well this is my plan, heads, headers, cam ( c306),injectors and the rest if the bolt ons. I want to run mid to low 12's. the car is a 94 z with the 6 speed. will the rear live to tell the tale of running 12's or do I add the 12 bolt and 4.10's and be done with it. I already have the drag radials and KNOW they really hook ( MT's). If I yank the rear out ( which has 3.42's) what is the thing actually worth?
thx,
jonesy

 

I have no idea what it would be worth...but I can tell you this. I haven't modded all that much....nothing more than 350 hp. With street tires and 3.23 gears on an A4, I'm on my 3rd rear...it's not hype, it's fact.

 

Step one: Engrave head stone for current rear end now. Step two:Purchase new 12 bolt. Step three:Believe the hype. It will break eventually. Especially with those sticky drag radials. The'll even break on the street with a good street tire and a good hard shift. Sad but true.

Ken R.

 

you can spend the $ everytime you break it or bite the bullet and do it once.when i broke mine on steet tires, in my driveway I believed and ordered a 12 bolt

 

Hmm,
My 10-bolt went 140,000 miles.
This year I put on 60 dragstrip passes, did 145 MPH on the road course, made seventeen autocross runs, countless burnouts, and cranked 396 RWHP out of the car on the Livernois dyno.

...with a six speed...

Then there's the guys who have been bracket racing with a 10-bolt and running low elevens with 1.6 second sixty-footers, like Al Fox. He put in a 12-bolt this year not because he broke his 10 bolt, but because he's in the 11.teens and wanted to ensure reliability.

Try these tricks and you can make the ten-bolt live for a mid-12 second car: I've gotten dozens of emails over the years from guys who are regularly running their 10 bolt with these mods with very few failures:
http://www.ws6transam.org/10bolt.html

It'll cost you about $600 to $900 to complete the upgrades.

Now that said, I've gotten to where I want a 12-bolt. My 10-bolt ate the crush washer this summer and one of my axles got scored on the bearing race from either excessive heat or improper heat treat. Since the gear lash needs to be reset and the axle needs replacement, I'm choosing to upgrade. Especially since I'm now doing 115 MPH and should hit 120 MPH and mid-elevens next summer. That and the nitrous kit in the garage tell me that I've finally exceeded my ten-bolt's capacity. However, I'm sure that if you put the time into building your ten-bolt, it should hold up.

 

thanks!

 

One thing I learned the hard way. The 12bolt is a POS too. Get a 9" and never worry about a rear again. 12bolts break. Its the posi. If you wanna drag race and race hard eventually, get a locker.

I've got ~$1800 in my 12bolt (bought it used) and I won't be "testing" it from all the horror stoies I've heard. I went through one 10bolt because I didn't believe. I'm not going to chance blowing a 12bolt.

Then again, an M6 is a lot harder on a rear than an A4.

Ryan

 

Hmmm... I've got a 10 bolt in my 12.0 second '93 Z that pulls mid 1.6X 60 ft. times...AND a 12 bolt in my '70 Camaro which pulls low 1.5X 60 ft. times, and runs 10.83.

Frank