrx/aps_turbo.htm

Tony

 

Hi Tony, yes i was thinking this, recently new to the subaru scene and car had these supporting mods when i purchased it, i suspect it feels like it is running around 330 - 340bhp, best idea to just get it booked in for a rolling road run and go from there?

 

Probably best to get a mapper to check how its running, if they have just been bolted on and no map then I suspect the car isnt going to be very happy, do you have any documentation showing that the car has been mapped etc? A mapper will be able to say how well or what the car should be running.

Tony

 

yes the car has paperwork showing the remap, i suspect it is mapped to slightly overfuel due to the level of popping and banging ond flames on overun, seems to peak at about 1.5 bar aswell if that sounds about correct, think i will get it booked in, was going to do it with Simon at JGM before xmas but did not get the chance.

 

personaly i'd dump the motec and the aps turbo, alot of money for what can be done by cheaper other items.

i'd go syvecs and then sc46 billet myself for what you want.

 

Pops and bangs are likely to be mapped in.

If it is a 400 bhp capable turbo, then a re-map may help...

dunx

 

cheers guys for the quick response, will look at getting it remapped first then and power run

 

The SR40 is not a great turbo, not sure what APS were thinking tbh.

It is more like 360 to 400bhp turbo and is best suited to 2.5.

Got one customer running 390bhp on 2.5 and another running similar on 2litre sti, just two recent ones that come to mind.

You wont get beyond 390~400 on standard injectors btw regardless of turbo.

Simon

 

thanks for the info Simon, need to get it booked in with you, will email you to arrange this

 

no problem

 

A list of mods doesn't really mean a lot without more information. For instance there are good and bad front mounts, some aid power and some hold it back. As pointed out by Simon you will struggle to do much more than 370-380 bhp because of your injectors just for a start. The whole thing about modifying the car is that all the modifications compliment each other and that is the only way to get good results. Eg. headers, what headers, what uppipe.
Then to complicate that what rolling road? Different rolling roads, different figures.
With well thought out mods and properly mapped you will get close to 400 bhp as we have done from several of these in the past.

 

PS: 3.5" exhaust. Another piece of APS crap. Sold with glossy advertising and bullish claims. 3" exhaust will see you all the way to around 700 bhp. At least you didn't have to buy it/pay for it.
Same goes for the front mount. If it is APS swap it for a Hybrid for about a third of the cost and add 10 bhp minimum.