Auto diff on manual car?
 

What would the effect be if I put a diff off an auto on my manual S12?

Anybody got any figures or anything?

i have a feeling the auto diff has a higher ratio which would give you less mph in each gear (prob only get 60mph in 3rd) but it would feel quicker

it would prob lower your 0/60 time but your 30/70 time would prob improve

i've got that set up on mine and when my speedo says 90 my road angel says i'm only doin 74! and at 34 on my speedo i'm actually doin 30 and thats on standard 15 inch wheels

Did a long run down the M62 today and I was thinking how nice it would be to have a 6th gear or a lower axle ratio to cut the revs down there is easily enough power. For a road car I wouldn't like to have the auto axle ...i don't think the improved acceleration is worth the loss of refinement unless car is mainly for track use to be honest :) .

Get an FJ20E diff if you want to get the car working through the gearbox quicker

The fj diff is diferent?

Yes I used to have one

Hm... I checked the manual, and the s13 diff is 3,916, whereas the fj is 4,111 (from the topic about ca boxes). So in conclusion i should be geting shorter gear ratios... Not bad, i hope.

How are you using the S13 crown wheel and pinion then?

Hm... I have the s13 gearbox (its not in the car yet), but diff the will be staying the same, from my s12, if everything fits ofcourse. (im not sure what exactly is crown wheel and pinion, but from what i found realy fast in google, these gears ar in the diff, so im hoping i wont need to change them)

Yeah they're in the diff.

You need to compare the gearbox ratios not the diff ratios

Hm... Im a little confused now (the gearbox ratios are also a bit different, thou the 4 gear is the same), but dosent the final drive ration depend on the diff? (so if compared to an s13 i should have shorter gear ratios, since the final drive is different).
Or am i totaly wrong here now :confused:

No if you want to compare it to an S13 its fine, but I though wanted to see what the effect of using an S13 gearbox would be in an S12?

Thought so, thanks for clearing out everything for me ;) .

P.S. Since the gearbox is together with an ca18det engine, it makes more sence to compare the final setup with an s13 (in my opinion).

Yeah thats fairly good reasoning if you ask me

Is this pisble that i have dif ratio 4,3 ???
I chcked my speed with GPS today and at 3000 rmp on 4-th gear it says 80km/h after some calculations it turns out 4,34 mayby im wrong with my math. Weels diameter is 615 mm 195/60/15

Would work out that way to me as well, but I can only think your rev counter is over by about 400 rpm

I chcecked the rev counter with the piggy back and it shows the same revs. Mayby my GPS is a bit of. It is inacurate ba 5-10% so it would not be used as a guiding gizmo.