Power limit of modded 10 bolt

[formula218]

At what point does it become more cost effective to start looking into other rear ends (ford 9" probably) rather than just beefing up the stock 10 bolt.

If my goals for the car are 500-600hp with 4-5 track days a year with sticky drag radials and the rest of the time just aggressive street driving/racing. Am i better off looking at a Eaton diff or is a 10-bolt going to be getting problematic at that point. I want something that's strong and i'm not going to be worrying about if i want to flog on her a little. Car only gets 3-4k miles a year.

[Jdseibe]

the problem with 10 bolts are that you can beef up every aspect of them.. but they will still have the weak ring gear. most people say that you will be fine as long as you don't plan on putting a sticky tire on the car.

[farmington]

If its a 4l60e car, a 10 bolt might survive. some seem to last while getting beaten and some don't. Any wheelhop will destroy one. Its a pity that GM didn't spend another $100 to put a stronger rear under these cars. Hard to justify spending $3k plus for a strong rearend for our cars.

[JoeliusZ28]

Autocross and track day use is VERY different than quarter mile.

Imo, you can do fine with a stock 10 bolt and a 6 speed at that power level as long as you set it up appropriately and arent doing standing clutch drops. The sticky tires will actually help keep it alive at the track because your posi wont get roasted trying to fight all the one-wheeling in corners. A TA girdle *with* gussets actually does a pretty decent job strengthening a 10 bolt. (Prevents gear seperation). i also would not use a gear bigger than 3.42 for pinion size. A strong tubular torque arm is also a must.

My 10 bolt has taken years of holeshots, power-shifting, auto-x drifting, and general abuse (on street tires) and i think the posi is going to be the first thing to die, the gears are still quiet. 10 bolts just arent meant for hard launches on sticky tires. I don't have gussets on mine either.

I know of two cars that had 500rwhp where the 10 bolt actually lasted a decent amount of time before they popped. Proper setup and knowing your limit is everything. Its not a dana 60, dont treat it like one.

[birdie2000]

I'm going through this right now myself. Used to be you could find used 12 bolts for $1500. Not so much anymore. At that price point I'd buy one hands-down.

I've more or less made the decision to beef up my 10 bolt. I'll probably have about a grand into it since I'm going to upgrade the axles too (already have a good diff cover) but it still beats the hell out of $2500+ for a decent aftermarket option considering it's 100% a street car and won't even have drag radials on it. Even at 500rwhp, it should hold up, and the quietness combined with the Torsen diff I have will suit my needs better than an aftermarket provided I don't grenade it. I actually have a spare Torsen diff lying around too, so even if I do grenade it it'll only cost me another few hundred to rebuild. I'd have to break the axle a few times to be close to what an aftermarket would cost.

That said, there's something to be said about not having to worry about it...

[formula218]

I'll probably be running a Nitto DR, No slicks. and it is a T56 car. I also got a Summit Diff cover on trade that i'll throw on, but i'm not sure how much good they really do or if they're a gimmick. I don't mind loud gears or losing some driveability for it to be strong, the car is already pretty unpractical.

[JoeliusZ28]

I think the diff covers help. Theyre cheap insurance but they certainly dont fix the problem. My car seems to "thud" less on a clutch drop with the cover on than it did before... Whatever that highly scientific data is worth, i have no idea. I have seen a car with a girdle and gussets rev-limiter launch on slicks all day at the track before it eventually broke... And it ended up the axles snapped instead of the gears so thats telling you the gussets did something as the weak point is usually the gearset.

[landstuhltaylor]

I wish I was allowed to use the pinion support covers but they aren't legal in the class I'm running. Putting a fresh gearset in my rear and using the originals as a backup. I'm really hoping I can at least get a full season of each set. Scheduled to run at least 24 full on drag launches on 315 Hoosier A7s this year, maybe a few more. The rest of the use will be normal autocross runs and street miles.

[BlackJesus]

So you build a 10 bolt ($200 R&P, $160 Cover, $80 install kit, $400 Tru Trac, $300-$400 Install). You now have $1100 into an axle that "might" last. If you break it all the parts you just bought are junk.

IMO just buy a used 9" or 12 bolt for around 2K and be done with it.

[birdie2000]

So you build a 10 bolt ($200 R&P, $160 Cover, $80 install kit, $400 Tru Trac, $300-$400 Install). You now have $1100 into an axle that "might" last. If you break it all the parts you just bought are junk.

IMO just buy a used 9" or 12 bolt for around 2K and be done with it.

I know this is probably directed at the OP but to play devil's advocate, finding a used 9" or 12 bolt for $2k that is fully functional, has the right gears already, has the desired differential (most at this price have a spool), is quiet, and doesn't require another $1-200 to ship (assuming the seller is even willing) seems to be a pretty tall order from my experience. Even more so if there are any other criteria involved.

All that said, I think everyone who does it knows it's a gamble. Either pay now or take the chance you'll pay later. For me, even though I may end up overall paying more if I have to upgrade eventually, I need a rear end now and at least this will buy me some time before having to come up with $2-3k. And you never know, it just might work out. It wouldn't be the first time.

[Jdseibe]

I've heard of people taking a ford 8.8 and having it modified to fit an fbody, I think this can be done for a good price too.. there are multiple articles on thirdgen.org about it.. an 8.8 isn't a terrible rear end either.. just something to consider.

[1BADAIR]

The drag radials are what will kill it. Slick would last longer imo. I have a 12 bolt and would never recommend one . 9 all the way

[pnyklr]

The drag radials are what will kill it. Slick would last longer imo. I have a 12 bolt and would never recommend one . 9 all the way

why wouldn't you.. I just got a strange 12bolt with a spool....but i would like a limited slip...know anyone?

[1BADAIR]

Moser now recommends a 9 over a 12 in a stick car too. If you launch hard enough the torque arm flexes the housing and pulled the pinion away from the ring gear. I've broke mine many times. Shattered an auburn diff in half , crushed the crushed sleeve , 3 ring gears , . Currently have a spool, custom solid spacer, and put an auto in it

[farmington]

S60 is the way to go. Heavy but STRONG and has a sturdier torque arm mount than the 9".