Got my hypertech friday and installed it in about 20 minutes. Talked to a guy from hypertech and i was told to set my rev limit to +500 and shift points to +300 and increase my shift firmness, i also set my tire height at 34" (35" tire). So far so good. I notice a pretty good difference so far in power and shift firmness, but mainly in gas mileage. Friday night i drove a good 6 to 7 hours and i went from getting 11mpg to about 14 in the city and 16 on the highway, truck says 15.2 (driving like a grandma that is). Only concern is that it idles very low now. Buddy told me his would shut off sometimes when he first got his but it doesnt do that anymore... also, while cruising at 45 i stomped it to see what it would do, preformed well until about 5,000 rpms or so and i heard a knocking in my motor (i think) so i let off, ran fine for another mile or so until i was parking and thats when the truck shut off. There was no smoke or anything just a lil knock for that split second then it quit. Started back up and has ran fine since then. Has anyone heard of or encountered these problems? Should i reprogram my shift points and rev limits? Keep in mind i tow a tandum axle trailer with lawn mowers on it during the week and a 20ft. ski boat every few weeks. any help or advice would be greatly app.

 

Possibly, the shift point adjustment was too much? Maybe try +200? Sounds like your device applies a "global" adjustment to all shifts, rather than individual ones to each shift. 34" is probably pretty close for a 35" tire allowing for "squish".

I don't know why you'd have "knocking" at 5000 rpm. The engine is very near the top of it's power curves there. When yu say knocking, do you mean "pinging"?

Don't you have an idle speed adjustment with the Hypertech?

I think you need to talk to Hypertech about towing with your tune. Tow tunes set shifting strategies to minimize wear and tear on the transmission, in addition to some other adjustments. It doesn't sound like you pull a lot af weight, but a tandem axle trailer probably has a fairly high GVWR.

- Jack

 

yeah or a tapping noise, scary... but after two days now my truck runs normal again and no more low rpm's. i guess it just needed a day or two. just drove it again and punched it from 30, very impressed and so far no knocking or belt squeeling. Im still wonderin if the +300 shift point is okay or should i drop it a little?

 

"Tapping" isn't "knocking". I wonder if you were hearing valve tap?

And, I haven't a clue why a tune would cause valve tap.

- Jack

 

Could it cam phasers ticking, knocking, etc just being generally loud on these modular motors?