12 Bolt or 9" ??
Thread Starter
Launching!
Joined: Jan 2016
Posts: 224
Likes: 1
12 Bolt or 9" ?? I finally got the new LS3 dropped in my WS6. I have already upgraded the trans to a Performabuilt with FTI 9.5 Billet 3600 stall. Im still sort of torn between a Strange 12, S60 and the MWC 9"...I'm a little over 500 at the wheels and its 90% street driven, but it will also make a few passes at the track on drag radials also. No trans brake. I have searched thread after thread on pros and cons of each, but those threads were like from 5 yrs ago, some even older. I spoke with MWC yesterday and they have many option on their set ups, just not sure which I actually need or don't need. If I do go with Strange, I plan on changing the TA set up and getting it off the trans with a BMR set up, also heard this is why most 12 bolts will eventually get noise leaving the stock TA in place? From what I have gathered the 12 bolt and 9" are very close in weight? I guess my main concerns are gear noise, parasitic loss and fitment. I will probably never runs slicks on the car at all, MT drag radials at the track would be about it. I spoke with someone at MWC yesterday and they were very helpful, but not sure I would really need the Pro Nodular Case and Gear Pro set up? Im looking to change gears from the stock 3.23 to somewhere around 3.42-3.56 when I swap over. Just wanted to get some fresh input on options etc...
For an automatic at your power level I'd go with the 12 bolt. Less parasitic loss and cheaper. Fitment should be similar on both. The MWC 9 is great but a bit overkill for your setup. Thats just my opinion
Staging Lane
Joined: Mar 2007
Posts: 58
Likes: 4
I finally got the new LS3 dropped in my WS6. I have already upgraded the trans to a Performabuilt with FTI 9.5 Billet 3600 stall. Im still sort of torn between a Strange 12, S60 and the MWC 9"...I'm a little over 500 at the wheels and its 90% street driven, but it will also make a few passes at the track on drag radials also. No trans brake. I have searched thread after thread on pros and cons of each, but those threads were like from 5 yrs ago, some even older. I spoke with MWC yesterday and they have many option on their set ups, just not sure which I actually need or don't need. If I do go with Strange, I plan on changing the TA set up and getting it off the trans with a BMR set up, also heard this is why most 12 bolts will eventually get noise leaving the stock TA in place? From what I have gathered the 12 bolt and 9" are very close in weight? I guess my main concerns are gear noise, parasitic loss and fitment. I will probably never runs slicks on the car at all, MT drag radials at the track would be about it. I spoke with someone at MWC yesterday and they were very helpful, but not sure I would really need the Pro Nodular Case and Gear Pro set up? Im looking to change gears from the stock 3.23 to somewhere around 3.42-3.56 when I swap over. Just wanted to get some fresh input on options etc...
How many passes have you made on it so far? No increased whining?
TECH Apprentice
Joined: Apr 2016
Posts: 313
Likes: 16
From: Lincoln, NE
I run a 12-bolt and it's been in the car for probably over 5 years now. I'm off the top of my head 466rwhp and 460rwtq on a mustang dyno through a 4L60E & 3600 Yank. My 12-Bolt has moser 31 axles, 3.73 Richmond gears, c-clip eliminators and will admit is a bit noisy. Had my rear rebuilt due to a local transmission shop installing my pinion nut on with a 3/4 air impact until impact was stalled out lol. Well after transmission shop put 15-20 miles on a rear with bearings crushed I had the "The Shop Inc." rebuild it and to be honest was pretty noisy for I'd say 100-150 miles but it's quiet down a lot after some road miles.
I think 12-Bolts get a bad rap mainly due to noise but my choice of running Richmond gears does contribute to my noise, as others have found certain gear brands run much quieter than others. If I didn't have a 12-Bolt or something catastrophic happened to it I'd look hard at a S60.
I think 12-Bolts get a bad rap mainly due to noise but my choice of running Richmond gears does contribute to my noise, as others have found certain gear brands run much quieter than others. If I didn't have a 12-Bolt or something catastrophic happened to it I'd look hard at a S60.
Awesome. Thanks for the info. Everyone says stay away from the 12 bolt if you're a manual making big power and launching hard on slicks, but i've always wondered how true that really was. This is good info
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Thread Starter
Launching!
Joined: Jan 2016
Posts: 224
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I think the 9" may be overkill as well, but if they are close in price who knows..The Strange 12 is $2720 without powder coat and have to pay shipping which I think is around $200, so just call it an even 3k...MWC depending on having them assemble the rear and options may be a little less and come with TA and mount I believe...Also wasn't sure about pinion angle with the 9" center being lower?
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TECH Regular
Joined: Jun 2008
Posts: 453
Likes: 14
From: Utah
I went with a MWC Fab9". I know it is a big investment up front but it really is a awesome rear. I mainly use my car for auto-x/road race stuff and I know a 9" may be "overkill" for that type of racing but with the lightweight of the fab 9" I hardly even felt a difference as far as weight goes. I am also lowered on a set of UMI coil overs and with the stock rear and a UMI torque arm I had on before I have a huge dent and actually a hole where the torque arm would contact the tunnel on big bumps. With the MWC setup I have tons of room now. The install and fitment was spot on with the 9" and really was a smooth experience. My only complaint with the rear it the breather location and ABS issue. The way I use my car the breather location out on the drivers side axle tube is a silly location. Hard corners force oil out and it got everywhere. I wish they would have located it closer to the center. I installed a barb and a 2' hose and it still pisses fluid out of it. I am most likely going to pick up a catch can for back there. And the ABS issues. I have a 4 channel rear and although there are tons of people with 0 problems, I along with some others have ABS error at speeds above 70ish. I have a few more things I want to try over the winter like true up my tone rings and ensure sensor location is perfect so I may be able to fix both issues fairly easy. I was also in a huge time crunch this spring with LSfest West, and MWC pulled through and hooked me up big time. Overall I am a very happy customer and like most things in the automotive world you get what you pay for.
Last edited by Chrisingermany; Oct 24, 2018 at 11:07 AM.
Joined: Aug 2007
Posts: 24,241
Likes: 89
From: Turnin' Wrenches Infractions: 005
s60 1st, 12 bolt 2nd, and i hate cast 9" torque arm designs. ******* garbage. Now fab 9s designs are pretty sweet, but thats a whole other price range.
TECH Fanatic
Joined: Jan 2017
Posts: 1,758
Likes: 442
9" is much stronger, distorts/deflects less under torque, easier to service and adjust, more aftermarket options, need I go on? The weight difference can be made up easily with the extra power you can put through it.
Thread Starter
Launching!
Joined: Jan 2016
Posts: 224
Likes: 1
01SS how has your 12 bolt held up? I found an old thread when you first got it and installed it. MWC Fab 9 is going to run me over 4k so that kind of puts it out of the running...I would rather spend the extra grand on other suspension mods than have overkill on a 9" that I would never get full use of...
Thread Starter
Launching!
Joined: Jan 2016
Posts: 224
Likes: 1
I think the S60 is going to win out...price diff in it and the Strange 12 bolt is very close. I went to Spohn Performance website and the S60 with 3.54 gearset, 3 channel abs and u joint conversion was $2464...Was also told the S60 would be more quiet than the 12
Why the S60 over the 12 bolt? I'm just curious to hear your reasons
