Coyote Drive by Wire

[Railroad]

I am getting my Coyote Aluminator crate engine tuned. It is going pretty well, but I noticed something while driving. I want to be a little more informed before communicating with the tuner.

While driving and applying the throttle, the car accelerated, but did not feel proportional to the pedal movement, as the car increased speed, it felt like the throttle was gradually opening more.

I know the throttle is controlled by a drive by wire throttle. My question, is the ratio of pedal movement, throttle movement, 1 to 1, or scaled, or controlled by input from the ecu.

My thoughts are, it is NOT 1 to 1, which would lead me to believe the ecu uses input to determine the opening ratio or rate.

My intentions are to ask the tuner to put a more aggressive rate on the response, if possible.
They might be hesitant to do this, due to increase risk of engine damage?

Anyone got any knowledge on this aspect of ecu tuning

In trying to search for Coyote/Ford tuning specific, it seems common that the throttle movement gets managed by the ecu.

[Bob Cowan]

This is very common in all modern DBW cars. You need a lot of pedal movement to get moderate throttle opening.

There is a product that's been on the market for a few years to fix this problem- Pedal Commander. I have one on my 2020 truck, and it made a HUGE improvement in pedal feel. Rather than retune the ECU, I would recommend this product instead. Why? Because it's easily adjustable on the fly. Lots of choices so you can get it right where you want it.

http://pedalcommander.com

[edwardb]

You're working with Lund Racing, right? They can adjust the sensitivity of the DBW -> Throttle body. Did that on the Gen 2 in my Roadster. I have no idea about the specifics, only that they were able to dial the sensitivity up and down with tuning settings.

[Railroad]

Thanks for the replies. That confirms my thoughts on the operation.
I think I convinced the turner to improve tip in, from about 2 to 3k rpm. I think the rest of range could stand some improved response. Maybe my request will sound feasible.
I am using Lund and very satisfied with their service.
Bob, my engine instructions stated a tune is required, so I am already in the saddle on that part.

Thanks,

[Railroad]

Some unrelated good news, I got my license plate yesterday and some extended seat time.
Without data logging, I sent a request to my tuner.
I ask, if I could get a linear pedal to throttle response. I do not know if the ecu will let this happen in all instances, but we will see.
I felt like at times the engine would reach redline, before the throttle was open completely. If this does happen, it would not be ideal for competitive driving. Not on my radar, although I would like to make some passes at Barber Motorsports.
Also, I might need a shift light, the engine is just so smooth through the rpms.

[Bob Cowan]

I felt like at times the engine would reach redline, before the throttle was open completely.


This is normal. At 1/2 - 3/4 pedal, eventually you'll hit redline.

[Railroad]

This is normal. At 1/2 - 3/4 pedal, eventually you'll hit redline.

I agree. My concern is the pedal is WOT and the throttle body has not reached Max opening, but the engine has reached red line.

I got 2 tunes in the email this morning and an explanation of how this stuff works and the results.
I am eager to get the tunes into the device and loaded.

[Svtfreak]

Just a little info for you. The throttle position is not actually controlled by the pedal. Your pedal input basically is then converted to a load commanded value. Then, the ecu figures our the best way to achieve that load value. Sometimes, it doesn’t even move the throttle. It may only move the cam timing. Now that that load is calculated, and decision made, it commands those changes. Assuming a throttle position change is commanded, it then checks and makes sure the position reaches what it’s commanded and then recalculated actual load on the motor. Then it adjusts to try to get as close to what load is being commanded. And it does all this while also trying to be as efficient as possible. That’s why sometimes, the feel doesn’t quite feel like what you expect. The good thing is that, theoretically, the car should feel exactly the same no matter what air temp, coolant temp, etc changes. The reality is that there are so many variable, that it doesn’t always feel exactly the same.

That said, tuners can tweak the pedal feel. To give the feeling of faster or slower throttle response. Many people claim “I can feel more power down low!” after putting tunes on vehicles when actuality is just a change in throttle gain down low (to make it simple). They just make it open a little faster at a low throttle movement, let the motor rev out a touch longer, or sometimes even just lock the converter earlier. There are SOOOO many things they can do. It’s actually a quite astonishing. I tune my own A9L (87-93 style efi) but so much has come so far and gotten so complicated, that I don’t even attempt the coyotes. I know that I understand just enough to blow it up.

Mr Bob mentioned the pedal commander. And that is a perfectly viable alternative. But if you already have a custom tune from a tuner who is willing to work with you (Lund generally is), then that is the best route to tweak the pedal feel to your liking.