Annular clutch questions

[Kitcat]

My new Birkin as the optional annular clutch, made by Tilton. It is supposed to be more reliable, have quicker release, and better feel. So far my experience has been it's either off or on. There is little "feel" or sense of progression during engagement. And I am getting a really bad smell. My experience so far has been very limited (mostly driving my car on and off my trailer on trips to my mechanic's- 3 so far), but I am not sure I like it.

 

My old Evo VII had a similar off/on clutch along w/terrible smell unless shift was perfect. I owned it 3 years and never mastered it or got very comfortable w/it.

 

My Caterham clutch has a nice progressive bite, plenty of feel, and has been going strong for 30K miles approximately.

 

Any thoughts on whether the annular clutch is an improvement? Do I need to change my shifting style and not let the clutch out as slowly? Anything else? I think I am either missing something here, or the clutch is a step backwards.

 

BTW, the Birkin site notes the engine has to be pulled to change the clutch slave cylinder(!).

[a.moore]

Looked at Tilton's webpage - so that is like a sportbike clutch right?

[bsimon]

The on-off binary feel of a clutch has to do with the choice of friction materials and number of driven plates in the clutch assembly itself. There is no correlation to the type of release mechanism.

 

The annular clutch release slave cylinder is simply a substitute for the long lever of a linkage, cable, or external slave cylinder type setup.

 

If your clutch feels binary, I'd suspect it's fitted with a metallic driven disk as opposed to an organic or synthetic type disk. Great for racing, not so great for engaging at an uphill stoplight.

 

If the pedal is extremely hard to push, this can make a clutch somewhat hard to modulate as well. This is usually due to a poor choice of master/slave cylinder ratio in a hydraulic release setup like yours.

 

The fix for the heavy pedal is to change out the master cylinder for one with a smaller bore.

[Kitcat]

Thx.

 

Not hard to push. Just hard to modulate-like when driving up a steep ramp at slow speed into my trailer.

[yellowss7]

Sounds like a good excuse to install a winch. :seeya: Easy job, and I, like Karl, installed a small solar panel to help keep the battery charged up.

 

Sounds like a good rainy day project.

 

 

Tom

[blubarisax]

I used a little Warn ATV winch and glued a solar panel from Cabellas to the roof of the tralier. Throw in a couple of marine deep cycle batteries, a remote control for the winch and a disconnect switch and you will be all set. In fact, you may not even need a clutch at all this way.

 

Karl

 

http://i913.photobucket.com/albums/ac336/blubarisax/IMG00139-20110612-1639.jpg

[Ross]

A new Birkin with annular clutch slave should/will have equal performance as compared to the external slave cylinder.

 

The problem may be in the selection of clutch assembly or type of disc. In the past few years I have successfully installed annular cluch assemblies in a Lotus 7 and a TVR. Once properly installed, no problem.

 

Bob

05 Caterham

69 TVR

[Kitcat]

Sounds like the problem, if there is one, is with the disc material. What's with the powerful smell tho? Is it trying to tell me something(like stop abusing the clutch?).

[Marine7]

Kitcat,

 

I'm just completing the build of my Birkin. I chose the anular release over the external slave cylinder and lever arm. On the Birkin, the stock roll pins on the clutch arm are a weak point and fail in short order. All new cars are fitted with anular release bearings and the theory is sound. Now, I too have found that the actual modulation of the clutch takes a fine touch. The "engagement" area or sweep of the pedal is quite short. I'd say it feels like 1" in or so at the pedal. Please keep in mind that my car is essentially in its break in period. It has less than 50 miles on it. The choice in friction material is also going to play a part. I'm running a Spec stage 3 clutch for street applications. The puck style racing clutches are not a very good option for the street.

 

The guys at Taylor Race in N. Texas can provide you with a wealth of information on the Tilton release bearing. They also make the custom pedestal for the Birkin/T-9 tranny to bellhousing.

 

The bad news is that any future service for your release bearing will require removal of the engine and tranny from the car. The good news is that once properly setup, it should be trouble free.

 

Good luck

 

Jason

[danilo]

Possibly the master cyl and the slave have a Missmatched Ratio??

Wouldn't be the first ones to make this basic mistake.

Might also not be fully releasing?

As a decades long Saab owner, I've a love hate relationship with Annular Slaves. Often wishing for the simplicity of a normal, laughably easy to replace advantages of an external slave with lever arm.

[Kitcat]

I am told I have the standard single dry plate disc that Birkin uses for street cars. The clutch pedal has about 4" of travel.

 

I am getting the hang of pushing it in abt 1" (where my left foot hit the frame member on left side) and shifting. I clearly dont need to push it all the way to the floor. For what ever reason, not much feel and very quick engagement, disengagement. And that terrible smell to let me know every time I let it slip too much.

[jlumba81]

Is it possible that the clutch needs bleeding?