Blew up my Kaaz Diff! Now what do I go with?
 

I thought the Kaaz diff was indestructable as long as you were within about 600hp. I think my car is about 500 hp and launched at the track today with MT street ET's with a burnout of 180 degrees. I did pretty much drop the clutch from 7500 rpms like I normally do but this time the track was a little stickier then I have ever seen it.


Anyways, I blew it so whats the next step? Anything a little stronger I can go with? Anyone know what the guys who run 9's use?

You need someone to build you a diff. cage. If you can call up Ray Wilson(www.PFSupercars.com), he may be able to tell you more about it. Kaaz diffs are fine.

Dee E.

cobra rear ?

What do you guys think about just welding the diff so it's a solid rear axel. I very rarely drive the car unless its a car show or a race. How bad is it to drive the car then?

Can I weld the Kaaz diff or do I need the stock diff parts?

Weve had great success with the Carbonetic (ATS) diffs, the metal 2 way is the best for drag racing.

did you blow up the kaaz diff itself or break the mazda R/E housing??? do you have a pic?

I'm curious about this as well.

I will find out in the next day or so....I jacked up the car and everything looked ok.....I have to work today...but tomorrow we will pull it apart. Thanks for responding Ari, I was going to call you tomorrow once I figured out what I did too see how I can prevent it next time.

With out oil pouring out it sounds more like axle broke. I find it hard to belive the kazz broke before anything else!

Well, I do have Chromoly Axels from the driveshaft shop.....plus the diff doesn't make the clicking noise when you turn corners anymore.......

Here's a video of the run..

http://videos.streetfire.net/video/e...4400f0b50d.htm

Any updates?

You should have your head checked for completing that pass at anything more than a crawl. You could've put your life in jeopardy.

I will have updates tomorrow.

The thought of me being in danger didn't occur until right about the finish line where it was very hard to control it. All I could think about is trying to qualify and fix it before first round!

It looks like axel you were pulling hard off center but it still was pulling maybe half the diff let go. Any way hope its not too bad to fix!

That is most likely the inner stub of the axle that broke and part is in the rear still. It's not the rear or the shaft of the chromoly axle. You are not hearing any noise since only one side of the rear is turning.

Anthony

Any news Mike?

We (Precision Import Repair) didn't tear it apart since I had a huge car show to go to this weekend. So I drove it there on one wheel! Took best "Tuner" and got a 5 ft trophy which was cool! So, now I'm about to get off my lazy ass and take the car over there and check it out. Will update as soon as I find out.

Here's the damage......

Looks like I did break the Chromoly Axel. We spend hours trying to get the axel to come out and looks like we tried a little too hard cuz we ended up accidently breaking the pumkin too trying to get it out. Tried to press the axel out of the Kaaz but it ain't budging. Was told the Kaaz is no good.......so


Does this look like I'm buying

New Axel?
New Pumpkin?
New Kaaz?


Starting to look like this is going to cost at least $2000 and who knows if this will happen again. Any ideas?

Here's the pic's
http://s2.photobucket.com/albums/y34...roken%20Parts/

Looks like a melted them!

No axle just the inner CV stub plus the diff.

Is this pretty common? What else could I have done? I guessing I'm only about 500hp....what are the 650+ hp guys doing?

Try using a press to push it out from the other side. And i dont think the stub axle is molly. What kind of 60's do you pull, i have been pulling 1.52 on stock stuff, it will break some day but i dont just slip my foot of the clutch and wait to see what happens. Any way good luck on getting it back in one piece.:icon_tup:

What are you using for a two step?

Ahhh, see... I thought you broke the axle. You seem to have had some fun taking it apart, :rlaugh:, J.K.
It shouldn't cost you that much to repair, although that depends on the Kaaz. You can't get the stub out of the center plate? If you can, check the splines in the Kaaz for wear or burrs. And clean all the floating debris out of the clutches. It looks pretty bad, so you may have to replace the Kaaz. You can find a used diff case on this forum for a couple hundred bucks, usually. That will give you the case, ring and pinion, and bearings, etc...(as long as the diff is in good shape). Then you just need a Kaaz (maybe, depending on previous), and here's how you keep this from happening again....

Buy some NEW inner cups from Mazdaspeed motorsports (these are few and far between, Ari and I have had trouble finding them in the past due to availability. You may have to buy the whole axle to get them). Send them to a company called "300 Below" in Illinois (or comprable place) to get cryo treated properly(it's not that expensive), and then install them. Do not swap sides once you have installed them, or cryo used ones, they WILL break again. This will fix your problem, guarunteed. Give me a call if you need.
I feel ya...been there :icon_tup:.

Since my 2 step on my datalogit sucks ass and always freezes....I have been launching off of Rev limiter. I set the Rev limiter to 7500 rpms and pretty much drop the clutch with 16 lbs of air in the tire (trying to be safe) By doing this I usually get a 1.55 60ft as long as I get the tires pretty warm. The tire temp was exactly 180 degrees.


After breaking this....I will have to rethink my launching technique to something thats not so hard on the poor car!

The problem with that type of limiter is that it's not like the two step or soft touch limiter as it's known on the popular ignition boxes. The limiters on most ecu's are exactly what they are supposed to be, just limiters. They are too harsh by going in and out at such a slow sequence in that it's a hit and miss when you release the clutch. Depending on the release time of the clutch the rpm can be droping at the same time which results in the same effect as what would happen when you do what's call a neutral drop on an auto tranny vechicle.
Do your pocket and drivetrain a huge favor and get a proper two step installed.

Thanks for the info! I didn't realize there was a difference. I still have stock ign so I had planned to get the MSD with 2 step....You think this would be a good choice? I don't have to do the red one do I? Someone said they now sell a chrome one? Anyone have the part number for it?




