2 disc VS 3 disc clutch

I have a 3 plate x 11" Crowerglide clutch on the back of my Nitro 392 Hemi. Im thinking about modifying it to make it into a 2 disc clutch.
Why??...to make it lighter
Just wondering if anyone has advise on whether or not a 2 disc would still work OK in my application?
6.90ET Front engine dragster with 392 Donovan hemi on 90% nitro. soft tune.
email me. linkplas@exemail.com.au

 

Clutch

I am no crowerglide clutch expert and this was for a pedal clutch but I was told years ago that a sintered iron clutch disc that is high cf will hold about 1000hp. So a dual disc high cf disc clutch should be good for 2000hp. But as I said this is for a pedal clutch, not a fully centrifugal. For what that was worth.


Corey

 

2 disk more forgiving

Running a three speed Lenco, we ran a three disk 11" Crower pedal clutch. The three disk was a bit heavy on the 1-2 shift and would rattle the tires on a marginal track at 1200 HP. Just too much clutch. We converted to a two disk, and it was a lot more forgiving. We turned it up to 1700 HP with no clutch problem at two disks.

If you run high gear only, you will probably need the three disk. With either the two or three disk setup, just cool it well betweeen rounds. Twice we did not cool our three disk crowerglide at a low 950 HP level with a 3 speed Lenco. We were in the final round both times and the track staff said hurry up. Both times, we ruined our disks. The clutch worked both times but it threw lining off, and the disks could not be run again. From then on, when the track said hurry, we ignored them and cooled the clutch.

Bob Szabo
www.racecarbook.com
bob@racecarbook.com
(916) 419 6649

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Tuning with an air to fuel ratio reference becomes exact.
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Agreed.. It wasn't all that long ago that Roots Pro Mods were only allowed a dual 11" and they seemed to run okay.

It boils down to plate load too. If you were running almost no counterweight with 3 discs, 2-discs should put you in the wheel house. If you're running a decent amount of weight to get it through the big end on 3-discs, you may see if you can get a heavier lever when you go to 2 disc.

 

Thanks for the feedback.
I had decent weight on the 3 disc. 140grams total weight and I believed the clutch was still slipping in the top end. On close inspection I just discovered that when the levers are thrown all the way out (clutch clamped up with the locking screws) the levers are very close to touching the throw out bearing. so I suspect at high RPM the levers may have been prevented from providing full clamping force.
I need to fix this before I do anything else!

cheers
Dave

 

clutch disks

Nice Job guy's. You all did a really nice job of explaining it. Even I understood it. and that is saying something. Don

 

I made a call to a friend who runs a nitro fed and he said yes it can be done. He says several of the 5 second cars are running 2 disc 10in. clutches and it's on his bucket list of things to try with 98%.