I have a 1986 camaro iroc z. my question is this. what should my rpm be at 60mph?. I had my car verified on radar and it is significantly off (10%) which would indicate a gear swap. when I bought the car I was told it had 3.73 gears. I also have the disc rear brakes and a limited slip from the factory acording to the build sheet on the car g80 code. my radar speed @ 60mph I am turning 2100 rpm on the tach. Also why does just one wheel spin when I spin the tires if I have a limited slip? Is somthing broken back there?

 

come on anybody any ideas?

 

posi could be worn out. I had ran the numbers on my rear and found that it was supposed to have a posi. I opened up the cover and found that someone had put an open diff in it. I would pull the cover off and check.

as for your speed. on the main page of this site there are equations to find out what you have


https://www.thirdgen.org/newdesign/t...ulations.shtml

 

check out this tech article, it will tell you what should have been in your car from factory.

https://www.thirdgen.org/newdesign/tech/techdb.shtml

 

If someone had swapped this to an open end rear what is required to get it back to a limited slip or posi. I want the extra traction of both wheels during acceleration. I did the calculator as suggested and I do in fact have the 3.73 ratio. Also is limited slip the same as posi as far as posi for street use? I plan on doing an engine swap to a 350 or larger so this one wheel getting traction issue will have to be resolved. Its already a pain to drive in the wet weather.

 

I actually have just done this. all you have to do is get the posi unit and put your gear on it. as long as your pinion gear bearings are fine all you need to do is put in the posi with new bearings pressed in. put it in and bolt it up. it is very easy, as long as you are not doing a gear swap.