Uas One Piece Tailshaft

[Greg]

At the top of the page: http://nismo.com.au/pricelists/pricelist_skylineclutch.htm

I'm thinking of getting one of these, wondering what is involved to fit it, and if anyone has used this one specifically and your impressions

Thanks

Greg

[predator]

Looks pretty good to me.. And good price.

Wonder how it would go with a lightened flywheel? Surely it would have to reduce the rotating mass by a significant amount.

Wonder if it has any possible downsides?

[Kinks]

the purpose of a flywheel (apart from giving the clutch a surface to push against) is to smooth out the power pulses of the engine. lightening the flywheel will increase noise, vibration and harshness (NVH) - but the engine will rev better as it doesn't have to put energy into a heavy rotating mass.

a one piece tailshaft wouldn't reduce rotating mass by much, because inertial effects of mass are proportional to the distance from the axis of rotation. Because a flywheel is large diameter changing its mass will have a bigger influence.

The links in a tailshaft are also designed either to improve ground clearance or to reduce vibration, so although a 1 piece will be stronger (fewer CVs/unis to break) NVH will suffer.

[predator]

a one piece tailshaft wouldn't reduce rotating mass by much, because inertial effects of mass are proportional to the distance from the axis of rotation. Because a flywheel is large diameter changing its mass will have a bigger influence.

That makes sense. How would the gearbox effect things? would a lightened tailshaft reduce any strain on the workings of the gearbox in turning the input shaft ?

[Russco]

Having had a one-piece tailshaft on an R32 I would not recommend this option to anyone. Total bitch to get balanced, suffers from a high speed vibration that even the experts can't fix. Going back to a 2-piece shaft.

[Kinks]

^^ really.. after i had issues with my 2 piece blowing up, getting the CV replaced, having vibration issues, getting the centre bearing replaced (mech's idea), still having vibration issues, getting the tailshaft rebalanced (mech getting desperate), and having the tailshaft expert say both shafts were bent and the unis should also be replaced - and STILL HAVING VIBRATION ISSUES I gave up after a few hours rooting around with a hose clamp doing DIY balancing fixed 90% of the problem. My next step would have been a 1 piece but I sold the car and bought an R33 instead

I came to the conclusion that tailshafts are a black art. After reading up on the net about balancing them and how unis should always be angled (ie tailshaft never in a completely straight line) and unis being installed out of phase with each other and so on... fark there's a lot to know and you REALLY need to know your stuff to be working on them.

That makes sense. How would the gearbox effect things? would a lightened tailshaft reduce any strain on the workings of the gearbox in turning the input shaft ?

no. the torque on the gearbox's input shaft is transferred to its output shaft via the gears. the output shaft doesn't give a rats whether it's accelerating an exceptionally heavy tailshaft and a light car, or a light tailshaft and a heavy car. Both instances just act as a torsional force resisting the torque applied by the gearbox output shaft.

[Bl4cK32]

Having had a one-piece tailshaft on an R32 I would not recommend this option to anyone. Total bitch to get balanced, suffers from a high speed vibration that even the experts can't fix. Going back to a 2-piece shaft.

i run an alloy 1 piece in my r32 in between a rb25det box, and a nismo gt pro 2 way diff. Never had any problems with vibration at any speed.

[Kinks]

a 1-piece tailshaft should be easier to balance because it doesn't have an extra joint in the middle.

[Russco]

a 1-piece tailshaft should be easier to balance because it doesn't have an extra joint in the middle.

That's what I originally thought as well but the tailshaft place said they are harder to balance than a 2 piece as 2 piece shafts are much less prone to high speed vibration due to the shafts being unequal lengths. I still managed to bend my 3.5" chrome-moly one piece shaft at the drags (400rwkw + slicks running though the rears). I have spoken to a heap of guys who have had 1 piece shafts fitted in VL's and Skylines and with the exception of Bl4cK32 everyone of them had vibration issues - most went back to a 2 piece. A 2 piece shaft is less likely to kill you if it fails (unless you're running a tailshaft loop on your one piece). But if anyone wants to buy a cheap custom one piece shaft...............

[Kinks]

2 piece shaft is less likely to kill you but you're in for an interesting ride if the CV in the middle lets go!! (I thought I was going to lose a few fillings when the one in the R31 went).

the 2-piece was designed for less vibration but I always saw it as an extra part that could be f**ked up... lol

[r33_racer]

Ive been told the samething about 1 piece shafts being harder to balance. Two piece shafts having the centre bearing not only make it stronger, but take any drivetrain misalignment out in smaller amounts by having two shorter shafts they are less prone to wobbles or vibrations because they dont cover any long distance. However they all should be balanced with counter weights after they are done. Depends who you goto as well. We had our first tailshaft rebuilt by one shop(wont say) who used dodgy unis and couldnt balance a tailshaft if their lives depended on it. So after i spat that one out, we went to Hardy Spicer and they made us another one and its been absolutely perfect with no vibrations and no tailshafts spitting out chromemoly shafts are expensive as cost about 2g. Wouldnt want to be spitting them out in a hurry all the time.

