Competition 4 hi or 4 lo ????

[Silver Bullit]

One more question and i will get off for a while. We truck pull our truck on weekends as well as work it during the week. When truck pulling should you use 4 hi or 4 lo. I know track conditions make a world of difference but which gear should we use. I usually pull in 4 lo and put the gear selctor in 2 and let the truck shift once, because in drive it falls on it's face on that last shift. But i get no speed with this combo. The duramax that has whooped me twice now runs in 4 hi and gear selector in 2. it goes like it was shot out of a cannon. But it has a different trannyy than us. Mine has an ATS transmission so i know i have a good transmission and don't need to worry about breakage. That is my last question for a while.

 

[RMcCulloch]

Try asking this on the Competition forum where most of the pullers hang out.

 

[snowracer69]

Mine has an ATS transmission so i know i have a good transmission and don't need to worry about breakage.

I wouldn't be so quick about that. Unless you are full billet, input/output/intermediate, there is ALWAYS the possibilty of breakage when pulling w/ an auto (and a stick for that matter). Any number of things can go wrong at any point and cause things to mangle themselves. Namely, if you get wheel-hop, you've got problems. Wheel-hop is bad and can thrash u-joints, shafts, and other internals of the transmission like it's nothing.



On pulling, use 4-low and third gear. Don't know why you're falling off so hard on the last shift into 3rd. Both times Denis has pulled he's been in third by the time he's moved about 20 feet. Then all ya do is hold it to the floor till it stops moving. One thing on his pickup that appears to help is that he never loses RPM's, EVER! He builds boost at about 2000 RPM's. At about 7-10 psi he lets off and holds it to the floor... the shift to second is almost instantaneous, and the shift to third is nearly right after that. He is then sitting right at 3000 rpm's for the entire rest of the length of the pull, all in 3rd gear. I can show you a video of this if you like. He does lose some speed, but never RPMs or tire speed... just forward velocity. Both of his pulls have been on extremely bald street tires aired down to about 37 psi and at 8000 lbs.



Would ya please smoke that dmax next time? It's not cool for them to be winning... makes us look bad... .





::tounge-in-cheek ON:: maybe it's your transmission :-laf ::tounge-in-cheek OFF::