# differential question



## SVP5TEN (Apr 27, 2004)

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.


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## C33LaurelRacer (Nov 13, 2004)

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.


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## MaxQuest (Sep 11, 2004)

C33LaurelRacer said:


> 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.


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## fveten (Nov 5, 2004)

*diff QQQ*

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.. :thumbup: Mark


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