qwikz28

iTrader: (12)

i didn't know what thread to put this in, so i picked this one...

but anyways, my question is simple: i am going from a stock rear (2002 M6 Camaro) to a 4:10 moser 12 bolt with a detroit tru-trac diff. i understand the tru-trac is a better diff for handling bias, but will the extra weight of the rear offset this? will the difference be noticeable for a street driven car?

i remember a member (i think it was viper) who said he lost time around the track going to a 12 bolt, but how noticeable is that on the street?

thanks and i apologize for the annoying hypothetical questions.

Jacob

coolformula

iTrader: (21)

Its a light more unsprung weight. Will it make the car a dog? Depends. Jsut be sure you got good shocks. But sometimes the 12 bolt is a good thing better posi and can hold the power. Even if it does add some weight.

z28bryan

iTrader: (7)

I've heard the trutrac isn't much improvement over the T2 other than being a hell of a lot stronger. It can take a beating on the strip.

Picking a good handling differential is quite a challenge with whats available to us. I'd go with a T2R hands down if they made it for a 12 bolt or 9 inch. The 9 inch has a trutrac with preload that I've heard a tiny bit about but there isn't much info on it, but I think it's closer to the T2R. Also the Auburn Racer's diff is one that Sam recommends but I don't think that's available for the 12 either.

chupr0kabra

iTrader: (10)

I have a 2000 M6 Camaro with a Moser 12-bolt, 4.10 gears, and a Detroit TrueTrac diff, so I might have some insight here.

Yes, the difference in unpsrung weight is very noticeable. When I first got mine, I was very unhappy with the ride. After I adjusted the shocks (Koni SA's), it was much better, but the biggest move in the right direction was getting lighter wheels. I went from 17x11 ZR1's with 315/35/17's to 17x9.5 Fikse FM/5's with 275/40/17's. I still have a couple adjustments to make (LCA relocation brackets), but the ride is much better now.

Maybe this thread will help:
https://ls1tech.com/forums/suspension-brakes/697206-unsprung-weight.html


-Mike

z28bryan

iTrader: (7)

Does anyone know how the weight of the 9 inch with aluminum center section compares with a 12 bolt?

qwikz28

iTrader: (12)

thanks mike! thats an awesome thread. the wheels i have are pretty light so that does make up for it. i will also be installing the relo brackets for the LCAs. i think i'm on the right track, i just need to adjust the shocks accordingly i guess. i have the Konis as well. so the 12 bolt isn't extremely detrimental to my handling is it? cause thats a great relief.

chupr0kabra

iTrader: (10)

If you have Koni's, you should be able to adjust it to your comfort. I certainly was. My car still handles great, and now that I've tweaked it a little more (and grown accustomed to what the rearend has changed), it's VERY close to where I want it. The stuff I'm not totally satisfied with can likely be fixed.


-Mike

qwikz28

iTrader: (12)

i knew i shoulda stepped it up to the 4th gen rear shocks adjusting them are gonna be a pain in the butt!

qwikz28

iTrader: (12)

mike- you don't happen to remember you're settings do you? i think it would save me a bit of time to start from your settings.

chupr0kabra

iTrader: (10)

Front - Four sweeps from full firm.
Back - Pretty sure it's at a full turn from full soft.


-Mike

qwikz28

iTrader: (12)

thanks mike! you are the man! this kinda gives me hope about my decision to get this rear. i can't thank you enough, you've been most helpful

Jacob

Sam Strano

iTrader: (41)

A 12-bolt is not in any way a good handling move. The unsprung weight is a lot higher than a 10-bolt is (and there aren't as many diffs to choose from). I'd sooner say a 9" if you have to change, but I'd say with a 10-bolt if you aren't in imminent danger of fragging it from 600 HP.

Unsprung weight is helped by compression damping, something SA's don't have the ability to change. While a little tweaking helped Mike, it's likely that would have helped with the 10-bolt as well. He somewhat countered the 12-bolt mass by moving down to smaller and lighter wheels (who's idea was that again???). But then consider if those wheels were on the car *with* the lighter axle too, even more help!

chupr0kabra

iTrader: (10)

Point of clarification, Sam. I was completely satisfied with my handling before upgrading the rearend. With the added mass of the 12-bolt, I became unhappy with it, so all the adjustments I made (including lighter wheels, which you are definitely credited with suggesting...plus they look badass ) were to get me back to completely satisfied. Which I am.


-Mike

Sam Strano

iTrader: (41)

I just like to point out details. After all I'm the one always telling folks the details matter. I'm just glad the car got back to working appropriately.