my new build will be starting soon,not going for alot of power but wondered what power/torque/boost pressure etc it will be able to run.
ver 4 sti type r (98)
jdm sti8 shortblock
completely overhauled sti 4 heads
decat downpipe
oe centre section
h&s backbox
walbro pump
vf24(oe)
apexi power fc.
oe gearbox
exedy pink clutch
exedy lightweight flywheel.

any comments welcome.

 

I would say about 320bhp give or take 10bhp on that spec at about 1.4bar, I see you have no fmic or headers? U budgeting for these?

 

no mate im not,thats it for the mods as i dont have the money to replace the gearbox.....maybe in a couple years i may upgrade to six speed then 450bhp could be on the cards.just want my oe gearbox to last for a good while yet.

 

Would consider a vf34 or vf35, get a little more out of it and still in the safe zone. Good luck

 

no point pushing the box,ill be happy with 300 tbh,300bhp with the type r gearing would be pretty good.
i would be more than happy with over that.

 

what is the vf24 capable of?

 

you dont need headers mate until about 400hp, the vf24 is a good little tubby and with the s/r gearbox it will feel quick. i think you can get 340-350 on a 24 btw.i have heard the v4 r box is about the best one on a classic but its pot luck. i think you should be ok upto 350 on it ,some have run alot more.

 

i wouldnt have thought i will reach that sort of power with the mods listed will i?
i was thinking maybe 300 or just over?

 

well if you think about it stock classic v4 sti are meant to be 280 standard and ive heard they are more like 300 in reality, if you decat and raise the boost cant see why you would nt get 330 -350 with the spec youve got, a mapper wouldnt want to push the standard top mount and the standard airbox on v3/4 is a restriction aswell.

on my car i`ve gone full 3" and sti8 tmic and ported standard headers to keep good spool but just bought a td05 -18g, and going to get some kind of decent induction kit looking at 370ish
ive got a sti ra v4 btw

 

VF24 will max out at around 320-330bhp, you will be lucky to get more than that. I would get decent centre section and you should easily see 300bhp.

 

It's a classic banny. No cat in centre

 

yeah , its only a resonator in there banny.

 

the oe 440 inj would max out alot earlier surely?

 

anyone?

 

They will max at about 330ish

 

ok cheers banny,so realistically i can expect 300-310 bhp and similar torque?(once ive ran it in obviously)

 

Somewhere in that region

 

thanks.

 

You'd never see 350 on the turbo he has, not on a proper dyno anyway. And 370 on a 18G, that's a push buddy. Probably more like 350/360 to keep it on the safe zone. It really depends where you have it dynoed, I know a place where my car would make +400 but at an accurate dyno would maybe see 390 now.

 

thanks alot guys.

 

If it helps you, on standard fuel pressure ie. no aftermarket fuel pressure regulator your yellow 440 injectors are likely to max out in the 320-330 bhp range. Even with a pressure lift they will be at 100% typically around 340 bhp. The most I have ever seen out of a VF24 is 335 bhp on V-Power and NF on a Simtek and typically you could expect a little over 320 bhp.
Unfortunately your TY752VB gearbox will break at some point and they struggle beyond 350 bhp and don't seem to last long.
The best of the 5 speed gearboxes are the TY754 that were fitted from MY99 onwards.
Don't get caught up in the chasing figures trap. I can take you to a rolling road near here where you can have 350 bhp but if I take you to an alternative venue you might be lucky to have 320 bhp.
Your objective should be to get a quick spooling car you are happy with that will be reliable and then take stock of where you want to go from there.

 

thanks fot the input havey,ive already mentioned that i want the gearbox to last and be reliable.the mrs uses the car daily,im expecting 310 ish and will be more than happy with that.
im hopeing if the car is driven with care the gearbox will be ok.the car standard would be roughly 275 bhp.
so im only after another 25bhp and around 50lb ft.
i know the 752 box is a little weak but i really like the close ratio as the car can accelerate quickly.
im hopeing it will be all good.

 

will be mapped for uk fuel(normal super unleaded)
not v power as hard to get hold of.

 

Box will be fine at the power you going for buddy. They are weaker but not that weak. You just need to be a little considerate with it, no launches etc. Mine has been fine at much more power than that for a good few months, it has now started to crunch in a couple of gears so I'm swapping it for a P1 box.

 

its kinda pot luck,but there would defo be NO launches,my mrs will be driving it daily and drives respectable,then out for a bit of a blast at weekends for me!
but i wont be thrashing or abusing the car at all,so fingers crossed it will last a good few years at approx 300bhp.

 

If it does give up it's not the end of the world. P1 boxes can be picked up for under £400 now, plus a few hours labour and all sorted.

 

p1 box?
if it broke then surely i would have to go 6 speed,as then big power can be run?(my engine would be good for 450 bhp.)
what will the p1 box take? is it any different to the uk spec my99-00 box?
i would be gutted if mine broke,not just because of the cost but i love the close ratio box.it makes the car much more rapid than a standard 5 speed uk box.

 

Yes 6 speed box can safely run big power but your looking at £2K. I'm going to be using a P1 box at circa 410 which should be fine with my considerate driving. All in and fitted for under £500.
I couldn't justify another £2K for box and then more for bigger injectors and tubby.
The P1 box is stronger than the box in your (and my) car, it doesn't have quite as close ratios but are still close enough. It also has a much longer 5th so at motorway speed the car won't be revving it's nuts off.
Your box will be fine anyway at 300ish.

 

P1 box is the same as STi 6or STi 5 so you can widen your search. From memory TY754VBCAA and it has a 4.44 rear diff.

 

will bere that in mind thanks,would i have to change rear diff aswell or will my oe diff be ok with a p1 box?