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Ok people I have a huge problem with the mx5 rear end....

I have a borg warner, full spool diff, larger axles, CV's and Billet stub axles.

Now I have gone through 3 sets of these and keep on snapping them.

Does anyone have any suggestion on what I can do to get better stub axles on this.....

Anyone ever put a live axle diff on an mx5 (I know it will ruin the cornering etc)

Help....

If you are serious about your 1/4 miles (which I think you are), you surely must be considering a shortened 9 inch diff. It would be the ultimate solution by the sound of it.

CT wrote:If you are serious about your 1/4 miles (which I think you are), you surely must be considering a shortened 9 inch diff. It would be the ultimate solution by the sound of it.

Yes, the problem with that is there isnt really anywhere to attach it to..... My mechanic has said that it will rip the floor out when I launch and I would need to put a new chassis in to hold it under the car....

Im now thinking of changing the hubs to commodore ones which would hopefully take a larger stub axle.

A new rear chassis would be absolutely essential for a solid rear axle. Not that hard to do, but could get exxy. You said you are using a borg warner diff, 8inch I assume - explain your full setup, are you using the MX5 axles and hubs with a borg warner? What about a hydratrac conversion? Shouldn't be too hard as the bullet guys have done it. Plenty of good bits around for them as well. Have you spoken to someone like Sydney Competition Warehouse?

I have the 8 inch borg warner commodore diff, with a mini spool. Diff is great and have no problems. I then have commodore size billet axles made up with commodore CVs. I then have custom billet stub axles which go from the commodore CV into the mx5 hub. It is this Billet stub axle that is twisting then snapping.

I need to get a bigger diameter stub in the hub but im not sure that is possible with the stock hub.

Have not spoken with sydney competition warehouse..... What do they do?

nfs - I'd be talking to the guys at Sainty Engineering at Wentworthville. They are one of the best engineering firms in town and know all about drivetrain design for drag racing. If they can't fix the problem they'll know someone who can.

SCW used to tbe the rear end drag racing specialists. I have no idea if they are still around but I'd suspect they are. They used to do lots of custom axles and housing plus nice floating hub from romac etc. Worth a phone call at least.

there are a small handfull of guys in america running a complete RX7 drivetrain... these guys are running 9sec MX-5s. do a search on google and ya might be able to find one of there sites. they have all the info you need to know.