Dynamic Map Sensing Throttle Feedback

[greasemonkee]

This might be a little premature to post, but as I thought someone may have an idea or spot a problem I might be overlooking, maybe now is the time before everything gets locked in place. I created a thread a few days ago with the idea, but there seemed to be no interest. I feel the system really has a chance at succeeding, but we'll see where it goes whether it's failure or success.

The basic objective is that the driver feels an increasing resistance in the throttle pedal with increasing manifold pressure, therefore without monitoring a manifold pressure gauge one should be able to "feel" the load of the engine in the pedal feedback. In theory, you should be able to take a constant rate spring and apply a constant pressure to the gas pedal and the pedal should ride where it wants to retaining a constant manifold pressure throughout the entire rpm range. This will aid in preventing inefficient manifold pressure conditions and increase economy significantly in the city for the untrained ecohead.

Not only could this benefit the economy crowd, but for the "go fast" nut as well in the name of traction control especially in non-linear torque curves as in boosted engines.

There were several constraints that had to be worked around as well as guesswork. At present, the pedal should increase pressure by 5 lbs of force at ambient MAP. I have no idea what that will be in reality during regular driving whether it fatigues the foot or isn't noticeable at all. I can make another hinge pin and step up a cylinder size if necessary, but hopefully it doesn't come to that.

I'll post progress or antiprogress as the system matures.

[RobertSmalls]

++ for innovation. Where did you get the pneumatic cylinder? What kind of car is it going in?

You'll have a lot of vacuum (heavy pedal) at idle, and little vacuum (light pedal) at wide throttle, low RPM (where I try to drive). You might find that you have less control and smoothness during the transition between the two. Maybe the extra feedback in your foot is worth the loss of sensitivity.

This would probably be great on a car with a slushbox, where you can't drive at wide throttle, low RPM anyway. Added bonus: You'd feel it every time the transmission shifts, and you'd become better at controlling those shifts.

I'm curious to hear how this thing drives.

[greasemonkee]

It's actually the other way around - light pedal at idle, heavy pedal at WOT. The rear of the cylinder will have constant vacuum, the shaft end will be exposed to manifold pressure . Because of the shaft deducting a portion of the surface area on the forward side of the piston, some force was lost. Hopefully the approximate 5 lbs of additional resistance will be adequate.

Mcmaster-carr has those cylinders for about $20.

And thanks, I've gotten mostly nothing but criticism since the idea, but hey, I admit a lot of my ideas don't work; however, some do.

[greasemonkee]

Unit complete



Tight fit, but everything clears





I can't believe how underbuilt these honda pedal clusters are. With the added 5 lbs of force I decided it would be best to add some more welds to the the frame and hope it holds up in the long run. I'm not particularly happy with the way the whole cluster frame moves when the pedal is depressed. Using a lighter pedal spring may compensate.

Now I just have to get the car running...

[pgfpro]

Looks great!!! Very nice work.

Keep us informed on she goes.

[greasemonkee]

Finally the day has come. The Integra is together and running after a mild restoration and a few custom eco mods. I've moved the car over to the next bay to torque the suspension and it looks like the system is going to be a success. At light load the throttle has no more springback than the return spring, but when I load the engine especially when loaded heavy from a dead stop it really gets some resistance and is quite noticeable that it's pushing against you. I'm going to turn the sensitivity up to the max and see what happens soon. I think this will be a winner. Oddly enough, popularity among the device seems to be that of a black sheep among economy modifications. Go figure. Nevertheless, I'm quite tickled with the final product, from an idea conceived in the middle of the night.

[pgfpro]

Originally Posted by greasemonkee

Finally the day has come. The Integra is together and running after a mild restoration and a few custom eco mods. I've moved the car over to the next bay to torque the suspension and it looks like the system is going to be a success. At light load the throttle has no more springback than the return spring, but when I load the engine especially when loaded heavy from a dead stop it really gets some resistance and is quite noticeable that it's pushing against you. I'm going to turn the sensitivity up to the max and see what happens soon. I think this will be a winner. Oddly enough, popularity among the device seems to be that of a black sheep among economy modifications. Go figure. Nevertheless, I'm quite tickled with the final product, from an idea conceived in the middle of the night.

Major Kudos's to getting to the final product. I still think its a great idea.

I know with my own car it would be nice to have a product like this, because its so easy for me while driving in town to get carried away with the gas pedal. I have to many other things on my mind when driving and because of this my make a terrible eco driver sometimes. LOL

[greasemonkee]

Why thankyou sir.

I drove the car around the block several times today, it's an unusual sensation having that thing push back at you while encountering a hill. I think it will take a little getting used to because of having a nature of "stab the pedal to death" for so many years, now learning to let my foot "float" will be the depending factor in it's success.

Unfortunately, the option of making a "kit" of sorts to bolt in place just wasn't possible. The only way I could duplicate it is to weld the hinge bracket directly onto a pedal cluster, and the cruise equipped pedals are different than the non-cruise. With another 10 lbs or more acting on the cylinder via forced induction, you'd really get it talking back to you.

[Jeff]

Cool! What has the net effect been?

[cfg83]

greasemonkee -

Great Job! I admire your effort. The pictures are fantastic.

CarloSW2