Throttle lag and filtering?
 

I don't care about turbos, E85 or power numbers. I just want the throttle filtering to be removed.

I've owned 28 Corollas, 13 ae86's and I cannot stand how laggy and delayed the throttle is.

Digging through the BIN file in rom raider, I can't seem to find any definitions that I understand that will fix this throttle delay and throttle filtering. I even started opening up the BIN files in hex editor to see if I could identify things that weren't already in the definitions files. But I've not found anything as I'm not quite smart enough to do that.



I'd love some good guidance before I start drilling holes and ruining my motor with a throttle cable botched in. Like I get angry in the car because of this throttle filtering. :help::hitcomputer:

Really common mod in Japan. But there are ridiculously cheap ones on AliExpress.


https://www.vividracing.com/toms-rac...151571649.html


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Holy shit. So it's just a japanese Pedal Commander?

What settings in the BIN file is this overcoming?

I fail to see, how they can "eliminate lag". What seems more probable to me, that all they do - remap pedal travel scaling a bit differently for different commanded power vs actual pedal travel. And if it's so, i fail to see why pay for it, if it's allready in ecu tune, for which one is better off paying for as it will rise overall performance instead of being fooled by it's mapping, and also i'm not too fond of even stock pedal mapping, which lumps most change in initial travel to make false impression of bigger engine .. robbing precision from pedalwork with more linear mapped pedal.

Yeah idk what it’s doing. But I know it’s like really common mod in Japan.


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Are you referring to throttle blips that get ignored? For example, you attempt a blip to do a downshift and it literally does nothing and you end up putting your head in the windshield with a mismatched downshift. A lot of this has to do with the TIR (Transient Ignition Retard) which pulls timing when there are big RPM changes such as a gear change. Out of the box the car will audibly detonate if you do a rapid gear change. In 2017 they revised the TIR tables to combat this but at the same time they killed throttle response. The only solution I've found is to use the pre-2017 TIR tables but with E85. So I get good throttle response without the detonation on quick gear changes.


There is a thread around here somewhere where someone was trying to come up with new TIR tables that were the best of both worlds but in the end I think they gave up. You say you don't care about E85 but it really does transform this car. The inconsistent throttle response completely vanishes and you no longer have that disconnected feeling.

Certainly you know that there will be input delay inherent to the delivery medium- there's a computer between your foot and the butterfly valve interpreting and action on your behalf. Nothing will be as fast or snappy as cable driven

Look at the DBW drive by wire throttle tables sometimes called torque calculation tables. and ues you can mess with these to improve the low end throttle response


which tune system do you have ?

Yes. I can tap the pedal a thousand times, but until I commit to a throttle position, it just don't respond, regardless if I'm accelerating or decelerating.






I live on an island and E85 is a 2 hour ferry ride away.

I've managed to rumble up a KESS V2. Sadly I don't think I can live log with it, but it works great for reading and writing.

Sucks you can’t easily get E85. I’m lucky enough to find it at every major intersection.

Another question, what it the longest you’ve gone without an ECU reset? I ask because the throttle response is really bad for about 200 miles after a reset. If you are playing with RR and reflahing constantly and you never make it to 200mi then you’re not getting past that training phase. When I first got my car I got a Tactrix cable within the first week and spent the first month flashing a lot and hatted how bad it drove. Once I left it alone it settled down and became tolerable.

If you are running a 2017 or newer rom then try running the pre-2017 TIR tables and see if that is better. But give it time to settle in. A quick stab at the idle right after a flash will literally be ignored. It takes a ridiculous amount of time to go back to normal. I drive 40 miles per day and it takes a good week for mine to settle. I just replaced my battery a few weeks ago and it’s just now getting back to normal.

correct kess just reads and writes no logging

You can get cables on Amazon for $18 that will work with Toyota Techstream and live log with that but it’s not very user friendly to start/stop and requires a laptop in the car. But you can’t beat the price.

These add additional layer of filtering before the ECU even receives the signal from the throttle pedal. There is no way they can increase response, all they will be doing is sending a signal to the ECU that makes it look like you wanted more throttle initially.

A tune helps with throttle response and I've read people claiming in these boards that doing the pedal dance improves throttle response. Personally I think it is just something we have to live with on this car with its electronic throttle. I am not even sure the stock ECU will be able to work if you put a cable throttle on the motor.

I agree. It’s something I have learned to live with. I’m not even bothered by It.


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I'd try to check with an external wideband if the O2 sensor is off and the engine is running lean without any sign in the log.
Could also be nailed with fooling the calibration of the O2 sensor a tad into the lean area around stoich to force running a slightly richer mixture in closed loop.

The answer really is in the TIR (Transient Ignition Retard) tables. These threads have some good info:
https://www.ft86club.com/forums/showthread.php?t=50088

https://www.ft86club.com/forums/showthread.php?t=118629

“transient” is when there are big fluctuations in the RPMs, for example blips or shifts. In the early days there was an issue with detonation on shifts at redline which was eating injector seals. The cause was that the original roms had the TIR table zeroed out so it wasn’t pulling timing on shifts. Shortly after the release of the car they filled in the TIR table which fixed the injector seal issue but also impacted blips a little. In 2017 they got WAY more aggressive with the TIR table which fixed some knocking on fast shifts but really killed blips.