Dan....your right....I couldn't find brand new inner CV stub so I can get them Cryo frozen. Anyone know where I can find them?


I did pick up a diff today and I happen to have a spare CV stub. Trying to be able to reuse the Kaaz. Hopefully things go well tomorrow.

Also....how much would both inner CV stubs run me and how much should I expect to cryo freeze them?


Once I do this......what will most likely be the next thing I will break? I'm guessing my weak point is the 430 gears and the J-spec Tranny I have. I'm guessing the car is a high 10 sec car and I'm doing a 1.4? 60ft.

Did you try Mazdaspeedmotorsports.com (1-800-435-2508)? If so, I told you they would be hard to find!! You have to start an account with them, but you meet the criteria. All I can reccomend is Driveshaft shop (if they use new ones), or call others like Ari, or Demetrious to see if they have any. A used one may work for a while, but it will snap again, and make sure it hasn't ever swapped sides or wit will snap like a twig!! The metal gets stressed one way and if you stress it the other it will snap, immediately (kind of like a Pillsbury crescent roll).

If I remember right the stubs are about $250 each (pricey). But cryoing them is like $30 + shipping or something, its really cheap. You shouldn't break anything for a little while after that, although the next thing to go will most likely be the outer cv joints or internal tranny. The key is to slip the rear tires off the line with suspension and launch technique.

Thanks Dan.....The spare inner CV joint I have is the wrong side....damn! It's off of a Auto RX-7 that was stock....would it still most likely snap like a twig?


I talked to the guys at Hinson Supercars and they said they ran a 9.22 with stock inner CV stubs.....Maybe they weren't getting the 60ft I am?



One last thing.....Anyone know how much harder is it to twist the outer CV stub? Is it much stronger then the inner one?

Yeah it'll snap. The guys at Hinson are running a totally different setup than we are from motor to tranny, to launch RPM, etc... You can't really go off what they do, since it won't apply to you. Trust me I've tried that approach with other companies, i.e.- how do you think Abel hit the wall at LACR...

The inner ones seem to be the easiest ones to go, the outers, some people have issues with, and some don't. Ari had trouble with his once, in the parking lot pulling the car around! However he hasn't ever had a problem on the strip. WHat might have caused this fluke is a long story. I have had trouble in the past, but if you do the same as I recommended with the inner, they will hold fine.

I have tried to get brand new inner CV stubs and they are on back order.....My cost on them is $226.88 each.

or I can order the whole Axel which would give me both inner and outer and I can probably sell the axels for $805.43 my cost from Mazda but they are also on backorder. I would like to get the car ready for the next race on July 8th.....anyone have any other ideas? Thanks to an idea Ari gave Mike and Mark at PIR Motorsports, my Kaaz plate is at a machine shop and will be salvaged. Now what? Just wait for parts to become availible? Any other vendors have inner CV stubs in stock?

The part numbers I got for these parts are.....

22520 for the Inner CV stubs (same one for each side)

and

MA10-25-500 is the part number for the entire axel with inner and outer CV stubs


Can anyone verify this is correct?

What are your 60 ft times?

On old set up they were 1.55.......That was with 431hp.....Now with about 500hp I'm guessing I was going to get about a 1.49 if I wouldn't have snapped the inner CV stub. My tire tempature was exactly 180 degrees.


It sounds like you will start snapping the inner CV stub at 1.52 60ft times or faster.

Crap i dont like to hear that i cut 1.522 60 ft on stock axles and t11 diff. I guess im on thin ice. Good luck and keep us informed.

I think you are on thin ice.....I'm shocked you haven't done the same thing that happened on mine! Your car has more power then mine.

I try not to shock the drive train by side stepping the clutch i preload and try a little slip at 7,000 with 11.5 et's. Im sure its a matter of time thats why the old tralior goes racing with me.

I'd try driveshaft shop. See if they use new inners and outers.

I called them....maybe I just talked to the wrong person, but they just told me they don't sell them. The guy didn't seem very interested in helping me.....I think I'm just going to put my car back to the set up I had before and not be as hard on it and just wait for the parts to come in. I hope Mazda isn't going to discontinue the part.

Good read...

Well, I hope I don't break them again tomorrow! Theirs a heads up race and I'm basically got the exact same set up as I had when I broke last time! This time, since I can't adjust my rear coilovers due to a broken knob....I am going to run 20 lbs of air in the tires to get them to slip.

I really wish I could find some brand new inner CV stubs, but they are backordered everywhere!

I broke exactly the same part on my FC last year, and I was only making enough power to go mid 11's.

are you preloading when you launch? This is generally the #1 factor in breaking shit if you aren't. (I wasn't :P)

Well whats the story? How did you do and is everything in one piece?

Well, I didn't break......I ended up just running with 22lbs of air in my MT Street ET's....I was only cutting 1.71 60 ft times. Ended up finding a new problem.....My secondary injectors were leaking and only boosting to 1.03 bar. Still ran a 11.9 @ 117 so pretty sure I have a good chance to click off that ellusive 10 here for the next race on Aug 26th.

FYI: I'm currently working with a drive-line manufacture to develop some bulletproof inner CVs as well as axles for our FDs. Keep an eye out in the GB section within the next few months.

Rob Labardee

Oh hell yea! Keep us posted!


BTW....Ended up running a 11.2 @ 123mph. Still didn't really launch it since I have stock inner CV stubs. It would be nice to know that I'm not going to break the same thing again.


I posted the video here...

https://www.rx7club.com/rotary-drag-racing-167/video-mike-bs-fd-getting-run-down-civic-w-142mph-trap-speed-684548/

Congrats man your soo close it will happen!