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Old 07-05-2008, 12:11 AM   #26
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Might be a little off topic, but what about the slight Drive By Wire unresponsiveness that people sometimes report? I hear that the ECU has a delay to save economy at the cost of responsiveness.
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Old 07-05-2008, 12:16 AM   #27
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The only actual delay I've encountered in either car is if the car has been in neutral with the accel pedal at 0% for a while. Just stand on it until it listens. That's logic burried in the DBW control code somewhere and there's no tuning that.
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Old 07-22-2008, 09:08 AM   #28
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How would making these changes affect an AT? I'd really love to do it 'cause the cruise accelerating annoys the crap outta me.
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Old 07-22-2008, 02:32 PM   #29
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Quote:
Originally Posted by lebshiff21 View Post
How would making these changes affect an AT? I'd really love to do it 'cause the cruise accelerating annoys the crap outta me.
No idea. Don't have an AT, never will. Try it and see if it explodes.
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Old 07-22-2008, 04:43 PM   #30
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thanks for putting this together! i will have to see if i can have this phenomenom looked into when i get my '05 tuned. the response was always a bit funky.
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Old 07-23-2008, 12:33 PM   #31
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No idea. Don't have an AT, never will. Try it and see if it explodes.
we'll see. I just have to wait for the guys at RomRaider to write a definition for my ecu.
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Old 09-13-2008, 11:21 PM   #32
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Quote:
Originally Posted by williaty View Post
No idea. Don't have an AT, never will. Try it and see if it explodes.
automatics are really awesome for strait line drag cars in my opinion whatever.

so after reading this it makes sense and when i try to cruise in traffic im ussually right above idle and it sucks. way too jumpy. feels like it bucks . im sure its doing great things for my entire driveline. so even if i wanna tune the low end where say 20% angle only gives me 20% torque for example . i could fudge it how ever i like right . say at 50% throttle plate angle i just boost to to 100. and have that power available. at any rmp? i would like that for everyday cruising probably better on gas that way too around town. it would just take some getting used to launching.

how much requested torque does it take to produce enough power to not stall out or is that a silly question?its accually the rpm that matters more doesnt it? i mean like how much requested torque does it take for the ecu to throw enough gas on the fire . could i set my throttle plate at say 20/20 and be cool as long as my rpms were fine? or do i need to floor it to get that insane torque the stock ecu requests?

just a thought that popped up when the car starts in neutral what position does th ecu set the throttle plate to? is it closed like a choke on a two stroke? or does it let the air flood in? or is it some variance?
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Old 09-13-2008, 11:25 PM   #33
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total after thought. on an old style cable throttle like i have on my 94 pontiac. ( automatic ) . or on an older subaru , how did the relationship between the throttle plate and the accelorator work. as far as requested torque and throttle angle .
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Old 09-14-2008, 12:25 AM   #34
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I think you need to sit back and study the maps a little more. They are fairly simple, but you might need to think about it for a couple hours before you get it.


On a throttle-cable system, your gas pedal goes right to the throttle plate. half throw on the gas pedal is half throw on the throttle plate. It may not be perfectly liner if the cam the wire rests on is not a constant radius, but it's probably close. This results in the power to the wheels NOT following the gas pedal nicely. There will be lots of change in the first half of the throw, and not a whole lot after.

The first set of maps, from the '05, exhibit this same behavior, because while it's DBW the throttle plate is still slaved to the pedal.




What williaty was doing is making the throttle, in all cases, provide a fraction of the available power. It is important to note that the angle of the throttle plate does not change the available power in a nice linear manner. That is to say, 75% throttle opening is almost identical to WOT. So, in order to make the throttle plate respond nicely to the gas pedal, you need to make the changes in the throttle plate small for the first section of pedal throw, then ramp it up towards the end.


For example: In those maps, 80% pedal causes the throttle to open to ~32%. 40% pedal causes the throttle to open ~15%. 10% throttle nets you 4% throttle plate.
On the other hand, 90% pedal nets you 65% throttle plate, and 95% pedal ges you maybe 85% throttle.



Anyway, the result is that your power to the wheels will vary linearly with the degree to which you press the gas.
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Old 09-14-2008, 12:38 AM   #35
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Quote:
Originally Posted by sniper1rfa View Post
I think you need to sit back and study the maps a little more. They are fairly simple, but you might need to think about it for a couple hours before you get it.


On a throttle-cable system, your gas pedal goes right to the throttle plate. half throw on the gas pedal is half throw on the throttle plate. It may not be perfectly liner if the cam the wire rests on is not a constant radius, but it's probably close. This results in the power to the wheels NOT following the gas pedal nicely. There will be lots of change in the first half of the throw, and not a whole lot after.

The first set of maps, from the '05, exhibit this same behavior, because while it's DBW the throttle plate is still slaved to the pedal.




