MikeWS6

My car is a mild heads/cam ls1 street car (see sig). I am looking to buy a rear end. I know that I want to run 4.10s for sure.

1.) How much power can I expect to lose going from a 10 bolt w/3.42's to a 9" or a 12 bolt with 4.10s? I know it doesnt matter because the car will be alot faster but id like to know what to expect.

2.) 9 inch or 12 bolt? Other?

3.) How can you tell when the 10 bolt is about to go? Any warning signs?

Thanks in advance.

00ZNewb

iTrader: (2)

1) The only place you will be affected by any power loss will be at the dyno, and it wont be much. Besides, cant race anyone when your strapped down to the floor.

2) Since you have an M6, most recommend the 9". I've read that high RPM launches on a 12 bolt will cause it problems.

3) If it is under the car, especially behind an M6, and the car is being driven, that's a sure sign your rear is going bad.


If you are pressed for cash, find a set of CHEAP gears and drop them in your 10 bolt, if not order a 9". I'm pressed for cash, so i did the cheap gear swap. I made it 2 full 1/8 passes before it broke.

MikeWS6

Its not the money I just dont like having any down time with my car. I work full time so I have no time to do the install and I would have to bring it to the shop.

It looks like from all the research I have gathered everyone says 9 inch is the way to go.

Guitar

iTrader: (9)

Go with a 9". There's no reason to go with something less in my mind, especially in a manual car. Also at this point where I've spent so much on my used rear I bought, I should have just gone and bought a new one and saved time and hassle. Hit up Bob or MWC (but they will take a while) and get them to price you one. As said, you're not going to lose that much power, and even if you lose a few you're gaining a lot with the gears.

MikeWS6

Okay. The 9 in w/ 4.10s should make it about half a sec quicker in the 1/4 right?

BrntWS6

iTrader: (7)

I think a 9" is a 1% loss on the dyno.

MikeWS6

Really? Thats it? I thought it would be way more.

edwardzracing

iTrader: (59)

No, not necessarily. Keep in mind you're adding a lot of rotational weight by throwing a 9" in there. Bigger axles = heavier. A fabbed housing won't add too much weight, but depending on the center section you choose, (ie. aluminum case, iron case, locker, spool, etc), that's where you'll be adding quite a bit of weight... all rotational of course, which is very important as far E.T. goes. A lower ratio might even things out, but if all things are equal in the engine and transmission department, and all you did was change rear-ends from the 10-bolt to a 9"... my guess is, even with a fabbed housing, aluminum case and spool (lightest options), the car will run about the same times as it did with the 10 bolt. Rotational weight is just that big of a deal, and a 9" will just flat out eat horsepower up. Worth it? ABSOFUCKINGLUTELY.

NOTE: The above is my opinion. I could be wrong. Not all cars are the same.

Whatever the case... it's still worth the investment.

Bob@BruteSpeed

iTrader: (16)

Thanks, I appreciate it! Bob

Bob@BruteSpeed

iTrader: (16)

http://shop.brutespeed.com/Brute-Spe...nformation.htm

I have info at the above link that should help to answer a lot of your questions.



http://shop.brutespeed.com/Moser-9-a...Ends_c2632.htm

Here is the link to the Moser rears I sell. These rears are shipped out just two days after the order is placed. Let me know if you have any questions. Bob

MikeWS6

I actually read that when I first started researching. Im going to see how long the 10 bolt lasts then i'll upgrade to the 9 inch. Thanks.

MikeWS6

That is kind of depressing lol

Bob@BruteSpeed

iTrader: (16)

You're welcome. Thanks. Bob

edwardzracing

iTrader: (59)

It's depressing until you realize you can start throwing power at the car as if it was candy and not have to worry about the rear end going

You won't regret making the change... maybe at first, but if you're wanting reliability... make the investment.

MikeWS6

I also have a stock replacement clutch