10 spline "may" hold up better with Twin disc than Single disc clutch

[musclefan21]

So folks, I just bought a twin disc clutch kit which is rated at 950ft lbs tq.

Now we all know the twin set up holds the power much better, and it makes sense that the input shaft would have more stress due to that.

I found a really good deal on a twin disc set up and i couldnt pass it up. But it was a 10 spline set up. I have been worried a lot about it.. thinking I won't be able to run the car really hard or else I will probably snap the input shaft, even though I will be at best 500 /500.

But today, while checking the kit out, I noticed something. Since the kit has two clutch discs, more surface will be covered on the input shaft. So, I am thinking that would reduce the stress on the input shaft by 50%. I may be wrong, but it looks like the more surface of the input shaft covered, the easier it will turn...

Here is a quick pic, let me know what do you guys think on this theory:

 

[silver03svt]

Couple of 5,000 RPM launches and you should have your answer.......

 

[P49Y-CY]

i recently went from a conventional ram single disc to the mcleod rxt. when i had them apart i was sort of comparing the two and trying to figure out how they work and went together, etc.

the center section hub (that engages on the splines) is twice as thick on the single disc as compared to the twin discs. so i think your diagram is wrong because the single disc would actually be the same thickness as the two twin discs together when they are side-by-side.

personally however, i think you are going to be ok, and you should just go with it. many guys have been ok with the 10-spline even at higher horsepower. and then if it does break, you can just upgrade and replace the discs with the rebuild.

best of luck with it

 

[musclefan21]

Couple of 5,000 RPM launches and you should have your answer.......

This isnt about 10 spline being bullet proof. It is about having less stress on it with twin disc vs single disc.

 

[musclefan21]

i recently went from a conventional ram single disc to the mcleod rxt. when i had them apart i was sort of comparing the two and trying to figure out how they work and went together, etc.

the center section hub (that engages on the splines) is twice as thick on the single disc as compared to the twin discs. so i think your diagram is wrong because the single disc would actually be the same thickness as the two twin discs together when they are side-by-side.

personally however, i think you are going to be ok, and you should just go with it. many guys have been ok with the 10-spline even at higher horsepower. and then if it does break, you can just upgrade and replace the discs with the rebuild.

best of luck with it

You are right, single disc clutch disc hub is a bit thicker than the twin disc discs. However, twindiscs have a floater plate in between the two discs. when you combine the two discs and the floater plate in between them, the amount of surface covered on the input shaft is still greater than the single disc.

I will be installing this next week. I hope she will hold up... fingers crossed.

 

[Mach828]

The twin disc isn't going to slip like the single disc would. Its not going to give. And things will be more prone to breaking.

 

[Speed Demon]

the biggest problem is where the disc/discs sit on the input shaft isn't generally where they break. They usually break where it necks down after the splines

 

[musclefan21]

the biggest problem is where the disc/discs sit on the input shaft isn't generally where they break. They usually break where it necks down after the splines

True. I know mine will break too. I am just hoping some clean runs, some sort of enjoyment before it happens.

It sounds like people even at 450rwhp/tq level broke it right after a clutch upgrade... :nonono:

 

[ProchargedSN-95]

Had Mcleod RXT with 10 spline in my 730 whp SRA Terminator and never had problems. Was launching it at 5k rpms with 325/50/15 drag radials and 28x10.5W's MT slicks. You'll be fine.

 

[97RioRedSnake]

More contact area between the clutch disc(s) and the splined section of the input shaft will spread force over a greater distance on the splines, basically preventing the splines themselves from failing. From what I understand, however, most input shaft failures are torsional shear near the end of the splined section (not individual spline failure) and that won't likely be affected by adding an extra clutch disc.

 

[coposrv]

I get what your saying OP but if that clutch is engaged quickly and grabs hard on a prepped track on good tires I don't think a 10 spline will live long. Twin disk or not.