Mark,
I know this is probably a sorry excuse, but, understand how many people I deal with daily and, unfortunately, I don't have total recall. I try to keep good notes and return all calls that I have missed. About your clutch, you stated that the 2nd one burned up but it appears to still be in your truck and working without slipping so I don't think that it actually burned up as stated. Now as to horse power numbers and clutch capabilities, all of my clutches are rated with hp and torque numbers. For some reason your truck was producing a higher torque number then the standard equation that goes along with hp numbers. The OFE is only rated to 1000 ft. lbs. of torque and you're exceeding 1100 which is over my FE. Now that the turbo has changed, the torque band must have come down, thus the clutch not slipping.
It's kind of funny, I get quite a few phone calls of all types of various situations and I need to listen and weigh and try to learn what each and every performance product actually produces so I can better suit the clutch to the needs. Now, some torques come on at different RPMs whereas others come on at other RPMs. Now I'm not saying this is what you did, but I have had people call me and say that if they try really hard at a particular level they can actually break my clutch away for a second and could I please send them another to see if we can not have this happen. Now correct me if I'm wrong, if you try really hard to make something happen most likely you will succeed. Should I instantly send out another clutch?
Now with the comment about Piers's clutch slipping I chose to use Piers to test our clutches because of his knowledge in the field and knowing how powerful his truck is. As a matter of fact, Piers has installed approx. 5 clutches. This is what is enabling us to find a limit and rate the clutch. I believe his truck is in the mid to upper 700 hp so if my first designed slipped, I certainly didn't mean to sound cocky or arrogant but more that I was surprised that it did. It did however put me back to the work bench to make it even stronger. Some of his issues for taking the clutch back out would also be due to shifting situations. Now understand that Piers is a drag racer at heart so we are trying different things and working with very little tolerances to create a speed shifting double disc clutch, which has not been done yet. So yes, it will take some work to get that just right. Unfortunately I do not have a truck sitting in my shop to play, so I have to use the field to do my work. As we sell clutches for all makes and models of vehicles I could no way own one of every vehicle that is made. We have the original dd clutch that piers was using at 3100 lb. plate load. We are now using pp that offers 3600, 3850, & 4200 lbs. With the 3100 it appeared to have broken away at approx. 600 hp so we are rating it for 550. Now you can kind of take the calculations as to plate load and figure it on up.
To answer some of the questions above as to when and where to use DD clutches. I am still not a fan of sticking a DD in every situation. I strongly believe it will have a deteriorating effect on the transmission and drive train because there are no longer any dampening springs to absorb the diesel spiking. If one is not needed I don't believe it should be used. When is it needed? Obviously when the hp and torque power exceed the power of the single disc or if you intend to put yourself into extreme conditions such as sled pulling, continuous drag racing or grossly overloading. Now we have worked very hard to make our DD as smooth as possible. If I had to compare the drive ability of the DD to one of my single disc I would say it is very similar, if not a little better, then the FE. You may ask why not put the 4200 lb. in all applications to ensure no slippage, well that is because, with the higher the plate load the harder the pedal effort and the more the strain on the vehicle.
Now Mark, if you do choose the competitors clutch I completely understand. Will I give you one to offset? No I will not. Will I work with you price wise? Of course I will. But it sounds like your clutch is holding just fine and doing what you wanted it to do. Correct me if I'm wrong.
Peter
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