I have installed a 2.5 engine in my car and still running the standard box. I've been running around in the car for over a year with 320bhp+ on the standard box and I think it won't last long on with the 2.5

I've been told the P1 or sti 5 box is the strongest without going PPG.

What parts do I need to fit into my 93 wrx? Is it just the gearbox and rear diff? Is there a center diff attached to the box already?

cheers

 

also will the clutch I have fit the box?

If I remember correctly there was 2 clutches for my car a thinner one and a thicker one. I am sure I went for the thicker one

 

You are correct the centre diff is already attached to gearbox, all you need is the gearbox and diff.

The clutch will fit no problem but may not handle the torque from the 2.5 engine.

Banny

 

thanks for the reply, by diff you mean rear diff?

I'll take my chances with the clutch at the moment as it is pretty new. I don't mind replacing the clutch if it slips just rather the box was up to scratch

cheers

 

Yes I meant the rear diff

Banny

 

hmm plenty of p1 owners have have killed their boxes with standard power
let alone 2.5 grunt. nice gearing if it,ll rev that far though.

 

the sti and p1 box's arnt much different from a uk box im afraid, for the grunt of a 2.5 then 6 speeder or ppg are your only real options if you want it to last

 

My P1 box is currently hanging on under 440bhp and 370 torque (2 litre) and the ratios are nice - long but seem well spaced with the extra grunt - but I'm fairly sure it'll die in due course.