electronic throttle?

Bill Jones opined in news:3aUnd.26690$5b1

Dunno... but you can pretty well bet it's not a simple potentiometer system like the TPS... would have to be something that automatically fail-safed.

Imagine the law suits..

There are fail-safes, self diagnostics, redundant sensors, and a 'limp home' mode.

Here's a link to some more info:

DP

Yep... no cable. Similar to the system installed on the '04 and up three valve 5.4 pick ups (and other models, too). It is triple redundant.... most problems will give limited throttle response and turn on the "wrench light" on the cluster. There were some problems with a few of the early 5.4s but they seem to have been ironed out. The ones I have driven took some getting used to but seem natural, now. The big problem is "tip in" but, as I said, it is easy to get used to.

First one I drove was in last years Santa Claus parade here in town........ I learned about the tip in response real quick.....

Yes, drive by wire, or at least partially. No, not in my case. My Nissan will slam you into the seat and send groceries flying if you aren't careful leaving a light. It's a little strange getting used to. Now my mom has an RX330 which I think is electronic also and it doesn't do that, infact it's too light. I'd like to find a happy medium.

Tip in? Maybe that's what I am talking about where if you are stopped or barely moving and you jab the pedal a little too much and a little too fast you get a holy crap kind of lurch. Now, this is on a small SUV (XUV) with 280 HP. It seems it would be more than "holy crap" on a Mustnag with say, 340 RWHP.

That's where the problem lies.... from closed throttle to small throttle openings. This is that area that is much easier to do with a cable than a wiring harness. Don't forget that we are now at the mercy of computer dweebs...... these are the guys that can't find the hood release let alone do what anyone tells them....

Hey!

I'm a computer dweeb and turn my own wrench too. Sadly, as much as I love computers, I think I might rather just have a cable. The only benefit I can see is custom programming for drag racers with automatic transmissions to just hit the throttle on by a push button. All the computer trickery to adapt to its surroundings sound nice, but I might rather be able to control it. I realize it could do a better job, but the same can be said about automatics vs. 5-speeds.

I say "might" a lot because I haven't driven a drive-by-wire system yet...

JS

I see this as the harbinger of things to come..... firstly, since he PCM will decide the throttle angle, it can simultaneously decide the correct fuel and timing setings to achieve the programmers desires. Secondly, it brings us one step closer to autonomous vehicle control... no driver input required.

At least we have been all lucky enough to decide our own driving styles.

Imagine the owners of the early FX35 models with the defective TCM. They would go out and once it does you get NOTHING but idle. The lucky person had it happen in their driveway / garage, I suppose the less fortunate had it happen while somewhere on the Interstate....

Same here... Spent 20 years in the trade but the IMPORTANT part is that I ended up doing User interface / integration and this reminds me of the new systems a few years ago that replaced terminal emulation with java and HTML GUI's ...

I did two call center installations and after spending days building the screens, was told to pack up before we got tab flow done because the agents needed to learn to use the mouse... "We'll do tab-flow later, maybe"

For you that say WTF? heads down people should NEVER use a mouse except for rare occasions!

Same thing applies here... the thing is done for ease of assembly, PERIOD!!!! ... it doesnt do ANYTHING that couldnt have been done with sidereal sensing while giving primary control through the cable.

The crap about: "Because the stiff metal cable between a traditional accelerator pedal and the engine is eliminated, so is a traditional pathway into the cabin for noise and vibration."

ranks right up there with

"Magnesium cam covers suppress valve train noise and reduce weight. Taking weight out at the top of the engine helps lower the car?s center of gravity and its roll-center axis, improving handling."

as a mistatement of the talking points the Ford engineering group gave the PR idiots.

Lighter valve covers = better handling on curves... yep! Was MEANT to refer to the lighter heads.

JS opined in news:m2Xnd.2223$Gw.1389@trndny09:

It sounds like a computer conditioned servo-mechanical circuit. The airline industry has used these for years for many reasons like lower weight than all those cables, facilitate autopilot, record flight commands, and maintenance is concentrated in just several places (the sender, the computer, and the receiver) and not the entire length of the cable. Some folks think it'll eventually lead to eliminating the co-pilot and later possibly the pilot. I have a friend that pilots the big ones on the Europe/US routes, and he says there is *not* a single, traditional mechanical cable in it now. Everything goes thru the computer.

You have to admit it consolidates components for the cruise control real nice.

I wonder how long throttle commands are stored in the computer and if the police will ever use it?

I see it as a thing that is already here. For instance, BMW's valvetronic system uses intakevalve lift alone to meter air flow. No need for all that pumping loss. Another area where electronic control of the throttle is required is for cylinder de-activation. When running on 4 or 6 instead of 8, more air is going to be required at what would have been the same throttle position.

