[Jackpine]

I'm getting in on this a bit late, but the 5400 rpm limit I've been posting is one that was posted by Mike Troyer (Troyer Performance) a couple years ago. It's the ONLY reference to an RPM limit I've ever found. Clearly, it applies to a specific transmission too. But, it seems to be a limit that doesn't ruffle anyone's feathers.

I think Bill has put the rev limit at 5600 in some tunes. My thinking here is that you're not really going to spend much time at all at this RPM, and, he posted somewhere that in early testing of the Edge, they set the RPM limit at 6000 on the test truck without causing damage. I would not risk that number. So, setting the limit a bit above the start of ballooning should not be a problem.

It's obvious you don't want to spend a long time at high RPM, ever. In my driving, pulling a trailer up long 7-8% grades of 8-10 miles, I regularly see RPMs over 4000 for longish periods in 2nd gear. This causes the Transmission Fluid Temperature to go up to between 215-220 degrees rather quickly. You're going to get fairly rapid breakdown in the fluid at this temperature and that can lead to early transmission failure.

Hope this all makes sense! I DO wish we could get a "Ford specified design limit". I know it has to exist, I just can't find it!

- Jack