My HPP3 arrived today for my HD, and I'm wondering if it's okay to have the power tuning installed while towing; it didn't say in the manual. It gave me a choice between 87 and 93 octane tuning, and I chose the 87 since I run 89 octane in it. Besides, I figured it was just adding more timing for the 93 tuning, and I didn't want that while towing.

As for the shift firmness, it doesn't let you select how firm you want the shifts like the HPP3 does for the f-bodies. Does anyone know how much the shift firmness from the HPP3 increases the line pressure? FYI, I have the 4L80E. I've tried it out, and it's firm but not too firm...feels good. Any input would be great.

Trevor

 

It firms the shifts up a little. If you want more you can give the pressure controller a 1/4turn clockwise the next time you have the pan off. Facing the front of the truck there is a two pin white connector. Pull it off, and you will see a allen socket on the controller. Only give it a 1/4 turn, anymore and you will get soft shifts at 1,2 and much firmer at 3,4.
I did it when I put in the stall and combined with the HPP I had before the supercharger, it really firmed up the shifts.
This was done with a 20year GM tech. He said the only way to get firmer shifts on the 4L80 is to install a shift kit. Since it shifts differently than the 4L60 by turning on one solinoid at a time progressivly as opposed to turning one off and another on like the 4L60 does.

 

Power tuning is @ WOT only. I think it is safe to run power tuning while towing, as long as you don't race with the trailer on. <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by -BigJ:
<strong>Power tuning is @ WOT only. I think it is safe to run power tuning while towing, as long as you don't race with the trailer on. <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" /> </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">good point! I got up on the wrong side of the bed this morning. <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" /> As for racing with the trailer attached, I don't promise anything! <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

Thanks for the responses guys.