Acura TSX Forum banner

1 - 20 of 23 Posts

·
Guitar and Amp Junkie
Joined
·
465 Posts
Discussion Starter · #1 ·
Do you like this feature? Does anyone notice or even care? According to the TSX marketing, the dbw throttle is supposed to "sense" driving conditions, and respond accordingly. So, in theory, if you were sitting in traffic, throttle response would be slower to keep the car from lurching forward.

If you do notice it, is it a "cool -- this car is really an extension of the driver" kind of impression? Or is it a "damn, that's annoying" type of impression?

Just curious as to what they every day driver thinks.


Ferg
 

·
, Moderator Emeritus
Joined
·
10,086 Posts
If I didn't know it was there, nothing ever would have occurred to me.
But then again I'm the guy who didn't know if the Legend that I had for 14 years had leather seats or not. :D

Some people, mostly on other sites, have occasionally said (mostly just as a little annoyed utterance) something like "Well, that's DBW for you." I usually didn't understand what they were talking about, but I guess usually it was some possible lack of total driver control; sometimes it was musing about possible defects in their cars.

The only thing I notice that may be relevant is how smooth the car is -- "refined," if you pardon the cliche -- yet still with plenty of response, road-feel, and car-feel. A combination like that is nothing to sneeze at. I decided against a Lexus (at the time it was the ES300) because of lack of those latter things. (I also didn't find it so "refined" either, but that's another story.)


BTW here's a nice piece about DBW that I found on Edmunds.com. It's a few years old, but what the hey:

Why Drive-by-Wire?
By Karl Brauer
Date Posted 11-29-2000

Each year the automobile gets just a little bit more refined as new technology replaces old. It started with "luxuries" like electric start and hydraulic brakes and continues today with direct injection, yaw control, and drive-by-wire.

Those first two items were the subjects of previous Innovations, but drive-by-wire has yet to appear in this column's Web pages. However, as a technology that already graces the C5 Corvette, Acura NSX and Toyota Tundra, it's one you can expect to see on an increasing number of new vehicles.

Like so many of today's technologies, drive-by-wire is primarily a response to tightening emission standards. As with fuel injection and integrated engine controllers, drive-by-wire systems improve engine efficiency while cutting vehicle emissions. They do this by replacing clunky and inaccurate mechanical systems with highly advanced and precise electronic sensors. Currently, drive-by-wire applications are being used to replace the throttle-cable system on newly developed cars like the models already mentioned.

These systems work by replacing conventional throttle-control systems. Instead of relying on a mechanical cable that winds from the back of the accelerator pedal, through the vehicle firewall, and onto the throttle body, drive-by-wire consists of a sophisticated pedal-position sensor that closely tracks the position of the accelerator and sends this information to the Engine Control Module (ECM). This is superior to a cable-operated throttle system for the following reasons:

1. By eliminating the mechanical elements and transmitting a vehicle's throttle position electronically, drive-by-wire greatly reduces the number of moving parts in the throttle system. This means greater accuracy, reduced weight, and, theoretically, no service requirements (like oiling and adjusting the throttle cable).
2. The greater accuracy not only improves the driving experience (increased responsiveness and consistent pedal feel regardless of outside temperature or pedal position), but it allows the throttle position to be tied closely into ECM information like fuel pressure, engine temperature and exhaust gas re-circulation. This means improved fuel economy and power delivery as well as lower exhaust emissions.
3. With the pedal inputs reduced to a series of electronic signals, it becomes a simple matter to integrate a vehicle's throttle with non-engine specific items like ABS, gear selection and traction control. This increases the effectiveness of these systems while further reducing the amount of moving parts, service requirements and vehicle weight.

Many of you may be saying, "Sure, this sounds great in theory. But what if the "wire" in my drive-by-wire system, um...breaks?" In other words, what if an electronic malfunction disrupts the flow of information between the throttle position sensors and the ECM? Could give a whole new meaning to the term "sticking throttle," couldn't it? The reality is that, just like fuel injection and ABS, a drive-by-wire system is only as good as the programmers and manufacturers who design it. While the first generation of fuel-injected cars had its share of technical gremlins, the fuel system of the average 1999 model is far more accurate, and dependable, than any carburetor-equipped vehicle from 20 years ago. Because drive-by-wire technology was first used on military aircraft over 10 years ago (except it was called fly-by-wire back then), you can be assured that its reliability under less-than-ideal conditions has been tested. It is now used on everything from industrial equipment (like Caterpillars) to cutting-edge ground-assault vehicles (like the upcoming Grizzly Tank).

Speaking of airplanes, many of today's jets use fly-by-wire technology for turning and braking, in addition to throttle control. Could the same thing eventually happen to cars? Could a simple joystick someday replace our steering wheel, gas pedal and brake pedal?

Naaah. That'd be like suggesting that someday cars will be able to drive themselves without any driver input...

© 1995-2004 Edmunds.com, Inc.
 

·
, Administrator Emeritus
Joined
·
10,660 Posts
Great article Larch, thanks for that!
I do not really notice the DBW, so I guess that would be a good thing :)
 

·
Registered
Joined
·
258 Posts
My problem with DBW is when the car goes over bumps my foot hits the gas pedal, the car jerks. Also sometimes when i hot the gas pedal har it does not downshift. Its not a big problem for me, i can live with it.
 

·
, Moderator Emeritus
Joined
·
10,086 Posts
netoperek said:
My problem with DBW is when the car goes over bumps my foot hits the gas pedal, the car jerks. Also sometimes when i hot the gas pedal har it does not downshift.....
Makes me wonder.....Although I don't have any big complaint about the power, and as I've been saying I think the TSX is fine on things like 0-60, the car is a little sluggish during that first moment after you "hit it" -- you know, that first second or half-second or so. And what I'm talking about isn't anything related to torque (I don't think), it's an actual delay. (This is on the 5AT.)

