Denroll

I was just melding brainpowers with Bramage. Together we are pretty much like a handsome, funny version of IBM's Watson supercomputer. We were talking about how dumb out throttles are.

Example: I was watching the TPS% readout on the Zeitronix software and it's ridiculous. I have my ZT-2 tapped into the ECU for TPS, so it updates real-time. I am at max throttle by the time I get 1/3 of the way through the pedal travel. I can move my foot all the way from that point to the floor and back with no change. Furthermore, if I jab the throttle quickly, even just an inch or so, it spikes out at max throttle. If I jab and hold it, it spikes up to max and then settles down to around 30% or wherever I'm holding it.

Just doesn't seem to make sense in a car like this. If you've ever been in 1st gear at like 3k-5k rpm and done the herk-jerk rodeo, you know that this can be annoying. There's got to be a way to adjust or modify this thing to get more of the pedal to work.

GunMoto

I'm with you on this. Drive-by-wire sucks...and just to add, our brake-by-wire is like WinME.

Denroll

Yep. It's like someone went, "This isn't broken, but we can fix it until it is."

E55Greasemonkey

First, don't ever question the Germans. Second, the throttle curve is coded in the engine control unit, ours is set to "AMG" of course. If you have star/das developer I suppose you could try different curve settings, probably for the V6 or something.

chiromikey

If you've got a tune I wouldn't be surprised if there's been some changes to the throttle maps. Actually, I'm near certain there has...

phunter

http://www.sprintboosterusa.com/
saw this on two guys garage

justinwrock

You mean the accelerator isn't just "on" and "off"?

biggking

There's not a 'sport' throttle setting like M3s? Also what about doing that sneaky ECU reset and then lightly driving that car. I did this and it seems when I go 1/2 way its WOT or maybe I'm trippin.

AMGPilot

Torque request (Throttle pedal displacement) is measured over time.

You jab the throttle the ECU thinks that you want to go fast now. it's doing EXACTLY what it's programmed to do. I've played with throttle mapping on LOTS of cars and I find the E55 to be pretty damn good. But if you Drive it like a tosser it's going to treat you as such

Denroll

It has nothing to do with driving like a tosser. Why have all that pedal travel if 2/3 of it is wasted? I can see what they were trying to do with altering what happens based on how quickly the pedal is depressed, it's just that it, well, sucks. 50% throttle should be in the same place every time (halfway down the pedal travel!), not changed based on some needlessly/overly-complex algorithm. If I jab the pedal halfway, give me 50% throttle ASAP because that's what I'm ordering.

AMGPilot

It's not wasted travel.

A few things, first off your tuner most likely changed the throttle map. Your 50% jab example? it gives 100% instantly until the motor makes 50% of it's programmed torque. then it will hold that.

Throttle of the motor isn't just based on TPS position, The motor also uses waste gate bleed, timing, injection and transmission loads. All of that is used to maximize Ve while throttling the motor.

as for your "3K-5K Herk jerk" again loo at your tuner, he's not doing the load maps very well

Denroll

I'm on my third tuner; fourth if you count it as it was when I got it. It has done the same thing with all of them. One told me specifically he did not touch the part throttle maps.

But I see what you're saying about the torque. I'll see what other signals I can log.

Crissus

Maybe your TPS sensors are broken?
And maybe that would explain the hiccup issue? How is that system working anyway? Need to check the WIS out soon. There is no real wire going from the pedal i assume? So all the values a taken from a sensor directly at the pedal?
I know from various brands that such units going bad quite often because of residues from the scratching inside the potentiometers.
And if i mean "going bad" i dont mean necessarily that they totally went out and not functioning anymore, but rather some values in between the whole pedalway getting bad.
The software in the electronic throttle actuators ecu can compensate for it, but not to an unlimited extent.

Just some food for thought.

GregMB

Something does sound a bit fishy....

Denroll, do you have access to a different pedal assembly you could swap in for a few days? I don't have any direct experience, but have read that the pedal is relatively simple to replace and contains all the electronics for the TPS stuff....

Datalogging with a different pedal assy would quickly prove or disprove if you've got an intermittently failing pedal (I've see a few cases reported around here). It sounds like you know EXACTLY how to create the hiccups when you want to.... so this could be a pretty fast troubleshooting exercise for you.


-G

ArmoE55

Maybe I'm alone on this, but I enjoy the "Herk jerk" throttle moments when driving my car, makes me feel alive.

Denroll

We're expecting rain this weekend, so maybe I'll take my pedal assembly out and examine the switch.

400RWHP

Don't you have a manhole cover in place of what used to be a throttle body? I suspect that may be contributing just a little to the on-off feel of your throttle. Just sayin


Regards

Denroll

Bringing this topic back for discussion. Maybe any others with an 82/90mm tb can chime in. did your throttle get much more sensitive after you did the swap?

I did try the Pedal Box, which others loved. It just made mine even more of a hair trigger while in its sport modes.

Still watching on the DashDAQ with the engine off, it takes like maybe an inch of pedal travel to go from nothing to 100%. It makes taking off from a stop require lots of concentration. If not, it's either granny slow or anti-social maniac fast.

Where are the settings in STAR?

kponti

Did you ever swap the throttle sensor and datalog?

Larger throttle body giving faster throttle response is actually very normal. I have done throttle bodies on most cars I've modded with the same result. That is why a larger TB was the first "mod" I did on this car way back

e500slr

Yh these things aren't very sharp, from the RPM rise and drop to the throttle response. I kind of like it. I've driven a car with ITBs and drive-by-cable and yes, it's nice, so damn sharp, even the slightest change in throttle pedal can be heard and felt. Drive-by-wire feels different.

On another note, ever driven a proper setup carby car, so damn snappy