I can see on an airplane or something where there are probably miles of hard cable, but we're talking a couple foot piece of low-tension cable. On the plane, it would be lower weight, easier to assemble, and perhaps cheaper on the plane, depending on how much it costs to wire it and if it's a bussed system or single wire per servo. On the car, it adds ease of assembly and the possibility to locate the throttle body anywhere on the car (helps the ram-air systems I guess) without the unsightly cable, but I doubt it'd be much cheaper. Yes, the cruise control already operates under the same idea, but the CC servo can't be remotely capable of what the throttle servo would need to do - a nearly instantaneous opening of the throttle just isn't in the typical CC servo's operation capability. When was the last time your cruise baked the tires off? (note that this isn't a shot against you, just a general rant about the system)

That it does....

Throttle commands are most likely stored to allow the computer to better respond to the driver and anticipate the next move. I don't know if the police will use it... speed logging would be more beneficial than throttle. There's times you need to floor it... highway onramps, etc. I'm sure they could already pull a speed log if they really wanted to.

JS

If one doesn't want to drive to work while driving to work, they should take public transportation. If it's not available, they should lobby for it. Automobiles are part of our lives and passion... to totally automate them would take away a lot of that.

I've been offered a decent job through my company in NYC, but part of the stumbling block is that there's nowhere near Manhattan that I think I could actually enjoy driving. I'd probably leave the Cobra back here (SW PA) and just take the beater, for that occasional run to the store. It would be rather depressing, actually.

JS

yup, no cable. There's sensor at the the pedal which measures the position of the throttle, and there's some sort of servo at the intake that is controlled by the computer, using the input from your pedal. Fly/drive by wire, used in almost all new commercial airlines after airbus started using it. Now, I have driven a bmw 3 series and I think they have this system already. Like other people have commented on, slowly accelerating from a light is harder than on 'wired' cars. Not sure why, it's almost like a slight delay, then it takes off.

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Actually, the old Cadillac 4/6/8 system (lovingly called 3/5/7 by those of stricken with these beasts) would have changed air flow requirements. The modern version is to simply shut off the fuel injector(s) as required leaving flow through the motor unchanged. Let's not forget that the throttle plate does exactly what it's name implies..... it chokes off the air supply into the gasoline motor - of course volumetric effiecency heads for the toilet and we start to incur pumpng losses. ETC (Electronic Throttle Control) does nothing to change that. It is simply a new way to achieve an old result.

I'm not familiar with this BMW system of which you speak but I picture it as horrendously complex as well as extremely hard to do with only 14 volts. More common is variable valve timing which may be what you're thinking of.

I do recall reading something about during WWII, people would disconnect spark plugs in attempt to save rationed fuel. I hope the Cadillac system worked a bit better than that! ;)

Yeah, an electronic throttle does nothing for pumping loss when applied to an existing throttle body. I wasn't clear at all in my previous post, sorry. What I meant was that as an overall system that replaces the throttle body, an electronic throttle is required and that the whole system is desireable.

Here is a very brief blurb about the BMW system from the SAE website -----

The gasoline-fueled V8 engines powering BMW's new 735i and 745i feature a combination of three significant "infinitely variable" technologies for valve timing (via BMW's Double VANOS system), valve lift (Valvetronic), and intake-tube length-the last an industry-first. These systems enable the V8 in North American tune to produce 242 kW (325 hp) and 447 N.m (330 lb.ft). Double VANOS (VAriable NOckenwellen Steuerung: German for variable camshaft control or variable valve timing) steplessly varies intake- and exhaust-valve timing by 40 and 25°, respectively.

Valvetronic adjusts intake-valve lift infinitely and facilitates breathing without a throttle butterfly. It adjusts both the effective cam lift and the opening cross section of the valves via an intermediate lever between the camshaft and the two intake valves of each cylinder. The distance between this intermediate shaft and the camshaft is varied infinitely by an additional, electrically operated eccentric shaft. Via the eccentric shaft, the lever converts cam movement into valve lifts from 0.3 to 9.7 mm (0.01 to

The continuously variable intake manifold consists of two intertwined helical elements that, when rotated by an electric servomotor, vary the effective intake length steplessly between 215 and 607 mm (8.5 and 23.9 in).

Hey Jim, Does the throttle by wire allow Ford to ditch the Idle Air Control actuator or speed control servo unit and hardware?

I don't know, it seems very likely to me that one servo could do the job of both the cruise and throttle function. Granted, the servo at the throttle body would have to meet the most demanding requirements, i.e. the throttle function, but if it could do that doing the cruise part should be a piece of cake. I'd bet they are separate functions or subroutines or phases in the computers program though. DriveSpy posed the question of one servo below. Hopefully someone really knows.

You are right on speed logging, I was thinking post-accident investigation.