Advice on which rear end to go with?
03-20-2012, 10:27 AM
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Advice on which rear end to go with? It's getting about time for me to start looking for a rear for my car. My '02 M6 T/A has 195k miles on it and the rear is not exactly quiet anymore.
Currently, it's putting out 380rwhp, but I have a 6.2L ready to drop in. I've heard after a few good launches, a 12 bolt starts getting really loud... so I'm leaning towards a 9", even though I think it'll be overkill.
From what I understand a 12-bolt will use less power and weight, but will be noisier. And a 9" will use more power, weigh more, but will be solid/quiet/reliable.
Are there severe clearance issues w/ the 9" or have they made them now where that's not really an issue?
I'd also like to keep Traction Control, if possible.
Thoughts, suggestions, ideas?
Also... what gears would you recommend? This is NOT a track car very often. I road trip the hell out of this car. With it being a 6-speed, I was leaning towards 4.10's, but not sure how bad that'll hurt my mpg (I know... I know...)
Currently, it's putting out 380rwhp, but I have a 6.2L ready to drop in. I've heard after a few good launches, a 12 bolt starts getting really loud... so I'm leaning towards a 9", even though I think it'll be overkill.
From what I understand a 12-bolt will use less power and weight, but will be noisier. And a 9" will use more power, weigh more, but will be solid/quiet/reliable.
Are there severe clearance issues w/ the 9" or have they made them now where that's not really an issue?
I'd also like to keep Traction Control, if possible.
Thoughts, suggestions, ideas?
Also... what gears would you recommend? This is NOT a track car very often. I road trip the hell out of this car. With it being a 6-speed, I was leaning towards 4.10's, but not sure how bad that'll hurt my mpg (I know... I know...)
03-20-2012, 11:22 AM
#2
A 9" is the easiest to deal with long term. Most supported rear end ever. Its one weak point is the factory LS unit and no one would use one anyway. It's strong point, you can swap the pumpkin in about an hour start to finish. That means you can have a spare center all set up and just drop it in. Back in the day we would drive to Indy for the nationals, swap centers in the motel parking lot and street race all weekend, swap again and drive home with highway gears. Try that with a 12 bolt
I went with a S60 because I don't foresee any reason to change ratios, and the torque arm mounting is so easy. It's dead quiet, heavy and so on AND they are about as bullet proof as they come. And they just drop right in. No muss no fuss, everything just bolts up. Only mod to my car was the drive shaft.
Al 95 Z28 S60 w/4.30's and a spool.
I went with a S60 because I don't foresee any reason to change ratios, and the torque arm mounting is so easy. It's dead quiet, heavy and so on AND they are about as bullet proof as they come. And they just drop right in. No muss no fuss, everything just bolts up. Only mod to my car was the drive shaft.
Al 95 Z28 S60 w/4.30's and a spool.
03-20-2012, 12:01 PM
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Let me finish my 9 inch build and you can read all about it. Im diehard chevy but two things good came out of ford. 9" rears and remote starter solenoids. I doubt you can do it for the same cost but I will only have about $1600 in mine with some connections. If you want to keep abs it will be a ton easier if you have a 4 channel car. In that case you can just re use your factory brakes and backing plates. Then as far as the ABS/TCS knows you didnt change a thing.
03-20-2012, 12:10 PM
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A 9" is the easiest to deal with long term. Most supported rear end ever. Its one weak point is the factory LS unit and no one would use one anyway. It's strong point, you can swap the pumpkin in about an hour start to finish. That means you can have a spare center all set up and just drop it in. Back in the day we would drive to Indy for the nationals, swap centers in the motel parking lot and street race all weekend, swap again and drive home with highway gears. Try that with a 12 bolt
I went with a S60 because I don't foresee any reason to change ratios, and the torque arm mounting is so easy. It's dead quiet, heavy and so on AND they are about as bullet proof as they come. And they just drop right in. No muss no fuss, everything just bolts up. Only mod to my car was the drive shaft.
Al 95 Z28 S60 w/4.30's and a spool.
I went with a S60 because I don't foresee any reason to change ratios, and the torque arm mounting is so easy. It's dead quiet, heavy and so on AND they are about as bullet proof as they come. And they just drop right in. No muss no fuss, everything just bolts up. Only mod to my car was the drive shaft.
Al 95 Z28 S60 w/4.30's and a spool.
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03-20-2012, 12:52 PM
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i think my narrowed MWC FAB9 actually weighed the same as a 10 bolt....or if it weighed more it was only a couple pounds?
our 12bolt did exactly what you said,the harder you drive it the noiser it got.......
i dont know anything about the s60 but what i have read,were all good post.
our 12bolt did exactly what you said,the harder you drive it the noiser it got.......
i dont know anything about the s60 but what i have read,were all good post.
03-20-2012, 01:01 PM
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I think downside to a 9 inch is its not a GM part so youll have to have a custom TA mount and correct axles if you want to keep the ABS. That being said most everyone building these things for our cars has it figured out. In my opinion and this is strictly and opinion.....a 9 inch is the best bang for the buck. A spooled 9 will take about anything you throw at it. I understand it isnt always the best option for everyone though.
03-20-2012, 01:02 PM
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i think my narrowed MWC FAB9 actually weighed the same as a 10 bolt....or if it weighed more it was only a couple pounds?
our 12bolt did exactly what you said,the harder you drive it the noiser it got.......
i dont know anything about the s60 but what i have read,were all good post.
our 12bolt did exactly what you said,the harder you drive it the noiser it got.......
i dont know anything about the s60 but what i have read,were all good post.
03-20-2012, 01:05 PM
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means my rear housing, axles, and brakes weigh 76 pounds before adding the center section with the gears and locker (referred to in a 9 inch as the "third member") The reason I said that like I did was everyones third member will weigh different based on the type of locker or spool, case, hell even the amount of teeth on the gear
03-20-2012, 01:09 PM
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Another really dumb question.... will it still be limited slip? Like I said... I keep the car on the road a lot. Having the rear locked seems like it'd be a PITA as a DD.
03-20-2012, 01:17 PM
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it depends on what type of carrier you choose. Don't run a spool on the street (locked soild all the time) its just hard on parts, kills tires, etc. I have a detroit locker which is often not recommended for street use but I got it so cheap Im gonna give it a shot. Its so easy to change centers id be dumb not to. In your case you will probably want a tru-trac which is a lot like the stock Torsen unit. Some people don't like those also though. Seems like its just what you are into. I know that the Detroit locker will make noise and be a pain in the rear (no pun intended) but I actually looking forward to it. My friends think I'm slightly insane. I daily drove a 253/253 110LSA cammed, carbed SBC to high school so this thing still seems tame to me.
03-20-2012, 01:22 PM
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Well, that stinks... I just want something that will not be loud, will not be locked, and will hold a decent amount of power w/ minimal beating on the car to get it to fit.
03-20-2012, 01:29 PM
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the trutrac is limited slip is what im getting at. If youre wanting bolt in just get that strange 12 bolt. That being said the 9 inch will last longer and be quieter if you get street gears. You can make a nine inch what you want is what im getting at. I reall hope I dont have to beat on my car to get it to fit. Not expecting to thats for sure.
03-20-2012, 01:37 PM
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dude im in college. Theres a guy talking about statistics and have no idea what he is talking about. You are helping me pass the time until I get home and stuff a 9 inch in. Ask away and anyone else feel free to chime in if you have another opinion.