rally car snapping shafts, what are my options?
 

Hi Guys


I keep snapping rear shafts in my rally car and would like to upgrade them to prevent this happening again. The car is a classic, tarmac car using R180 rear diff, hubs and shafts. DCCD set to open. At the last event I basically got the tyres warm and snapped one, then got aloud out to play later in the day and exactly the same thing happened again. It happens when the wheels spin and then grip, then a shaft lets go, always in second gear.


Here are some pictures, this is typical of every shaft I have broken:


Attachment 46102


Attachment 46103


Attachment 46104

I have done some research and found several different options:
GKN ~ £1200 each. pretty much indestructible
Driveshaft shop ~ £650+ postage and tax from America
DJM ~ £400, no CV joints. 30% stronger material


Does anybody have any experience with any of the above manufacturers? Or can you recommend somewhere else?


Cheers
Tom

have you seen the ones boosted made for his car?
https://www.scoobynet.com/projects-4...12-second.html

his whole setup is pretty unique but might give you some inspiration?

HI
Looks like they are snapping on the undercut , was having the same issues with my old Golf , every event I was snapping them , even taking care on bumpy bits.

Tried Drivelink shafts , cost me £900 odd quid for a pair of shafts with inner and outer joints , and a full set of spare joints , snapped them on the first event , they couldn't understand why , made me another pair of shafts F.O.C and they snapped on the next event.

Was told about Berrisford who advertise there shafts as guaranteed unbreakable , gave them a try and never broke one since

http://berrisford.co.uk/index.php/driveshafts.html

Very sensible costs as well , give them a try , my son also had them made for his 205 and they were perfect on that as well

Send them shafts and joints to copy the bars , they make the splines so they bottom out on the splines in your joints so no need for lips or undercuts on the bars which usually ends up a weak spot, and they make them to order , takes about 4 weeks

Cheers Ian

Hey Ian, thanks for the reply
On the golf or WRC?

I haven't seen this thread, i'll have a read through when I get a minute, thanks for the link

I feel your pain 😂😂😂
The problem arises with factory shafts, the cost to manufacture them was as cheap as subaru could do it, also age plays a part on shafts now. Apparently they should only ever transmit power in one direction too (maybe an old wife's tail) so OS and NS shafts to remain on said sides.
The Berisford shafts are probably your cheapest and easiest option, the joints are unlikely to fail.

These were for my golf , 250hp through the front wheels , Berrisford ones were great.
My WRC car has the same Prodrive ones on , apparently they don't break either , only done an outer CV cage on the Impreza so far , outer joints are £700 each though !

Thanks guys

Did you go for solid or tube type?

I'm lead to believe gun drilled solid from 4330 material is the strongest. You are unlikely the get this though.
Berisford will use a heat treatable steel and actually roll the spines on rather than cut them, then heat treat them.
I made mine from 4145 steel, machined the splines, no heat treatment.

I just got off the phone to Berrisford, for those interested,
The material they make shafts from is 300M http://www.suppliersonline.com/propertypages/300M.asp
The shafts are £160/each+VAT
They haven't seen any failures from the rally cars they have supplied
They don't recommend 'gun' drilling

Much cheapness

They are , for what you get they are very cheap , I was very dubious , but having tried them myself , and now know of many others using them , I won't go anywhere else

Still faaaaarrr too dear for me 😂😂😂

I think that's pretty reasonable! But how the hell do you get your rally car to spin in 2nd? Is it on 102 octane? Mine does not do that :(

my rally car spins in second as well lol

I thought that was ian replying- fancy sharing?! lol

Lots of engine mods and yes was using 102. Had about 450lb/ft torque, the next car should have more 😁