TransAmcoupe98

iTrader: (10)

What is the make up of a good rearend and what parts make them so good compared to our 10-bolt?

EPP

iTrader: (22)

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.
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.

Link to the Moser 9 inch that I sell.
http://www.exoticperformanceplus.com....html?item=145 Bob

Steve Burger

iTrader: (33)

That is a very general question. What is good for you may be wrong for someone else. Can you be more specific? What use will the car see, what HP level, what tire.........

We can work with you to design a housing and internals package that is right for you.

jmm98LS1

iTrader: (28)

The reason the stock 10 bolt sucks is because it's so small. The ring gear is only 7.5" and is just way undersized for the application. You can upgrade the 10 bolts with good axles & gears, but that doesn't fix the fact that a 7.5" ring gear is too small to handle much power. Aftermarket rears like the 12 bolt, 9" and S60 are so much stronger because they are MUCH bigger than the 10 bolt. Bigger = stronger in this case.

TransAmcoupe98

iTrader: (10)

Yea, the car is a street car but it will see track time but mostly draggin around on the street and it will be driven pretty frequent. I plan on strapping on slicks whenever I'm at the track and radials on the street. I'm planning on around 550hp and around 675 with nitrous.

blue98Z

iTrader: (29)

Dude, go ahead and do it right the first time. I see your running an auto so a 12 bolt would be good for you. I'm about to give EPP a call here hopefully next week to get my 9inch on the way before the M6 scatters this 10 bolt. Good luck on your decision.

Steve Burger

iTrader: (33)

With the auto and HP level you are at a 12 bolt could work good. A 9" would be a good upgrade depending on the diff choice you make.

What do you want for a diff? Spool, Locker, Posi.

Z28Fanatic

TransAm, you wanna see what happens to a 10 bolt when you're makin just over 370 to the wheels, and you have good traction? Have a look...

http://youtube.com/watch?v=E-sR0bUZp74

TransAmcoupe98

iTrader: (10)

I'm not too familiar with differentials...I really dont understand. Someone enlighten me on their purpose to a strong rearend.

Z28Fanatic

A spool is just a piece that holds the ring gear, and is connected to both axle shafts. The spool turns both axleshafts at the same speed, all the time. There are no gears or clutches or pins in a spool. A locker allows a little bit of differentiation in how fast the axles turn, such as when you turn a corner at slow speed, but very little. These act almost like a spool, but there is a little bit of speed differentiation allowed, whereas with a spool there is none. A posi is also referred to as a limited slip rear end. Most of them involve clutches, and they lock the two axleshafts together when there is a significant amount of speed differentiation between the two axles.

Naturally, a spool is the strongest, since it has no moving parts to break, followed by the locker, which has some moving parts, but not many, and lastly the posi, which are usually the weaker of the 3 because of the wear parts like the clutches, and also because a posi bears some resemblance to the plain old open differential, and no one likes those...

Steve Burger

iTrader: (33)

Good summary above. In practical terms:

Spool is great for a drag car not so great for a street car
Locker is good for a track car OK for a street car. Not so good for the twisties
Posi is great for a street car and twisties but not so strong in a full out drag car

It is a comprimise you will need to make.

linegtdt52

iTrader: (12)

If you arent making over 550 hsp, you really dont need anymore than a Trac-Loc. You dont need a nodular case, you dont need the daytona pinion support, and you dont have to get a locker or a true-trac. ALOT of people tell buyers that they highly reccommend a true trac over the trac-loc but I have seem a True trac break from 35 more horsepower than what it was launching with in a trac-loc. The only reason he switched to a true-trac was because he got it from his dad and it had a better gear 4.10 vs 3.73. Do some research. There are people running 4.40 in the 1/8th spraying 250+ nitrous wholeshots and run trac loc all the time. Good builder = strength and dependability

NINET3Z

4.40 in the 1/8? on 250 nitrous?

linegtdt52

iTrader: (12)

big block drag vehicles oh by the way that's 2 stages of 250, sorry for the miscommunication

linegtdt52

iTrader: (12)

try taking a 538 world block and spraying 2 stages of 250 with a progressive controller and a window switch. It'll put you through the back of a stock drivers seat. lol

NINET3Z

I'm not trying to argue, but you should do a little research. A 4.40 1/8 mi. would be a great pass for an Outlaw 10.5 car. Nitrous Outlaw 10.5 cars usually run 2 or 3 stages of nitrous, sometimes more. We are talking 1000 hp or more of nitrous. Your telling me you can run the 2500+/- horsepower that it takes to run a 4.40 1/8 mi. through a True-trac? I think not.

LSGunZ28

iTrader: (8)

Im still waiting for the day a sponsor finds a significant metal to make a 7.5 ring and pinion gear out of that is both lightweight and stronger than a 9" ring gear... Oh how I hope this day is soon...

and we can finally have a significant track and drag car all in one..

PowerShift408

iTrader: (44)

Don't hold your breath. I'm sure there is a metal out there capable of ascertaining your goals, but I'm sure the price won't be able to compete with just throwing in a good ole 9''.