It’s a trade off between throttle response or knock when it comes to the TIR table. I run the 2013 TIR table but don’t get the knock because I’m on E85. I think if you have a lot of time to play in RomRaider you could come up with a perfect table that will avoid the knock on high RPM shifts without killing blips.

So for some updates to this very old post:

I tried a few different 'hardware' solutions.

Chinese Pedal Commander: $26CAD
https://i.imgur.com/TETJjus.jpg
https://i.imgur.com/wwYMzFo.jpg
https://i.imgur.com/4I1ExHT.jpg

Results? Only changed how fast the throttle goes to 100%. It didn't change the throttle hang when letting off the pedal, and it didn't improve the input filtering. You can still hit the pedal 40 times quickly, but the throttle wont respond unless you hold an input.

Decided to try the bad idea as well. I knew it wasn't going to work, but had to try. Had the spare parts to test the theory.

https://i.imgur.com/groaPzf.jpg
https://i.imgur.com/HBgxXp4.jpg
https://i.imgur.com/k3OMMw9.jpg


What was most interesting is the firewall, carpet, and pedal all had pre-made notches or holes specifically to fit a throttle cable. They all line up perfectly.

https://i.imgur.com/6KH1VsU.jpg
https://i.imgur.com/Jcifbhm.jpg
https://i.imgur.com/w6ggyjZ.jpg

The motor would rev up if I matched the pedal position to the throttle plate position, but otherwise would choke and throw limp mode at me. Worth the shot, but man I fucking hate the throttle feel in this car. I am creating a drift kit, but I don't want to force people to buy aftermarket ECU's just to open the idea of throttle control during drifts. Like, you can't 'pedal' these cars. You could if the throttle pedal and throttle plate were actually working together.

Wow thanks for taking the plunge and testing. I hope someone comes up with something.


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I attempted similar stuff on my IS300 but if the input doesn’t match what the ECU expects it freaks out. You say you don’t like the DBW in the Twins, you should see how bad it is in the IS300 or the Z/G3X or Porsche. The Twins have by far the best DBW of any modern cars I’ve driven.

So, I guess you still haven’t played with the TIR tables. ;)

just try modify the tables of DBW, also if you have ecutek you have an extra table to modify it's sensitivity

I've seen a number of videos discussing Ayrton Senna's throttle technique. He rapidly cycled the throttle in corners from apex to exit. These DBW systems would have made his driving style impossible.

I've spent about 30-40 hours of seat time in around 15-20 different IS200s. Maybe the 1GFE is different than the NA 2JZ, but the throttle control of those cars was far more direct than the BRZ/FRS.

https://i.imgur.com/m8poW9q.jpg

I've also got somewhere in the 300ish? hours in a Caymen on circuit, but the porsche I can completely confirm is similar to the twins, where you are required to keep it planted to get any sort of torque delivery.

https://i.imgur.com/HsEBtaW.jpg


Sadly, I just don't know how to tune ROMs. I've got a KESS V2 at my disposal to move tunes to and from the ECU, but that's about the extent of my knowledge. I'd rather just some VW down drafts and lock the cams in place. I really don't care about power, I just want predictability.

I MUST BUMP THIS THREAD:

This update is in anger. I spent some seat time in an ZZT230 Celica today. My work car is DBW, and my BRZ is DBW. Driving the Celica today was a huge reminder about the feeling I'm talking about.

The 'torque dip' really isn't the major problem. It's the fucking throttle input filtering.

I'm desperate to drive an FA20 car with a completely aftermarket ECU with a map made from scratch. I can't fucking stand the throttle plate doing things that I'm not telling it to.

In moments of oversteer in the celica today, I was able to subtly control throttle inputs there was no delay or negotiation of the wheel speed I needed at the moment. Immediately after I drove the BRZ in the same course to only have it constantly arguing with my inputs, and the delays themselves changed depending on some mystery maps and circumstances.



I really don't have the ability to know what others have done, but I'm so done with the FA20. I can't think of another N/A 2L I've driven that feels this disconnected from throttle control. The dip, and filtering teamwork to create random wheel speed control unless you hold it on the floor and hope. From 1%-99% you have no idea what the throttle plate is doing, and even sometimes when you hold or maintain a position the plate may change resulting in destruction on the art of throttle control. I need to find a solution that doesn't require me buying a new ECU and spending hours and hours trying to tell a dyno technician what I mean by throttle linearity, as I've not met one of those guys yet that gets it.

--End rant.

I assume you are doing the long hold on the TC button. Have you also tried the pedal dance? I’ve just not noticed the levels of filtering and lag you speak of. I have no problem at the razor edge of traction. Can’t say the same for other DBW cars I’ve driven. Nothing will fully replace a cable though.

IIRC he also was the only F1 driver to use that technique, rest did normal "smooth is fast". That technique may have roots from Senna's childhood karting history and not sure it's that usable in modern F1 cars either.

