Driveshaft toughening

Author
Discussion

db484bhpv8

Original Poster:

8,655 posts

219 months

Wednesday 7th January 2015
quotequote all
Ive managed to snap a few driveshafts in my IRS TVR Chimaera.
I am a regular at the drag strips and use Mickey Thompson street radials and nitrous oxide.
So i have plenty of grip and power but the standard driveshafts cant take a full power launch.

I approached Dave Mac to have a pair of so called indestructable ones made up but the quote was twice that i expected.

Are there any other manufacturers? Or maybe I could get my current shafts heat treated in some way.

All ideas appreciated. I need to get this sorted before the first race meeting at Easter.

PhillipM

6,515 posts

188 months

Wednesday 7th January 2015
quotequote all
What kind of price?
£2-300 per shaft for hardened S255 is about par for the course for ours, albiet they're pretty long (30"+) and have 6" of spline engagement on the CV's to cut.

db484bhpv8

Original Poster:

8,655 posts

219 months

Wednesday 7th January 2015
quotequote all
PhillipM said:
What kind of price?
£2-300 per shaft for hardened S255 is about par for the course for ours, albiet they're pretty long (30"+) and have 6" of spline engagement on the CV's to cut.
The shafts were quoted at £295 each + VAT so not far from that i guess.
There were also 4 CV joints at £49 + VAT each so the bill came to £943 + delivery.

I am considering trying cryogenic treatment of my current shafts

andyiley

9,106 posts

151 months

Wednesday 7th January 2015
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Simple maths will tell you if that is worth it, but it doesn't sound like a lot to me.

How many have you broken at what cost?


stevieturbo

17,229 posts

246 months

Wednesday 7th January 2015
quotequote all
Is it just shafts or joints that are breaking ?

And £300 each isnt that dear really for custom pieces.

You could try GKN, DJM Motorsport, Driveshaft Shop ( US )

Are they Ford Sierra fitment ? different ?

Tango13

8,398 posts

175 months

Wednesday 7th January 2015
quotequote all
£295+vat for a drive shaft is a bargain!

Your not buying a pair of driveshafts, you're paying for the hard earned knowledge of many skilled men to work some bloody expensive machinery, heat treatment, tooling costs, inspection and the purchase price of the original steel bar etc etc.




PhillipM

6,515 posts

188 months

Thursday 8th January 2015
quotequote all
Cryogenic treating of your OE driveshafts is quite probably going to do something between very little and nothing at all.

anonymous-user

53 months

Thursday 8th January 2015
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PhillipM said:
Cryogenic treating of your OE driveshafts is quite probably going to do something between very little and nothing at all.
And in fact, depending on the failure mode, may make them "weaker"..........

Richyvrlimited

1,824 posts

162 months

Thursday 8th January 2015
quotequote all
How tough is the Chimera's diff/gearbox?

I'd personally be worried that you're moving the weakest link to a far more expensive component.

Megaflow

9,347 posts

224 months

Thursday 8th January 2015
quotequote all
Richyvrlimited said:
How tough is the Chimera's diff/gearbox?

I'd personally be worried that you're moving the weakest link to a far more expensive component.
This.

Standard driveshaft are reasonably cheap and a good insurance policy against breaking something much more expensive.

db484bhpv8

Original Poster:

8,655 posts

219 months

Thursday 8th January 2015
quotequote all
Its the standard TVR driveshaft that i have been breaking. Luckily i have managed to find replacements for beer tokens upto now.
I have over 500 bhp at my disposal with the nitrous but can only give the launch a 'blip' of stage 1 in first gear. Probably about 350bhp, anymore breaks the shaft. Once away and into 2nd its fine. I have all the grip i need if i smoke the MT radials. So now i just do a mild burnout and all is fine. I can run 1.70 to 60 foot but know the car is capable of 1.5's

The BTR diff should be strong enough to cope at this level.
The T5 gearbox could be the weak link but has some modifications and is healthy at the moment.

I have ran 10.89 @ 129 and the aim is to try and get down to 10.60 to take the current TVR record which is held be an LS3 powered Cerbera.
I believe i can get there with the harder launch.

NormanD

3,208 posts

227 months

Thursday 8th January 2015
quotequote all
db484bhpv8 said:
Its the standard TVR driveshaft that i have been breaking. Luckily i have managed to find replacements for beer tokens upto now.
I have over 500 bhp at my disposal with the nitrous but can only give the launch a 'blip' of stage 1 in first gear. Probably about 350bhp, anymore breaks the shaft. Once away and into 2nd its fine. I have all the grip i need if i smoke the MT radials. So now i just do a mild burnout and all is fine. I can run 1.70 to 60 foot but know the car is capable of 1.5's
How about not using Nitrous in fist, just to get the car rolling then nitrous from second gear onwards

Could find that even quicker as your not just burning rubber off the line

db484bhpv8

Original Poster:

8,655 posts

219 months

Thursday 8th January 2015
quotequote all
NormanD said:
How about not using Nitrous in fist, just to get the car rolling then nitrous from second gear onwards

Could find that even quicker as your not just burning rubber off the line
If i do a decent burnout then there is no wheelspin whatsoever from the line no matter how much nitrous i try and introduce.
I have found the point which i can launch without breaking a driveshaft but this isnt good enough. Hence stronger shafts required.

stevieturbo

17,229 posts

246 months

Thursday 8th January 2015
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Nike....just do it.

PhillipM

6,515 posts

188 months

Monday 12th January 2015
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Makes you wonder if it's the shock loading from the launch combined with 1st gear torque rather than just the torque alone, in which case some torsion bar type shafts might not only stop you breaking them but also help the diff/box out, rather than the opposite.

turbonutter

496 posts

207 months

Saturday 17th January 2015
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Have you tried Launching in second gear - or is that not an option due to the ratio being too high....

db484bhpv8

Original Poster:

8,655 posts

219 months

Sunday 18th January 2015
quotequote all
turbonutter said:
Have you tried Launching in second gear - or is that not an option due to the ratio being too high....
I now have a 3.08:1 diff and the car hits 75+ in 2nd so yes a little long geared.

andygtt

8,344 posts

263 months

Tuesday 20th January 2015
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are the TVR stock shaft not sierra items?... if so they MAY be the same as the GKN Ultima ones.. and surely there are upgraded sierra cossie items available?

Saying that the sierra didn't really ever have the kind of traction you have.

My stock ford shafts for my noble are £400 plus vat each so I kinda feel your expectation of cost may be out of align lol

PhillipM

6,515 posts

188 months

Tuesday 20th January 2015
quotequote all
If they're the 108mm PCD type sierra ones (?), just buy some Porsche 930-style joints and shafts, they use them for all sorts of offroad buggies in the states (it's what we're using), so you can can get a wide range of shaft lengths to suit and they're available in 300M material straight off the shelf, you can get tougher CV cages too.
I've an old set here but at 24" long they're probably too long to give them a try to see if they bolt up ok, they should do, the joints are very similar.

Edited by PhillipM on Tuesday 20th January 16:17

plasticman

897 posts

250 months

Tuesday 20th January 2015
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I think you will find Topcats can supply an uprated driveshaft