so who has managed to break a sideshaft or cv joint ?
 

just trying to figure out how strong the sideshafts actually are ? so has anyone broken the actual sideshaft between the inner and outer cv and has anyone broken an oem cv joint ?

i have seen the diff carnage so the cvs and shafts are stronger but how much stronger than the oem diff ?

if you have broken the sideshaft or cv post up how and at what power

I think I remember Fab9 breaking an axle at the drag strip on drag radials with a little over 300whp, but that's the only person I remember posting about it. I've made probably 10 drag passes below 12.5 on street tires and tons of launches on the street without any issues into the low 300hp range. Interested to hear what others had to do to break them.

I've now broken a handful of CV shafts on the car. Hard shifting, launching and wheel hop will kill CV's. Either buy some upgraded units or leave that as your drivetrain weak point to spare other, more expensive components. They started to break in or around the 330whp area. One launching the car, two of them were flat shifting into 3rd and the last one was accelerating in 3rd over a crack or bump in the road.

The car is now just under 500 wheel and I'd much rather go through CV's than a gear set.

Shit, really?

Yeah just went through another 6 speed this weekend :crx: - days before my dyno appointment.

I think it's time to dial it back and be happy with things.

They break at the strip with radials, even on cars as low as 200-ish whp.
I went with a MSM diff/axles, which are slightly larger. I can't tell you if that helps or not in reality.

If you're not on radials, you probably will never have a failure.

damn - i was hoping they were tougher
how do the v8 swaps get away with running oem outer joints and stronger inners

what actually breaks on the miata sideshafts/cvs
the shaft ?
the cup ?
the tripod ?

fab are you on std shocks or coilovers ?

Each time the failure has been the spline coming off the outer yoke. I'm running HKS coilovers, not intended for launching the car.

i've blown the Ford inners 4 times now.

ok so FAB its probably wheel hop that killed them
and if the ford inners are blowing up too
is the expensive driveshaft shop axles the only option ? or are those just rebadged oem cvs ?

I've help replace 4 drivers side axles on a 160hp N/A car on slicks. Kept shearing off right where the CV splines start on the outer end of the shaft. Wouldnt even move, go to launch, bang car doesnt even creep an inch. Fixed some weird suspension binding thing and its all good now.

I havent broken one yet but I think thats because I always pack a spare and my trailer has a winch on it.

If I ever get a beefier tranny that I wont be breaking with more power, then I'll just throw in an MSM torsen and use MSM axles.

Miata2fast has broken several while naturally aspirated launching on slicks at the drag strip. He determined that the failures he was having were from the shaft and joints not being in line with one another. It will not take as much abuse if the bend angles of the CV joints are more than a few degrees. After he got the ride height issue straight then they stopped breaking.

Out of curiousity, are you talking about a Mazda diff, Ford 8.8 IRS or some Ford/Mazda hybrid axle thing?

He has a v8 swap so probably the ford 8.8. Cant you get some stupid strong porsche cv units built for that?

The DSS CV's are not rebadged. I sell these regularly and if you go through a set (I have not had a customer do so) - they will replace it.

They aren't cheap but it's something you likely won't ever need to think about again. If you do decide to go this route send me a note and I'll see if I have any room to play with.

Found some pictures of the carnage...

https://www.miataturbo.net/attachmen...ine=1409952913
https://www.miataturbo.net/attachmen...ine=1409952913
https://www.miataturbo.net/attachmen...ine=1409952913
https://www.miataturbo.net/attachmen...ine=1409952913

Im on my 5th axle in 3 months... I'm trying to figure out what the hell is going.

https://www.miataturbo.net/attachmen...ine=1411953857

ride height?

10.5 from hub to fender

pinch weld?