whats exactly needed to fit a sti 5/6/p1 gearbox to a my99 uk turbo as i keep getting told loads of different storys and i want to clarify before i buy one
cheers steve

 

the P1 g/box is the only "straight" fit...........having the same 1.1>1 drop gear and a 3.9 front diff ratio.....................

the japanese cars will have to be altered to run your 3.9 front diff (as opposed to 4.44 std) and a UK centre diff (1>1 JDM spec)...............

can be done with the jap spec, just a bit more work..........hope this helps

alyn

 

so would i need the rear diff to go with the p1 box or will mine be ok and am i right in thinking they are the same gears 1-4 as the sti5/6 gearboxes (as this is what i'm told)
cheers steve

 

from memory the P1 is exactly the same box as the sti5/6.............just with the diff mods as above, you don't need to change the rear diff if you stay with UK spec thro'out

 

cheers stockcar dont suppose you know what kind of power it will take in that form do u i.e just swapping the gearbox/front diff and using my original rear one (makes a change as i kept getting told i need the driveshafts ,hubs and loads of other bits)
cheers steve

 

depends really on your use and driving style (or not!! LOL)..............we have a 2.5 conversion running around with approx' 400bhp'ish that handles this just fine (not quite the same set-up but near enough), but the driver is reasonably reserved.........

normally around 330+ they can start to struggle, although now of a few peeps that can 'sort' them into a slightly different configuration with less than 300!!!!!!!!!

alyn

 

Alyn, thats not correct. P1 gearbox and diffs are exactly the same as an STi5 being 4.444:1 front and rear with a 1:1 drop gear. If you install a P1 gearbox your need a 4.444:1 rear diff from a P1 or STi5.

 

stand corrected John.........................was always under the impression that the P1 had been "eurofied"..................

cheers

 

No, its pretty much a JDM STi5 mechanicals in a TypeR body. I have conflicting info on the rear LSD used, some say its a suretrack, others say its plated, it could be a VC too. Ratio is 4.444:1 whatever the LSD is though.

 

do we need the drive shafts then to hook upto the rear diff or will the box and diff just drop in without the need to change anything else

 

you will need the box and the rear diff. or you could just split the box and add your front diff

 

To clarify:
STi ver 5 and 6 comes on 4.44 diffs front and rear. The step is 1:1.
The UK car comes on 3.9 front diff and 3.545 rear diff but with a 1.1:1 reduction gear making it 3.9 overall diff ratio.

 

so the question now is do we need the drive shafts to able us to fit an sti5/6/p1 gear box and rear diff or will the uk shafts fit and work ok

 

Pavlo swapped the front CWP and installed 1.1:1 drop gears to allow my STi 5/6 gearbox to be ready to drop into a UK car with 3.9 front and 3.545 rear diffs. Not done it yet, it is waiting to probably go in a Legacy project car, status on hold at present, may end up selling it on again if not used - awaiting engine testing before doing any more. The gearing suits an engine with a 7000 RPM limit as it is lengthened by this operation, would be nice on a UK 2.0 or 2.5. Speedo will still read correctly as a result of the changes.

 

John: Let me know how much you're after if you decide to sell.

Cheers,

Bob

 

Will do Bob.