Question for those who launch in 4-hi
 

Do you keep it in 4-hi the entire run, or shift into 2wd shortly after the launch?

The entire run. If I remember the transfer case won't disengage until the pressure is released anyway.
I also leave the rear locker on but make sure you turn both off before you make your turn off the track.

Why 4H instead of 4A?

I couldnt launch any harder than 2750RPM in 4A. I wonder if 4H would make a difference in that regard.

I wouldn't try 4A because the IWE aren't engaged and trying to get them to engage them under stress might not be a good idea.
I made a few runs a couple weeks ago and anything over 3500rpm and the truck would nosedive after about 10 feet. Not sure if it is traction control or what but my 60' times were 2.5X. Found the sweet spot on mine is 2500-2700 and that gets me 1.9 in the 60'.

hmmm I wonder if the 10 speed would make a difference. Well this just gave me a reason to go back to the track. Thanks guys!

Just had to rub in the 10 speed, huh...:biggrin:

Hahaha it was not my intention but it is a great feature I am not going to lie.

I've done 3500 launches in 4hi and she doesnt like them that much especially at the track computer cuts power, but from testing i've had my best 60' and times launching at 1k and just letting converter flash then actually loading her up. If there was anyway to remove watever is limiting or cutting power on hard launches it would be a big difference since it was a pretty violent launch i'm guessing thats why computer killed it.