What clutch setting???

Hi Guys

I need some help with some settings with my pedal clutch.

Its a 10inch twin plate pedal made by L&T.

I dont have a base figure to work from and have been doing some test runs that seem very cruel. The clutch is pulling the engine down on launch then black tracking / wheelstanding and shaking.

I have a .740 base height with no extra turns on the base springs adjustment. I also have 15 grams counterweight on the fingers.

I dont know what the spring rate is and I dont know the weight of the fingers. I know I can pull the assembly apart and calculate / measure the springs but what amount of pounds would make a good starting point??

Appreciate the help.

Big Russ

 

First thing you should do is talk to someone that has an L&T to confirm that you have the right base height. If that is correct, I don't think the spring pressure is causing you problems; your fingers might be too aggressive, or you just have too much weight. 15 grams times 6 fingers is 90 grams, which is quite a lot. I run between 50 and 60 grams total in my TAFC, you could try that, but be ready to click it off early if the clutch is too loose (I doubt it though). As far as static goes, 2 or 3 turns should get you down the track.

 

Not knowing your application it's hard to tell but, I would check your discs to see what you have. If you have 0 turns on the base now and aren't slipping (even with that amount of weight)you don't need more base. See if you have 5135 or 5130 discs. 5135's are more aggressive. You'll have trouble making the clutch work with 5135's, unless the car is heavy and has alot of power. Any LT that I've worked on had a .720 base hieght. This will give you slightly more base pressure than the .740 your at now however.

 

Thanks Guys for your input.

The problem is actually worse than it appears.

I have a TOTAL of 15grams on the fingers and it just wont slip!

On my last pass, it took just three thousands off.

I was thinking I might have a problem in the fuel system that was making the car bog on the startline thus making the clutch not slip but it doesnt slip in top gear either!

I do have the tuneup a little soft but not crazy. It still ran over 200 in the traps.

Any thoughts??

Big Russ

PS How do I tell if I have 5135 plates?

 

Sounds like you have a combination of problems. You would have to list your entire combination so we could see if anything sticks out. Have you run this combination before? Is the clutch the only thing that's new?

You either have a lack of power due to a buggered up component, or your gear ratios and or tire size is too much for your motor. What kind of car is this, and how big is your motor? Do you run a screw blower or a roots? Lots more answers needed to figure this out.

 

OK here we go

Its an Outlaw type car. It weighs 2550lbs. I have a 526 keith black - 11:1 comp, R294 camshaft, early BAE fuel heads, 14/71 hi helix Littlefield @ 30% over, bird on top, Supermag three, Enderle 1100 pump with a 90 jet in the pump loop, I run a high pump loop with a 70 jet (60psi)Timing set at 32 degrees. The L&T clutch sits in front of a Lenco three speed, I think its got a 1.80 first gear (not sure if I have 32 or 36% packs)with a 4.11 rear gear and 33x16 slicks.

I figure If I could set the clutch to a known setting then I would know if the problem was in the tuneup area or in the clutch.

Thanks for your help

Big Russ

 

Russ;

A few things that could help:

A single super mag 3 is normally run at 38 degrees with these types of heads, that will help a lot on the bottom end. You can run 40 degrees if you are running at any kind of altitude (above 3000 feet). The compression is a bit low, but is probably OK if you are running sea level. The gear ratio's concern me too, as 411's could be accounting for the sluggish leave. Your car will run better all the way down the track with 4:56's. When you free up the motor, the car will run better et and mph. The 1.80 first gear is a bit low too, but don't change too much at once. I think you'll find with the timing and rear gear change that the motor will run fatter, and once you make a few runs and find everything is safe, you'll have to take some fuel away from it. Or you could leave the motor rich and start putting some blower in it. A 526 needs lots of air, and I doubt that 30% over is enough. We run 58% with the same size motor. Start bumping this up a tooth at a time and keep an eye on the plugs (and computer if you have one).

I think the clutch could just be left alone; adjust it afterwards if necessary.

 

The discs are marked but you have to look really close in the center hub area. (get your glasses out) Very small stamp or scribe will read 5135 or 5191 or 5050. Sounds to me the motor is real soft too. Are you limited to 30 over? Good luck.