any one have any tips on launching in 4wd under boost with a 4wd and when and how to shift back to 2wd?

 

Most guys doing that have DD clutches, your fe won't last long doing that. They shift out of 4x4 at the end of the run.

 

You can do the heel/toe launch, but I don't think the FE will like it much.

 

there's no way to shift out during third to fourth hift or something like that? I just need more traction

 

SB fe does not like it hence why I have a Sb DD 3600 coming, I would leave it in 4wh tecnically if you shift it out it won't relerase until you push the clutch and loose vacum but if something was to pill up copming out at wot you would tear half the truck up.

 

Just do the run in 4x4, if you shift it out during the run it wont do anything anyway. The cad on the front axle wont disengauge untill you let off the throttle and there is no strain being applied to the front drive. My truck sometimes need a little throttle blip to jerk the truck and have everything disengauge, under race conditions it will stay locked until your just coasting down to a slower speed. It wont bother anything staying locked up as long as your not turning on pavement, theres guys making more passes a year than you could imagine and no issues.

 

in the same situation 4x4, 5speed. If you had a front air locker, would you spool the front end for a drag race and get all 4 wheels rolling? or leave the front end open and just run in 3 wheel drive.

 

That would be a case by case thing, no? If there is no wheel spin, then leave the front unlocked. If they spin, lock it up. But in order to spin one of the fronts, you're gonna have to spin the back.

 

it will easily spin all 4 tires on pavement. i just didnt know if the extra traction is worth all the extra effort it has to do to turn it.

 

What kind of performance losses would I see running in 4wd? Is it better to deal with traction issues in 2wd then to have all that drag the entire 1/4?

 

The cummins is so torquey and the ram is so heavy, it will take a lot of money to be set up for great 2wd launches. Traction bars, racing slicks, adjustable rear suspension and you'd have to take out a leaf or two.