View Full Version : 12 bolt help


Ws6 Love
04-21-2007, 12:22 AM
im gonna order the 12, and was wondering which one to go with, the truetrac or the full spool? it will be for street and track

revtime
04-21-2007, 03:13 AM
How many miles a year you plan on running on the street?

I put about 3k a year on my car and I have a spooled 12 bolt sitting on jackstands waiting for me to get the lead out.

Ws6 Love
04-21-2007, 03:21 AM
well its my dd so i drive quiet a bit

EPP
04-21-2007, 04:51 AM
If most of your driving is highway or rural, and you plan on having over 600 rwhp, then I would go with a spool. If you are planning on pushing over 600 rwhp, then I would also recommend using the Moser 9 inch instead of a 12 bolt.

http://www.exoticperformanceplus.com/performance_parts/index.html?item=148

Put a 12 bolt into a early Chevelle, Nova, Camaro, etc and you can beat the crap out of it, and not hurt anything. Put one into one of our cars with a torque arm, make a couple 4000 to 5000 dragstrip launches, and I can just about guarantee you'll pick up gear noise. If it is a drag only car, you'll never know or care about the gear noise. Drive your car home from the track, and the noise will drive you nuts. I feel the torque arm stresses the 12 bolt housing, causing distortion. We have never seen this happen with the 9 inch housing.

Exotic Performance Plus strongly recommends the Moser nine inch. This rear is even tougher than the Moser 12 bolt, and the horsepower of the late model F Body cars keeps escalating every year, which requires a very strong rear. With the recent introduction of the 6.2L GM aluminum block and the excellent flowing 6.2 litre heads, the horsepower of these cars is going to just keep climbing at a very fast pace.The nine inch will handle the power, plus we prefer the way the torque arm is bolted to the nine inch in the same way the oem rear-end is attached. (This is the only good thing about the stock 10 bolt...) The Moser 12 bolt uses four short bolts to attach the torque arm, and they have a habit of loosening up, even when loc-tite is used. Why the nine inch is stronger than the 12 bolt. The 9-inch has an internal rear-pinion support that also supports the gear end of the pinion to limit gear deflection under high torque loads. This seems to be the major reason why the 9 inch doesn't start whining after high rpm clutch dumps, when the 12 bolt will pick up noise.The 9-inch locates its pinion gear lower on the ring gear to improve tooth contact, than the 12 bolt does.The 9-inch has a 0.125-inch larger ring-gear diameter and internal pinion support than the 12 bolt does. This is not much of a difference, but it is worth noting.
Bob

Ws6 Love
04-21-2007, 11:35 AM
i dont really plan on going over 600 so i just went with the 12 bolt truetrac, 33 spline , and 4.11's, about how long is shipping to 95630?

TT632
04-23-2007, 05:36 PM
I run a Moser 12 bolt with a spool in my third gen and have had no problems other than than those darn torque arm bolts loosening up. Time to fab up a re-enforcement bracket.

EPP
04-24-2007, 04:26 AM
i dont really plan on going over 600 so i just went with the 12 bolt truetrac, 33 spline , and 4.11's, about how long is shipping to 95630?

Approx 5 workings days for you to receive the rear out in Ca after you order it. Shipping would be $250.00. Thanks for inquiring. Bob