AFAIK throttle mapping linearity can be easily done. It had been done in OFT tunes, so assuming that competent ecutek tuners can do it too.
As for throttle dip .. if you want to keep engine in powerband you'll be above it anyway, and in normal easy driving along the traffic most of the time i'm below it. Until i first read about existence of such, i didn't even consciously noticed it myself. End it's not that car doesn't accelerate in dip, just does it slower. But ocasions, when i need to accelerate from 2Krpms to 5? Rarely happens. When i need quick acceleration i just row down few gears anyway.
Now for general throttle lag .. if it is left as only issue .. to me it certainly is not of that high priority, especially to think of engine replacement "to fix". Nice to have it improved, but can live without.

It is entirely possible that I am out of my mind, but I am convinced that the throttle mapping on my '15 changes when I do the long (double) press on the nanny buttons. I usually do that as the engine is warming up, but on occasion I forget. When I do I find myself being irritated that my shifts seem clumsier and the throttle blips less predictable, Eventually, I'll notice the absence of lights on the panel and fix it at the next light. :iono:

I appreciate the replies.

ABS fuse was thrown in the bushes the day I got the car. No ABS, no TC.

I should really setup a camera, as I can't live log the OEM ecu sadly. Maybe there is a way to log the ECU so I can look after, but I know live isn't possible with the OEM ECU.

I’ve seen others say similar about the long hold. I’ve never noticed much of a difference on blips. I’ve already said it in this thread but switching to E85 was the the only thing that solved the inconsistent blips for me. Before e85 it would randomly ignore my blips regardless of the long hold. I would do a big stab and the revs would literally keep falling as if I never pressed the throttle.

I will pull my ABS fuse today and see if I notice any difference in throttle response.

Live logging is possible with the OEM ECU. What sort of cable do you have? If it’s USB and is compatible with Techstream then you can log. If your cable isn’t compatible you can get one cheap on Amazon that is. Just search for “Techstream” on Amazon.

@ermax how did you manage to copy the 2017 TIR table to a 2013 tune as the table sizes don't match? I'm attempting to try out the 2017 on mine.

I don't recall them not matching. Have to dig up the two roms and compare. Out of curiosity, why do you want to run the 2017 TIR? It pulls a lot of timing on big transients (blips) so it actually hurts throttle response.

Edit: Okay I see the 2017 has one additional column for engine load at .80. I simply slid the whole table over to the left one column.

I created a pastebin for it here:
https://pastebin.com/raw/U5GqRfP3

Just copy that to the clipboard, then go into the TIR table for your 2013 ROM and then hit Ctrl+V. It should overlay the whole table with the 2017 values. You will notice the 2013 ROM hardly pulls any timing at all between 4000 and 5200 where as the 2017 ROM pulls up to -25 in that range. It has a significate negative impact on throttle response.

Hmmm. Our pedal techniques could be different, but mine will accept blips in normal mode (although a little sluggishly), and seems a bit sharper after the long press.

Nevertheless, I have been contemplating flex fuel for a while now. May pull the trigger soonish. Which kit (if any) do you have? Any pros/cons to the rest?

Thanks for that - I initially wanted to find out on how you 'adapted' the larger table to the smaller table size.

I'm on Wayne's tune (which the TIR table is based on the A01G but with the 4000 to 5200 RPM hole plugged in) but I'm still getting audible tip-in knocks hence wanting to try the 2017 TIR table if the throttle response is manageable.

I've attached the comparison below - stock A01G ROM is on right.

https://i.imgur.com/wtnHdlk.png

I'm a bit confused by the many variations of the techstream cables, otherwise I would've bought one by now.

The lagginess on the 2017 table is fairly signification but yeah that tip in knock clicking crap is unnerving. The 2017 fully solved that for me but when switching to E85 I was able to go back to the 2013 table and still not get tip in knock.

This is the one I ordered but this exact one isn’t available anymore. https://uploads.tapatalk-cdn.com/202...267dba9b18.jpg

@DiscoQuinn i completely feel your pain with these fa20s. The throttle "delay" as I call it is also my #1 frustration with these cars.

Sadly, it can only be remedied with an aftermarket ECU as I understand. Its just impossible to get rid of the 200ms (ish) delay from off to on throttle transitions with the stock ECU. I guess it does a bunch of calculations before it starts to move the throttle plate relative to your pedal position.

That said, there COULD theoretically be another solution, but it'd take some good programming and wiring skills. You could use a microcontroller that directly trsnslates your pedal movement to throttle plate movement while also mimicking the throttle pedal and throttle plate positions that the ECU is expecting. Essentially it would trick your ECU into thinking it's getting an acceptable pedal and throttle position reading. This should prevent any limp home conditions assuming it's coupled with an appropriate remapping of the ROM.



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Many in Japan use the Max Orido throttle controller.
Differently from the others, it has to be connected to the throttle body instead of the pedal, so it can really make the pedal 1:1 with the throttle body.
But, shouldn't this turn on the engine light, as there is a mismatched between the expected position and the real one?