i know that. that why i stated only on take off for smooth engagement. no clutch is designed to slip while fully engaged.

for the most part anything short of putting a sled behind you with about 700 plus HP will not slip a well designed dual disc like southbend makes. when not slipped purposely.(spelling)

 

I'm putting down about the same power as you and I can't get mine to slip after two whole seasons of hardcore, spark-spittin sledpulling. Your Edge slip meter is a joke. You'll be spinning the tires WAY before that clutch slips. Get that thing to a dyno!

 

I had a edge at one time and that slip gauge is a joke. Right when I put my OFE in the first time I back up the was showing 30% slip to. I now it didn't slip because all did was let off the clutch. Then it always show that I was sliping the clutch 5018% when I started to spin the tire on a wet road. So I don't think it work to well.

 

Whitesport, you are pullin with a 3600? 12cb?

 

No, it's a 3850 12cb BUT plate load is only used to compensate for excessive heat, the 3600 would be just the same.

 

Gotta love the 3850! Have you found that the smoothest way to start out (in 2nd) is take the RPMs up to about 1500-1700 and then as you are easing the clutch out you actually ease off the gas a little as well allowing the RPMs to come down and synch with the speed as opposed to most cars where you would hold the RPMs steady until the road speed caught up ad it fully engaged? This seems to work best for Optimus.

 

Daily driving, I just let it out slowly at idle until it starts to grab, then quicker as it pulls the truck, it's pretty smooth. My only beef w/ it is trying to back up a loaded trailer, then I have to rev to 1700 or so and ease the clutch out to keep it from "hopping"
Sledpulling, is a little different though I bring RPM up to 2600 or so, and start loading the drivetrain, while keeping an eye on boost, and keeping RPM above 2500. When boost is at 30psi, and RPM is 2500, I drop the clutch and stand on the gas! it's never phased this clutch.

 

Tell me about backing up a loaded trailer! Especially if you have to go up hill! People probably though I had hydraulics in this bad boy I was hoppin' so badly! I eventually had to just put it in 4LO so I could just use the clutch. I am hoping that my new spring upgrade will eliminate that. The fact I have taller gears exagerates the issue.

 

I tried the 4LO thing but then you can't turn!!! It really sucks up a hill! I'll take it though, I got tired of changin clutches! What spring mod are you talking about?

 

I believe it is some sort of spring design to absorb most of the jarring friction of the two clutch plates going together and it reduces the noise so much so that no one who doesn't know you have a DD will ever think you do. It should make it such that you can engage in 2nd gear for starting with no throttle just like a stocker.

I know about the 4LO, I had to do some turning but just had to muscle it through because my driveway in pittsburgh is so steep that I couldn't get the rev's high enough such that sliping the clutch lightly enough so as to not hop would work. It sucked, but I got it in there!

 

Oh, yeah... I read about that. Sprung hubs in the clutch discs, should help alot, but I'd worry about longevity of the springs in sledpulling applications. I've seen dual disc racing clutches w/ sprung hubs and springs laying in the bellhousing! They should be fine if you're not shocking them too often though. It would be nice to have a quiet truck again! I start off in 2nd w/o throttle every time, just like a stocker... I wonder if your wheels and tires are why you can't do it?

 

Probably given the fact my gear ratio has dropped from 3.73 to 3.19 and soon to 2.89! Peter (@ SBC) said that I will loose no "toughness" or "longevity" using the sprung hub design because I told him I may want to take Optimus to a pull or race now and again !

 

Jeez!!! What are you going to put 24.5's on opti?? Peter is the man! He's taken good care of me in the past, and I will always stick with his clutches...(pun not intended) lol
Sounds like when mine finally dies from the abuse, I'll have a quiet option.

 

Not 24.5s, just 41" tires on the 22.5s I am going to a 295/75 up front and a 455/50 rear!

 

455/50??? That's a super-single isn't it?? That's gonna look