I would like to be able to launch my car without worrying about breaking something. Not crazy **** 7k RPM launches, but enough to get my car into the low 11's if not the 10's when I go for 20 psi. I go to the track very little, so it may only have to endure a couple of hard launches every month or two. I originally was going to go with a Kaaz unit, but I don't want a noisy diff. I like driving my car as a street car, and don't want to do anything that will make me not want to drive it on the street. My mech. suggested that I swap out a used Turbo II diff. This option would be considerably cheaper than a Kaaz, but is it worth it? I will be swapping to 4.3s as well.

Thanks for the input!

Alan

 

turboII diffs are pretty strout. there are several people running 450+ at the wheels on the stock drivetrain with no problems. that crispeed guy runs 10's on his stock drivetrain i believe. i've never had a problem with my diff but i only had about 245whp on my prior engine so yours would obviously be seeing more tq.

just make sure you get the series4 clutch-type diff because they are better suited for dragging and are rebuildable (kits from mazdatrix available for not too much, way cheaper than a kaaz rebuild kit)

 

Bump...

 

Hi Alan,

I think that it is a much better choice than the Kaaz. At your power level you will need one. I have a brand new one sitting in a box waiting to install. I haven't been to the strip in a long time, so I haven't had much motivation to install it.

 

Rich,

It's good to hear from you. What does a new TII diff. cost? Would you have qualms about using a used one?

 

I found mine at a killer deal....I think they are around a grand retail, but you can find them for about half that. I wouldn't have a problem with a used, low mileage one. How has that spec clutch been working out for you?

Rich

 

Even with my TII i am still worried about my axels. Just a thought

 

You will definetly snap some axles and that torsen diff trying to break into the 10s. I bring an extra axle when I go to make it home on the occasion that one breaks.

My advice is...

You are going to blow up your stock differential. I blew up my diff and broke my axle in the same burnout running my stock turbos. With the Kaaz I made it just 10 runs before I snapped my second axle. Then I got rid of my wheel hop with the help of nylon diff mounts and a mazda speed ppf run fine but I still bring an axle with me to the track, just in case. They are fairly easy to change out once you've done it a few times, the tracks I go to are around 1 to 2 hours away and leaving your car at the track over night sucks and to tow it sucks even worse.

Get the TII diff and an extra axle, that would be economical. PM Frtz Flynn here on the forum, I am sure he at least has the axle and he may also have a diff for you. I have the Kaaz and hear very limited noise and really is not a bother, in fact, knowing that the thing is almost indestructible is a relief and the noise is the least of my worries. The trick I've found is to use Red Line heavy duty anti shock gear oil that is 75w and under high load increases its viscosity to up to 250w. It works for me.

 

A retraction:

I typed that I used Red Line Heavy Duty Shock Proof gear oil and lauded its effectiveness. It was very effective for a week but just today the gear noises increased to much and I had to flush it out. So, stick with the Kaaz oil and the GM diff additive, I am going back to that combination.

 

How much power is enough to break axles? Right now my car is at KDR getting rebuilt with a T78 and all the supporting mods. I have already decided on a KAAZ diff but will that be enough for going to the strip on the weekends with Nitto drags in the back? For suspension the car has Tokico 5 ways, Eibach springs, Racing Beat sways along with toe end links and trailing arms on 18x10 Enkei RPO1s.

Most tracks are an hour from me too and I definitely don't want to snap an axle that far away.