[beleive]

will be taking truck to track in couple weeks(f250 crew auto XL 4x4)ID tunes on sct,4inch ex.Whats best way to launch truck?Just looking for advice,thanks a million.

 

[David6]

I launch in 4 wheel high at around 2100 rpm's.Don't sit there and hold it for too long because it builds up too much heat in the torque converter.
Have fun and post your numbers after the run.

 

[cmirabile]

Like iracemx6 said, launch with a fair amount of RPM's. I have read in Diesel Power Mag that you should also launch before the green. As for 2100, I don't know if I could EVER do that. A little too worrysome for me.

 

[David6]

Trust me I about crapped the first time I wheelhopped it in 4 wheel drive at around 2300 rpms. /ubbthreads/images/graemlins/phoney.gif.Some people go by boost and some rpm's.I have seen some that said they launch at 20 lbs,but my truck starts pushing through the lights at around 10 lbs.
The best way is to just run it and go with what works best for you.

 

[cmirabile]

iracemx6, What kind of mods are you running? Updated tranny?

 

[David6]

I have a Magnaflow 4 inch from the turbo back and a SCT with custom files from Innovative.
My best is a 8.8 in the 1/8th with my Xtreme Street file.I have some issues with my race file and still haven't got it figured out yet.
I also have a Edge Platinum with the Hot Juice upgrade that I run on level '0' for a display.I quit using it due to the dreaded FLARE shifting,but am going to get a trans only file from SCT so I can run the Edge.
I haven't done anything to my trans yet,but the Edge was getting ready to FRY it if I hadn't switched to the SCT!!

 

[henryhill]

I have the SCT and a few other mods. I put it in 4hi and let it build till the boost levels and you can tell it is not going to build anymore power, just over 22psi. The best thing to do is to go out and try it on your own so you know how long it takes to spool it up and get going so you don't sit there burning the convetor.

 

[1SickHarley]

Don't know how and why you guys are launching at 20-22psi! I ran a buddy;s 150 H.D. Edition Supercharged and built 12 psi in 4hi and that was it. When I let off the brake a 4 wheels spun like mad and the truck torque steered left to right all over. I did yank him by 2 truck links right off the bat and spanked him though. You guys sure your guages are correct? I launch my truck at 4-5 psi in 2 wheel drive and it's a rocket. I feel sorry for ya'lls transfer cases.

 

[David6]

I agree!! There is no way my truck will boost to 20lbs. plus without pushing me through the lights.I just build mine up to around 2000-2100 rpm's and let it go.Anything above that and it wheel hops like crazy and the 60' goes down.

 

[ipkyss]

anything above 12-15 psi and mine wheel hops like crazy. Horrible feeling. And its not wheel hop like in a car. With 4wd it kind of bucks and hops striaght up and down. As long as the turbo is spooled even a few pounds you are good to go. My 60ft times don't change much from 2-3 psi to 10+

 

[David6]

What kind of times have you run?

 

[Jassman]

Ive done it three times, launched at around 1900 rpms. 13.71 with the mods listed below in my sig, on xtreme race.

 

[DALPilot]

What kind of tires are you guys running? I can launch at 22-23 PSI and it just grabs and goes. If your running stock tires, they are gonna spin pretty easy. 13.4 in the 1/4

 

[Jassman]

[ QUOTE ]
What kind of tires are you guys running? I can launch at 22-23 PSI and it just grabs and goes. If your running stock tires, they are gonna spin pretty easy. 13.4 in the 1/4

[/ QUOTE ]

The stock factory tires @ 35psi

 

[Shadow_Grey]

When do you guys shift back out of 4x4 to two wheel drive? 660'mark? 330' mark? 60'? Some time in second gear? or third? or at the end? Will it truely disengage under that full power throttle or not?

 

[David6]

I'm running 285 BFG's.
I can run mine up to about 10lbs of boost and then it
starts pushing /ubbthreads/images/graemlins/shrug.gif