ZF6 Pullers out there?

[wilsondiesel]

I have a buddy with a ZF6 LLY, south bend dual comp clutch, 68mm charger, 10mm pump and 45% over injectors. He is running to aggressive of mud tire, and is having a hard time coming out of the hole smooth. Any advice on to switch to all terrains that he can blow off out of the hole? Or what gear to run and what rpm to leave at? Thanks!

 

[Bdsankey]

I have a buddy with a ZF6 LLY, south bend dual comp clutch, 68mm charger, 10mm pump and 45% over injectors. He is running to aggressive of mud tire, and is having a hard time coming out of the hole smooth. Any advice on to switch to all terrains that he can blow off out of the hole? Or what gear to run and what rpm to leave at? Thanks!

Mud tires, around here on our hard clay tracks, take 800+ to run them properly and spin out at the end of a run.



What gear and RPM is he leaving in now? Personally, I think an all terrain may be better for him but I'm nowhere near as experienced with manual trucks as I am with autos.

 

[wilsondiesel]

He was trying 3rd 4 low and letting out of the clutch at 3200-3000 rpm. Yeah the zf Pulling game is new to me compared to auto.

 

[Bdsankey]

He was trying 3rd 4 low and letting out of the clutch at 3200-3000 rpm. Yeah the zf Pulling game is new to me compared to auto.

68mm vgt or S400?

 

[wilsondiesel]

Vgt on this truck

 

[dirty_max]

He's having trouble in 3rd? Oh boy. Come out of the hole way higher on rpm. I had mud terrains and pulled in 4th gear and i left the line closer to 4k rpms. And if it was a sticky track i would side step the pedal and send prayer up to the big man

 

[wilsondiesel]

I tell him to leave higher as I’d like to see him run 4th but can only lead a horse to water, can’t force it to drink lol

 

[dirty_max]

He has to be tached out all the way down the track. I had a track once that i could absolutely not get off the line in 4th and had to run in third and it was terrible. That was the hottest i had ever seen that truck. The engine was ticking, my coolant temp was still climbing while i was driving away from the sled, pyro was burried for quite a while. But it was fun

 

[Bdsankey]

He has to be tached out all the way down the track. I had a track once that i could absolutely not get off the line in 4th and had to run in third and it was terrible. That was the hottest i had ever seen that truck. The engine was ticking, my coolant temp was still climbing while i was driving away from the sled, pyro was burried for quite a while. But it was fun

After looking at the rpm/speed calculator I can see why. 3rd gear is only 2.1:1 ratio whereas 4th is 1.31:1. Every auto duramax guy until up until 800-1000hp runs 3rd gear in an Allison which is 1.41:1 so he should be able to run it in 4th.

 

[Chevy1925]

After looking at the rpm/speed calculator I can see why. 3rd gear is only 2.1:1 ratio whereas 4th is 1.31:1. Every auto duramax guy until up until 800-1000hp runs 3rd gear in an Allison which is 1.41:1 so he should be able to run it in 4th.

but you are not accounting for converter torque coupling that basically reduces 4th gear ratio by 2 or 3:1 UNTIL you hit lock up. that helps get you out of the gate with enough speed before hitting lock up and carrying it through.

you slip a clutch like this and it wont last long

 

[Bdsankey]

but you are not accounting for converter torque coupling that basically reduces 4th gear ratio by 2 or 3:1 UNTIL you hit lock up. that helps get you out of the gate with enough speed before hitting lock up and carrying it through.

you slip a clutch like this and it wont last long

All depends on what evil you want to play with. RPM the thing out for all its got or slip the clutch out the hole. Every stick sled puller realizes the clutch is a wear item and knows that it doesn't have infinite life.

 

[Chevy1925]

All depends on what evil you want to play with. RPM the thing out for all its got or slip the clutch out the hole. Every stick sled puller realizes the clutch is a wear item and knows that it doesn't have infinite life.

youre missing the point of my post....

 

[clrussell]

He's having trouble in 3rd? Oh boy. Come out of the hole way higher on rpm. I had mud terrains and pulled in 4th gear and i left the line closer to 4k rpms. And if it was a sticky track i would side step the pedal and send prayer up to the big man

This is what we did with an s475 and 100%s running 35” mud tires

 

[dirty_max]

After looking at the rpm/speed calculator I can see why. 3rd gear is only 2.1:1 ratio whereas 4th is 1.31:1. Every auto duramax guy until up until 800-1000hp runs 3rd gear in an Allison which is 1.41:1 so he should be able to run it in 4th.

sounds good on paper but just like the other guy said, getting out of the hole is an entirely different story. yes we realize the clutch is a wear item but either way you come off the line, it rough on things. moral of the story is, auto trans is better.

 

[wilsondiesel]

Well guys he made a lot smoother pass this weekend! He bounced just a bit out of the hole but came out of it very quickly, he ran third but could tell it was tached out going down the truck. Thanks everyone for the advice. Now to play with fire on my LB7 and get the other 10mm pump put on for the rest of the season!