mfrosty

iTrader: (14)

So I'm getting back into the hobby and getting into nitro off road this time (used to race elec) anyway I'm looking at all these clutch shoes and springs and I really have no idea what the different weights, hardness, spring rates do. Anyone care to lay it out for me?

Take M2C's clutch shoes
They've got ultra light, light and normal weights and soft, medium, and hard.
Now spring rates, 0.9, 1.0, 1.1

How does the weight affect the clutch action, same question for the hardness of the clutch shoes, and again the same question for the springs.

I'm guessing that the spring rate and the weight make a difference in how the clutch engages and how fast the engine has to spin before they expand and grab the clutch bell

Lighter spring=lower RPM engagement, softer bottom end
Heavy=Higher RPM, snappier

Am I on the right track here?

Now how about the hardness, I'm guessing that the harder the alum the more it slips before it fully engages the clutch, kind of the way a slipper clutch works in an elec, so the softer would grab it without as much slipping?

Is my thinking here sound or am I way off?


Thanks

jasandsrc8

Your close. Hard shoes with stiff springs will give more punch. Soft shoes with soft springs will be smoother. Some racers will run 2 soft shoes and 2 hard.

mfrosty

iTrader: (14)

Thanks!

Now to the weight of the shoes, I'm guessing it's not the best idea to use different weight shoes (especially in a 3 shoe clutch) because of balance. I'd think like 2 ultra light shoes and one normal would throw the rotational balance off?

jasandsrc8

Correct. That's why in a 4-shoe clutch you run same composite shoes opposite of one another. Same for the springs. Hope that helps

Integra

iTrader: (8)

wrong....harder the shoe...the more it'll slip..therefor it'll hit softer....the softer the shoe the better grip it will have therefor making the take off harder....for springs....ALWAYS start at .9's as you dont know the power of the motor till you test it really....a Hard hitting .28 will NEVER need any more spring then .9 a high revving .21 might require some more spring stall to get the motor in the power band....there's ALOT of factor's to consider when stepping into a M2C clutch and we NEED all the details to give you a functional set-up.


I have witnessed a MANGLED M2C set-up from WAY too much stall and the Wrong shoes.

Integra

iTrader: (8)

sorry again...but Wrong....alot of guys run 2 different springs on their 3 shoe set-up...and having 1 alum and 2 carbon or w/e will not throw off the balance of the motor....alot of guys mix carbon's with alum.

mfrosty

iTrader: (14)

I wasn't actually looking at the 4 shoe clutch of theirs, just their clutch shoes for the RC8's stock setup. As for my engine it's a .21 PTM modded Go-Tech 5 port.

I'm not really looking to get a setup from someone here, as no one could give me a clutch setup because they're not me. Everyone drives different and sets their car up different. I was just looking for an explanation of how the differences make the clutch react so that I can tune the clutch to my driving style, track and engine.

Thanks

Integra

iTrader: (8)

well i said most of it...basically the stall on the springs will determine how much rpm is require'd till the shoes Lock on the bell and move the truck....the higher the stall the more RPM it takes to launch the car.....But the higer the stall the more heat and more slip will occuring...for shoes...like i said a Hard shoe will take more abuse/slip more then soft shoes...But still can be burnt down if your not careful....the weight of the shoe will also contribute to the "grab" the shoes have...a lighter shoe is easier for the motor to rev up and make power.. but will have sligtly less grab as apposed to a heavy shoe which has centrifugal force helping them bite......after reading you initial question you have the idea bang on.....jasandsrc8 was potentially leading you the other way on the shoe compound...but you seem to have the whole clutch functions down pat.

FWIW i would recommend a set of Reg Hard or Med lites and get some .9 .95 and 1.0's.....you should be set to get w/e feel you want.

NCWC

Think of the hardness of clutch shoes like the compound of tires. The softer the shoe the more grip it has, but a soft shoe will wear faster. And there is no problem with tuning the feel of your clutch with different weight shoes. Different weight shoes have an effect on how the springs feel. The heavier shoe will make a spring less effective in holding it down, allowing the shoe to engage earlier than it would with a lighter shoe and the same spring.

On my 3 shoe clutch I like to use 1 carbon shoe and two aluminum shoes. A .95 spring on the carbon and 1.0's on the aluminum. That setup just has the feel I like for high-med traction. If the track is slick I will swap 1 aluminum with a carbon and keep the spring the same for less aggresive power to the wheels.

The clutch is an effective tuning tool and even has an effect on the engines temperature. They take a good bit of matinence also. Aluminum shoes "mushroom" over at the surface that meets the clutch bell. You need to file this smooth after every race day or hard practice. They are worn when the long end of the spring is level with the surface that meets the clutchbell. Springs lose their effectiveness after a while and need replacing to keep you clutch feeling consistent. The clutchbell bearings need alot of attention. The smart thing to do is replace the bearings often to keep from having a failure.

jasandsrc8

Running 4 Aluminum shoes will have the most punch. Running 4 plastic will give you a smoother acceleration. Stiffer springs will give more punch. Softer springs will will engage at a lower rpm and will be smoother.

Integra

iTrader: (8)

and.....no one is disputing this fact.


You said and ill quote
"Hard shoes with stiff springs will give more punch. Soft shoes with soft springs will be smoother. "

which is partially wrong....Hard shoes slip therefor you dont have the Grip(punch) as compared to a Soft shoe...your spring theory is correct but your material is backwards.

Madbrad

iTrader: (30)

A lot of good info on setting clutches.
Thanks for sharing your knowledge everyone.

I have also heard that if you running aluminum shoes and want to swithc to carb, that you should use a differnt CB becuase of the way the aluminum will ware the CB. Is this correct? Im using aluminum right now but was thinking of experimenting a little with some carbon shoes

Integra

iTrader: (8)

100% true

NCWC

I agree also. You should install a new clutchbell, or at least one that has been used only with carbon shoes. I would probably only do it if I went straight from all aluminum to all carbon, but i guess it would be slightly beneficial to use a new one if you wanted to mix shoe material up. The heat from the aluminum shoes, and the way they groove and transfer material onto the clutchbell will shorten the life of the carbon shoe(s) anyway.

mfrosty

iTrader: (14)

Thanks for all the useful info guys! At least I was on the right track with everything, I think I'll be able to tune my clutch now without any problems.