Does anyone know how high you can (relatively) safely rev a 5.4L 3V? I mean if you were to extend the rev limiter. I know that with an over-square bore to stroke ratio it wont be very high, but my 06 takes off like a rocket at 4000rpm only to disappoint me with a ~5000rpm shift point. In fact it rushes so hard to redline that sometimes it hits the RL before it can shift. They must have at least another 500rpm in them. Anyone got any info on this matter? Do the tuners extend the redline? if so how far? thanx fellas

 

I would think higher than 5k. My 4.6 is programmed to shift at 5,400, and could be set a bit higher. The limiting factor is the stock torque converter. Much over 5,500 they begin to "baloon". Try looking around in the Chips and Tuning forum for better info.
I wouldn't try to shift these trucks manually, especially is you are bouncing off of the rev limiter. If you want to make a quick run, tun off the OD and mash the pedal.

Here's a starter.

https://www.f150online.com/forums/sh...hlight=limiter

 

5.4 is a long stroke.. and doesnt like anything more than 5,000rpm safely..

 

i would never manually shift a stock automatic, but mine occasionally hits the rev limiter when it is in drive. it takes off strong as usual and then at about 4000 it takes off like VTec. i know these engines have variable cam timing but i didnt think it was this abrupt. not saying i dont like it. just trying to understand it.