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Cal-look/High Performance => Technical stuff => Topic started by: Garrick Clark on February 24, 2018, 16:59:22 pm



Title: Clutch slip
Post by: Garrick Clark on February 24, 2018, 16:59:22 pm
Hi Guys.
I'm experiencing clutch slip.
Pressure plate is a kennedy stage 2
Disc is a Daikin .
Motor is turbo
It doesnt slip till 3rd gear on a straight. And only when at full operating temp.
Is this heat related. like does the disc material FADE like brake shoes do.
Thanks.


Title: Re: Clutch slip
Post by: Erlend / bug66 on February 24, 2018, 18:22:01 pm
Switch to a stage 3 or a better disc


Title: Re: Clutch slip
Post by: Garrick Clark on February 25, 2018, 00:15:23 am
Hi Erland. What would be a good disc to try.


Title: Re: Clutch slip
Post by: Erlend / bug66 on February 25, 2018, 00:19:22 am
Depending on use..

I run a RLR Black Magic. And Stage 4..


Title: Re: Clutch slip
Post by: PPRMicke on February 25, 2018, 11:26:34 am
Here in Sweden, use (95%) Stage 1 and blackmagic 
If you use stage 4 with blackmagic, the gearbox will go into pieces   >:(
I would start with pressure on the pressure plate  at 200mn  ( 147 lb)
/// Micke


Title: Re: Clutch slip
Post by: Erlend / bug66 on February 25, 2018, 11:49:32 am
Here in Sweden, use (95%) Stage 1 and blackmagic 
If you use stage 4 with blackmagic, the gearbox will go into pieces   >:(
I would start with pressure on the pressure plate  at 200mn  ( 147 lb)
/// Micke

Well the gearbox did split in half.. but stage 3 and BM did slip in a dynapack..


Title: Re: Clutch slip
Post by: Garrick Clark on February 25, 2018, 12:24:45 pm
OK. I'm going to weld a socket on my spare in put shaft and get a foot pound figure of when the disc slips. I'm sure it's gunna be a false reading as I think heat is playing a part as well. A little info.
It's 21 psi boost on through a type 4 and the torque hits the clutch pretty fast and hard.


Title: Re: Clutch slip
Post by: Neil Davies on February 25, 2018, 12:36:05 pm
Do the clutch pressure plate and flywheel need resurfacing?


Title: Re: Clutch slip
Post by: Garrick Clark on February 25, 2018, 16:32:04 pm
Oreet  Neil. The fly and the P.P are new items with low low miles.


Title: Re: Clutch slip
Post by: mikko k on February 25, 2018, 18:37:42 pm
At this page you can see how much torque different stage Kennedy pressure plates can handle, with stock disc.

http://www.racereadyproducts.com/transmission-components/clutch-pressure-plates/

Stage 1 = 180 ft.lbs = 244Nm
Stage 2 = 220             298Nm
          3 = 260             352Nm
          4 = 300             406Nm

Metallic disc can add 25% more torque. I don’t know about Black Magic.

If somebody tells you that a lot of people use stage1, it only means that they have less hp and torq...

At my race engine (N/A 2,85L type 1), I had 300Nm and Stage 1 + BM disc, the clutch start to slip.. Now I have Stage 3 for next summer. I hope it helps me.


Title: Re: Clutch slip
Post by: Garrick Clark on February 26, 2018, 20:41:58 pm
Ok thanks Mikko, I'm gunna check the plate face 1st , see if the disc has made a nice even pattern on the surface of the P Plate, and the fly wheel face.
I'll be back.


Title: Re: Clutch slip
Post by: spoolin70 on February 26, 2018, 21:12:17 pm
Hi Garrick

My old turbo motor made just over 300hp and I only ever used a stage 3 Kennedy pressure plate.

I can't remember exactly what disc I used but it wasn't anything fancy - organic something I think.

It never once slipped, even with R888's on the rear. Personally I didn't find it too heavy either.

Hope that helps
Darren


Title: Re: Clutch slip
Post by: Garrick Clark on February 26, 2018, 21:35:46 pm
Thanks Darren the stage 3 might be the next step then. Unless this stage 2 plate face shows a bad contact patch.
The RB racing engine calculator recons I'm getting around 300 hp with 21 psi going through it.


Title: Re: Clutch slip
Post by: Erlend / bug66 on February 26, 2018, 21:41:11 pm
Stage 4 and Black Magic. 552nm/407 ft lbs to the tires.


Title: Re: Clutch slip
Post by: hotstreetvw on February 27, 2018, 03:26:02 am
I ran a stage 2 and black magic.  Lesson learned.  I couldn't preload without jumping through the beams.  Got to eliminations, I didn't preload for fear of the red light, smoked the ring and pinion and case.  There is a reason why RLR suggest at most a stage one with BM.


Title: Re: Clutch slip
Post by: Fiatdude on February 27, 2018, 04:33:42 am
I'm running a stage two with a 5 puck on my 2332 turbo, but at only 7 pounds boost with no slippage....

