How long will stock axles live?

DAKDOG99

New Member
May 29, 2006
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COLUMBIA, S.C.
Going to the track tonight to try out the nitrous. It's set up for a 100 shot. I am a little worried about the stock axles. Anyone know how much power the stockers can take. I did put a girdle on the rearend and 3.73 motorsports gears. But axles and diff. are stock.
 
I made probably 50 passes last year on a 125 shot on my Nitto dr's and no problem. This year I put some ET street radials on and it snapped the drivers side axle on my 10th or so pass. I have a 5 speed car with 4.10 gears also. With the auto, like stated above, you should be okay but theres always a chance running the stock axles.
 
I made probably 50 passes last year on a 125 shot on my Nitto dr's and no problem. This year I put some ET street radials on and it snapped the drivers side axle on my 10th or so pass. I have a 5 speed car with 4.10 gears also. With the auto, like stated above, you should be okay but theres always a chance running the stock axles.


I think I am going to upgrade to a 31 spline cobra diff. and some usa alloy axles. No reason to take any chances.
 
I think that is probably a good idea. If you can get it to hook when leaving with N2O the axles will see a lot of stress. It is really the amount of torque not HP that is the problem. Here is a computer simulation of a stock engine with a 100 HP shot of N2O.
Stan

nitr-hp2.gif
 
You'll be fine. It's when you start hooking hard and dumping at 5K that you have to worry. Your posi will burn out before your axles go.

My buddy just called me and told me he pulled his left front wheel off the ground last night. He launched his auto car at 3K with VHT and 315 Nitto's and got it to lift. He is still on stock 28 splines. We'll see how long that lasts.
 
It's funny how an NA stick car with gears and less than 300hp can break an axle, but others running deep 12s with power adders are just fine. It all comes down to shock loads. An NA car will need lots of revs to launch hard out of the hole and that causes a pretty significant shock load. So bye bye axles. The power adder cars can use their low end torque to get moving from the hole, which interestingly isn't as hard on axles as the high rpm launch Of course, automatics are much softer than a stick and a true slick deforms to reduce shock loads, while a drag radial causes more shock loads (given similar 60' times). So there is no set rule to know when you need 31 spline axles. If you are launching at high rpms or running better than a 1.7 60' time, you should probably be shopping though.

As a funny example, my stock 97GT on street tires ate a pinion bearing of an 8.8, but my 2.3 with 20psi and nitrous has gone 12.2 on a stock 7.5" rear end. Well, the 97 is a manual and saw high rpm launches. The 2.3 has an auto and lots of torque to get the car moving without rpms. Not much shock in the driveline when I launch, so that poor 7.5 with more than 140k miles is still alive. :rlaugh: