ok, I am talking about the 91 RS(in sig). ok, as far as I know it hasn't had any mods done to it other than the ones listed. When I do a brakestand both tires spin but after I let off the brake , sometimes I can get both tires to spin, but other times only the driver's side wheel spins. I know that usually on open diff rears, the passenger's side wheel spins. Does this mean I have posi? I have checked my RPO's and it did not come with posi from the factory.

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89 RS 350 TBI auto Hooker SC/LT headers Open element 3in K&N CVT protorque mini-starter

Daily driver 91 RS auto LO3 63k

New project- 89 Formula 350 WS6
383 or 400 to come!

 

raise the back wheels off the ground rotate tha rear wheels if both wheels rotate in the same direction good possiblity you have a posi if one rotates and the other in the oposite direction possible an open rear diff. best advise remove the rear diff cover and if you see a clutch pack in the carrier you have a posie if no clutch pack no posie. good possibility the clutch pack is worn if you do have a posie

 

you either have a dying posi carrier or an open rear. My vote is for the open rear

Eric

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My 1986 Z28
GM350, T-5, 3.23's, lots of go fast goodies, 4th gen Firebird interior etc...
85 IROC w/ 1364 miles!

You'll always find what you've lost in the last place you look

R.I.P Dale Earnhardt

 

I supposedly have posi, but when I get the passenger side tire stuck in slush the drivers side refuses to spin. Does that mean that I have a dying posi carrier? The posi was put in before I bought it.

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1984 Z28 Camaro
Mods: 350 ci built by Ultimate Performance Inc, 4 bbl Quadrajet rebuilt by Holley, 700R4 Rebuilt by Level 10, Hyptertech chip Stage 2, K+N air filter, Edelbrock TES exhaust manifold, Flowmaster Muffler, 3.73 Richmond gears, Auburn Posi Limited Slip Differential, KYB Shocks and Struts, Edelbrock Panhard Bar, Trailing Arms, and Strut Tower Brace, TRW Springs, 245/50/R16 Embassy Tires(Yeah, I have no more money.)
Future Mods: Paint!

[This message has been edited by watchmesuck (edited August 07, 2001).]

 

look for a g80 rpo. the only 100% sure way to know is to pull the cover on the rear and take a look. most likely it wouldn't hurt to change the oil and posi additive if it's posi.




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ICON Motorsports
1st & 3rd
MM Black Diamond 538 F&AM

 

Thanks for the help guys.

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89 RS 350 TBI auto Hooker SC/LT headers Open element 3in K&N CVT protorque mini-starter

Daily driver 91 RS auto LO3 63k

New project- 89 Formula 350 WS6
383 or 400 to come!

 

One more question, what rpm should a car with a 2.73 rear be running at 70mph in OD?
It's an automatic. Mine runs just below 2000rpms like 1900 or so. Just curious.

How much gas mileage would I lose if I moved up to 3.23's? I need higher (numerical) gears and mileage is a concern, so would 3.23's be ok, or 3.42's??

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89 RS 350 TBI auto Hooker SC/LT headers Open element 3in K&N CVT protorque mini-starter

Daily driver 91 RS auto LO3 63k

New project- 89 Formula 350 WS6
383 or 400 to come!

 

My car runs at about 2500 to 3000 rmps at 70mph, but with all the stuff in my car I only get 150 miles to the TANK.

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1984 Z28 Camaro
Mods: 350 ci built by Ultimate Performance Inc, 4 bbl Quadrajet rebuilt by Holley, 700R4 Rebuilt by Level 10, Hyptertech chip Stage 2, K+N air filter, Edelbrock TES exhaust manifold, Flowmaster Muffler, 3.73 Richmond gears, Auburn Posi Limited Slip Differential, KYB Shocks and Struts, Edelbrock Panhard Bar, Trailing Arms, and Strut Tower Brace, TRW Springs, 245/50/R16 Embassy Tires(Yeah, I have no more money.)
Future Mods: Paint!

 

You shouldnt lose any gas mileage at all by going from 2.73 to 3.23, and maybe half a MPG for 3.42's. Its not that bad at all for stock engines. For modified engines, who knows? Its different on every car.

I'm getting 23-24 MPG on the freeway and averaging 17 MPG with my 3.70 gears.

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1991 Camaro Z28
5.7L 5-Speed (originally 305)
13.23 @ 107.62 MPH
Southern California
Member: SoCal 3rd Gen F-Bodies
Webmaster: SoCal F-Bodies
-=ICON Motorsports=-

 

So would you suggest going to 3.73's? I am going to put in one of those SLP take off posi's or something similar. I am also about to swap in a 350. I am looking for solid mid to low 13's as my eventual goal. I will also be keeping TBI.

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89 RS 350 TBI auto Hooker SC/LT headers Open element 3in K&N CVT protorque mini-starter

Daily driver 91 RS auto LO3 63k

New project- 89 Formula 350 WS6
383 or 400 to come!