Tuning electronic throttle position

[Lonnie]

Does anyone have experience with adjusting the throttle travel?

On my d-max conversion, I would like to shorten the throttle pedal travel. I would prefer to put a stop on the pedal so it does not come up as high.... essentially I would like it to be at idle when the pedal is approx 15% down.

Any ideas if this is possible? I would like to know now (hard to test when the truck in is a million pieces) so I can try to modify the pedal more if I have to.

Any advice is appreciated.

 

[dubious]

I think you can adjust the APP ( applied pedal position) with efi live...
I think it can be done because the EDGE tunes make the torque curves behave like full throttle at only 50% APP

Rather than accelerate the APP torque curves , you want to decelerate the rate or
detune the torque TABLES below 15%,

I am new EFI LIVE, but this is how I percieve it

 

[05maxlly]

try table b1024 idle mode throttle limit change to where u want throttle positon to be when its not idle anymore

 

[Lonnie]

I also saw this min TPS value in timing tables as well & wondered if I had to change this value in numerous places to actually make it do what I want.

 

[Brayden]

Which platform are you using? If it's an LBZ you can use any double redundant throttle source and calibrate the APPS yourself in EFILive.

I think I would just orient the throttle bracket a little different if the pedal starting height is too tall for you.. but that's my opinion.

 

[Lonnie]

It is an 05 LLY setup.

I had limited places to mount the throttle pedal on the firewall & due to the length of the lever, it is slightly high, but still allows enough travel for full throttle.

I would like to push it down about 3/4" & put a stop on the top limit to make this new position "idle".

 

[THEFERMANATOR]

This may not be the answer you want, but did you consider a 94-00 6.5 pedal assembly? I know it is quite a bit different from the DMAX pedal, and is supposed to easily bolt into the older GM pick-ups. The only issue I have encountered is that at roughly 55% throttle application it is reading 100% as the 6.5 used twice the voltage swing of the DMAX. I wished I could adjust the TPS via EFILIVE for it, but I haven't found anything in EFILIVE for an LB7 yet to do so.

 

[JoshH]

This may not be the answer you want, but did you consider a 94-00 6.5 pedal assembly? I know it is quite a bit different from the DMAX pedal, and is supposed to easily bolt into the older GM pick-ups. The only issue I have encountered is that at roughly 55% throttle application it is reading 100% as the 6.5 used twice the voltage swing of the DMAX. I wished I could adjust the TPS via EFILIVE for it, but I haven't found anything in EFILIVE for an LB7 yet to do so.

Could you put a resistor in line to drop the voltage?

 

[THEFERMANATOR]

Could you put a resistor in line to drop the voltage?

I thought of that, and I don't think it would work. I know the guy that did the drive by wire 8.1L into an early 80's truck said he used a 6.5 pedal and bent it so that it would only use about half it's travel and said it fit perfect. If you put a resistor in you would have to do all 3 sides of the sensor, and I think it would throw the base voltage off enough that it would limp from the pedal being off. The first 55% of a 6.5 pedal reads almost identical voltage to that of the DURAMAX pedal for it's full travel, the 6.5 pedal just keeps going once it reaches the max voltage change that the DMAX pedal has. It hasn't caused me any issues though, and I have found that the ECM does learn to it somewhat after awhile. It is REAL touchy right after a flash, but smooths out after a day or two and a few WOT stabs.

 

[duratothemax]

cut/reweld the pedal "arm" that attaches the pedal itself to the APPS? I did that with the brake pedal in my offroad buggy.

Either that or shim the whole pedal assy out a bit. I had to do that as well in my offroad buggy (yes, its drive by wire, same pedal assy as a dmax)

 

[Lonnie]

Everything is already cut/welded to make it fit the truck. I have to work with the limitations of the existing firewall & floor. I'm a mechanical engineer, so I already went through all the measurements to make it work... they just dont work without cutting the truck up or lowering the electronics down to where it does not look good.

The 94-00 pedal may be an option... thanks for the info. Half the travel may be a little touchy, but I would consider trying it.

I'm hoping the EFI Live tables above can solve my issues...
If it can't be done with programming, then I'll have to build a circuit to modify the signal.

 

[duratothemax]

might be difficult because there are three sensors that sweep in different curves.

maybe some voltage dividers that are setup in a linear map of some sort.

 

[THEFERMANATOR]

The 94-00 pedal isn't really touchy at all as it uses about 1/3 more movement than the DMAX pedal. So it is pretty easily driveable once you get used to it.

 

[Lonnie]

Time to start looking I guess.....

Thanks for the info.