I recently put in 4.56 gears (previously had stock 3.73's) and the truck doesn't seem/feel like its shifting/downshifting right.

I'm N/A, nothing special w/my setup. HD2 kit is all that's been done to the trans. Does anyone have a bin file?
It messed me up at the track last year too w/not figuring it out, as I was running a 27" tire. I'm still a beginner w/HPt.

31.9" tire
4.56 gears

anyone run something similar?

 

I thought when you change the numbers in the tire/gear calc under speedometer table it adjust the shift tables it self?

 

It does, the upshifts are ok on my 31" but the downshift isn't there at cruising speed. I can step on it in 4th and it only drops to 3rd when I'm WELL in my range for 2nd.

On my drag tire, 27", the upshift is off. It hangs up and bounces off the rev or something even though its set to shift at 5600 and rev is at 6000.

 

Are you retuning for the smaller tire at the track? I never changed my tune when running a shorter slick, cause at the track I wanted RPM to control the shift more than MPH.

 

I didn't at first i believe, but I can't recall. It was a struggle trying to get a good pass from the start. From the trans anyway, lol. I managed, somehow, to crack off a some what good run but that was like 1 of 12 passes

 

I was gonna try setting the points off this, but they are way to spread apart w/what I have on hpt to what the graph says

http://www.f-body.org/gears/

 

These are my shift settings from what HPT adjusted me to after changing to 4.56's and a 31.6" tire

Labels Speed
1 -> 2 Shift 20.38672
2 -> 3 Shift 44.84766
3 -> 4 Shift 61.16016
2 -> 1 Shift 28.53906
3 -> 2 Shift 52.18750
4 -> 3 Shift 69.31250

using the calculator/or a spreadsheet I got off here someone made (can't remember where I got it )

Labels Speed
1 -> 2 Shift 48.2
2 -> 3 Shift 80.7
3 -> 4 Shift 119.7
2 -> 1 Shift
3 -> 2 Shift
4 -> 3 Shift


this is of course the speed it says at the 5800rpm shift point. Is that accurate and what should the downshift be set at?

 

and for a 27" tall slick


Labels Speed
1 -> 2 Shift 41.2
2 -> 3 Shift 69
3 -> 4 Shift 102.2
2 -> 1 Shift
3 -> 2 Shift
4 -> 3 Shift

before long a tr220 will be swapped in place of the 212/218 "low" lift cam

 

I just filled up the tank went out in the middle of nowhere and moved the shifts around until I was happy with it. The. I did the same thing with the tow/haul button pushed. Mines a blast with tow/haul mode, because it holds gears longer and downshifts a lot sooner. It's really fun on a twisty curvy road.

 

lol, that's typically what my brother does I found this spread sheet on HPT, I'm tryng to understand it. I'm trying to figure out how to post it but it won't let me post an excel file

There's a few parameter's I'm confused on

edit: here's the link but I wanted to post up my file setup

http://www.hptuners.com/forum/showthread.php?t=27981