Ants SR20DET '75 Gemini track car

[ralcool]

Its a double edged sword. Street Machine did their article on the Gemini, that probably put the price up immediately.

Bad for hunting.

But for the sellers.... Well, $$$.

Shooting from the hip, would it bad that hard to fit a poor mans 9inch... a hilux diff? Big choice of gears, lsd... bit of fab work.

-sean

[HQ355]

Keep the gem it's the aussie corvette ! That's what I heard anyway, somthing older and unique is allways better than somthing newer and more common and I'd say a Gemini will increase in $$ quicker than a nissan. Do what bigg G said and put an lsd or trutrac and some billit axles and it's done, easier than starting from scratch

[antus]

I put these axels and this LSD in the road gemini back in 2012. But I dont drive that car much so Im going to move this hardware to the track car. That'll mean I end up with 28 spline and the LSD. its the Altra 9 gemini kit center, and commodore axels shortened and converted to 4x100. Probably will take tdracer's advise and convert back to 4 stud for simplicity and more wheel options. Most 5 stud cars have people wanting and running 16" and larger.

Bottom pic shows gemini axels and commo modified.

[TdracerTd]

But with that setup, are you getting away from the re splined/ machined commodore axles? I think (and I do mean think) you would be better off with untouched Gemini axles, than a machined commodore axle?

[TdracerTd]

Probably a really fun idea, but what about extending the gem axle housing to accept standard commo axles. Never done the measurements, but if you have to run in sports sedans, who cares if it's a bit wider in the rear. It will probably help with handling. You could counter some of the track increase with wheel offset.

I like making dumb ideas work.

[antus]

Yeah, it wouldnt get away from needing modified axels, but it would increase the spline count to 28, and being lsd would reduce the stress on the center significantly. And im assuming its a tougher center too. So in theory I would hope I dont break any more axels

Thinking about it though, to do that swap would be heaps of work. I'd need to rip apart and swap brakes and bits from 3 different diffs and 2 different cars. If I pull a gemini axel out the spare diff in the shed, and get it redrilled to 5 stud then im back on the track and have more time to consider better options. Just need to sus out if Ive got commodore or gemini axels in there now... I cant remember on that car. The car does understeer though and Ive got bigvls words going through my head about oversteer instead of understeer... that would be a good improvement.

[VK_3800]

Aussie-built live axle R31 Skylines have the Borg Warner diff with 4 stud 28 spline axles that are shorter, must still be a few around? I would have to think with that much difference in diameter though even modified Commodore axles are going to be stronger

[TdracerTd]

Don't get me wrong. The altra9 setup looks sweet. I would just do it different. I would extend the housing after the trailing arm mounts, fit an early model commodore diff centre and the skyline axles sound like the go. Already 4 stud and closer to the correct length. I don't like cutting and machining forged parts. IMHO you are asking for trouble. Commodore rear disk brake setup bolts straight up to a Gemini diff housing. The handbrake setup is the only issue, I have done something, I could send you photos.

[Holden202T]

from your previous pic the axle that snapped looks like a turned down commodore one.....

I'd be pulling the other side out too and see if its halfway twisted up, that might help decide one what to do!

[antus]

Ive decided to rebuild this just as it was, because that'll be cheap and easy and get me back on the track. It lasted a few years so if I get that again its worth it. I went to u pull it on the weekend and ripped a couple of axels out a VN. The diff shop I would have gone to, CDS, are shut for 3 weeks starting tomorrow for holidays. They advised rod-tech could do it so I gave them a call and its looking promising. I'll take them down there tomorrow morning. Might take up to 2 weeks as they need enough hardware ready for heat treating to do a batch. I'll still plan diff upgrades but at least my car will be on the track while I get the cash together and plan. Holden202T, watching your thread with interest and seriously wondering if I could possibly pull off cutting up an LSD diff myself and making it fit. Probably not, but im tempted to try. Other forum threads on the net recommended Adelaide wheel and rim works. I tried them but they said while they can do trailer axles to order, they dont do this type of Axel work.