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Prop Shaft - Single or 2 Piece
Posted: Sun Feb 15, 2009 7:03 am
by r2d2hp
Need to get a replacement propshaft and was wondering if I should just have my 2 piece modified or have a single piece made up
Anyone know the the Pro's and con's of each?
Posted: Sun Feb 15, 2009 10:17 am
by Coops
i stayed with my 2 piece mate and had no probs,
propshaft services made me a new 2 piece one in feltham,
Re: Prop Shaft - Single or 2 Piece
Posted: Sun Feb 15, 2009 11:34 am
by stevieturbo
r2d2hp wrote:Need to get a replacement propshaft and was wondering if I should just have my 2 piece modified or have a single piece made up
Anyone know the the Pro's and con's of each?
What car, what drivetrain, what are youre requirements ?
How much room in the tunnel ? Fixed rear diff, or one that moves ?
There are lots of things that dictate what can be used.
Posted: Sun Feb 15, 2009 3:09 pm
by r2d2hp
Thanks Tony
Stevie, its a Mk1 V8 Capri, T5 box, leaf springs and Atlas Axle. Only used on Road and maybe track days.
Posted: Sun Feb 15, 2009 3:22 pm
by stevieturbo
There is already a slip yoke at the front...so that allows a 1 piece ok.
Diff ratio ? potential shaft speeds ?
Again...long 1 piece shafts have rotational speed limitations. Although also have the potential to be stronger, and of course lighter than a 2 piece.
The longer the shaft...the slower it can spin before trouble.
I'd say you'd be fine either way though. A 1 piece could likely be cheaper and stronger, hence some people favour them.
In cars with potential for high propshaft speeds...and a very long overall length. Sometimes a 2 piece is the only option, aside from carbon fibre etc.
In my case...for all these reasons, a 2 piece was my only option
Posted: Sun Feb 15, 2009 6:39 pm
by r2d2hp
Hi Stevie
Its a 3.09 diff, prop length is 114.5 cm, 15"wheels, tyres 245*45 and engine is currently around 320 bhp on 3psi boost
So if the tunnel will allow shall I go for single piece prop?
Posted: Sun Feb 15, 2009 6:59 pm
by stevieturbo
A 45" long steel shaft, 2.5" diameter can safely spin to about 8800rpm....
That's enough for 200mph on your setup.
2.0" steel would drop that to 7000rpm shaft speed, circa 160mph
2.25" steel 8000rpm, circa 180mph
That's actual tube length as far as I am aware...so if its 45" overall...flange to box, then potential speeds could be higher.
Critical speed.
http://en.wikipedia.org/wiki/Critical_speed
Posted: Sun Feb 15, 2009 7:08 pm
by r2d2hp
Many thanks for the reply Stevie
Posted: Sun Feb 15, 2009 8:14 pm
by r2d2hp
Been out to me shed and found a 2.5 and 3" dia single prop so just need to get shortened and correct yoke fitted.
45" was from Diff flange to end of tail shaft so the tube is about 39" long so will go with 2.5" dia shaft.
Just need a yoke to fit TVR T5 box, anyone have one spare?