Hey guys...i am very new to cars..have recently bought a 2003 TL and just love driving it. I was wondering, because the TL does not have the drive by wire system, what's the advantage of this system compare to the regular mechanical throttle system (is that what's is called??)...do u feel less "vibration" when u step on the acc pedal with the drive by wire sys???

 

throttle by wire gives driver a much faster throttle response than traditional mechanical setup.

On BMW, the throttle by wire system will monitor how quickly the pedal is pressed and will adjust air intake accordingly. Hence, it has better reaction to heavy footed driver. BMW claim that the throttle by wire system chopped off about half a second on 0-60 run.

On the M series, there is a sports mode, that will speed up the throttle response even further. Hence M3 can launch 0-60 as low as 4.5 sec with only 333HP. Under sports mode, a tiny pressure on the throttle pedal will result in full throttle response. Hence, it is difficult to get a smooth shift under such fast and deep response

 

Great that you asked...i just did my presentation/report on X-By-Wire.
Everything Chiawei is corrrect.

X-By-Wire system is basically replacing a mechanical or hydraulic system with an electronic one.

So the conventional drive system is having a direct cable linkage from the pedal straight to the throttle body.
Drive-By-Wire...you have sensors on the pedal and it sends the signals to the computer which will activate the electric motor which turn the throttle body. There is several different ways the pedal is activated...the position or the acceleration of the pedal or a combination of both.

Benefit:
1) No pedal vibration
Since there is no direct linkage

2) Different/Custom profiles
The car can have no linear acceleration profiles

3) Active Monitoring
Since the computer controls the throttle body it can actively monitor it instead of passively.

4) Emission Control
Drive-By-Wire was first introduced on the BMW 12V 7 series back in 1988 to reduce emissions from cold starts

5) Faster Response
Takes about .1-.2 sec to floor the pedal..with DBW just slightly stepping on the pedal can result in 100% throttle like Chia said.

6) Reduce weight can cost
Components are smaller, reduce weight. Electronics can easily be mass produced, reduce cost. Easier to assemble, less parts.

7) Improve fuel economy
The computer will know when and how much to open the throttle body, since it's constantly monitoring the system

8) Reliable and Dependable
Doesn't really need to be maintained. Probability of system failure is 1X10^-11

As you can see, there are more advantages than just from a performance viewpoint. The DBW system wasn't developed for the purpose of performace...but the marketing dept surely done a good job selling cars that way.

About 2 dozen cars have DBW now. The TSX has it..and i think the 03 accords has them too. Acura MDX, NSX, Corvette, Toyota Tundra, BMW...

Look forward into wide spread implimentation within the next several years. the next 04 Ford Explore 4.6 Liter V8 will be LEV II, same as the TL-S

Look next for:
Shift-By-Wire
Suspension-By-Wire
Brake-By-Wire
and finally the Steer-By-Wire

Steer-By-Wire will be implimented last since it will be the most severe and critical system if it fails.

 

Man, you must have sensitive feet! I've never even thought about vibration from the gas pedal. You seem to be preoccupied with it. Either something is wrong with your car or you have the most sensitive feet in the world...

 

Pauli Man, you must have sensitive feet! I've never even thought about vibration from the gas pedal. You seem to be preoccupied with it. Either something is wrong with your car or you have the most sensitive feet in the world...

I feel it on my 03 TL-p too. Its not like the accelerator is jittering but like a faint vibration on hard accerlerations. I think I can feel it b/c I used to drive a '02 Altima and that had TBW.

 

Steer-by-wire is the last invention that most people would want on their cars. Only direct physical linkage between the steering wheel and the front wheels can the driver knows how the car is handling on the road. Because even the slight vibration in the steering wheel can provide valuable tire-road adhesive feedbacks to the drivers. Steer-by-wire will completely isolate the linkage and cut off all natural feedbacks.

A classic example is the Mecedes steer-by-wire system used in the new E-class. It has received nothing but negative comments in varies car reviews.

 

I don`t know if this is true or not...but I heard that with DBW you can`t `HEEL & TOE` because the electronics senses that the brake pedal is being pressed thus the throttle won`t respond when you tap on the gas at the same time.

Can anyone enlighten me on this point???

 

I think you are mistaken MB doesn't have steer by wire on their new e-class. They have suspension by wire and brake by wire. THe suspension is electronically controlled and continously adjusted... the brakes are hydroelectric system...you press brake pedal, computer activates the hydrolic pump and controls braking.

Ppl complain that the brake system is too touchy..i slightly step on it and it will BRAKE.

Well, you have to consider there will be a feed-back system on Steer-By-Wire... Like those PC/PS2/XBOX steering wheel controllers, where it will shack and stiffen up. The feedback system will vary from about 2 to 9 lbs of force depending on ur handling situation. You won't see steeer by wire for awhile...until they get all the safety issue covered. If drive by wire fails, their is less danger compared to a steer by wire failure. Steer by wire will be the last system to be futured in cars after all the other systems have be incorporated.

The X-By-Wire system was first build by NASA, and they are currently using FLy-By-Wire on ALL Aircraft, commerical or fighter/bomber, tanks, etc. When the FLy-By-Wire system was first integrated into Aircraft, the fighter pilots didn't like it either because they thought the system would interfere with there pilot skills and will provide no feedback. But they were wrong...they came to like and love the system. And the pilots demand it. And i expect the general consumer/driver to react the same way; they won't like it at first becuase they don't understand the full benefit of the system, but they do, they will like it. It depends on the car manufactur on how they program the steerbywire system to work.

 

It just depends on how they program/instruct the computer to respond/react. I think that they will program the system to allow brake and gas at the same time. YOu have to consider which system has precidence? Will the brakes over power the gas, or will gas over power the brakes?

What i believe will happen is that the computer will adjust and adopt to the driver. Or you can get the computer software updated at the dealer.