12 bolt rear-end

[99BlackW68]

I always hear that the rear-end of F-bodies is the weakest point. I was wondering at what point horsepower wise does this need to be swapped out for a stronger rear-end. Guys on LS1Tech say the entire job costs about $2000-$2500...making me really not want to do it. I plan on running around 350 wheel horsepower when all my modding is said and done, forced induction. I'm getting 18x9.5 rims with performance tires, so they'll have some good stick to them. Am I going to be in danger of breaking my stock rear-end if I get a good launch? I have a '99 Firebird Y87. I never hear any talk about it on this forum, so I'm hoping that the answer is no...

[SilverRS96]

Re: 12 bolt rear-end

no u dont need it...a 10 bolt can hold that....get a ta girdle and stud kit for it and u should b fine

[Smoke Panther]

Re: 12 bolt rear-end

you're not in any danger of breaking a 10-bolt. Get the TA girdle and call it a day

[crushedout]

Re: 12 bolt rear-end

I broke my 10 bolt and my car is stock. If you plan on being hard and racing from a dig alot you may want to upgrade. But because of money you may want to wait to upgrade once you do brake something.

[greasemonkey]

Re: 12 bolt rear-end

If you actually plan on keeping the car for a while, upgrading and drag racing a lot, a 12 bolt will be needed sooner or later (but not for only 350 whp). However, I would spend the money elsewhere though, as having an upgrade that expensive won't even really show until you start making some serious power.

Also, sticks are much more prone to breaking 10 bolts, but an auto can too.

[99BlackW68]

Re: 12 bolt rear-end

so the general consensus is that ill be fine? this is really good news. its a stick too. yeah, i figure ill upgrade once / if it breaks. but if i did decide to do some upgrading for strength, what parts should i get? silverrs, you said a T/A girdle and stud kit, explain please.

[coolbet13]

Re: 12 bolt rear-end

these are the same thing just a lil cheaper due to it being the summit brand.....http://store.summitracing.com/partde...5&autoview=sku

[99BlackW68]

Re: 12 bolt rear-end

oh ok yeah i got ya. thanks a lot you guys.

[SilverRS96]

Re: 12 bolt rear-end

[QUOTE=crushedout]I broke my 10 bolt and my car is stock.QUOTE]
how many miles do u have on ur car and who drove it b4 u? im not gonna say that its not gonna break...but 350hp is not somethin that is gonna break a 10 bolt with a ta girdle on it

[coolbet13]

Re: 12 bolt rear-end

I broke my 10 bolt and my car is stock. If you plan on being hard and racing from a dig alot you may want to upgrade. But because of money you may want to wait to upgrade once you do brake something.

He is not the only one my car only had like 30k on it and I have broken two 10 bolts with just intake and exhaust once it split the whole diff right down the middle, the other time it killed the spider gears on the alburn style LSD now I have a Torsen no problems (yet)..... however a 5 speed car is much harder on the driveline.

[97rs4life]

Re: 12 bolt rear-end

what trans do you have?

350 wheel hp is gonna eat up a manual tranny faster than the rear. Also manual trans are harsher on the rears usually. but yea you don't need a 12 bolt for your goals

[tbird31]

Re: 12 bolt rear-end

if your car is automatic I wouldn't worry about it. if it's a manual then i'd keep it in mind but unless you're racing at the strip have fun on the street. our cars don't hook up with that much power anyways.

but 350hp is not somethin that is gonna break a 10 bolt with a ta girdle on it

ta girdles don't do that much to help. my buddy has a TA making 360 to the ground through a T56 and he snapped 7 teeth and the carrier...it'll happen...

[97rs4life]

Re: 12 bolt rear-end

if your car is automatic I wouldn't worry about it. if it's a manual then i'd keep it in mind but unless you're racing at the strip have fun on the street. our cars don't hook up with that much power anyways.



ta girdles don't do that much to help. my buddy has a TA making 360 to the ground through a T56 and he snapped 7 teeth and the carrier...it'll happen...

that is false about ta girdles not helping, they do help beef up the rear end. Anyone looking to make their 10bolt last longer knows to put a ta girdle on it

[crushedout]

Re: 12 bolt rear-end

how many miles do u have on ur car and who drove it b4 u? im not gonna say that its not gonna break...but 350hp is not somethin that is gonna break a 10 bolt with a ta girdle on it

She had some miles on her, like 150k, and about 80k were me. Most are highway with trips from Va Beach to Ohio frequently and then 1 hour, one way commute to work for a good bit. I was rough on her the first 2 years or so but when it broke I wasn't being hard at all, it was all the times before that had weekend the rear. Just saying if he plans on abusing the rear it will break. I've heard of pleanty of stock V8's breaking rears and they dont even have 300HP to the wheels and he wants 350 at wheels.