I recently bought an '06 IX MR and was hoping to take it to HPDEs semi-regularly. Initially my understanding was that while the 6-speed is weaker than the 5-speed, I didn't need to be too concerned about it if I wasn't modifying or drag racing it. However, after reading a bit more on this forum, it seems that the main problem for the 6-speed is heat that builds up after 20-30 minutes of track/road-race.

My main question is: do I need to be concerned about this heat build up in a 20 minute session on the track at stock power levels?

I've searched quite a bit in the Drivetrain forum and found lots of second- and third-hand anecdotes, as well as very informative posts from people like GEARS, but it's never clear whether people are discussing stock power or 400+ whp in regards to the 6-speed strength.

Should I consider installing a transmission cooler even if I have no plans to modify the motor?

 

Not at stock power levels but I would change the fluids often though.

 

Not at stock power levels but I would change the fluids often though.