At the monent i am scatching my last pounds for a EJ257 conversion for my 95/96 V2 STI but have been told the gearbox is sure to go as we start cranking up the horsepower.

Please can anyone point me in the right direction with what gearbox to use to handle up to about 400bhp. Would i need a diff with that? What about having my classic box rebuilt to handle such power, can it be done?

 

You have a few options..

Firstly, the six speeder from the later spec STi's. These will more than handle the power you will be putting out. I'm not sure of the rear diff you have in yours but I understand the 6 speeder requires a 3.9 ratio so I expect you will need to buy that as well.

Secondly, is the PPG. You will need a donor 754 casing (I suspect yours, being a V2 will be 752 and PPG didn't make a kit for the 752 AFAIK). This should retain your rear diff. This also retains your current 5th gear (or change it for a longer one from a P1 for example).

If you're looking at 400bhp/400 lb/ft. Both of these will suffice (there are stories of >500 breaking PPG's).

The sixer is much heavier (think an extra passenger) than the PPG.

You will also need to consider the clutch as well.

Transmissions aren't cheap.

My recommendation would be to give David at APi a call. Top chap and very helpful.

Good luck

 

exactly what rossi said, 6 speeder will be around £2500 ish for a rebuilt box, ppg about £3000 ish for helical or straight cut.

somethign to bear in mind, some folsk hate the change in ratios between a 5 and 6 speeder box in a classic.

 

6 speed / ppg would be my first choice however you can use a Sti5/6 TY754 box which would be the strongest of o.e. 5 speed boxes, Im currently running 400/400 on one of these without any issues and so are many others but only time will tell....

 

Thats great help guys, thank you so much.