Hey Peter,
What makes Sled pulling so hard on clutches? Is it because you have to slip it to get out of the hole?

Do you think the OFE would handle unloaded speed shifting once in a while?

 

I don't know anything about the Zoom offerd for diesel other than I have seen it advertised, but I can say this. I bought one from Summit for a SB chev p-up I built and I don't have much good to say about it. It was supposed to be good to 500 HP and at 400 it toasted pretty quick. When it was spakin new it held fine but after about a week of hammering on it it would not release when you wanted it to. Double clutching became a must. I pulled it out after three weeks and replaced it with a center force.

 

To answer the first question....YES! Heat is a clutches enemy and the hotter it gets, the harder time it has to grab. Dual disc clutches do two things, keep temperature down and obviously have more holding power.

For the second question... yes, if properly done. Meaning, foot off the clutch before you hit the go pedal.

Peter

 

That wouldn't be a speed shift would it!

a speed shift to me, would be never letting off the go pedal and and just start grabing gears!!!

I don't thing any body has been able to make a slick shift for our tranny so that we could just let the clutch out and keep banging gears like the pro stock drag racers do.

 

Or is that a powershift? What, exactly, is the difference between a speed shift and a powershift? 'Course I don't really have to worry about it, just put it in D and floor it

 

So are you saying then that I WOULD need a dual disker if I want to "no lift" shift?
I have done this quite a few times on the Zoom, but it's had enough. If I just keep her to the floor and bang through the gears my truck is scarry fast!


NOTE: I misquoted the ConOFE in an earlier post by a long shot. I apologize to South Bend for that! I need to be more careful!
I bad mouthed Gear Vendors on this site for not offering replacemnt parts or a service manual and now they won't even answer my emails, so Peter from SB has been very cool about it.

 

the center force holds up ok in the 5spd trucks. the main problem and differance between the zoom and center force is where the weights are. they are both diaphram type clutches. the weights pull on the fingers in the centerforce design and the plate in the zoom. I have sbc in old rig and zoom in new. both great units one has considerably less pedal effort, that being the zoom. I do not work for zoom I work for dc in the auto trans plant.

 

I ran Zooom clutches years ago.

66 Chevell 302 DZ tunnel ram
2 - 660 Holly Center squirters
5.57 locker m22 Muncie 4 speed.

They sucked then and they suck now......... period

I ripped the centers out at least once a week leaving the line at 7500
The R&D "team" kept blowing smoke up the wazooo for the entire season.
I switched to Schifer the next season and NO more problems.

The above comments are mine and mine alone.

59

 

Well, I can tell you that the Zoom I have in my truck ir rated 600ft/lb and it has held up under more pressure than that. It won't take any more speed shifting, but it hasn't broken.
I agree that Zoom used to make junk, but I think they have improved.
Merry Christmas!
Mark

 

Kinda funny you work for Mother's auto trans plant and drive stick shifts! I love irony.
Thanks for your input. It is valuable. Have you beat on that zoom at all yet? Will it clamp down a full boost speed shift?

 

sorry to open this thread back up but im runnin a zoom in mine and have had no problems with it. Im runnin right around 1000 in torque and i cannot make it slip at all and believe me i've tried its a really good clutch and is very strong to hold up to my lead foot and i would buy another one again if i needed to.

 

Have you tried a full (or nearly full) throttle power shift? If it'll lock your 1,000ft/lb's down at full boost then I will be getting one soon!!!!

 

I don't think you gain enough in a full throttle "power shift" to justify it, I can keep the momentum going nice and strong when just speed shifting. But I can attest to his clutch being pretty dang good! I've rode in it before and it wasn't too grabby for how well it holds... Me and Blake (olbetsy) are going to hit up Gullo Ford's Mustang dyno and see what his beast is putting out soon hopefully. I am hoping to get some numbers as well so I can give a good comparison to before/after head P&P and a cam swap.

 

Not to split hairs, but speed shifting is no lifting!
Actually, I blip the throttle when I speed shift because the darn thing revs so much higher than it used to, I don't want to spin a rod bearing or something. My Zoom performance clutch "only" took about three full power shifts before it told me it had enough!

 

mhuppertz I dont think you will have any problems with your no lift shifting. I have done alot of speed shifting with no probems. Another reason i know the clutch will be fine is that i was haulin a 20k lb load of round bales and put it on the floor an twister my imput shaft. The clutch didn't give at all and when i pulled the trans off to change the shaft i pulled the clutch off to check it and it still looked brand new.