[`nigno]

the purpose of a flywheel (apart from giving the clutch a surface to push against) is to smooth out the power pulses of the engine. lightening the flywheel will increase noise, vibration and harshness (NVH) - but the engine will rev better as it doesn't have to put energy into a heavy rotating mass.

a one piece tailshaft wouldn't reduce rotating mass by much, because inertial effects of mass are proportional to the distance from the axis of rotation. Because a flywheel is large diameter changing its mass will have a bigger influence.

The links in a tailshaft are also designed either to improve ground clearance or to reduce vibration, so although a 1 piece will be stronger (fewer CVs/unis to break) NVH will suffer.

Ive been told the samething about 1 piece shafts being harder to balance. Two piece shafts having the centre bearing not only make it stronger, but take any drivetrain misalignment out in smaller amounts by having two shorter shafts they are less prone to wobbles or vibrations because they dont cover any long distance. However they all should be balanced with counter weights after they are done. Depends who you goto as well. We had our first tailshaft rebuilt by one shop(wont say) who used dodgy unis and couldnt balance a tailshaft if their lives depended on it. So after i spat that one out, we went to Hardy Spicer and they made us another one and its been absolutely perfect with no vibrations and no tailshafts spitting out chromemoly shafts are expensive as cost about 2g. Wouldnt want to be spitting them out in a hurry all the time.

Conflicting information... and to be honest i was under the impression that the first post is correct. Can someone please elaborate on how having a 2 piece with a center bearing would be stronger or confirm my beliefs and back up the first post.

Reason in the interest is that i will need tailshaft loops on my car for DA next year (cams requirement), a 2 piece requires 2 loops, a 1 piece one loop, was contemplating going the 1 piece for both strength and ground clearance. If I have one i can slot it up into a recess and itll make hardly any difference, if i have to have 2 only 1 can go in the recess the other will be quite low.

[r33_racer]

well the blokes i was talking to about single piece and two piece make the tailshafts for stone brothers for their supercars. They had some chart with tech specs on it for single piece shafts and the amount of torque they can handle and driveline angles and so on...they didnt recomend one as they believed it to be weaker then the std two piece setup they have. Either way so long as its strong and doesnt vibrate then who cares. Though in most cases the weakest link in a tailshaft is the unis so big solid unis will almost always fix this. We have two loops on our r33, no problem with clearances or height.

[giant]

i also run a one piece tailshaft and havent had any issues, fantastic!

we were having problems with the two piece shaft destroying center bearings after a hundred odd launches, (which incidently feels like axle tramp when the bearing has to much movement)

btw ours is a carbon fibre one piece, rated at two thousand horsepower.. big unis (i think it cut about six kg's off the weight)

cost was 1800 delivered

and we give our car a very hard time on launching. cant recomment them enough

cheers russell

[nsanity]

A 2 piece shaft is less likely to kill you if it fails (unless you're running a tailshaft loop on your one piece)

I can't think of a good reason why you wouldn't run a tailshaft loop anyway? seriously...

[giant]

I can't think of a good reason why you wouldn't run a tailshaft loop anyway? seriously...

for sure!!

[sh@un]

i hardly think Nissan would have fitted a 2-piece shaft to the GT-R if a single-piece was the better option, do you? (surely it would have been cheaper)

[Beer Baron]

better option for what though? better for shopping? better for racing? I would think the group A race cars probably used a 1 piece, or a carbon 1 piece even. i could be wrong though.

[r33_racer]

I can't think of a good reason why you wouldn't run a tailshaft loop anyway? seriously...

Well its not that you cant think of one, its that most racing regs stipulate you MUST have one and for obviously good reasons too. Ive shot my std tailshaft out before and its scary when you look at the damage they do when they fly out....

[GTRsean]

Pic in UAS is the one they made up for my GTR.

They have been doing the one piece for 300zx for a while now and made up one for me.

Only issue I had was insufficient end clearance on the shaft which caused plenty of vibration above 80km/h and got worse the faster you went.

I.E the guys who made it didn't make it short enough and I ended up with an interference fit. Had to get 20 or so mm cut off and the whole shebang rebalanced before I could put it in again.

After all that it was fine and no more vibs or bearing noises.

So, be very careful when measuring up tailshaft length and remember no end clearance will cost you dollars. (bearings, gearbox, uni's, vib kills em at either end).

No bull.