my h165 lasted two seconds behind my supercharged A12, and that was on dirt at a motorkhana with bald 13in tyres. the funny thing is i've now got a vanette diff thats locked and it's lasted four so far. unlees i had a boggey h165 to start with. have fun at the drags.

i run a locker in my 1000. i'm pretty sure it's the stock diff but is been going great guns. i've only got an A12 infront of it but the stress on the axels should still be the same right? if it is the stock diff its the H145 right.

Nah, the stress will be very different. The A12 puts out considerably less torque than an A15 or a supercharged engine.

And a "worked" A14 may put out less torque than a stock A14.

Remember, 100 HP at 2000 rpm results in more torque than 250 HP at 6000 rpm. And torque (twisting force) is what breaks axles, diff gears and transmission gears.

the same 'forces' im talking about is the ones that broke all of my mates axles..... the ones when you roll around corners in car parks thats when (in my experience) most axles get snapped. digg?

I think you are talking about the tire-scrub forces. Which don't apply to regular differentials, but would with a locked rear. Doesn't this simply put more "traction" on the back tires?

In any case, it's still the torque from the engine, multiplied by the transmission gears, then multiplied again by the CWP/Ring & Pinion, that breaks the axles.

I reckon when both tires are spinning, they are really quickly gripping, then slipping, then gripping, etc, causing extreme shock to the drivetrain.

Bart if you blow the diff on the line I will be most dissappointed, as I want to see what time you can do. As I have been for a very fast ride with you I think that you know how to handle your self on the line, just do let the red mist come over you. Good luck!!!!!

yeah, I'm really keen to see you go well at the drags too. Good luck mate!

for what its worth, I'd weld it up if it was me. The initial load at the start line won't be any different to what it is with the open centre. Because even with an open centre torque is always transferred 50:50 to each axle, its just limited by the the wheel with the least traction. So the full load is being transmitted to both axles anyway until one wheel starts to turn faster than the other.

Bart,
When is the next drag meet? I think that you would be much better to run the Yoko A008 RS's that I think I can get hold rather than some old, hard slicks that will require bulk abuse to get some heat into.
Remember too that you have got an engine that will pull like crazy as soon as you snap the throttle open so why not do a couple of runs first by just letting out the clutch at say 1500 then floor it once your're moving? Infinetly easier on the drive chain and at least you should get some idea of what she'll do before you run the risk of destroying the back end.
Re all the comments on the H145, well all I can say is that (touchwood) I've run the same back end ( H145 ) for 13 odd years and that includes plenty of circuit work with a fairly healthy 1400 that was( until the new head went on) producing 100 hp at the wheels and no problems. I must say that I NEVER abuse it off the line. I guess alot of it comes down to how much sympathy you wish to extend to your drivechain.
Cheers
Dave