Hi Guys,
Today I bother you on behalf of a friend who recently bought herself a beauty of a GX Coupe. This would be her second GX and this one's being built purely for drag racing. The car's drivetrain is entirely original from the engine down to the tires. Unfortunately the former owner did a lot of highway driving and the diff moans quite a bit at 130km/h. Now her A12GX engine and gearbox are being rebuilt for drags as I type this, but she's worried her diff won't hold up with her heavy foot. However, yesterday she spoke with a gentleman who said GX's were produce with 2 types of diffs:
1 -imported - diff center removes to the prop'shaft's side
2 - local - diff center removes through a rear backing plate

He also said she'd be better off rebuilding the original diff if it is an import, rather than buying another. We have mentioned to the man that the car would be driven abusively as its a drag car.

Any advice would be highly appreciated

Borg-Warner diffs were used by some South Africa assembled models. Perhaps somr 1200s were equipped with the BW60 model.

Thank You Sir.
We read nismo used to sell different centers for racing. Does anyone have experience with these?

H165 diff is the biggest you'll find that bolts straight in and can take a fair bit of punishment. They range from 3.9/4.11 to 4.875. (easy to find) And I think vannetts went higher.I'm sure Nismo had H150 for the race cars and lsd are rare. You can just weld the gears and make a lsd is one option. Do a diff swap which can be expensive or spend big bucks and maybe find a lsd. Im sure there are plenty H165's in your bakkies and cheap.

Quote:

More like a NSD [no slip diff] for this example. lol...

Spider gears

I would get the original diff rebuild and see how it goes. Don't underestimate it. They can take a little bit of punishment. And by the sound of it, you are going to keep the A12 which won't give as much torque as the A15 would.
The original A12 diff also has a very nice ratio.

Give us some more info on the setup. What are you guys going to do to the engine?
If she is going to use it for drag racing, what class is she going to compete in with the A12 sized engine?

By the way. I also have a stock standard A12GX. 1977 model and live in Bloemfontein.
Drop me a PM if you wanna chat private.
Regards

Thanks for the ideas gentlemen. I mentioned the H165 to her as I did this for my GX with the A15, but her idea is to keep it GX. She's having new gears cut for her H145 and ordered shims. She'll be doing drags under 4 cyl N/A classes.