Searched around plenty and looks like anyone making over 400hp should definitely be running an upgraded unit, kaaz, cusco etc as any wheelhop at this level will kill the stock rear.

Well, I'm not interested in launching or drag racing my fd. I make 520rwhp but strictly stick to rolling on power and track days.

I have had zero problems so far with stock rear and street tires however I spin 1st and 2nd at WOT.

If I choose to run r compounds what's my risk of breaking this diff if I'm avoiding all launching and wheel hop? Do people blow these things rolling in 2nd and 3rd?

I'm running kg parts diff brace and solid delrin motor mounts. Soon to be running R888s or NT01 rubber.


Thanks!

 

I can tell you from experience I blew mine with 403hp by running nitto and launching on the street, the wheel hop will kill it.

And please do not get the KAAZ a friend has a KAAZ that ******* thing is annoying as hell.

maybe a turboII unit will be better. but that is my experience with the stock diff.

 

Thanks for the reply. I anticipate that the stock unit will blow if I launch on the street. My intentions are to never launch this car. Rolling on throttle, highway pulls, and occasional road racing are my goals. Will horsepower affect integrity under these circumstances?

 

what's so annoying about the kaaz unit?

 

Loud clunks during hard turn

 

...mostly indicating a solid diff on a car!

 

Get a diff cradle and don't worry about it anymore. You can even launch the car after installing it.

 

Not at all. From the time I broke my diff I welded the diff solid and it's much different from what that KAAz sounds like.

And the welded diff I can live with! But that KAAZ clunking sound just gets old fast!.

 

And yes that 2in1 diff cradle thing looks like a good idea.

 

With a little over 600WHP I am running a Turbo II diff with a 2 in 1 diff cradle on 295 BFG Drag Radials and have not had a problem yet.

 

I have the KG Parts Brace, looks pretty solid nice and heavy/strong. Haven't installed it yet but hoping this should definitely add protection?

 

No it wont. You gotta get something like this. Its a cradle and brace combined, great piece and the best investment for the money.

https://www.rx7club.com/group-buy-ce...brace-1041399/


You can also get this and just keep your brace on also.

Mazda -Drivetrain

 

So if i'm not braced up with this cradle I can ancitipate breaking the diff from ROLLING onto the throttle?

 

I've seen it happen. Why not just spend the $400 for the peace of mind. Its a very small investment and if you break a rear you will spend double that easily to repair it. Just seems like a no brainer to me whether rolling or launching from a dig.

 

Will the Banzai diff brace help with wheel hop/ help keep the rearend together?

 

I use both PFS Cradle and Banzai Brace

 

It won't hold up forever. I've broken the stock rear just on a hard 1-2 shift on street tires.

 

One of the issues with the Torsen is that the teeth get stripped off the worm gears at higher hp, even without launching the car from a stop. The Torsen is a great diff it just can't handle over 400hp, this should not come as a huge surprise since the car only made 255hp stock. I have customers that have destroyed the Torsen at just a little over 300whp.

The diff brace stops wheel hop which reduces the chance of breaking the case, additionally it reduces the shock to the worm gears and ring/pinion gears.

You don't expect the stock clutch to hold up to 500hp, can't expect the stock diff to be able to handle it. ATS makes several silent carbon LSD units, I run one in my 20B FD it handles everything I throw at it. ATS carbon LSD, one of our Banzai diff braces and Powerflex diff mounts, I have never broken a case or destroyed an LSD unit. ATS LSD (93+ RX-7)

The Kaaz is very noisy, same can be said for the Cusco, lots of popping/clunking during slow speed turns.

 

Have you tried the newer Kaaz Super Q? I've had good results with it. Its almost undetectable.

 

Ford 8.8 Rear end swap

 

Zach, I ran my stock diff for years on 500rwhp, lots of drag passes. Trick was to slip the clutch on launches. That being said the et streets took a great deal of shock off the driveline. I didn't beat it much on the streets , like banging gears just hard pulls through a gear.

I now run a TII diff with pfs brace. Cheap and has handled 700rwhp with 7500rpm launches , 1.36 60 foot times!

 

Reality is you can drive your car until you destroy the diff then upgrade everything.

As with anything on the forum you will hear examples of opposite extremes. I also drove my car at 500rwhp with the stock diff, when I removed it there chunks missing from every worm gear.

Then there is the carnage from a 310rwhp street driven stock twin turbo car that destroyed the gears completely.

 

Thanks for all the information guys!

I think I will slap on the brace and some R-compounds and enjoy the car on the street and novice road racing until it breaks and line up a TII conversion or KAAZ if/when it blows.