WheelmanWS6

Hey yo,

I wanna start heading to the track as soon as possible, and I definitely needed this 12-bolt like...yesterday... but I have been going back and forth on which route to go.

I have heard MANY pro's and con's for both Strange and Moser. I really have no idea which route I should go.

My car is making the power in the sig. Built motor and Supercharger coming next year. I plan on street driving on Drag Radials and eventually getting a slick/skinny combo for the track. I will probably make about 5-10 track visits a year. I'm looking for the least amount of possible whine. I know that some hard launches are going to effect this. I want to keep the stock ABS, and would like to run 4.10s.

So hit me with your preferences and experiences. I need to make a decision soon and I'm very torn.

ssvert99

iTrader: (26)

at this point you better just start pricing a 9 inch rearend... the 12 bolts wont do the trick with where your'e going. and we all know where the best deal on a true bolt-in 9 inch rearend is....

EPP

iTrader: (22)

You said you need it, like, yesterday. That situation would lead you to a Moser rear, and I too, agree that a nine inch is the way to go. Moser ships their standard nine inch and their M9 fabricated rear just two days after the order is received, not two months...

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

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

99Hawk262

iTrader: (19)

I've done a lot of research on this site because I was in the same boat as you....I wanted a 12-bolt, but which one? After weeks of searching and reading, I decided that a 9" was better for me. If I was still going the 12-bolt route, based on what I found on this site, it would be Strange hands downs. I've read of too many problems with the Mosers and I'm not comfortable paying that much money for something that I feel is questionable when it comes to quality. On top of that, a local guy had problems with his and I didn't want that headache.

When the time comes, I will be buying a Midwest fabbed 9"....they are the highest quality and one heck of a deal. I don't mind waiting two months or longer if that's what it takes. I'd rather wait two months for a rear that I know is going to work as opposed to two days for something that I personally haven't been too impressed with. No offense to those who run the Mosers with great success.....it's just not for me.

WheelmanWS6

heh, just when I think I'm out of the "9 in. vs 12 bolt" decision, you guys pull me back in lol


But in all seriousness, thanks to all three of you for your honesty and good information.

I guess my biggest concern is driveability. 9 inch does not utilize ABS right? That is kind of a big factor for me, since the car is going to be daily driven more than its going to be a track car, at least for the next few years.

Also, Bob, you mention the pinion angle of the 9 in. as more of a positive feature (in torque arm relation anyways) whereas I had always thought it was more of a negative. (drivetrain loss?) Are my concerns in that area without merit? Again, I appreciate your experiences. May help to ease my mind.

I wish there was an easy decision to be made here, but it seems like there are going to be significant pros/cons on either side.

Thanks again, and please keep the information coming.

Nightrydass

so when would a 12 bolt be a correct choice? I plan on upgrading my soon also; even when my motor is done i can't really ever see myself doing 4-5K launches. My sytle is street driving (cornering and such). I would prob see the strip a few times a yr but max launch would be like >2.5K RPM.

Is a 9" just for beating the **** outa it?

ssvert99

iTrader: (26)

the 9 inch rearends are available with 3 ch and 4 ch abs/tcs. i was the first to release the 3 ch to the public, Strange and Moser do a good job with the axle mods to install 4 ch reluctor wheels. all the rearends can re-use the stock brakes.

the 9 inch pinion is located lower in relation to centerline than the 10/12 bolt rears. this is going to cause a 2-3% higher parasitic drag comparably. not much to worry about considering the durability and noise issue.

my fabricated 9 inch is an extremely streetable rearend. we just did a in shop install where the customer drove here 3 1/2 hrs on the stock 10 bolt, installed the 9 inch, and he drove it back home the same afternoon. i rode in the car and it did not make any noise worse than the stock rear. it was also changed over to my chromemoly adjustable phb and lca's.

ssvert99

iTrader: (26)

a 12 bolt is good for cars that will see limited track use, or not use slicks. any auto car(no transbrake/high stall). the torque arm 12 bolts seem to distort slightly if abused at the track with hard launches and good power. if all you are ever gonna do is 2500 launch and radials, a Strange 12 bolt would be fine for you.

