A very close friend of mine has been custom tuning Chevy's, Fords, and Dodge for about 5 yrs. now with HP Tuner. He hangs out at the local drag strip during the summer months and has tuned many modified cars and trucks which run in the 6s and 7s on the 1/8 mile.
One year ago I bought a 2008 Tahoe Z 71 with 140,000 miles and took it to him one afternoon. We spent the next 3 1/2 hrs. driving around making one run from dead stop up to 105 mph (he shut off speed limiter before the run), several hard pulls from 30 mph and so forth. He records what is going on with the stock tune while making these runs and then makes adjustments here and there, down loads the changes, we make another run and repeat the process while making fine adjustments through the r.p.m. range from off idle to shift point. After all was done he set the shift point from first to second at 5700 and had him shut off the delayed shift which eliminated the lag between shifts. I had him shut off the cylinder cancellation feature that switches from V8 mode to 4 cylinder mode. So much happier without it and mileage is no different without it due to a more efficient tune.
The only other mod I have at this time is a K&N air filter which was installed before the tune. I don't run my truck hard, just really enjoy the MUCH improved drive ability it has. The tune added very noticeable power and torque which makes it move effortlessly and has a snappy shift and feels very much like an early 70s Monte Carlo I had with the 454 and TH 400 trans. The 2008 Tahoe has the weak 4L60E trans. which won't take a lot of abuse and I wouldn't recommend completely shutting off your delayed shift with with this trans. unless you have good discipline and are able to keep your foot out of it 99% of the time. I like the locomotion torque so it isn't much of a problem for me.
I was his 96th tune and he is really sharp on how to get the most out what he is tuning. The only annoying change he couldn't make was to shut of those obnoxious chims for the seat belt, rear deck lid opening and what ever else it is programmed to chim about.
We have been friends for 40 plus yrs. and have done a lot of street racing years ago.
I have put 12,000 miles on it since the tune and all is well. He has my stock tuned saved so if I ever want to return to the factory settings.
One year ago I bought a 2008 Tahoe Z 71 with 140,000 miles and took it to him one afternoon. We spent the next 3 1/2 hrs. driving around making one run from dead stop up to 105 mph (he shut off speed limiter before the run), several hard pulls from 30 mph and so forth. He records what is going on with the stock tune while making these runs and then makes adjustments here and there, down loads the changes, we make another run and repeat the process while making fine adjustments through the r.p.m. range from off idle to shift point. After all was done he set the shift point from first to second at 5700 and had him shut off the delayed shift which eliminated the lag between shifts. I had him shut off the cylinder cancellation feature that switches from V8 mode to 4 cylinder mode. So much happier without it and mileage is no different without it due to a more efficient tune.
The only other mod I have at this time is a K&N air filter which was installed before the tune. I don't run my truck hard, just really enjoy the MUCH improved drive ability it has. The tune added very noticeable power and torque which makes it move effortlessly and has a snappy shift and feels very much like an early 70s Monte Carlo I had with the 454 and TH 400 trans. The 2008 Tahoe has the weak 4L60E trans. which won't take a lot of abuse and I wouldn't recommend completely shutting off your delayed shift with with this trans. unless you have good discipline and are able to keep your foot out of it 99% of the time. I like the locomotion torque so it isn't much of a problem for me.
I was his 96th tune and he is really sharp on how to get the most out what he is tuning. The only annoying change he couldn't make was to shut of those obnoxious chims for the seat belt, rear deck lid opening and what ever else it is programmed to chim about.
We have been friends for 40 plus yrs. and have done a lot of street racing years ago.
I have put 12,000 miles on it since the tune and all is well. He has my stock tuned saved so if I ever want to return to the factory settings.
