I've launched my srt8 twin turbo as high as 5k on stock half shafts with no breaks. In fact over a weekend I had 20 passes with launches between 4k and 5k.
Now the real kicker is when I had minor mods and 7 day off the showroom floor I broke the stock half shafts 3times over a 60 day period...and this was at a time when upgrades for the axles were all but nonexistent. I did upgrades and broke those too.
It seems that the launches best at 4800rpms, the car hooks and I get 1.85 to 1.80 60 foots. My time slip is posted in the 12 second club best time was 12.14 the car will do 11 s but I am still tweaking tunes and suspension.
The tip or trick you are looking for is the fine line between quick slipping and side stepping the clutch. Do not side step the clutch, just let it out fast and smooth and give throttle equal to half of what your clutch release is...you will shoot out like a rocket if you don't get pushed back in your seat and the hair doesn't stand up on the back of your neck you either slipped the clutch too much or you broke an axle.:thumbsup:
Speed shifting is easy you will have a rougher time convincing your mind to not lift which is the discipline. **** at 5500 to 5800 Rpms don't lift off the throttle. I recommend 5500 to start with as this will provide you 200 rps of error if you've increased the rev limiter to 6800 then you shift at 6000 but I don't recommend this unless you have mastered the speed shift at 5800 Rpms first. Essentially at 5500 you have to shift fast and the car will jump to 6000 Rpms before the shift is finished. At 5800 there is no room for error unless you have increase the rev limiter. Onnce the shift is complete the car will lurch forward and continent accelerate you may chirp the tires this is normal. Speed shifting in our cars is worth about .50 on the quarter mile, unless your stock then it's worth about .30 on the quarter. I've never ran an eight mile track.
The 12.14 I ran was shifting like granny. I was feeling out my turbo setup and ran a that time which was better than my days average which was 12.30 @ 11# s with a da of 1700. Last Saturday I ran 12.40 with a da of 2700 and air temps at 75+ degrees. Btw I run nt05 rs 325'sx40x20.
Your milage may vary...that's my experience with just under 100 passes on my car:redcap: