differential question

SVP5TEN · Nov 15th, 2004, 02:21 AM

im running a 3.90 diff with a ka tranny. now on the freeway im under 3000 rpm at 65 mph. now switching to a 3.70 lsd, what am i looking at? lower revs?, higher revs?. thanks in advance.

C33LaurelRacer · Nov 15th, 2004, 08:35 AM

If I remember correctly, your revs should be slightly lower with a lower rear end ratio. Don't quote me, but I believe that is right.

MaxQuest · Nov 15th, 2004, 09:53 AM

Quote:

Originally Posted by C33LaurelRacer

If I remember correctly, your revs should be slightly lower with a lower rear end ratio. Don't quote me, but I believe that is right.

You are correct. Smaller ration rear ends will give you lower reves at the same speed.

fveten · Nov 25th, 2004, 01:28 AM

the answer to your Q is the revs will increase slightly,with the higher ratio combination. but the adv is that if your car has a increased cam profile, you'll find that you wont have to rev as much to pick up the next gear...it will be on cam earlier. In my 510 i changed from a 3.45:1 to 4;1 and the increase was phenomenal in accelleration terms. But if your after lower evs for the freeway then the lower the ratio the lower the revs..

Mark