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-   -   Blew up my Kaaz Diff! Now what do I go with? (https://www.rx7club.com/rotary-drag-racing-167/blew-up-my-kaaz-diff-now-what-do-i-go-658813/)

MichaelB145 06-15-07 01:43 AM

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.

MichaelB145 06-16-07 09:16 PM

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.

Dan Schechter 06-18-07 10:24 AM


Originally Posted by MichaelB145 (Post 7044885)
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.

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).


Originally Posted by MichaelB145 (Post 7049678)
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.

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.

MichaelB145 06-18-07 11:23 PM

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?

Dan Schechter 06-19-07 04:18 PM


Originally Posted by MichaelB145 (Post 7056346)
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.

MichaelB145 06-27-07 06:56 PM

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?

MichaelB145 06-27-07 07:11 PM

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?

Busted7 06-27-07 07:58 PM

What are your 60 ft times?

MichaelB145 06-27-07 08:06 PM

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.

Busted7 06-27-07 11:00 PM

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.

MichaelB145 06-28-07 08:08 PM

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.

Busted7 06-28-07 09:25 PM

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.

Dan Schechter 07-01-07 11:38 AM


Originally Posted by MichaelB145 (Post 7086018)
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?


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

MichaelB145 07-02-07 02:15 AM

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.

Jay7 Nyc 07-28-07 03:07 PM

Good read...

MichaelB145 08-04-07 12:40 AM

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!

Terrh 08-04-07 07:43 AM

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)

Busted7 08-05-07 12:18 AM

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

MichaelB145 08-20-07 08:56 AM

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.

wanklin 09-01-07 01:09 PM

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

MichaelB145 09-01-07 05:05 PM

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/

Busted7 09-02-07 12:02 AM

Congrats man your soo close it will happen!


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