Has any one done this with a tunner and how are thier any fail safes to prevent your hemi from taking a trip into outter space?

When I'm in race car mode with a my 2500 hemi that is not made for racing, I can't go over 4000 rpm in any gear, rev limier shuts down the engine.

How high can a 5.7 run ( rpms ) in stock mode.

I do understand I don't have a drag racer, but lately I'm driving my truck like a racer, I'm having lots of fun with 5.0 mustangs ...

 

You can set them using the Superchips or Diablo. They have a rev limit setting where you can set it to thier maximum setting, Superchips is 6500 I believe and Diablo is 7500 if Im not mistaken while in drive. I have mine set to 6100 which is more than enough. Diablo has a setting though where you can raise the rev limit for park/nuetral from 4000 up to 6000 (without it sitting in front of me I couldn't tell you how high it can go up to) but there is really no reason move that one unless you want to hurt something.

 

Yep, as said, SC is 6500. Ive done it on mine and I can spin way on up there if I want (and sometimes do)

 

4,000 is the rev limit in neutral only. i assure you your engine shifts at 5600 or so rpms in every gear WOT.

As others stated, a handheld tuner will allow you to raise both of those features higher. Problem is, the Hemi doesn't make any power past 5300rpms. It drop like a rock after that. Some have reported quicker E.T's raising up to 6k by .2 & .3tenths