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-   -   Gas Pedal Sensitivity (http://forum.gopowerhungry.com/forum/showthread.php?t=27)

Coke734 Thu, December 4th, 2008 05:33 PM

Gas Pedal Sensitivity
 
I have been using the Gryphon for several months now, first with Stage 1 then Stage 2, and it has been great. Mileage and performance gains are definitely noticeable and very welcome.

I have one problem, however, and that is with the extreme sensitivity of my gas pedal. I realize that the sensitivity has been increased to enable faster pedal response, but when I am driving down these Michigan roads and hitting potholes, I can't keep my foot perfectly still. This leads to my tachometer needle jumping up and down, my engine revving and idling, and my exhaust going from loud to quiet to loud over and over until either the potholes end (rarely) or I give up and coast until it's smooth.

I am not planning on cashing in my custom tune vouchers for another few months, after I order my intake so they can both be installed at the same time.

Is there a way for me to change the pedal sensitivity myself in the meantime, or would I need to wait until I can get custom tunes for this adjustment?

Jackpine Thu, December 4th, 2008 06:03 PM

I wonder if this is similar to my feeling that the truck is too eager to unlock the torque converter or come out of a higher gear range with increased throttle pressure? I posted on this in another thread here: http://dygytalworld.ehost-services13...hread.php?t=13

You might try lowering the TC unlock speeds or even the downshift speeds a bit in the gear ranges you are using when this happens. My limited testing of this so far seems to indicate I'm on the right track.

But, Bill can probably do something in the custom tune to reduce this "skittishness". It's not throttle sensitivity that's the issue here (and you wouldn't want to change that anyway), it's a transmission skittishness. I think it's set to unlock or downshift too quickly.

- Jack

Power Hungry Thu, December 4th, 2008 09:43 PM

What he's referring to is how aggressive of the throttle pedal is at light throttle. We used to get similar complaints from the diesel folks. This is a phenomena that is often associated with Drive-by-Wire systems. Since there is no direct relationship between the accelerator pedal (APP) and the throttle plate, there is a transfer map that takes the linear voltage from the pedal and applies a logarithmic curve to the output for the throttle actuator.

One of the more common modifications is to make the curve a little more aggressive to help improve throttle response. Once in a while, we get a little too aggressive in the light throttle portion and what you end up with is a "touchy" throttle.

This does NOT affect the shifting since those work on the actual voltage signal from the a APP. Those issues are usually caused by mis-adjusted shift strategies.

I'm looking into the throttle problem and will have an answer sometime in the morning. :thumbsup:

Take care.

Coke734 Fri, December 5th, 2008 06:12 PM

Thanks for the help, JackAndJanet, I have noticed this as well. The problem I'm talking about seems more like what Bill mentioned. The touchiness/sensitivity is most evident before the lock appears in the COMM GEAR display.

Please give us an update as soon as you have something, Bill, and thanks! :2thumbs:

Jackpine Sat, December 6th, 2008 06:28 PM

Quote:

Originally Posted by Coke734 (Post 133)
Thanks for the help, JackAndJanet, I have noticed this as well. The problem I'm talking about seems more like what Bill mentioned. The touchiness/sensitivity is most evident before the lock appears in the COMM GEAR display.

Please give us an update as soon as you have something, Bill, and thanks! :2thumbs:

Yup, Bill's explanation is far more on the mark than my feeble attempt, wasn't it? :o

But, I'm glad you notice the sort of "over aggressiveness" of a downshift or torque unlock when adding a little throttle to either speed up a bit or to maintain speed up a mild incline.

We drove back from Phoenix today in Janet's Toyota (4 cyl, 30mpg, easier to park) and were on a several mile long upwards incline on the interstate at 75mph and the car stayed happily in 4th gear overdrive all the way. I know the Ford would have been going in and out of an RPM shift between about 1900-2400 on this same stretch.

But, I haven't been able to test the Ford again on the same kind of incline since playing with TC unlock and lock points.

- Jack

Coke734 Sat, December 13th, 2008 11:57 AM

Quote:

Originally Posted by Power Hungry (Post 107)
I'm looking into the throttle problem and will have an answer sometime in the morning. :thumbsup:

Anything yet?

Power Hungry Sun, December 14th, 2008 02:59 PM

Sorry about that. Just got back from a dyno event in Tennessee.

Give me a shout in the morning and we'll get your update online. :thumbsup:

Coke734 Mon, December 15th, 2008 12:43 PM

Quote:

Originally Posted by Power Hungry (Post 278)
Give me a shout in the morning and we'll get your update online. :thumbsup:

If it makes a difference, I went back to stock tune and the touchiness/sensitivity is still there but much, much less drastic. I have a vague recollection of adjusting a few values in the custom power programming settings, so I could have brought this upon myself.

Let me know how/where to get this update.

Buckeyes903 Mon, January 26th, 2009 05:17 PM

I noticed how touchy my throttle is, is there any more news on this?

I have kinda gotten use to it, but driving in gravel a lot, its hard not to make spin marks haha. Even my girlfriend drove my truck the other day and got out and was "I don't remember it being that hard to drive"
But when its back to stock it seems fine, but on level 2 and 3 I feel like I have to move the pedal a lot more to get a response and when I do it usually jumps.

jerodr Mon, January 26th, 2009 08:29 PM

Suprisingly my throttle is actually opposite. I felt no change over the stock setting. We discussed this in another thread and it has to do with my throttle body for some reason. I'm hoping that when I order my custom tunes Bill can make it a little more "touchy."


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