I'll be looking at replacing my rear soon... I've just started putting power to it, and I noticed some unsettling noises coming from it. I just hope it holds out until I have the money to get a 12bolt or 9" setup.

 

Spending money on something that won't necessarily make me go faster is always hard for me to justify. Always has been, always will be. I have been racing on and off since 2002, it's the reason why my last 3rd gen wasn't painted but had a $900 set of rocker arms on it .

lol sorry but it's the truth. If you handed me $2,000 or whatever a nice 12 bolt or 9" setup would cost and told me to call up Summit and order it, somehow I would end up with a Procharger or Cylinder heads at my door

 

^^^truer words never spoken....i ended up doing some wheeling and dealing to get mine cause i wasn't going to spend cold hard cash on it....

 

Ha yep, that's how it is for most of us. Broke my 10 bolt pretty sure from the 1-2 shifts on slicks. 60 ft's were 1.8's in the past without a problem, then with more power and better trans and slower 60 fts it cracked pinion gear teeth on my last run down the track till she went on the way home rolling into it in 3rd gear.

 

I did about 10 sub 1.6 60fts with mine.

All I did was weld the axle tubes and rear diff cover.

That was on my 383 with a 145hp shot of nitrous.
When it blew, I just sold the diff cover. Don't spend money on a turd diff if you are throwing power at it!

 

ok im very confused by the 60' times i ran a 1.8 60' and only got a 16 second quarter mile time

 

That is a very good 60' for a 16 second car, it means you have great gearing and traction.

 

I like this thread!! I broke mine after about 20 passes goin 1.5x for 12.00 1/4 mile in my iroc. Put a little more power in the motor and it broke the auburn posi on the starting line...which also cracked the tailshaft of my th350. Haha

 

Just took my 2.73 4th gen rear out after 2 yrs of running 800 hp thru it. Been 1.49 60 and 9.73 at 142. Most were 1.5-1.6's but couldnt kill it. Thanks turbo power for being softer on rears

 

Mine survived 7 sub-12 second runs, not nearly as much as Orr's! I'm pretty sure the 2.73's with the larger pinion gear add a little bit of strength. If your carrier is stronger than your gears, it seems the pinion gear is usually the weakest link. After cleaning out the debris I bolted the tru-trac to another ring gear and swapped the pinion it's still working great.

 

I broke mine once and didnt look back. Was lookin for rears and found a whole new 8.50cert chassis for price of a rear. Lol

 

I've run 11.9's consistently for the last couple of months with 1.62-1.65 60 foots almost everytime and my rear has yet to break. But i would be lying if i said it wasnt in the back of my mind that its going to blow every time i stage. lol

 

I'm curious to see what I can do with my 10 bolt. Only running a diff cover in my 85 IROC with 3:42 factory gears and LSD on stock IROC wheels wrapped in Mickey Thompson ET Street Radial TireP255/50R16 (26'' x 10.5'' - 16'') on 11psi foot braking to 2500 rpm and pulling 1.8 60 foots spinning off the line and running 7.70 in the 1/8 at 95 mph and finishing the quarter at 11.7 @ 120 mph. Car has KYB AGX all around and I didn't even touch the settings or the S&W torque arm. I'm gonna drop in the famous moroso trick springs, remove front sway bar, remove the OEM Conteur sears front and back and put a pair of kirkeys only. Along with some weld runners and 275/60/15's and some 3:73's and hope for a low 11 or high ten naturally aspirated. I'm crossing the finish line at 4800 RPM in third. I need more gear! By the way it's powered by a solid roller 406 on c16 RMVB TH400 through open hooker super comps but I'm going to run some bullets right after the collector dumped.

 

You just contradicted yourself, though it seems you don't realize it: The 28" tires will effectively cancel out the 3.73:1 gears. Either keep the 26" tires, or go on up to 4.10:1 gears.

 

Well, an update. I ran the car for the final time yesterday. Made 6 passes all with 1.44x 60' times running 10.74 and it didn't break....yet. Looking through my logbook I made 70 runs this year all with 60's in the 1.4's. Just lucky I guess. Should have the funds for a nice 12 bolt for next season though.

 

So true.

 

while the effective gear ratio will be the same, the longitudinal contact patch of the tire will be larger, making it easier to 60' without breaking the tires loose.

this is the same reasoning behind Stock elimninator guys running a 30x9 and a 5.13:1 gear even though a 4.56 and a 28" tire would be basically the same thing.

 

Gotta know the math Can't just guess while thumbing through a Summit catalog on the pooper.

 

i will say, that in my experience with the 10 bolts, i wouldn't go with anything numerically higher than a 3.73 in a car with any sort of decent power. the head of the pinion gets really small, and though a solid pinion spacer can help keep things together longer, it's only a matter of time before you rip the teeth off that baby pinion gear.

a 9"/12bolt/s60 really should be the first thing done to these cars after a set of sfc's...then there's no worries

 

1.625 60' ft @ 2870......didn't break, got lucky (3.73)

car was setting and when I checked....well, now there is a 9" under it!


Check sig....

 

PowerTrax Lock Right Locker...Has anyone ever used this? If so how did it hold up???THX...Joe