I've read many posts of UK spec cars with much more BHP than I was led to believe was possible - I was told that the Jap Classic WRX runs about 0.7 bar boost as opposed to the STi models running 1.0.

The UK models running only 0.65 or so - this may be completely wrong so no shouting please!

My question would be if you can tune the UK cars to the same / more than some Jap WRX / STi models are they still as reliable (exeption for STi with 'blueprinted' engine) but the UK Turbo V Jap WRX - Can they take the same levels of boost, I assume the UK specs need bigger fuel pump, injectors, bigger turbo etc?

Just want to get clear in my mind the differences as I have seen many UK Classic specs with near 300bhp with decat, slight boost increases etc.. rambling now soz!

 

Id also like to know what my standard UK cars boost is supposed to be...

 

I think its 1 bar on the MY03 STi .....but I may be wrong

 

Unfortunately SD it's not possible to give you a complete/accurate answer to that question as it's so generalised. There are specific differences in the UK and Japanese models over the years such that the answer would depend on exactly what cars you were comparing.

In general terms, the UK Turbo 2000 (or WRX if you're talking new age) will have very similar engine internals to the Japanese equivalent of the same model year. Thus, it follows that they'll take broadly similar power increases before crying "enough", provided said increases were obtained in an equally safe manner.

If you start comparing different model years, it then becomes quite a bit more complicated!

 

so do we know what a standard UK turbo/WRX runs in the way of bar?

 

What model year?

 

My WRX runs ~1.2bar on a VF29 turbo, peak I have ever hit is 1.25bar

Forget boost matching as it depends how big your turbo is as well. Most UKs run a TD turbo where as JDMs run TDs and VFs

 

03 WRX.....not sure what turbo that is...

 

TD04 in the MY03 WRX UK IIRC

Standard boost is 0.9 bar again IIRC

 

greasemonkey ,

Should have been more specific. I'm interested in the Classics 96/97/98 WRX / STi models

Cheers

 

My UK 03 WRX runs around .95 BAR, but peaks around 1.15 which surprised me. This is out of the standard TD04 turbo. (I think it's a TD04)

I think the STI PPP peaks at around 1.5BAR which is *significantly* more , plus the turbo is a VFtwentysomething, which flows rather a lot more air too.

Cheers,
Nick.

 

1.5... think that would be like hitting the 'BOOST' button in Kit....

 

sti ppp is 1.2 I think maybe 1.25

 

This sti6 runs a vf29 like my ra and new age uk sti runs a vf30 the import spec C runs a vf34 IIRC

 

I have a early 97 jdm wrx, it runs a vf22 and 1.1 bar boost, the model is apparently rated at 280 ps.
Hope this helps

Glenn

 

ive recorded 14.7 psi not sure what its in bar mine a uk my 99

 

14.5psi = 1bar

 

only a 1994 wrx import but got to 11.5 psi other day with full decat i,ve got 220bhp approx ,been told normal import 1994 anyway comes with 215 standard. unlikely could get 300 bhp in this one without something going bang .would love to try though

 

The STI's have forged pistons and sodium filled valves which should allow the car to run with cooler exhaust temps for the equivelent spec uk engine.

Also i beleve the con rods are different along with the valve gear, allowing an 8000rpm redline rather than 7000

Also to go with this the cam profiles should be different (must be, but i don't know for sure) which would help breathing in the higher rev range yet again helping egt's on a similar spec'd car.

I suspect since the high powered cars run about the same you would likely see that the jap cars with the same mods make the same power with slightly less boost than the uk ones.

Maybe STI owners just dont put the effort in to get the most power though

Or possibly the cooling system is the limiting factor here.

Dave.

 

So on an 03 WRX, is a TD04 a good turbo?? why did people seem surprised at 1.1bar peak?? (just out of interest....)

Neil.

 

The TD04 is a good turbo as its bit smaller and spools up faster so there is less lag. The downside is that with it being smaller it doesnt flow as much air at high revs than a bigger td05 or vf series turbo. 1.1bar IIRC is the target boost for a PPP conversion. Does it hold 1.1bar though or just peak and drop to 0.9/1.0bar ?

Its really swings and roundabouts if you want your cake and eat it i.e. a fast spool low lag turbo that flows loads of air at high revs you need a hybrid turbo but they aint cheap and need to be mapped to your car.

 

Well personally when my foot is to the floor in the right range, it holds "just" below 1.0 on my boost guage...so im guessing the 0.9-0.95 is about right (i just didnt know what units my boost guage was in ) for sustained boost, ive never managed to get mine above 1.0 though to my knowledge.

When the time comes (i.e. when the cash allows and the car is a little older) i should endeavour to get a larger turbo

Neil.

 

What sort of pressure can a TD04 handle safely then?

 

my (standard) 97 turbo peaks at 0.95 bar in the higher two gears yet on a very cold day it has reached 1 bar from time to time, I have heard this is normal. The pre face lift turbos I thought were slightly lower in boost pressure but had the bigger turbo, so more or less the same power and torque but at a higher rev point. 1.1 bar for a standard wrx seems really high to me! I always thought the ppp ecus were around that figure? dont quote me on any of this though, Grease monkey is the man to speak to. By the way what does IIRC stand for?

 

Mine has a VF36

Tony

 

yep the new new spec c runs the vf36

iirc = if i recall correctly

 

1.2bar on mine