Diff lube for drag racing
Thread Starter
Racer
Joined: Aug 2000
Posts: 420
Likes: 31
From: Greenville SC
Diff lube for drag racing
Most posts regarding diff lube refer to the new lube with increased high pressure additives to limit diff noise with cornering. My street driven daily driver c6a6 sees the drag strip frequently. I am going to change out the diff to a different ratio and want to know what you are using to get max lockup at the strip and at what cost as to drivability and noise from the diff.
Team Owner
Joined: Feb 2001
Posts: 27,254
Likes: 136
From: Short Hills, NJ
Some stock C6 rears have been know to get a little noisy after a few miles of use and most people will recommend the latest GM fluid (or one of the good aftermarket ones such as Amsoil) that include the limited slip/friction modifier additive already in them to quiet it down.
They are correct in that recommendation but I personally chose the older school method of a regular old gear lube with the separate little bottle of GM Limited Slip additive in my C6 A6's rear and it has worked well, no noise or clunking on the street and clean/consistent two wheeled burnouts (so far) at the track.
They are correct in that recommendation but I personally chose the older school method of a regular old gear lube with the separate little bottle of GM Limited Slip additive in my C6 A6's rear and it has worked well, no noise or clunking on the street and clean/consistent two wheeled burnouts (so far) at the track.
Le Mans Master
Joined: May 2002
Posts: 5,446
Likes: 1
From: 10.70 @ 124mph, Stock Bottom End @ 3620lbs, ECS Racing Team Member. The 1st NMCA LSX Index Rumble World Champion. 2011,12,13 Champion
AMSOIL is the only way to go. I will shoot you a pm with more details.
Premium Supporting Vendor
Joined: Aug 2001
Posts: 5,364
Likes: 38
From: King George VA
I've been using this in my SCCA road course racecar since 04 without any failures other than the common left axle seal:
AMSOIL Severe Gear Extreme Pressure Synthetic 75w90 (Product Code SVGQT)
This fluid comes with friction modifier in it and adding extra to prevent diff chatter is not normally needed for the C5 (and I don't use any). For a street drive C6, I'd add a few ounce of the AMSOIL Slip-Lock Differential Additive (Product Code ADATB). But for a drag strip car where you want as little slip as possible in the diff clutch plates, I wouldn't add extra.
AMSOIL Severe Gear Extreme Pressure Synthetic 75w90 (Product Code SVGQT)
This fluid comes with friction modifier in it and adding extra to prevent diff chatter is not normally needed for the C5 (and I don't use any). For a street drive C6, I'd add a few ounce of the AMSOIL Slip-Lock Differential Additive (Product Code ADATB). But for a drag strip car where you want as little slip as possible in the diff clutch plates, I wouldn't add extra.
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C66 Racing #66 NASA ST2, SCCA T2
AMSOIL Dealer (Forum Vendor)
AMSOIL Preferred Customer Program (Members buy at Wholesale - a savings of about 25%)
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