Has any one used this for racing. I've never use it till this past weekend to haul dirt and thats when I thought about it. the shife points are higher but I don't know at what RPM max tourqe is made for each gear. I never had my truck Dynoed yet!

 

word, it just holds the gears longer...i have noticed its a bit faster when i punch it when its in tow/haul mode...

 

tow haul manipulates the transmissions electronic controls, it commands the PCM to reference different tables in the tune for shift patterns and firmness

 

It's just a trans modifier.....we've ALL looked a this at one point or another to see if it could be made into a Tow/Haul *** mode

 

does it bump line pressure at all? it feels firmer aside from just different shift points. mine is tuned differently wnyway so I know it wouldnt apply but what abou the stock tune?

 

Yes it does bump the pressure a little

 

I get better times at the track with tow haul mode. I have my shift points set a little hight in tow mode. Shift firmness is the same because I have a vacuum modulator

 

Thunder550
I was noticing your 1/4 times in your sig. I am a .10 faster but 5 mph slower

 

The following article discusses setting tow/haul mode to tow/haul *** mode using hp tuners:

http://gmhightechperformance.com/tec...uck/index.html

 

What engine and cam are you running? I have noticed that people running the Radix'ed 5.3/4L60E or a 6.0/4L60E combo seem to trap a little better but have slower speeds. My 5.3/4L60E combo was a 13.57@99, 1.92 60'.

I think it's cause of the gear ratios. The 3.06 1st gear in the 4L60E gets you out of the hole faster, but the 1-2 shift generally makes the trucks fall on their faces. I think 2nd gear in the 4L60 is 1.75. Big drop from 3.06 to 1.75. Plus, you are crossing the traps well into 3rd gear.

The 4L80E has a 2.48 1st gear which sucks getting you out of the hole, but the drop from 2.48 1st gear to a 1.48 2nd gear is much less dramatic and keeps me in the meaty part of the power band. I cross the traps right at the top end of 2nd gear.