3.15 to 3.42 diff swap
Thread Starter
Pro
Joined: Dec 2006
Posts: 575
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From: Mooresville NC
3.15 to 3.42 diff swap
I was wondering if anyone could tell me how much of a performance difference there is between a 3.15 and a 3.42 rear diff in an A4. Surely some of you have made the swap and can offer up some opinions.
Oh, and please don't tell me the difference is ".27". haha!
Thanks - Wayne
Oh, and please don't tell me the difference is ".27". haha!
Thanks - Wayne
Race Director
Joined: Mar 2007
Posts: 18,308
Likes: 21
From: Marlton. Increasing performance one speeding ticket at a time! NJ
Thread Starter
Pro
Joined: Dec 2006
Posts: 575
Likes: 0
From: Mooresville NC
OK I checked out the web page and he gives a lot of good info about the swap and what is involved in doing it but what I'm really interested in is the results of 3.15 to 3.42 change (performance wise). Does anybody have any "SOTP dyno results" or before and after track times?
Last edited by wb8169; Aug 17, 2007 at 05:21 PM. Reason: typo
Team Owner
Joined: Apr 2001
Posts: 54,204
Likes: 180
From: S.W. Ohio. . . . . . NRA Life Member
it will be faster, but it won't be a day/night difference.
The 3.15 to 3.42 swap is the smallest jump one can make on a C5... it's only 8.6%. I personally wasn't looking for an "amount of change"... but had a specific goal to reach.
Your wants/needs/goals may be different than mine.
it made about a .15 difference in the quarter mile. But you should read this as well - a converter upgrade that is inexpansive and doesn't require an added external cooler:
http://forums.corvetteforum.com/show....php?t=1715694
if you do the 3.15 to 3.42 and add this converter as well... it will be a day/night difference in WOT; but be hardly noticeable in normal driving.
The 3.15 to 3.42 swap is the smallest jump one can make on a C5... it's only 8.6%. I personally wasn't looking for an "amount of change"... but had a specific goal to reach.
Your wants/needs/goals may be different than mine.
it made about a .15 difference in the quarter mile. But you should read this as well - a converter upgrade that is inexpansive and doesn't require an added external cooler:
http://forums.corvetteforum.com/show....php?t=1715694
if you do the 3.15 to 3.42 and add this converter as well... it will be a day/night difference in WOT; but be hardly noticeable in normal driving.
Le Mans Master
Joined: Jul 1999
Posts: 5,005
Likes: 38
From: jackson nj
I was wondering if anyone could tell me how much of a performance difference there is between a 3.15 and a 3.42 rear diff in an A4. Surely some of you have made the swap and can offer up some opinions.
Oh, and please don't tell me the difference is ".27". haha!
Thanks - Wayne
Oh, and please don't tell me the difference is ".27". haha!
Thanks - Wayne
Melting Slicks
Joined: Aug 2006
Posts: 2,167
Likes: 11
From: Powell TN
Cruise-In VIII Veteran
Not a vette, but I had a GMC pickup truck that had a 3.08 gear in it. I changed it to a 3.42 positrac. I was really surprised at how little difference it made. There was more "seat of the pants" difference when I removed the cats and changed the exhaust out to a Flowmaster system than there was doing the gear swap.
Instructor
Joined: May 2002
Posts: 242
Likes: 2
From: Fort Washington MD
Gear Change
I made that swap. It was OK but not much of a jump. I now have 390's which is a good gear for me. I also do a lot of driving in my C-5 and my mileage is not too bad. I think 390 is the way to go personally.
Earl
Earl
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Race Director
Joined: Mar 2007
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From: Marlton. Increasing performance one speeding ticket at a time! NJ
There's not much difference and, IMHO, not worth doing. However, going to 3.73's and High Stall would be. All depends on you final goals and what YOU want.
Team Owner
Joined: May 2005
Posts: 23,682
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From: Flagstaff Az.
