Just picked up a Spec-C (after chopping in my UK STi), running a sports catted exhaust and re-mapped for UK fuel, running approx 330/330.

The car currently peaks at 1.5bar, tailing off.

I am aware that there are differences between the Spec-C engine and a normal JDM STi, so was wondering what options and gains are available.

At this stage I will not be looking at "going internal" as the car is rapid as it is and really looking at a top handling really fast road car. Car must be run on super unleaded only.

Initially looking at a 3" Decat, induction kit & re-map perhaps.

Anybody played with these and know whats what?

Are the changes in turbo, internals stand me any better for modding?

Regards,
Shaun.

 

There is a couple of differences, all are mechanical, all make a difference but you wont notice it, otherwise the engine is exactly the same as any other JDM STi of the same year (fuel pump, roller bearing turbo which is low friction but the same size as the VF37 and oil cooler).
Remaps for either the Spec C (2003 onwards) or the JDM STi can bring similar results, 350+bhp and 380+lbs of torque, this ive seen with a full decat and exhaust, cost about 1000 all in. Would also add that id not go for an induction kit, rather a replacement panel filter, the STi one is very good and is a service item so its replaced every year, i got very good gains off one (12bhp and 15lbs of torque on the jap map).

Tony

 

Tony,

I was under the impression (perhaps I got it wrong) that the turbo, cams and heads were different?

Cheers,
Shaun.

 

Cars from 2003 onwards were similar in engine components (pistons, cams etc), previous to this i think they were also similar (vf34 rollerbearing for the spec c v vf35 turbo), the S series cars have different cams etc but they are tuned by STi so.....
The turbo on the MY03> car is a VF36 rollerbearing v the VF37 sleeve bearing on the normal JDM STi.
Both are similar in tunability, ive seen a MY03/4 car tuned to 360bhp and 400lbs of torque with just a decat exhaust and remap, very nice (done by Richard Bulmer).

Tony

 

Hi m8 can i ask were your getting your spec c from as im looking at a few iat litchfields.

 

Decat/ remap = 400lbs of torque, are you serious????

 

Yep, it was actually 402lbs and 362bhp if i remember correctly

Tony

PS, i do have a readout of it somewhere i think?

 

Who mapped the car Tony, and was it on the stock turbo/tmic/headers etc

Deep

 

Richard Bulmer mapped the car, and yes it was stock turbo/tmic/headers, only the exhaust was different (possably an STi panel filter also)

Tony

 

got me thinking now......

 

Tuscan,

Mine already runs 335bhp just via a UK fuel re-map but with a sports catted exhaust system...... aiming towards 380bhp with a proper mapping session, 3" exhaust system and induction change.

Regards,
Shaun.

 

R.B

 

 

zorst will be ONE of my next changes. well the rest of the system as it was TOO quiet with the standard STI b/b so have a H&S 4 1/2 jap style rear box. think i will try to get my de-cat before the 5000 mile service so i can have it mapped @the same time...... altho with 3000 miles now completed wont have long.... (1600 miles in 4 weeks)

 

Way to go, Jo

 

not that im enjoying the car at all.....