After a several tests, I discovered that at some situations, the stock ECU/TCU cannot shift fast enough (in D, drive mode) that the rev limiter kicks in.

I will post more information after some more testing, and just want to let everyone know about this.

G/L modding

 

The issue of the engine revving up so fast (primarily with FI) that the tranny can't shift before hitting the rev limiter is well known and is one of the reasons for having the transmission valve body upgraded, roughly a $1K mod.

A couple of weeks ago, I posted my experience with a valve body upgrade from Level Ten in NJ. The tranny shifts very fast now and shift speed is load dependent. That is, the greater the load, the faster the shifts. But someone who didn't know anything about the VB upgrade who was driving the car in "D" and not pushing it would have no clue that anything is different. Shifts are smooth without banging into gears.

A less satisfactory solution would be to raise the rev limiter as with an ECU reflash.

 

That was always a concern for me. I also didn't like the fact that cruise control becomes flakey and will not work at speeds above 70mph. And finally, after calculating the ideal shift points for the 5AT through the 1/4 and actually testing the 1/4 mile with 23.5" drag radials (effectively gearing the car to a 3.55 ratio), the 3.5 gear ratio is actually worse for 1/4 mile performance because of the forced shift into 4th a couple hundred feet short of the finish line.