Stock propshaft strength

[TerryS]

Posted this on FB but thought I would try here as well to see if I get more of a response:

Out of interest, whilst it seems many high power cars (talking VT-VZ) use "uprated" propshafts, has anyone actually broken a stock one using road tyres?

[mfp4073]

I don’t think Monkfish ever recommend anybody needed to change a propshaft for a road car even with 600HP.
Obviously you would have to keep checking the centre bearing and the two rubber couplings at either end just in case
I would pm Wormus on this forum, I think he’s pushing 800HP+, he will have a ton of knowledge to share.
He’s also got one of the best high powered Monaro’s in the Uk.

[SturdyHSV]

TerryS said:

using road tyres?

I'd imagine this is the key point, any road tyres you could fit in the rear arches wouldn't be enough to break a prop I imagine, most likely just upgrade when the centre bearing goes, I know that's what I did, and it was largely just because shiny parts

[TerryS]

I think I will take my chances with the stock prop with new bearing and doughnuts, I will probably be traction limited anyway. I really don't want a single piece due to potential vibration issues. The DSS sell a 2 piece but it's over £1500 once in the uk.

[SturdyHSV]

I have a carbon fibre one peice from the DSS, it didn't vibrate at 150mph but I've only tested that once.

Sat on the dyno near the top of 4th it felt like it might have been vibrating a little bit, but I haven't sat in a car on a dyno before to know to be honest, I shall investigate in future once it's back on the road and in Mexico

[anonymous-user]

mfp4073 said:

I don’t think Monkfish ever recommend anybody needed to change a propshaft for a road car even with 600HP.
Obviously you would have to keep checking the centre bearing and the two rubber couplings at either end just in case
I would pm Wormus on this forum, I think he’s pushing 800HP+, he will have a ton of knowledge to share.
He’s also got one of the best high powered Monaro’s in the Uk.

Most kind of you to say so. Yes I still use the original prop with no issues at all. Driveshafts are a bigger problem, try to get some that use Porsche cv joints. Top Cats made mine.

[TerryS]

I am trying to source the correct GKN CV joints and cages if anyone has the details?

[TerryS]

wormus said:

Most kind of you to say so. Yes I still use the original prop with no issues at all. Driveshafts are a bigger problem, try to get some that use Porsche cv joints. Top Cats made mine.

What RWHP are you making now Paul?

[stevieturbo]

TerryS said:

I think I will take my chances with the stock prop with new bearing and doughnuts, I will probably be traction limited anyway. I really don't want a single piece due to potential vibration issues. The DSS sell a 2 piece but it's over £1500 once in the uk.

Just get one made locally ?

I got my shaft from IEDLS in the US...it was expensive.

Before that I had Carolina Driveline make me a 2 piece shaft, just a little smaller at the CB section than the IEDLS one, but it was very very reasonably priced.

In general, a simple steel 3" shaft with 1350 joints shouldn't be too expensive. Although a lot of the 2 piece tend to use generic centre bearings, as opposed to what might actually fit your car without any work.

I would assume the only slightly awkward part would be whatever flange is on the diff but I'm sure there are options for that

But locally, I had Dave Mac balance mine just a few weeks ago, they seemed decent. I'm sure they could make you a 2 piece.

[TerryS]

Stevie I am going to take the stock shaft to a propshaft specialist near me and see what they think.

[anonymous-user]

TerryS said:

What RWHP are you making now Paul?

just over 600.

[TerryS]

wormus said:

just over 600.

Nice Paul, any drivetrain failures?

[anonymous-user]

TerryS said:

Nice Paul, any drivetrain failures?

No, standard CV8 diff too, albeit with Harrop cover, Gforce drive shaft CV joints gave up early on, hence using Porsche 930 ones now. Drivetrain is pretty strong and of course, once you get beyond a certain power, it just spins the wheels.

[TerryS]

wormus said:

Gforce drive shaft CV joints gave up early on, hence using Porsche 930 ones now.

Out of interest do you still have the knackered Gforce drive shafts Paul?

[anonymous-user]

TerryS said:

Out of interest do you still have the knackered Gforce drive shafts Paul?

Afraid not, they went in the bin.

[TerryS]

Shame

[anonymous-user]

TerryS said:

Shame

They weren’t worth saving as there was play in the splines, they are pretty poor quality tbh.

[TerryS]

wormus said:

They weren’t worth saving as there was play in the splines, they are pretty poor quality tbh.

I have heard similar about their stub axles.

[monkfish1]

Both Harry and Jez's cars ran stock props. Though LS2/6.0 props with the bigger spider and donut.

Easy-ish to retrofit to LS1 cars.