I put my car on a 2 roller (1 front and 1 rear) dynojet this morning. The first warmup/speedo calibration run gave the operator a PSM error and he backed off. We turned PSM OFF and tried a warm up pull which resulted in a snapped front (driver's side) about halfway up the rev range. I thought all I needed was an AWD dyno, but maybe there is something else required?? I don't know any better as I have never dynoed any car before. Anyway, super bummed on what I thought was gonna be a pretty cool day.

Anyone want to weigh in on this and drop some knowledge on your boy? lol.

 

That is bizarre. I did not think the viscous coupling could transmit enough torque to snap an axel. I won't even spin the wheels in the rain.

 

Nobody has dyno knowledge?

Please help so I don't eff this up again after I replace my axle.

 

Some advice I have read regarding dyno for our car is to disconnect the front diff. That is what I did.

 

i've ran on awd dyno with zero issues. Wonder if there was some kind of load resistance they had on the front roller

 

This is exactly what I think especially bc the PSM error. Do you recall how it was set when you did yours? Or what I should do next time?

The guy mentioned something about 15 load on both rollers to mimic the road but I'm not a dyno operator and have no frame of reference. I got the impression that he was unfamiliar with the platform unfortunately it all came together a little too late!

 

I don't unfortunately. I'd remove front drive shaft next go around. I'm RWD now so won't have an issue

 

I owned and operated an AWD Mustang dyno for years. May be a silly question but was the front roller disconnected? Was it wheel or RPM speed calibrated? Could have been the load settings. I had tons of AWD 911 turbos spin the rollers with zero issues.

 

UPDATED:
The front roller was NOT disconnected he had it running at 15% load front and rear. Both rollers were the same: 15%

He wheel speed calibrated it, which is when we got the PSM error. Then on the next run (first actual pull) the axle snapped at midrange.

Should he have totally disconnected the front roller? And just had the dyno on 100% rear? I'd love to give you a call if you've got some time today.

I wasn't planning to go back there,, but I still want to dyno my car. If I can't find a better option nearby, I might just have to go in there and tell him what to do next time.

 

He could have disconnected the front roller but not sure how Dynojet works in that regard with the front axle being connected. Do you just want numbers or does the car need tuning? Down here we have NUR performance and 5 bar motorsports that both have dynos.
I'm happy to chat and available most evenings - PM or e-mail me.

 

PM'd!

Im just looking for numbers. I had my car tuned by UWM via remote/logs about a year and half ago. Car runs great. People always ask me how much power and I don't really have an answer other than "supposedly around 500/500..."

 

I have a front axle shaft that I took the stub off at the hub end. The shaft is in great shape. PM me if interested.

 

I ordered a new genuine one (complete) last week Monday. $577 shipped from CA.

Thanks anyway

 

Here's the damage. It broke clean right at the neck-down portion of the shaft for the clamp of the inner cv boot. Luckily it didn't even scratch anything else when it let go. No collateral damage!

 

weird