When I was running my 2990 turbo, it was with a stage one PP but with the Kennedy dual disc setup....

If you're really wanting to eliminate any possibility of slip I highly recommend the dual disc setup. Also one of the benefits of running the DD's you get away with a stage 1 PP and that is a lot easier on the thrust bearings in your engine while your riding the clutch


Title: Re: Clutch slip
Post by: BeetleBug on February 27, 2018, 09:24:56 am
Stage 4 and Black Magic here for years with a heavy streetcar, turbo, T1 gearbox and low 60ft. I used clutch management to achieve some slip and that is the key to keep you transmission alive.

-BB-


Title: Re: Clutch slip
Post by: Garrick Clark on March 27, 2018, 19:07:27 pm
Guys, wanna guess what the brake away torque is on my kenny stage 2 cover and daikin disc, with no shims
is gunna be.
I'll be getting a foot pound number at the week end.


Title: Re: Clutch slip
Post by: Garrick Clark on April 05, 2018, 06:37:23 am
Sanded the cover with some 600's wet and dry using a flat rubbing block. This has brought out the area of the cover that has the been slipping. Its from the outer edge going in a 1/3rd or the shoes surface.


Title: Re: Clutch slip
Post by: Garrick Clark on April 09, 2018, 18:12:44 pm
I tried the break away torque today.
My torque bar only goes to 100 ft pound.
So the bar clicked at a 100 no slip.
I put a bar on the end of the torque wrench and couldn't get that disc to budge at all.
Guess its definitely a heated up disc issue.


Title: Re: Clutch slip
Post by: Stev on April 17, 2018, 19:35:58 pm
Does anybody of you guys know the release force of the Kennedy Clutchs? Not sure if "release force" is the wright describtion.  I talk about the force you need to open the clutch? :-)


Title: Re: Clutch slip
Post by: 55ragtop on April 30, 2018, 23:49:03 pm
I don’t know if Kennedy has got better but for some time there PP’s would cup or concave as soon as got a bit of heat though em and they stay that shape. I had my stage 2 machined flat again.


Title: Re: Clutch slip
Post by: dragvw2180 on May 04, 2018, 22:37:02 pm
On my turbo race car ( over 450 dynoed HP ) I tried multiple clutch set ups , spent a bloody small fortune trying all the recommended packages. After destroying one trans after another I finally tried a Double disc Rev 6 setup from Ron Lummis ,I have not broken anything trans wise since . I sold my race car and kept my 2387 race engine which I installed in my street car , only change was traded my 600 Holly for a 48 Dellorto side draft prepped by Dave Kawell , takes getting used to but now very driveable on the street/track . Mike McCarthy

P.S my friend John Toomey liked my setup so well he put it on his new turbo car also with the same results .


Title: Re: Clutch slip
Post by: Garrick Clark on May 10, 2018, 19:17:32 pm
Thanks Mike.
I'll look into this if the CB Dual disc doesn't work.


Title: Re: Clutch slip
Post by: Garrick Clark on June 10, 2018, 21:05:04 pm
Hi Guys. I've now fitted the CB dual disc. So far so good no slip. It does have a bit of judder when you 1st set off ,I'll have to get used to it I suppose.


Title: Re: Clutch slip
Post by: Garrick Clark on June 15, 2018, 20:15:45 pm
Hi guys.
I'm looking for v dubbers to tell me about how your turbo bug drives on the street.
Mine with the stage 2 and the CB dual disc is getting difficult to drive. Yes the clutch doesn't slip which is Good,but the bug is getting more difficult to drive around town. I feel that this bug needs me to be more aggressive with the stand still starts from the lights, like more revs and let the clutch out quick in order to stop the clutch juddering. I think trying to be smooth with it will eventually brake something as it doesn't like it.
Looks like my bug isnt a street bug anymore.


Title: Re: Clutch slip
Post by: Martin S. on June 15, 2018, 20:51:15 pm
I call it chatter but whatever you call it my car has it too. It's a milder turbo, and the last time the engine was out the guy put in a Stage 1 vs the Stage 2 that was in it with a different disc as well. I don't race it so not sure about slippage, and mostly just do roll-ons and with the smooth turbo power I don't have any complaints.
Except for the chatter  >:(
After playing around with a few things, I did some reading on here and the next thing I will try is a kafer cup/ engine brace. What they said was that over time the frame horns drop down slightly and then wiggle up and down as you drive and release the clutch, and things start to move and cause the chatter. Stabilizing the frame horns is supposed to help. I just ordered one, along with a HD trans support which tie the frame horns together better. We shall see if it works  ;)

https://www.cip1.ca/ProductDetails.asp?ProductCode=C13%2D17%2D2975

https://www.cip1.ca/ProductDetails.asp?ProductCode=VWC%2D111%2D301%2D255%2DAHD