Would true drive-by-wire throttle control be possible?

[wild man]

This may seem a little "out there". I agree, but I still can't help but think about what it would be like. The thought of not having direct control over the throttle opening is a little unsettling, but you need to look past that.

Here's the scenario: Disconnect gas pedal cable from throttle plate and connect it to a potentiometer instead. Develop a simple control box that will take the voltage input from the pot, and compare it to the MAP voltage signal generated by the KLR (or separate sensor). Using this difference, it would then output a signal to the CC servo that will open the throttle plate until the voltages match. Basically, it would bring the actual absolute pressure up to match the desired pressure generated by the gas pedal. That's all there would be to it, save for maybe a "panic" type emergency cut button, should something go wrong. This setup would work for N/A's, as well.

I can't help but try to think what it would be like to drive using such a setup. But thinking can only go so far. The only way to really know would be to actually try doing it. You might be asking the question WHY? At this point, the only answer I can come up with is for "effect". If it would produce the effect of making me feel like I'm piloting a fighter jet, rather than driving a car, I would likely welcome it.

I would like to know what people's thoughts would be on this (I'm bracing myself for the backlash, so let it flow).

[Porch]

If you want to feel more connected to your car, why not just connect a positive electrical lead to one butt cheek and a negative electrical lead to the other?

[wild man]

Funny, but this thread wasn't intended to be a joke (am I getting some backlash already?). Since I doubt if anynoe else would be willing to be the first one to try doing this, I am seriously considering using my 924S as the guinea pig (won't be happening anytime soon though). If I like the way it operates, I would then consider setting up the 951S in the same manner. But with well over 2X the HP, it is still a scary thought.

[catfish]

This would be expensive, complicated, less reliable, and potentially deadly but there's no performance improvement, right?

[Pete R]

There would be a lot of hassle for zero gain but..There are a lot of cars that already have it. You could probably quite easily adapt one of them using their components. I've driven a couple Jags that have it. You can't tell. There is NO difference in feeling what so ever. Other than may be in your head, but that's what counts right. My momo wheel adds nothing.. but I does make me smile. so try it. " The only place it's usefull performance wise is like in F1. They program the pedal to act according to the drivers taste. Schumi liked it fast, kinda on off like a switch, Barricchello like it more progressive and linear.

[Lawrence Coppari]

Why make something more complicated than it needs to be. I have two cars with drive by wire and dislike it on both of them. It's just something else to malfunction. I put it right up there with those inane push to start buttons that seem so in vogue these days.

[wild man]

Originally Posted by catfish

This would be expensive, complicated, less reliable, and potentially deadly but there's no performance improvement, right?

All correct, except for expensive. If you did it yourself, it would be almost cost-free.

Originally Posted by Pete R

You could probably quite easily adapt one of them using their components.

Are you saying that IS the principle that the current OEM DBW systems operate under? If so, I wasn't even aware of that. But It does confirm that I had the right idea on how to go about it.

Originally Posted by Pete R

There is NO difference in feeling what so ever. Other than may be in your head, but that's what counts right.

Yes that is what counts. I will call it "perceived" feeling. Aside from that, there is absolutely nothing to be gained from such a modification.

[QUOTE=Lawrence Coppari;5689308]Why make something more complicated than it needs to be. I have two cars with drive by wire and dislike it on both of them. It's just something else to malfunction. I put it right up there with those inane push to start buttons that seem so in vogue these days.[/QUOTE

The answer to that can only be "just for the fun of it" or "just to see what it would be like". And don't get me started about "those insane push-to-start buttons". I think that's about as ridiculous as most people probably think the concept that I have presented here is.

[AaronM]

Originally Posted by wild man

Are you saying that IS the principle that the current OEM DBW systems operate under? If so, I wasn't even aware of that. But It does confirm that I had the right idea on how to go about it.

No, that's not the way current DBW systems operate. You've actually devised something far more complicated than actually happens.

Here's how most systems work:

1) Read position of accelerator pedal potentiometer (e.g. 0% to 100%).
2) Signal solenoid to open throttle plate an identical percentage.

No fooling about with MAP sensors or signals.

Now, some systems have overrides (e.g. don't allow 100% throttle plate on a cold engine, rev-limiter ability, etc), or a "Winter" mode that only opens the throttle plate to half the pedal position (or some similar reduction), or even CC functionality built in, but the basic principal remains the same. They just read pedal position and set throttle plate position to match.

Not only have you over-complicated the theoretical system by playing with MAP readings, but using the CC servo is a bad idea. The CC servo is not fast-acting and simply would not be able to react as quickly as is necessary to properly mimic a traditional accelerator. You'd be inducing quite a bit of lag into the throttle control.

