has anyone broken a tailshaft on a dyno??? at either full rpm or at back off just after full rpm runs????? if so what would cause this?? cheers brett oops sorry about the spelling

where did it break and what gearbox are you using? is it 2 piece or solid

Paul showed me the pic of the tailshaft, that's seriously ***ed up haha.. Going of the pics it's a solid 1 piece! Twisted like a banana!

yeh is a one piece unit . unsure of wot broke first ,think it was rear uni yolk. car is manual mx7 running borg warner diff(standard style 3.45:1) with ef falcon flange.

mmmmm that is very weird the only thing i could have though could have been the case was no spacers in the gearbox mount causing stress on tailshaft but that a wild guess ---------- Post added 25-09-11 at 21:32 ---------- however i have heard alot of stories of 1 piece tailshafts twisting and snapping on on vehicles but i dont know why they do it

have 20mm spacers and the diff pinion angle looks good too . thinking of putting solid upper trailing arm bushes in??? the back off on the dyno with a manual might be more severe than that of an auto???? going to go another one piece and bigger tube and 2 tailshaft loops .

yeah might be your best bet but i cant see how the back off would be harsh because the wheels are still turning its not like its a sudden stop got any pics of the tailshaft?

do have pics but do not know how to post ??? well with the car strapped really hard and the dyno brake engaged for the power run?? how much load is on the rear when the dyno brake is engaged????

If you want to post pics upload them somewhere like photobucket.com, and then post the [IMG] [/IMG] link it creates for you here. Otherwise email them to [email removed] and I'll post them for you. Quite interested in this. So you have a single piece with 20mm spacer onto an EF flange, MX7 and stock BW78?

the diff is as strengthened as possible ,full spool 3.45:1 gears 31spline dutchman axles and a rear cast cover plate with load on carrier bearings. the spacer is to lower the gearbox mounting point to help the pinion angle. spacer is between chassis rail and gearbox crossmember. will send you the pic now. cheers brett