Never thought of it this way before, but I wonder if that's related to the DBW. Anybody know?
 

·
Orangeblood
Joined
·
136 Posts
I agree with netoperek. The DBW throttle, particularly at low rpms, seems to be a bit twitchy, particularly when one lets off the throttle.

This makes my low speed shifts jerky sometimes. Dammit. :mad: Maybe just operator error! :p
 

·
, Moderator Emeritus
Joined
·
1,344 Posts
MarkPinTx said:
I agree with netoperek. The DBW throttle, particularly at low rpms, seems to be a bit twitchy, particularly when one lets off the throttle.
one of the few things that annoys me about the car.
 

·
Registered
Joined
·
332 Posts
I've noticed a few things about DBW:

- with AT, it blips the throttle to make the shifts smoother

- the cruise control is rock solid because there's no mechanical linkage to shove around when adjusting speeds

- I would think it simplifies the complexity of VSA because again, moving the mechanical throttle linkage isn't necessary.

- the feedback of the pedal is very linear, because it's just a spring pushing back.

BMW Active Steering (on the 5 and 6-series) is probably the closest thing the legislators will let us get to steer-by-wire. It basically has a second steering shaft attached to the main shaft. It's controlled by the computers, which can apply additional steering authority beyond the driver input (or reduce it) to improve handling to bail you out. If it fails, the 2nd shaft just centers and it turns into a regular steering linkage.
 

·
, Moderator Emeritus
Joined
·
1,003 Posts
kiteboy said:
I've noticed a few things about DBW:

- with AT, it blips the throttle to make the shifts smoother

Interesting, with the 6-speed I noticed it's not as responsive as a mechanical linkage. There isn't that instantaneous response.

Also noticed when the car is cold (not very long around here) and it's in 1st gear and moving REAL (~2-3mph) slow, the car sort of "bucks" as if you are not pressing smoothly on the accelerator? :confused:
 

·
Registered
Joined
·
94 Posts
Wow.. i thought i was just horrible at driving stick-shift lol.
It seems most of you are getting the same responses from the car that I am. Since I'm new to driving stickshift (bout 3-4weeks now) I thought maybe it was just my inexperience that was causing the car to be jerky at times, etc..
 

·
, Moderator Emeritus
Joined
·
10,086 Posts
Interesting stuff. OCICBW but I don't think these kinds of things have been pointed out before in such a focused and concentrated way.
 

·
Orangeblood
Joined
·
136 Posts
Well I'm new too, Nocturnal. But I have driven an MT enough to perceive a kind of low rpm/lowspeed jerkiness/buckiness that I havent seen with other mts. Maybe just because I havent driven one this much.

I notice that as soon as I get cocky and quit paying careful attention, I'm due for a stall or some kind of missed shift (3rd when I intend 1st or 5th seems common).

Oh and given that the AT blips for shifts (I assume you mean upshifts), I wonder if I should push through shifts a tad harder than instinct to avoid the problem? My general tendency on upshifts is to lay off acceleration. But I note that with foot in same position (not continuing to push) as soon as the clutch disengages from the engine, rpms drop like a rock. I may have answered my own question. ;)
 

·
, Moderator Emeritus
Joined
·
10,086 Posts
GRAYTSX said:
Originally posted by larchmont But then again I'm the guy who didn't know if the Legend that I had for 14 years had leather seats or not. :D
Huh? Please explain :laugh:
Well, it's not like I'm quite as stupid as it sounds. Almost, though.
I knew it was leather. But, when we started talking about how the leather in the TSX isn't all leather, I realized I never knew if it was all leather in that Legend. And never even thought about it. Just like I never thought about it on the TSX either until people started talking about it.

Our man MarkPinTx did a little "investigative" work and found out that it WAS all leather on the Legend.
 

·
BUM
Joined
·
1,242 Posts
Well I love it. I have now experienced all of the "bucks, jerks" etc that you have mentioned, but now have learned to control and manipulate the DBW. If you pay close attention to it for a couple weeks, you will figure out when to softly tap the pedal and when to really push it down. coordinating your shifts with your foot motions would be the next thing to learn. It does take some getting used to, but I think the benefits are enormous. I also think it engages you more as a driver.

FIRST POST
 

·
, Moderator Emeritus
Joined
·
1,003 Posts
pocketkiller said:
Well I love it. I have now experienced all of the "bucks, jerks" etc that you have mentioned, but now have learned to control and manipulate the DBW. If you pay close attention to it for a couple weeks, you will figure out when to softly tap the pedal and when to really push it down. coordinating your shifts with your foot motions would be the next thing to learn. It does take some getting used to, but I think the benefits are enormous. I also think it engages you more as a driver.

FIRST POST
Good point and welcome to the group pocketkiller!

I'm not advocating anyone do this, but I found if you drive "barefoot" you are more sensitive to the nuances of clutch engagement and throttle position.
 

·
Registered
Joined
·
24 Posts
I watched a Discovery Channel special on the Airbus which had fly-by-wire and watched it fly straight into a forest of trees. Hmm......
 

·
Registered
Joined
·
353 Posts
I dunno, sometimes I think either y'all have broken TSXs, or you're stepping on it at 2500 ("low") RPMs and complaining that it doesn't have torque. ;)

The 4 cyl is just going to have a lot of go at the low RPMS! Get the revs to, say, 3500, and it should be pretty responsive. I dunno, mine seems pretty sporty. Or maybe like the other person said, you get used to the DBW and adjust the throttle differently? I dunno. I do notice that it sometimes blips the throttle, but it just doesn't seem to bug me, whatever it's doing.
 
1 - 20 of 23 Posts
Top