Tip 2: Let upgrade your engines software

[playtoy_18]

Noticed this thread on a search,I tune GM vehicles from 96 to newer somewhat regularly.
Alot of the performance tuning itself will actually increase MPG,it's the difference in the weight of the drivers foot and their habits that usually drop it.

I've yet to mess with it,but plan to start building some "eco-friendly" tunes that will easily have plenty of performance and plenty of mileage savings.
I will be using my wifes 2004 Impala 3.8 as a testbed,and plan to play with things like water/methanol and hydrogen generators along with tuning to achieve the best mileage possible.
We make weekly 6hr trips usually,so i've got plenty of drive time to test with.
I'll be saving and keeping a log more than likely-I'll post it up sometime. Working out some software issues right now,plan to be up and running next week though.

[jazzie604]

for the drive by wire crowd, there is a tuning device by HKS that changes the readouts for the accelerator pedal position sensors. You can tune it to be more or less agressive, literally changing the curve of the pedal circuit allowing for more control of the throttle due to the clumsiness of the average right foot.

[playtoy_18]

You can do that with a rheostat wired into the TPS return signal.
Of course you need to datalog and test the vehicle response to find the right curve-but pretty simple.

[jazzie604]

I dont think we are talking about the same thing. You are talking about changing the value for the TPS that the computer sees, while not changing the actual position of the throttle plate eg: you open the plate to 50%, the computer only sees 45%. What I am talking about is actually changing the position of the throttle plate in relation to the throttle pedal. An electronically controlled throttle plate(drive-by-wire not cable) has 2 sensors on the throttle pedal that have an opposite sweep of each other (one sensor goes 0-5v, the other reads 5-0V) to determine how far you are asking to open the throttle. the computer then tells the throttle plate actuator how far to open. What I was talking about is a device that changes the rate of pedal movement, eg: on the stock car 1in of pedal travel may equal 25% change in throttle position. After the device is installed you can make 1in equal 10% or 50% change. For the racer crowd, this quickens throttle response. For the conservation crowd, this is like installing a hand lever for the throttle. You can be more precise with throttle inputs while still using a clumsy foot.

[playtoy_18]

I'm thinking same principle only the rheostat would be on the APP(Accelerator pedal position) input-I know on DBW GM applications these points can be tuned in the PCM,have not played with them specifically though.
Using a rheostat you could only go one direction though I'm thinking.

[Unforgiven]

Interesting, I will be trying to peek in when I can to see this thread as I have an 04 Impala as well, but with the 3.4L v-6. I know it can get some decent numbers, and have debated on getting it reprogrammed somewhere down the line.

[99LeCouch]

The 3800's respond nicely to tuning. I have a re-tuned computer in my LeSabre. I like it.