I have a 99 5.4 4x4 with a 4 inch lift. I had a jet power module in it and decided after reading all the posts about the 1715 and Troyer Performance to try them both out. I am very impressed, I took out the old chip out for a couple of days and drove the truck until the tuner got here. I would say the tow/perf program probably doubled the power of the old chip. It also shifts much more crisply and consistantly. My only concern is when the truck downshifts out of OD it is very harsh. Especially when cruise control is on it is like the rpms don't pick up in time and the whole truck jerks forward. Infact the first time it did it it chirped the tires. I am wondering if this will calm down as the truck is driven more.

 

Are you sure it wasn't the belt slipping?

 

it's possible, I wasn't expecting it so I wasn't paying cloe attention.

 

Hey merc, I know mine does some strange things shifting every time I change the programming between "tow and performance" the learning curve of the computer usually settles down within a 100 miles or so, then it's fine until I change it again.

T-man

 

thanks for the info, I wondered if that was the case.

 

Hi merc68,

A couple of quick points.............

As T-man mentioned, there is the basic relearn cycle you'll go thru any time you either disconnect the battery (which clears the PCM) or if you flash the PCM (change it's program) - either one of those clears the PCM so you go back thru relearn, and adaptive strategy adjustments begin again from scratch as well. In some trucks, the driver notices nothing obvious, while in some others, the driver many notice idle speed & quality changes, along with different shifting in the automatics for the first few hundreds miles or so - that's perfectly normal. In fact, if you take a close look at your vehicle's owners manual, in most of them you'll find that somewhere in there it talks about this - meaning, it tells you about how the transmission may shift softer or firmer than normal for a little while after disconnecting or replacing the battery, for example.

Now, in terms of actually shifting hard enough to chirp the tires on a 4-3 downshift...........well, these trucks don't have anywhere near enough power to actually chirp the tires on a 4-3 downshift, or a 3-2 downshift, or a 2-3 or 3-4 upshift, either - even if the tranny could shift hard & quick enough - which it can't. As OPIE mentioned in his post, that was just your serpentine belt squealing, which happens sometimes as the OEM belts are rather low quality in terms of their actual grip on the pulleys, even though they last a good while before significantly cracking the ribs. You'll also hear that belt shriek on a full-throttle 1-2 upshift, I'll bet - almost all these trucks do that with a good performance tune on board, and some of them do it even in bone-stock trim.

To cure that, simply replace that serpentine belt with a Goodyear Gatorback serpentine belt (you can find them on our web site at www.TroyerPerformance.com) & that sound will go away.

This basic relearn cycle (idle speed & quality, basic throttle response, etc.) is pretty quick, usually it's done within 100 miles or a few days or so - and the transmission should be shifting like normal within not more than 500 miles after the program change, many times less. Just make sure you take the "default" program upload in the 1715, and *not* go into the manual menus to crank up line pressure manually - if you do that and put it at more than about 2-3 notches above the centerline ("ST"), then it may shift a bit too firm for your tastes. We recommend everyone just use the default upload in the 1715 for the first month of driving, before deciding they actually have to have even more shift pressure than what the default upload provides - just FYI.

Good luck!