Do 87 Carerra's have LSD?

[BReyes]

Do 87 Carerra's have LSD?

Regards,

[klaucke]

It was an option.

[Por_sha911]

Got one. Price on the window sticker is $722.00

[BReyes]

I want to check if I have LSD. How do I check it.

I presently have my engine out and the axles loosened off the transmission (I think before I removed the axle bolts, I spun one side forward and backward, but don't recall if the other side followed suit).

Thank You.

Regards,

[Eric Coffey]

Look at the sticker on the underside of your hood. If the option code 220 is there, you have LSD. Or if both wheels spin in the same direction when off the gound, that will confirm it as well.

[BReyes]

With axles off, as I spin one side on transmission the other side spins opposite direction (do not remember if its in nuetral or in gear[shifter coupler is diconnected])

[BReyes]

What are my options for upgrade. Is it hard to do?

[KTL]

If the axles spin opposite, you have an open differential.

Options are:

Factory LSD
Guard LSD
Guard TBD
Quaife TBD

I have heard of another brand Peloquin, but i'm not familiar with them.

Factory Porsche LSD is sorta the same as a Guard LSD. But Guard uses better friction discs that last much longer than the factory discs which are said to wear out quickly. Guard makes a Chromoly unit that all the GT3R racers quickly exchange their factory Porsche Motorsport diff for the Guard unit.

Guard and Quaife TBDs (Torque Biasing Differential) are like Torsen differentials (do a search on howstuffworks.com, it's pretty cool how it works) and don't use friction plates. They use a worm gear arrangement and last a long time.

The LSD is said to be better for road course racing. The TBD is said to be better for street and autocross. The LSD is active under accel. and decel. conditions. A TBD only operates under acceleration.

I got this info. from Paul Guard (Geary ID on Pelican) last year. Nice guy and very helpful.

"Porsche Motorsports sells their 40/60 LSD for about 1,500, which is a much better diff than a used street car LSD. We normally sell rebuilt street car LSDs for 1,100, and rebuilt VERY low mileage Motorsports LSDs for 1,350 (we have a good supply of these from new GT3R owners who opt to change their LSD immediately to a Chromoly unit).

Furthermore, the standard friction discs in the street car LSDs are absolute trash which wear out almost immediately. These MUST be exchanged for good quality plasma-sprayed friction discs to enjoy proper limited-slip action.

Our hardened 4340 Chromoly LSD sells for 1,995
Our torque-biasing diffs sell for 1,175
Rebuilt Motorsports 40/60 LSD for 1,350"

Setting up a diff. in your transmission takes a bit of knowledge. Not a simple parts swap. You need to check gear backlash, measure shims, etc. Improper setup will quickly wear your ring & pinion and develop all sorts of noise.

Hope this helps.

edit..................

Also, you can identify a 87-89 trans. that was originally equipped with a LSD by the serial number on the bottom of the transmission case.

LSD equipped trans. has the first ID numbers as G50.00#######

Open differential trans. is G50.01#######

[Bill Verburg]

The Porsche Motorsports Diff is like the stock factory Zf types in that they both use friction disks, but the PMS have the additional trick of behaving differently under acceleration and braking hence the 40/50, 20/80, 80/20 designation.

A stock factory Zf type only has a single lockup factor, say 40, which is evident on both acceleration and deceleration.

Either type PMS or oem ZF type(properly modified w/ uprated disks) is desireable for road course use, the PMS more so.

The TBD or Quaiffe types do not use friction disks but reather a set of gears that drive in one direction only. These types also have a lockup # but they only work on acceleration but not on deceleration. These types are favored by the A/Xers