Nightrydass

That would be about it; i don't see DR's in my future, like i said i like corner carving. I would see some track time but nothing too competive; just b/sing around. There is no way in frealing hell i would dump the clutch >3K RPM; truthfully i couldn't see any higher then 2K.

The only reason i ask is b/c even tho the 9" and 12-bolt are like $50 different in price; i kno the 9" eats rwhp.

My end goal is to be 400 - 450rwhp w/ my M6 (not sure how i will get there tho and realistically no higher); is there a HP threshold for the 12-bolt?

99Hawk262

iTrader: (19)

The 9" eats a little more horsepower, but I don't believe it's enough to really matter. Another plus to the Midwest 9" is that it is lighter than the Strange 12-bolt and the Moser 9". Also, while only being a couple hundred dollars more it includes an adjustable torque arm and new tranny cross-member. So the only negative I can see is that it will take away a slight amount more horsepower than the 12-bolt. Everything else is a plus which is how I came to my conclusion. I don't race much now, but I know my future plans include much more power and a lot more racing!

EPP

iTrader: (22)

Moser has had the ABS option since last Fall, the option for ABS is $175.00.
http://www.exoticperformanceplus.com....html?item=145

The slight drivetrain loss from the 9 inch will certainly not be felt, plus the added insurance of having a rear that won't pick up gear noise after a few high rpm holeshots is well worth it. Bob

Black FormulaLs1

iTrader: (10)

so which is best for the M6 cars then? i should be making well over 600rwhp with the juice...and god only knows the ft lbs..

KENS WS6

Im running 12 strange, no problem here.

DrkPhx

iTrader: (15)

I've had a Strange 12-bolt for over 3 years without a problem except gear whine. At the time it was the logical choice because it was a direct bolt in and ships complete including fluid. Last week I helped my friend install his complete Midwest Chassis 9" and torque arm. It comes powder coated and all of the welds looked very good quality. They also include new hardware for all the rear suspension pieces. It was a straight forward installation and overall I was very impressed with it. If I were ever to change rear ends, this is the one I would buy.

SIC LSX

iTrader: (10)

I hate Moser 12bolts!

strokerblackhawk

iTrader: (4)

damn why are you hatin on the moser 12 bolt (probably cause you have a 10 bolt with stock gears) mines rock solid has a little gear whine but no worse than the 10 bolt and hell i drive mine throuh rush hour traffic, on the highway and the strip and it's never gave me any problems, i think alot has to do with who sets the rearend up if you pull it out of the box and bolt it in wihtout checking the gear patter or backlash, hell i can see why youd have a problem with it, so if your spending the money on a baddass rearend you might want to get a really good mechanic to set it up (ie LMR)

EPP

iTrader: (22)

Moser 9 inch with locker or spool, and 35 spline axles. Want to go as light as the 10 bolt, go with the Moser M9. Bob

WheelmanWS6

Bob, what are the negatives with the M9? Is it not as strong as the standard 9 inch? If I can save a few bucks, I'd rather go with the M9 and have something to keep me near stock weight.

Thanks.

EPP

iTrader: (22)

The M9 with the backbrace is a very strong rear. Video of my car at sema with this rear. http://www.exoticperformanceplus.com...html?item=1355

The M9 is more expensive than the standard Moser 9 inch, not the other way around. The housing and axle package, which comes with a torque arm and trans crossmember is $1,800.00. Then you choose which center section you want. Bob

mr_biscuitz

iTrader: (22)

I personally love my moser 12 bolt w/4.10 gears. I go to the track about 2 or 3 times a month and leave at 5500 rpm. It does whine like a son-of-a-bitch but hell every suspension mod you do there is a little more sound that comes with it. I normally don't drive the car besides on weeekends and nights but you get use to the noise. I was told you didn't need the nine inch unless you were going to be going over the 800hp mark. That is what moser said when I bought my rearend 2 years ago. I would have to say now I wish I would have went with the nine inch due to my newest plans. 408 w/F1a pushing 14 to 16 pounds. Guess time will tell. I plan on trying out the 4.10s before I change probably to a 3.71. Hell they are all pretty much the same price now so just go with the 9 inch.