43 replies to this topic

[harboged]

BTW. They sell this on eBay. Is that to change the FD ratio? If so, is it complicated to install it?

  Yeah that would pretty much mean you would have to strip the gearbox down to component level (on the output shaft at least). Fine if you're getting a full gearbox rebuild, but if you just want the lower FD (3.95) in your turbo, you'd be much easier finding a complete NA gearbox and just swapping the complete shafts, diff etc. over to your turbo clutch side housing / case.   P.s - You need to refer to the below link which will tell you the ratio's for each alphacode: http://www.opel-info...triebe/f23.html

One more question on this In order to change the FD from 3.63 in the z20let box to 3.95, would it not be enough to simply swap the crownwheel to one with 75 teeth that exists in many boxes? It's much easier than swapping the complete shafts etc and as a bonus you keep the taller 5th gear that's not in the 2.2 box.

Aaaaah. The pinion has to be swapped as well due to the larger diameter of the larger crownwheel?

[Rosssco]

 

 

 

BTW. They sell this on eBay. Is that to change the FD ratio? If so, is it complicated to install it?

  Yeah that would pretty much mean you would have to strip the gearbox down to component level (on the output shaft at least). Fine if you're getting a full gearbox rebuild, but if you just want the lower FD (3.95) in your turbo, you'd be much easier finding a complete NA gearbox and just swapping the complete shafts, diff etc. over to your turbo clutch side housing / case.   P.s - You need to refer to the below link which will tell you the ratio's for each alphacode: http://www.opel-info...triebe/f23.html

One more question on this In order to change the FD from 3.63 in the z20let box to 3.95, would it not be enough to simply swap the crownwheel to one with 75 teeth that exists in many boxes? It's much easier than swapping the complete shafts etc and as a bonus you keep the taller 5th gear that's not in the 2.2 box.

Aaaaah. The pinion has to be swapped as well due to the larger diameter of the larger crownwheel?

 

 

I was working on the basis you'd simply transfer all 3 shafts complete with gears and diff over to the turbo gearbox housing. If you want the longer 5th, then usually this is the easiest gear to change as its usually at the end of each shaft, meaning you don't have to strip other gears out to change it, but honestly I've never taken one of these apart so cannot confirm.

 

I'm unsure if the you can just swap the diff crown wheel - you'd need to at least check the helical gear spline spec to check angle etc. to confirm compatibility..

[vocky]

or just buy a zafira A z20let GSI gearbox, 3.95 and same gear ratios as the vxT

[harboged]

or just buy a zafira A z20let GSI gearbox, 3.95 and same gear ratios as the vxT

Yes but I have searched for the DZ box for two years with no success. The AW box is more common, not so much here but in the UK, but they usually have many miles on them and are SR boxes, not SRT boxes, with worse 5th gear ratio. Around here are plenty of 2.2 Astra boxes, many of the with few miles on them, much cheaper and with warranty, so I thought I could might as well buy one of those instead and swap the bellhousing. The dream would be to have an ever longer 5th gear, from a diesel box or something, for the occasional highway transportation