I have been doing a lot of reading using the search on this subject, and keep hearing about how the 12-bolts and M6's with sticky tires don't mix too well. I've read several threads with 12-bolts breaking after only a few clutch dumps on a good tire. I also keep hearing about having to get a locker or spool if you plan on doing clutch dumps at the strip. This kinda pisses me off, because I'd like to keep the streetability of a posi in a 12-bolt, but also want to make some runs down the quarter without worrying that my rear is going to give.

I thought the point of getting a 12-bolt is to not have to worry about it anymore. I'm currently saving up for a Strange 12-bolt and have done some research on rears. I guess what I'm trying to ask is will I be picking my 12-bolt up in pieces after a few hard launches at the strip. I plan on adding a nice set of heads in the near future and want to be able to get some nice times. Anyone else in the same boat as me? What are us M6 guys to do?

 

I was in the same boat as you. 'Still am too, I guess.

I got Strange thinking I can dump at 6k with slicks with a posi. From reading this board, I am now finding out that I am still not bulletproof.

So I guess WHEN I break the posi, it will be spool time . You can always go the 9" route with a locker.

 

Yes, very strong.

 

This really bites, that's two strikes against me, M6 and have ABS, but no TCS. That takes the 9" out of the picture, unless I want to get rid of my ABS (which I don't).

Scrude, what kind of abuse has your Strange been through? (what rpm dumps are you doing, what tires are you running) Any problems yet?

 

Good luck with the rear. A 12 bolt is a very strong rear end but if you have a posi in it, it becomes weak. There are people who break them on the first launch and then there are people who break them years later. It just depends on luck which is sad but true.

 

Dude, on my FIRST pass with a new clutch and the 3rd pass for my new 12 bolt, I was racing a turbo 5.0 and we were dead even. I started to pull, then he started to pull on me. I lost focus and shifted into 2nd at 88 mph

Needless to say I lost the race I didn't "get out of it" either, because it didn't dawn on me that I grabbed 2nd instead of 4th. My rear locked up, I smoked the tires, got sideways, and my mirrors were shaking when I looked back, preparing to see the "yard sale" on the track. And I think I shook a filling loose from my tooth. (Ok that was an exaggeration, but you get the picture)

I also had bad cases of wheel hops with my Nittos. Wheelhops KILL rear ends. So far mine is alive. I dumped the Nittos, put in LCA's and now all is good.

Like you, I have 3 channel which means yes, we are screwed (hence my screenname) for the 9".

Ok, now there is some good news. I don't think of myself as any kind of pioneer, but a recent experiment yielded good results:

I use a Harlan Two Step with my launches, and I think it reduces drivetrain wear. With the Two Step, I don't have to load up on the rpms to get a holeshot. With this device, you preset your desired rpm for the clutch dump. At the same time, your gas pedal is to the floor. As soon as you dump that clutch, you are at full throttle.

I preset my Two Step at around 3500 rpm, which is the middle ground between spinning and bogging. I got great launches last weekend when I first tried this. You see what I'm getting at? Better to dump out at 3500 rpm than 6000 to get a good hook. The only other requirement for this to work is to have a sticky tire, Nittos notwithstanding. I got MT DR's and they are great.

BTW, my Strange howls loud at 65-75 mph now, but it probably wouldn't have if I didn't misshift and wheelhop for 10 passes.

 

Hmmm, sounds like you've put yours through some decent amount of abuse (especially that miss-shift) and it's survived. I don't have any wheel hop, so that will help. I guess I'll keep saving up for a Strange 12-bolt then. Thanks for the info! Anymore comments/suggestions are welcome.

 

what about the 33 spline upgrade, is it the same exact posi, just different gears inside, I read that they upgrade the spring pack too. (on the billingsley website?)
so are the only options for the 12 bolt the eaton posi or a spool?

What would you say the performance breaking point of the 12 bolt posi would be (w/ M6)

thanks

 

You need a 12 bolt, but you realize that the motor will sniff out the next leakest link. I first started by changing my rear end, then went to sticky tires. Then my clutch went south. Changed to a Spec III and all was good for about 10 passes, then I snapped a driveshaft. Now I have a 3 1/2 inch driveshaft and I'm hoping for the best.

 

I've already got a spec 3, and I've snapped my stock aluminum driveshaft, so I put in a oem steel one. So, I guess that takes care of all the weaker components, except for the rear. It does look like a Harlan two-step will also make its way into my car. I hear it's easier on the rear when you launch with this.

 

It has been for me. If I dump higher than 3900 on Mickey Thompson DR's at 18 psi, I SPIN!

My range, depending on track prep and weather, is 3300-3800.