What williaty was doing is making the throttle, in all cases, provide a fraction of the available power. It is important to note that the angle of the throttle plate does not change the available power in a nice linear manner. That is to say, 75% throttle opening is almost identical to WOT. So, in order to make the throttle plate respond nicely to the gas pedal, you need to make the changes in the throttle plate small for the first section of pedal throw, then ramp it up towards the end.


For example: In those maps, 80% pedal causes the throttle to open to ~32%. 40% pedal causes the throttle to open ~15%. 10% throttle nets you 4% throttle plate.
On the other hand, 90% pedal nets you 65% throttle plate, and 95% pedal ges you maybe 85% throttle.



Anyway, the result is that your power to the wheels will vary linearly with the degree to which you press the gas.

how can your car produce 100% torque without the throttle plate wide open????? wility himself said you can request whatever you want! doesnt mean it will be there for you.

wouldnt it be ideal to have torque request low at like anything under 3250, and then request torque at 100% for the reat of the throttle opening? ( which orolates to the pedal angle)
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Old 09-14-2008, 12:44 AM   #36
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Because the flow characteristics through the throttle body don't change much once the throttle plate is past a certain point. The plate itself probably will generate a little lift, but we aren't trying to make flying throttle bodies to it's a moot point.


Keep in mind, the "requested torque" means NOTHING in any real sense. It is simply a number, used to compare to another number in the throttle plate map. It's a very misleading name. You could start your requested torque at 1000 right at the beginning, and if 1000 in the other chart meant "don't open the plate much" the car would drive just fine. Hell, you could map it backwards: start at 100 and go to zero, as long as you mapped the other part the same way. You could probably even make it go up for a little while, then back down, though that might screw with the interpolation.
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Old 09-14-2008, 01:04 AM   #37
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Quote:
Originally Posted by sniper1rfa View Post
Because the flow characteristics through the throttle body don't change much once the throttle plate is past a certain point. The plate itself probably will generate a little lift, but we aren't trying to make flying throttle bodies to it's a moot point.


Keep in mind, the "requested torque" means NOTHING in any real sense. It is simply a number, used to compare to another number in the throttle plate map. It's a very misleading name. You could start your requested torque at 1000 right at the beginning, and if 1000 in the other chart meant "don't open the plate much" the car would drive just fine. Hell, you could map it backwards: start at 100 and go to zero, as long as you mapped the other part the same way. You could probably even make it go up for a little while, then back down, though that might screw with the interpolation.
so the throttle plate map has set parameters set on what angle the pedal is? and that opens the throttle plate to whatever degree you want.i get this.but if its lineir and thats how pedals have worked forever then why mess with that? i should mess with the requested torque values that corolate with the pedal throttle angle. fine but your saying that even at like 75% throttle opening the flow doesnt change much ? .

wouldnt the same thing we are describing with the dbw in the way that the cable would open the plate to the angle of the pedal , wouldnt you have made most of your power in the first whatever percent of the stroke?? \

what does requested torque do then? throw more fuel on the fire??? if so how by checking fuel map parameters? and giving it that much gas for whatever requested torque value? i thought the fuel values were dictated by the map sensor which read how much air was flowing in. or do they work in concert? or is the fuel map not corolated at all to the map?

do ou have a flow chart based on throttle angle? how did you come up with that at 75% flows pretty maxed out?
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Old 09-14-2008, 09:06 AM   #38
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Yes, older cable-driven cars did the same thing. effectively full throttle without full pedal. You could change the lobe to make this change, if you wanted.




Ok, forget fueling. It's not important for the DBW. Here is what it does.

You push the pedal, say, halfway. The computer looks at the "requested torque vs. accelerator angle" chart. It sees you having 50% throttle, and it sees the engine is at, say, 4000 RPM. It finds the number corresponding to that - in williaty's map that number is 20. Go look.

Now, it takes that number, 20, and looks at the "throttle plate target vs. requested torque" chart. It sees that the engine is at 4000 RPM, and so it picks the number associated with a requested torque of 20 and an RPM of 4000. In williaty's map, that is 20%. The ECU then attempts to open the throttle plate to 20%.

Therefore, pushing the pedal 50% yields a 20% opening at the throttle plate. The "requested torque" number does absolutely nothing after that math has been completed.





