Alright boys and girls, I am building a high horse 2 rotor. I know Kaaz diff's are suppose to be indestructable, but I am still a little worried. Before I get into my options, I will tell you about the car. Minimum 600 horse, but I am shooting for 700+(it is being built in a month). I mainly do highway pulls, rarely go from a dig. Never do anything else besides that.

Option a:Chromoly axles, Kaaz diff, Banzai diff brace.

Option b. Cobra rear end, with custom sub-frame.(who make the sub-frame, I thought It was A-Spec, but I don't see it anywhere).

Thanks

Ty

 

I've always understood that the shock from launching a car from a dig is what can damage the diff. If you are only doing hughway pulls, I think the kaaz by itself should be sufficient for your needs.

Someone can correct me I'm wrong..

 

My understanding is the same as yours, but I will do a track rental once a year(hot lapping minimum 20 passes in 4 hours) and maybe 3 passes down a track a month. So I may do more dig racing than I let on. But I think it is rather rare.

Ty

 

I know LUPE on this forum was running a Ford solid axle rearend on his 600+ drag FD. Maybe you should look into that as an option.

-Scott

 

Maybe Dan Schecter can help give you some input.
https://www.rx7club.com/members/dan-schechter-1827/
http://www.jigsawrx7.com/

He has broken some stuff here and there.

 

Well from what I've seen with my own eyes, the kaaz diff. is very very strong... Mike B on here has a kaaz diff and chromoly axles and he launched hard at like 7k rpm's (he's at something like 500+whp) and his car broke (still ran a 12 second pass). After tearing the car down we found that the inner stubs of the chromoly axles fused to the differential... they couldn't be pressed out, they had to be drilled out. However his kaaz was still in perfect shape, and is being put back in, now with new cryo treated inner stubs and chromoly axles.

 

also I thought you had to go to a ladder bar setup to use the cobra rear?

 

My rear end consists of a Kaaz, Driveshaft shop 300M axles, diff brace, rotary extreme toe links and trailing arms. Stock suspension. I've been pretty happy with the set up so far.

When i come out of the hole it looks like this:
http://www.youtube.com/watch?v=9tSDesWntGs

and like this:
http://www.youtube.com/watch?v=8KjeT7GOUds

 

Nice runs, how much do you put down?

Ty

 

I made 512 on a DynaPack hub dyno, I wasn't making quite that much on those passes.

 

I'm pretty sure the reason I broke my inner CV stubs is my rear suspension was at it's softest setting, and my MT street ET's had only 11.5lbs of air. I can't find new Inner CV stubs anywhere so I guess for now I'm putting on stock ones with 30K miles.

But the Kaaz seems to be bulletproof!

 

what about the mazdaspeed lsd? I've heard it's as strong and a little less noisy for daily driving.... anyone have one?

 

reason I ask is they are the same price....

 

Anyone know how much it costs to get inner stubs cryo treated? They would need to be new also correct?