. Who says you can't break a ford 9" ?

[davidathans]

Well, im spending money, alot more than planned.

Trying to get the CS ready to run 10s at Autoclub speedway in Fontana on July 18th...

Went to do the gear swap from 4.11 to 3.70 and found a surprise that might have saved my life and my car.

Check out these pictures looking into my Auburn limited slip differential...on its last limb. That last nitrous run against that shelby must have been really stressful. Well it was about 6 years old with over 100 races, so it served its time.

Also cracked the gear case right where the pinion support is.

This gives me an opportunity to go beefier and save some weight. Going to a Currie Sportsman 9" gear case, Currie Aluminum Big Bearing support cover, Strange Billet Yoke for big bearing center, and a Detroit Locker Differential Carrier.

Might spend a little more and get a 4" aluminum driveshaft too for that extra 0.1

 

[davidathans]

more pictures...

sticking with the Superior custom 31 spline axles which are fine and luckily the 1979 Lincoln Mark V Continental 9" housing is in good shape still too

here is a curiosity poll....

If i had gone back out to the track without opening my rear end...

1) would i have broken down at the line?
2) would i have broken down at 80-90mph and went into the wall/flip the car/kill myself?
3) what do you think would have happened?

 

[di81977]

Hopefully you would have broken down doing your burnout and saved the track. I have always thought of drag racing as pretty safe (at least compared to autocross and track racing). But, I run a lot slower than you.

I am not an Auburn fan. Mine broke down in less than a year of racing. Really good customer service though. They provided a replacement at a very fair price.

Good luck with the 10's. That would be pretty cool!

 

[robert campbell]

David,
Looks like an early 9 inch case without the "Daytona" front bearing and pinion carrier. Yours is the basic 9 inch pumpkin. I know you have heard of the “N” or nodular steel rear ends. These were common on the high performance Cobra Jet cars. Both Torino and Mustang. Built for huge stress, but again not necessarily close to what you are doing. Running 10’s with slicks is even a step above what Ford envisioned in the late 70’s. The crack in your pinion support is amazing. Not being an engineer or a destructive test engineer it is hard to guess when it would have broke. The hammer stress at the starting line is one thing, but the total stress in top gear is another. My “uneducated” guess would have been at the line. Especially after seeing your car launch on you tube!! Your 60-foot times are amazing and must be hugely stressful at launch.

Your times indicate the need for the “big” stuff. No skimping. Your times equate to huge stress!! You are in the big leagues! The Currie big aluminum stuff or Currie 9 inch plus stuff. I bow to you!!!

I broke a 31 spline factory axle on the line. No danger. I destroyed a clutch on my 428 Cobra Jet on a 3rd to 4th gearshift. Again a slow stop. But these are high 11 times. No where near the stress you are generating on your stuff!!

Rob

 

[390cs68rcode]

breaking parts is fun! end result is you get to get better parts (to try and break again).

 

[Midnight Special]

breaking parts is fun! end result is you get to get better parts (to try and break again).

...Yep, then break the banks and maybe even the sound barrier, but don't break yourselves!