So, if you understand me, look at the STOCK 2006 tables on the first page of this thread. Tell me how far the throttle will open at 4000 rpm and 50% pedal.
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Old 09-14-2008, 01:55 PM   #39
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if the relationship is linear(stock) then 50% is 50% no matter what without even looking at it.

if your saying the relationship between the pedal travel and the throttle plate is linear then no value for requested torque would change that hence it being linear.

if it isnt linear and there are variables like the ecu looking at your rpms match that up with a value of requested torque .then mathching that up with pedal angle and then adjusting the trottle plate to control air flow to control engine load , then that isnt linear at all.

i undersand you can tweek it for whatever value you want , but stock is it linear or not?
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Old 09-14-2008, 01:58 PM   #40
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i mean throttle plate is one thing it allows air to enter but is that all requested torque does? it doesnt compare to more table to create the correct afr for the rpm? your saying it soley controls throttle angle???

are you sure you know what our talking about??? definatly not saying you dont i just dont know if you do or not. but on the oher thread even wility kinda called your desription out and directed the conversation over here about the flat throttle.
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Old 09-14-2008, 02:02 PM   #41
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i see kinda what your saying here after re looking at those cgarts and graphs.. pedal angle is one deal , then your computer looks at th requested torque based on pedal angle and rpm. it has a throttle angle set for it. and thats what the plate opens to.

well that is far from linear. if im correct in how it works
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Old 09-14-2008, 02:05 PM   #42
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"Wow! Something very different is going on here! The throttle is NOT linearly slaved to the accelerator pedal angle in this car! In fact, the relationship between the plate and pedal varies with both pedal position and RPM AND there are 3 Requested Torque tables and seven Target Throttle Plate Angle tables for the ECU to pick from! With something this complicated, the only way to attack it is to log the car. A lot. The plot of Pedal Angle (as a percentage) vs engine load (as a percentage of maximum) that appears below is the result of filtering out the reliable data from about 50,000 lines of logs."

not linear! ok so now that i have unconflicting thought in my head it makes sense to me
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Old 09-14-2008, 02:05 PM   #43
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No, look at the graphs. You tell me. It's homework. The '06 maps, btw, not the '05.

If you can't (or won't) look at the maps and figure it out yourself, you won't be able to tune it to your liking anyway. You *really* have to know what the ECU is doing before you can change it.



(hint, you're getting stuck on "requested torque". Forget the name, it's not relevant. The number has no relation to torque.)


EDIT: my god, four posts in the span of one of mine.
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Old 09-14-2008, 02:08 PM   #44
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"Wow! Something very different is going on here! The throttle is NOT linearly slaved to the accelerator pedal angle in this car! In fact, the relationship between the plate and pedal varies with both pedal position and RPM AND there are 3 Requested Torque tables and seven Target Throttle Plate Angle tables for the ECU to pick from! With something this complicated, the only way to attack it is to log the car. A lot. The plot of Pedal Angle (as a percentage) vs engine load (as a percentage of maximum) that appears below is the result of filtering out the reliable data from about 50,000 lines of logs."

its not linear at all , i get it now that , that though of it being linear is out of my head.. you press the pedal , the ecu takes that info looks at the requested torque value based on your input and the rpms and opens the plate to the angle its set up for . whatever that may be .
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Old 09-14-2008, 02:11 PM   #45
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Originally Posted by watchunglava View Post
its not linear at all , i get it now that , that though of it being linear is out of my head.. you press the pedal , the ecu takes that info looks at the requested torque value based on your input and the rpms and opens the plate to the angle its set up for . whatever that may be .

Yeah, thats how it works. To make sure, do the problem i posed earlier in the thread, to make sure you have it.

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So, if you understand me, look at the STOCK 2006 tables on the first page of this thread. Tell me how far the throttle will open at 4000 rpm and 50% pedal.
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Old 09-14-2008, 02:11 PM   #46
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Originally Posted by sniper1rfa View Post
I think you need to sit back and study the maps a little more. They are fairly simple, but you might need to think about it for a couple hours before you get it.

Anyway, the result is that your power to the wheels will vary linearly with the degree to which you press the gas.
see thats where i was getting messed up its not linear at all ,
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Old 09-14-2008, 02:12 PM   #47
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between 37.2 -39.2
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Old 09-14-2008, 02:51 PM   #48
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see thats where i was getting messed up its not linear at all ,

That was referring to williaty's maps. He made it so engine loading (not throttle position) was linear to pedal position.
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Old 09-14-2008, 02:56 PM   #49
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I just bought the op 2.0 for this fix. Its always bothered me when I lurch the car like I've never driven stick while trying to drive "responsibly". Thanks for the good work I'll post my thoughts after I implement.
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Old 09-14-2008, 03:14 PM   #50
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That was referring to williaty's maps. He made it so engine loading (not throttle position) was linear to pedal position.
that would throw me off big time while i was driving. i want my throttle plate to be linear with pedal. well thats not true ,(mostley true though) but this is cool!!!!!!! cause you can tweek your pedal to whatever range you like!!!!!

so i can keep the requested torque values the same , and just tweek the throttle opening to my style of driving? cause i do get jumpy right above idle . which wility described as a fuel kill . it really sucks in traffic im like wtf is my clutch shot. but above that i could even keep it the same if wanted cause im prett happy with everything above 3k through the whole pedal range , i like my touchy pedal , just not in low revs.

heres my question though can this be applied independantly in all 5 gears or is it soely based on rpms?

nice im going to start messing with it now that it make sence.
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