What are the advantages to posi over limited slip? Is the posi car easier to oversteer than the limited slip car?

Just wondering as I'm thinking of replacing my rear drums with discs and don't know whether to get a posi unit or just go for an aftermarket set-up.

Thanks for the help

Robert

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1987 IROC-Z Auto (LB9)
Black/grey interior with the stance of a streetfighter
"I like to think of her as Arnold Schwartzeneger in a dinner suit" RMK

Mods
Custom exhaust. 4 Inch pipe from the headders all the way back to a single muffler at the rear. No Cat.

Future mods due in March:
K&Ns
RAM Air
Air foil
AFPR

Hoping to get a couple of tenths with that lot

Current G-Tech times
0-60mph 6.26 seconds
1/4 14.74@100.2mph (about 98mph corrected)run with no gas and in the freezing cold

 

This seems like a common source of confusion. As far as I know "posi-trac" is just a trade name (like "traction-loc") for a limited slip differential. Are you asking about the differences between a stock open differential (commonly known as a one legger) and a factory type limited slip diff. or are you talking about the difference between a factory type limited slip and a "spool" where the two axles are physically connected together resulting in a locked differential (not really a differential at all)?

for street use a "limited slip" differential is the way to go.

my $.02

later
Clem

 

If I floor it at the moment only one wheel will spin.

 

You have an open differential then, although from what i hear, sometimes both will spin in extremely slippy conditions.
Limited slip is what you're referring to as Posi-Track, and it's where "both tires spin".
Easy check. raise the back end of your car and spin a wheel. If the other goes the same way Limited Slip. Opposite way, Open.

 

Trac-Loc, thats ford speak!



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60 Ranchero - Project ( Money Hole )
85 Sport Coupe LG4 - Daily Driver

Just another Hot Rod kid, or thats what they all tell me.
Livin' the Stereotype

 

main advantage of posi over limited slip is it's easier to spell, other than that it's the same thing

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ICON Motorsports

1st & 3rd

 

LOL

 

They both do the same thing. There are differences on how they work, some use clutches and others you cones to achieve a limited slip condition.
Hope this helps!

 

Yep, that's my point exactly they're all just trade names drummed up by our beloved oem's.

Clem


BIG THREE:

derrrr.......
(I work for the best of them)

 

Thanks for the help guys



Robert

 

There is another type of rear-end known as a Detroit Locker. It works on a ratcheting principle and is by far the best street rear-end made. The problem is they are loud and clunky when going around corners, but if you can handle it then they give the best handling and the best acceleration of any type of rear-end. A lot of people just call these locking rear-ends.

 

Lockers are much different, lockers usually don't use clutches and they offer no slippage (opposed to limited slip) which is why they are noisy on the corner. They are infamous for breaking axles before they break unlike limited-slip units that will wear out and slip over time

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1984 WS6 Hardtop Trans Am
Former L69 Car under restoration
1984 T-top Trans Am
4-bolt main 350, performer intake, headers, Holley 650, T-5, hayes clutch, dual elec. fans and 3.23's.
Daily driver and restoration
13.98 @ 101

 

There are no lockers made that use clutches. It is all mechanical just like I said it's a ratcheting mechanism. They don't slip, they ratchet but it has the same effect, letting the inside wheel turn slower than the outside wheel when going around a corner, and sending power to both wheels. Yes, they are noisy as I said and clunky as I said, but nothing is better than a locker other than a spool for fast 1/4 mile times. They also don't wear out like a limited slip does.