'911 3.3 turbo 4 speed gearbox of 86 era'
Discussion
Hi,
There is a bloke selling a '911 3.3 turbo 4 speed gearbox of 86 era' at the moment. Has anyone fitted one of these in an Ultima? He says they are pretty bullet proof, but would the gearing be an issue? What's the target speed for say 6500rpm in top for a nice road setup (i.e. happy on the motorway at 80)? Using a 7.lL engine (approx 600-650bhp) with EFI...
Thanks chaps,
Mart
There is a bloke selling a '911 3.3 turbo 4 speed gearbox of 86 era' at the moment. Has anyone fitted one of these in an Ultima? He says they are pretty bullet proof, but would the gearing be an issue? What's the target speed for say 6500rpm in top for a nice road setup (i.e. happy on the motorway at 80)? Using a 7.lL engine (approx 600-650bhp) with EFI...
Thanks chaps,
Mart
they are very strong, reputed to be stronger than the G50, also there are some good ratios available for it. 4th gear on mine could do 212mph @7000rpm and was blisteringly fast to 150mph but it could have done with another gear between 3rd and 4th as the difference was about 60mph.
Also bewarned that the clutch is cable rather than hydraulic like the G50 so you need to do your own conversion (I can provide some help here) and the gearchange is the opposite way around to the G50 so you will also have to make your own gearchange. However the mounting to the engine is the same as the G50 so all that side is easy to source.
Oh and the gearchange is not that smooth, I found mine a bit of a crash box that you slamed through the gears.
Also bewarned that the clutch is cable rather than hydraulic like the G50 so you need to do your own conversion (I can provide some help here) and the gearchange is the opposite way around to the G50 so you will also have to make your own gearchange. However the mounting to the engine is the same as the G50 so all that side is easy to source.
Oh and the gearchange is not that smooth, I found mine a bit of a crash box that you slamed through the gears.
I use that box simply because it's the strongest (stock)box Porsche ever made.
I've made a few adjustments to it so now I have wire shifter and hydraulic cluch.
You can see my hydraulic clutch bearing solution in this picture (on the splined shaft). Yes I had an small accident...
Here's the internals of the box. On the left side you also see the hydraulic release bearing (from a Saab)
My new fly wheel. I use a 7,25 inch tripple plate clutch from Quartermaster.
Picture of the wire solution. This was the firs prototype it looks better now... First I used porsches own wire shifter assembly but that plastic POS broke so now I have made a new shifter whith all metall parts. Works great!
Test this little web application, here you can "simulate" how this box will fit you engine.
www.kenson.nu/ultima/930T.htm
I've made a few adjustments to it so now I have wire shifter and hydraulic cluch.
You can see my hydraulic clutch bearing solution in this picture (on the splined shaft). Yes I had an small accident...
Here's the internals of the box. On the left side you also see the hydraulic release bearing (from a Saab)
My new fly wheel. I use a 7,25 inch tripple plate clutch from Quartermaster.
Picture of the wire solution. This was the firs prototype it looks better now... First I used porsches own wire shifter assembly but that plastic POS broke so now I have made a new shifter whith all metall parts. Works great!
Test this little web application, here you can "simulate" how this box will fit you engine.
www.kenson.nu/ultima/930T.htm
Thankyou for all the info. Looks like you did make a mess Mr.TT :-)
Need to decide what to do... To be honest, I was looking to get away from lots of mods route (done enough already..) and to have a 'straight fit' box.. Trouble is I haven't got £6K to spend on an uprated box capable of handling 600-700bhp...
If I was to source a G50/50 or 52, will it handle the power OK (for say 5-10K miles or so?). I plan to use as a road car with perhaps the ocassional track day. Nothing too stressful (hopefully)!
Thanks again for the comments. This forum is a mine of information!
Mart
Need to decide what to do... To be honest, I was looking to get away from lots of mods route (done enough already..) and to have a 'straight fit' box.. Trouble is I haven't got £6K to spend on an uprated box capable of handling 600-700bhp...
If I was to source a G50/50 or 52, will it handle the power OK (for say 5-10K miles or so?). I plan to use as a road car with perhaps the ocassional track day. Nothing too stressful (hopefully)!
Thanks again for the comments. This forum is a mine of information!
Mart
Mart
Suggest you shell out £1500 for this:
www.pistonheads.com/sales/134829.htm
Should be good to go.
Mr Mac
Suggest you shell out £1500 for this:
www.pistonheads.com/sales/134829.htm
Should be good to go.
Mr Mac
steve_d said:
If it's a G50/03
3.500
2.059
1.407
1.086
0.868
3.444 diff
Steve
3.500
2.059
1.407
1.086
0.868
3.444 diff
Steve
Insert those figures in my application and you will see how it fits your engine.
www.kenson.nu/ultima/930T.htm In my opinion it looks a bit tight in the higher gears.
Edited by gtr-tt on Thursday 15th March 07:25
All this gear ratio vs v8 engine stuff got me to thinking!
Since most of us are, oir will be running Chevvy V8s of not-dissimilar power and rev range, I would have hoped that there would be a guru somewhere that could have advised all of us of the diffinative gear ratio spread and final-drive to best suit the Ult for a comprimise between road, and the odd track day, say for 5 and 6 speed boxes.
If we had this, then we could use this as a template and starting-point for our search for the right gearbox?
Since we can't expect to have a box made to ultimate spec, we could at least know how far from the ideal we have strayed!
So....and gearing gurus out there???
Keith
Since most of us are, oir will be running Chevvy V8s of not-dissimilar power and rev range, I would have hoped that there would be a guru somewhere that could have advised all of us of the diffinative gear ratio spread and final-drive to best suit the Ult for a comprimise between road, and the odd track day, say for 5 and 6 speed boxes.
If we had this, then we could use this as a template and starting-point for our search for the right gearbox?
Since we can't expect to have a box made to ultimate spec, we could at least know how far from the ideal we have strayed!
So....and gearing gurus out there???
Keith
v8 vum said:
All this gear ratio vs v8 engine stuff got me to thinking!
Since most of us are, oir will be running Chevvy V8s of not-dissimilar power and rev range, I would have hoped that there would be a guru somewhere that could have advised all of us of the diffinative gear ratio spread and final-drive to best suit the Ult for a comprimise between road, and the odd track day, say for 5 and 6 speed boxes.
If we had this, then we could use this as a template and starting-point for our search for the right gearbox?
Since we can't expect to have a box made to ultimate spec, we could at least know how far from the ideal we have strayed!
So....and gearing gurus out there???
Keith
Since most of us are, oir will be running Chevvy V8s of not-dissimilar power and rev range, I would have hoped that there would be a guru somewhere that could have advised all of us of the diffinative gear ratio spread and final-drive to best suit the Ult for a comprimise between road, and the odd track day, say for 5 and 6 speed boxes.
If we had this, then we could use this as a template and starting-point for our search for the right gearbox?
Since we can't expect to have a box made to ultimate spec, we could at least know how far from the ideal we have strayed!
So....and gearing gurus out there???
Keith
agreed.. I wish there was a sticky on this.. just a simple one (i know there is loads in the forum but I get so lost in it all!)
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