383ss

iTrader: (14)

good post, so you can edit both modes with ls1edit???

KeukaZ71

i thought the Tow/haul mode was the same concept as raising the shift points with a programmer (e.g. HPP3).

it shifts at a higher RPM, which is important for towing. i tow alot and if an automatic tranny shifts to early, you slow down and stop pulling hard, which makes your engine work alot harder in that low RPM band.

ThunderZ28

iTrader: (7)

i downloaded the HPPIII tune off of my truck with edit, but i never turned on the shift firmness mode because of the servo's and shift kit. if someone wants to compare what ive got i could email it to ya if you want.

1LEThumper

Onyx, yeah shoot me a email or PM when you are heading down around this way. Maybe I'll have the Camaro done and tuned by then.

The only difference I saw like I said was it has shift speed differences for the 2, and base line pressure. Other than that I saw no difference between the 2. There might be some converter lock up differences but I haven't played with those to much.

Keith

On my stock truck I see:
5400rpm shifts with the Tow/Haul on
5600rpm shifts with the Tow/Haul off

Flyer

iTrader: (1)

Tow/haul raises line pressure, it locks the converter sooner under part throttle and also makes it so that it doesn't unlock without downshifting. The tranny will burn up if the converter never locks up, so under a load, they have it lock a lot of the time. I'm not sure about WOT shift points though.

sleepersilverado

iTrader: (1)

wide open shift points are lower with it on or at least it was on mine. it rases part throttle shift points. i use to drive around with it on all the time before my tune cause i did not like how soon it shifted just crusing around. so i turned it on and it held first and second and a little of third longer.

1LEThumper

yeah...thats what I was saying...it does raise the shift points as far as mph vs. TPS....WOT isn't that much different..it also seems like you can manualy hold 1st and 2nd longer as well with it on.

Jorday

I was gonna say that I thought it made it shift early in tow/haul in the 1/2 ton gassers that I've seen.

Flyer

iTrader: (1)

On the half tons .. it will hold a gear out until a set speed. If it doesn't break that speed .. it doesn't shift, period. It also doesn't do engine breaking unless you have the selector in the gear that the tranny is in. For example if your cruising at 59 (mine shifts at 60 into 4) and the selector is in D, it's pulling or holding the speed in 3rd still. If I let off the gas to coast to a light, the engine will fall to idle and the tranny goes to what feels like a nuetral state, and resumes 3rd as soon as you get back in the gas. That's my biggest problem with tow/haul. I like being able to use the engine to slow me down, even more so when I'm towing.