Posi question
Thread Starter
Le Mans Master
Joined: May 2006
Posts: 7,708
Likes: 266
From: indy indiana
Posi question
Took my 86 for ts first test drive today..had it 3 days now. If I nail it going about 20 to 30, the thing tries to get sideways on me. I do not beleve it has a posi..so...can I install one in the existing rear or is there a better way to go? At what cost? Dont know whats been done to it,but its darn quick. Thanks
Race Director
Joined: Dec 2006
Posts: 10,383
Likes: 4
IIRC it should have an LSD not a posi.
Change the diff fluid and don't put LSD additive in. If the clutches are too grabby and won't release then take some gear oil out and put in one bottle of LSD additive. Figure eights are a good test for LSD clutches, BTW. Too much additive and you get essentially a regular diff. Too little additive and you get grabby clutches. The ideal amount is just enough to allow the clutches to release and not a drop more.
Change the diff fluid and don't put LSD additive in. If the clutches are too grabby and won't release then take some gear oil out and put in one bottle of LSD additive. Figure eights are a good test for LSD clutches, BTW. Too much additive and you get essentially a regular diff. Too little additive and you get grabby clutches. The ideal amount is just enough to allow the clutches to release and not a drop more.
Safety Car
Joined: Apr 2005
Posts: 3,624
Likes: 431
From: Dale City VA
It wouldn't go sideways if only one tire was spinning.....
Sounds like your posi is working fine... However if you have a beam type TQ wrench you can check the breakaway on the clutch pack very easily.
Will
Sounds like your posi is working fine... However if you have a beam type TQ wrench you can check the breakaway on the clutch pack very easily.
Will
Thread Starter
Le Mans Master
Joined: May 2006
Posts: 7,708
Likes: 266
From: indy indiana
it is my believe that with a posi, it shouldnt get sideways, is this wrong? Seems to me only one wheel is tying to get traction, so going sideways.I mean the thing wants to come around on you..dnt get me wrong..i love it, but perfer to go straight when i nail it.
Instructor
Joined: Aug 2012
Posts: 154
Likes: 38
From: Western Massachusetts
If only one tire was spinning, the rear of the car would track straight with just that one wheel moving. Posi-traction will have both rear tires moving and if you break traction in both tires, the result is a rear end that wants to come around on you. If you need to see proof of that, next time you get the rear end all squirrely, go back and look at the dual stripes your tires made. The trick is to make the car launch hard with both rear tires maintaining traction with the surface. Cars without posi-traction have a difficult time keeping that one tire engaged when handling a lot of power, but they will not move the back end to the side.
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Safety Car
Joined: Aug 2009
Posts: 3,745
Likes: 275
From: Melbourne, Victoria, Australia
Hi get used to it as it is a common problem with limited slip differentials and the slide will follow the road contour, the locker type are even worse and can catch you out.
The corvettes do have some bad manners (they get even worse with extra power) that you have to watch out for, the back will break away without warning when pushing it and will snap back the other way even harder if you over correct it.
Go experiment on a closed track to get the feel of your vette, we don't want to hear another sad story of a totaled vette.
The corvettes do have some bad manners (they get even worse with extra power) that you have to watch out for, the back will break away without warning when pushing it and will snap back the other way even harder if you over correct it.
Go experiment on a closed track to get the feel of your vette, we don't want to hear another sad story of a totaled vette.
Thread Starter
Le Mans Master
Joined: May 2006
Posts: 7,708
Likes: 266
From: indy indiana
smile, its got posi and it works..tried it from a dead stop..Thanks for the help guys..been a while since drove anything that..when you pushed down the loud pedal, it did somthing other than just make noise.