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Old 04-26-10, 09:39 AM
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SC40V8
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Question Diffs

What is the best rocommendation for a rear diff that can give me better peformance and better MPG On my 1993 Sc400 any help with this i would be very thankful


thanks Jeremy
Old 04-26-10, 10:01 AM
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TLDriver
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the bigger you go (lower the number) the better MPG you will get on the freeway, but it will also make you slower. Example: 70 mph at 2.5k rpms

The smaller you go (bigger the number) the better off the line performance you will get, but get you worse mpg's. Example 70 mph at 3.5k rpms

There is a lot of info I left out.. but once again your post leaves out a bit too. Not knowing your mods, or plans on mods.. it's hard to recommend anything.
Old 04-26-10, 10:06 AM
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shern
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You can't have your cake and eat it too. Quite simple.

Pick up a Supra TT Auto LSD 3.76:1 and enjoy. Reward from having an LSD will outweigh MPG.
Old 04-26-10, 11:11 PM
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cino21
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here's my review swapping 4.27's into my 98 SC400

i have a 98 SC400 and i belive the stock rear end is 3.266 per lextreme.. and i had dynosaur performance install 4.27's with stock LSD from a Supra... AND IT FEELS LIKE A BEAST!!!

I was nervous it would start giving up on the top end.. but i went up to 120mph and it was still pushing.. dynosaur said i should be good up to 140mph per the 5th gear, and i plan on swapping a GETRAG 6SPEED TRANNY next

it loses traction easily at WOT AND BOTH TIRES ARE FINALLY SPINNING lol

with the stock rear end, all the power was up top, basically after 50mph.. now it feels like a real v8 from a dig as well!

and i found out that our speedometer is electronic b/c everyone said the speedometer would be off swapping the rear end out and it's still on point.. my friend has 430's in his camaro and it says he's going 100mph when he's only crusing maybe 30-40mph lol

NOW ON THE HWY AT 60MPH IT USED TO CRUISE AT 2000RPM'S...NOW IT CRUISES AT 2900-3000RPM'S AT 60MPH... but ehhh not that bad lol

your stock ratio is 3.92 per lextreme sooo if your already wanting better gas mileage and you want more performance.. then a rear end swap isn't for you unless you want to get a lower ratio, like 3.76 or 3.266, but then your power will be more up top at hwy speeds.... giving you the feeling of a "loss of power" down low

Last edited by cino21; 04-26-10 at 11:16 PM.
Old 04-27-10, 07:31 AM
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SC40V8
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thank guys i have learned alot i have plans on for performance but in the mean time i have to start from the beginning with this car
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