[Rogue_Ant]

This could be done with an inexpensive Arduino, potentiometer, and a 1/4scale servo pretty easily...
But I don't see the benefit - only added unnecessary complexity.

[ksudar]

[Pete R]

I kinda like the start button, well not so much the button, but all the cars I've seen that have them you don't need to use the keys. You just keep them in your pocket. It unlocks the doors when you get close and activates the start button. Those of us carrying stuff and with little kids, understand

[wild man]

So traditional systems do use what is, other than being electrical with override-ability, essentially direct control of the throttle plate(s). What I have devised (at this point, lets just say "envisioned"), is an entirely different way to drive, through indirect control of the throttle, by way of vacuum/pressure. That would simply HAVE to feel different in the way it operates, while still accomplishing the same thing. If turbo, the map sensor is already there, so it really wouldn't be very complicated to implement. The trickiest part would be in controlling the stock servo that opens and closes the throttle plate. But even that isn't THAT big of an issue. The response time of the stock servo is pretty fast, like 1 second or less, which should be good enough, I would think.

[wild man]

Originally Posted by Pete R

I kinda like the start button, well not so much the button, but all the cars I've seen that have them you don't need to use the keys. You just keep them in your pocket. It unlocks the doors when you get close and activates the start button. Those of us carrying stuff and with little kids, understand

That's definitely something that I would look at as an advantage. I HATE messing with & carrying keys. I do use keyless entry for my house and my 951. But the 951 does require carrying a transmitter, and you still need to use a key for the ignition.

[Pete R]

Why do I think I'm gonna see wildman on the news going 110mph yelling to the news chopper " I CAN"T STOP!"

[wild man]

That's exactly why a kill button would highly be advised. Also, If I'm not mistaken, the CC servo is spring-loaded, so if it looses power, the throttle will snap shut automatically. Hey, right now it is just a thought (maybe "fantasy" would be a more proper term), but so far it appears that the world isn't anywhere near ready to hear of it yet.

[catfish]

The world is ready to hear it - as part of a manufacturer developed, safe feature that integrates with modern fuel and ignition control. But as an overly complicated, unsafe modification to a 20+ year old car that drives fine without it? I just don't get it.

[wild man]

Sometimes my mind really stretches out there and bucks "common convention". I can see beyond conventional wisdom, which in this case states that throttle opening should be set to the amount that is desired by the driver. Most have a hard time contemplating anything other than that. That is in fact how the big players work it, so that explains why there is NO difference in the way it feels, compared to a mechanical linkage. My "theory" would provide power from the engine, based on how much power is demanded by the foot, NOT by how much throttle opening is demanded by the foot. That would have to feel different, but it is not possible to understand how it would actually feel, without actually experiencing it. What it comes down to, is that the only way to test the theory would be to actually implement it. Sure, you could use the CC servo to operate the throttle by comparing a signal representing how far it is open, with a signal representing how much "opening" is being demanded, but that isn't really what this thread is about. I'm talking about a whole new concept in the driving experience. Hey, maybe it just wouldn't feel right, I don't know. Problem is, the only way to find out, would be to try it. Just because the "world" isn't ready, that doesn't necessarily mean that I'M not ready for such an out-of-the-box concept.

[Porch]

The OEM's use DBW because it works well with traction control (they can close the throttle on you if you're spinning on ice), and because they can do things like preventing you from doing full-throttle launches. I could see it being useful on an F1 car because they could change the throttle tip-in too--but then again, that's easy to do with a custom throttle cam as well.

In short: there's no benefit to what you're describing. You're getting all the drawbacks (unreliable, potentially dangerous) and none of the benefits (traction control, abuse prevention). If you really have that much free time on your hands, you could do something to the car that would actually make a difference...like porting your cylinder head!

[nize]

Originally Posted by wild man

You might be asking the question WHY? At this point, the only answer I can come up with is for "effect". If it would produce the effect of making me feel like I'm piloting a fighter jet, rather than driving a car, I would likely welcome it.

how about installing a damper/delay system in the steering rack so that there would be a slight delay between when you turn the steering wheel and when the car's wheel actually begins to turn? that would also make it feel like piloting a fighter jet.

or how about installing a 3 second delay between when you hit the brake pedal, and when the car actually begins to slow down?

[chally72]

Originally Posted by wild man

Sometimes my mind really stretches out there and bucks "common convention". I can see beyond conventional wisdom, which in this case..............

This is called "imagination." This is great for building with legos. Not for messing around with your throttle linkage to get an admittedly totally "perceived" feeling. I've got another idea, as long as we are bucking conventional, though. Nize stole all but this one:

Why not make your brake master cylinder a remote-mount wireless activated unit with a high-powered servo? It would mean you could move 10 pounds into the trunk, AND it would be adding modern technology and more wiring, which is good, right?