Clutch Slippage - Turbo Busa

[Cecil_Stringer]

Today I accerated through 3rd at ~10-11psi.
I was not starring at the gauges but I believe the slip started around 7-8K.

The bike was pulling hard then sounded like it "free-spun" for a second.
I cut the throttle and rode in gently.

The plates look new.
The springs are HD.
The clutch center is welded.
Plently of oil.

Is this expected?
What should I look for?
What does this sound like problem-wise?
What are the potential options to correct it?

 

[Cecil_Stringer]

The more I think about it the more I believe it may have been wheel spin.

The bike is stock wheelbase and typically reaches for the sky more so then spinning... especially at speeds over 100mph.

This is the first time I have riden the bike since changing the sprockets to 17/39 and boosting at 10-11psi.

I did accellerate earlier through the higher gears without incident.

The clutch plates look cherry (no visible signs of wear)... and the clutch was inspected a couple of nights ago when we did the clutch mod.

I have been using MOTUL 10W40.

The tire is a fairly new Bridgestone BattleAxe BT014.

This happened after a 45 minute highway drive with air temps around 55 - 60 degrees.

 

[zukracer]

dunno, but wheel spin at 100+ would send the pucker factor WAY high for me

good luck with it, I'm sure some of the turbo gods here will chime in soon

 

[MET]

Even if yu have heavy springs you could have cracked one or 2 springs. If you did the clutch will slip. You will know this if in first gear you have to give a lot of revs to slide the clutch out. Check your springs, I am sure that it is not yor platess unless you have been banging that baby. I notice that you already ave your 6lbs of boost up to 10-11lbs, I hope that is the second stage.

 

[Cecil_Stringer]

Even if yu have heavy springs you could have cracked one or 2 springs.  If you did the clutch will slip.  You will know this if in first gear you have to give a lot of revs to slide the clutch out.  Check your springs, I am sure that it is not yor platess unless you have been banging that baby.  I notice that you already ave your 6lbs of boost up to 10-11lbs, I hope that is the second stage.  

Ninja.... as usual, thanks for the insight.

A couple of nights ago we did the Clutch Mod and visibly inspected the clutch.
It looked surprisingly good.

The slippage happened about 1 mile from my office and I have yet to see if it is repeatable.
I am leaning towards tire slippage at this point over clutch slippage... hope I'm right.
The bike has the 6lb spring in the wastegate.
The 2nd stage of boost is set to ~10-11psi (hard to accurately tell with my irratic boost needle).
This was my maden voyage on 10psi... was not sure what to expect.
When I decided to roll-on in third I did anticipate a wheelie and placed a lot of weight forward (lightening the rear).
Further reinforcement to supporting Tire Spin theory.

 

[Tufbusa]

More boost until something breaks!

Then you'll know what to look for

Most guys don't give consideration to just how expensive going fast really is? If you break the tire loose, you'll definately feel it in the cheeks of your arse. There is a lot to be said about that old saying "How fast can you afford to go"! In reality, you should start at the tire and work backwards to reach HP. Starting at the HP end and working your way to the tire makes for some spendy breakage with large HP increases.

Have fun and enjoy your ride but keep your wallet open! It definately takes money to go fast as well as the faster you go, the less reliable your ride becomes.

 

[Cecil_Stringer]

More boost until something breaks!

Then you'll know what to look for

Most guys don't give consideration to just how expensive going fast really is? If you break the tire loose, you'll definately feel it in the cheeks of your arse. There is a lot to be said about that old saying "How fast can you afford to go"! In reality, you should start at the tire and work backwards to reach HP. Starting at the HP end and working your way to the tire makes for some spendy breakage with large HP increases.

Have fun and enjoy your ride but keep your wallet open! It definately takes money to go fast as well as the faster you go, the less reliable your ride becomes.

Your words are proving to be true...
Tires...
Chains...
Sprockets...
Clutches...
Cush Drives...

Any waggers on what is next to be "The Weakest Link"?

 

[MET]

Hope that it was just the tire. If y feel it again check the sprigs. I had to springs that broke but could stil sde the clutch out, like I was trying to avoid a wheelie.

 

[STUNNAH]

I wonder if it could be the welded mod...This mod is designed to prevent the clutch from locking immediately and in essense prevent wheel spin when launching...Haven't read what effect it would have from a roll on...

 

[ALLshow.NOgo]

just a question about oil (don't mean to hi jack the thread hehehe) but on 'clutch slippage' will that happen to me aswell? I am about to use AMSOIL XL-7500 Pure synthetic 10w-30 Motor Oil and is rated API SERVICE SL, SJ, ENERGY CONSERVING. I would just like to know before I dump it into the bike you know? Thanks

 

[MET]

Syn your using is fine..

 

[ALLshow.NOgo]

awesome thanks much!

 

[fstbusa]

the motorhead says not to run the welded hub...

he says use stock clutch setup with heavy duty springs.

 

[Cecil_Stringer]

It is the clutch slipping... gonna take out the clutch mod and put back in the stocker.
While I am there I will check the stack hieght.

Thanks all.

 

[STUNNAH]

It is the clutch slipping... gonna take out the clutch mod and put back in the stocker.
While I am there I will check the stack hieght.

Thanks all.

Is it slipping because of the mod???

 

[Cecil_Stringer]

It is the clutch slipping... gonna take out the clutch mod and put back in the stocker.
While I am there I will check the stack hieght.

Thanks all.

Is it slipping because of the mod???  

Not sure... doubt that is the problem... some think so... some don't.
But logically (mechanically) is doesn't make sense that the welded center would cause slippage.
THe center peice is designed to limit backspin... nothing really to do with slippage... but what do I know.

I think the newly added HP is more to blame...

 

[MET]

Broken springs................ I will be surprised if not.

 

[STUNNAH]

When you find something out be sure and post...Even PM me...I would appreciate the info I'm having the clutch ring installed and based on what you discover I'll know what to look for...

 

[Cecil_Stringer]

When you find something out be sure and post...Even PM me...I would appreciate the info I'm having the clutch ring installed and based on what you discover I'll know what to look for...  

The two piece clutch has small "ramps" on it. When torque is applied to the center section, the ramps ride up on the outer portion, wedging it out and causing them to apply more pressure on the clutch. If you weld them together or put in an aftermarket one piece, this can no longer occur and the clutch must rely on the static force of the springs alone.
(Thanks SportBikeRyder)

The stock clutch can be considered a rudimentary lock up - as well as a "Back Torque Limiter" .
(Thanks Steve A)

 

[fstbusa]

yeah thats how the stock center hub works. its a "mock" lockup

so did the stock center hub fix your slippage problem?