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Discussion Starter · #1 ·
I like my Tiguan with one exception- the throttle response. I'm not talking turbo lag, it's the drive-by-wire lag.
It's so slow that I can quickly put the pedal to the floor and let off without the slightest change in RPM or throttle body position.

If you hold the pedal to the floor, the throttle body slowly opens in a gentle curve, taking 1.2 seconds from the initial pedal hit to fully open.
See graph of pedal position vs throttle plate:

Rectangle Slope Plot Parallel Font


I already have an APR tune, sprint pedal booster, and "Audi" mode in OBDEleven. No difference.

I know there's some smart people out there, or someone who knows how to get ahold of the engineers who did this.
Let's figure out how to remove this silly code and have the throttle plate track the pedal position with no delay.
Other cars do this, even VAG cars so it's clearly possible. I believe this car could be transformed into something much more fun!

I'll want you to talk me through how this curve is created, how to get rid of it, and show me a demonstration, then we can load mine.
$500
 

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2021 HiHy Platinum AWD
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Blame CBS for their fake news on Audi unintended acceleration, so VW puts a delay on the throttle.
 

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So, what is the point? My guess is that you think you want the throttle to match what you do with the pedal exactly, because you think that it will accelerate faster that way. Your car won't accelerate any faster, and it certainly wouldn't be happy with the throttle slamming open or closed. It doesn't work that way on any engine. Modern fuel injected engines and diagnostics just show you why that is. I can see wanting the throttle to close faster for engine braking, especially on tracks. In my experience, that is number one complaint I have from race car drivers, especially with the older fuel injected cars with manual transmissions. I think the newer cars has some better programming in this respect. Turbo cars have the added issue of turbo lag that complicates things as well.

As for your $500, you will need much more than that for a tuner to give you what you think you want (I am assuming to have the throttle to exactly match the pedal position), if it is even possible without a total reprogramming of the way the system works (which I think it would). The big thing to keep in mind that on a modern fuel injected car is that the throttle pedal is just an input, that being "torque demand". When you floor the right pedal, the ECU opens the throttle to the point that will give 100% of the available output at that specific RPM, load, etc. That does not correlate directly to the throttle plate, as anyone who grew up driving carburated cars will know, that you don't get the best acceleration by slamming the throttle open. This is just physics. You need to modulate it so you are not trying to give the engine more air (or fuel for that matter) than it can take. This is really apparent on engines with fairly low output, and less so with high horsepower or race engines with low internal mass. With our turbocharged engines, there is a LOT of lag between throttle and output just because of all that is going on in the system.

What you are showing is a great example of how fast this engine can accelerate under load in a specific gear. Do the same in a higher gear and you have even more of a "lag" in throttle opening vs. pedal position. It would have been good to add Mass Air Flow (in g/s) and RPM and maybe lambda as well. Or just a dyno plot.

VW is not just leaving throttle response on the table for safety's sake, or removing "fun" that could easily be had. There is a LOT to it, much of which is not obvious.

Hey, if you want you can send me $500. ;)
 

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Discussion Starter · #4 ·
@Qmulus
The car will absolutely begin accelerating sooner if the throttle plate is opened more quickly.
I'm reaching peak power 1.2 seconds later than I would have if this delay were not present.
Other drive by wire cars begin responding immediately- the difference is night and day.
The only time a slow open is better is if you have a problem with your fueling system which is not the case here.

It's also not a function of gear or load. The delay is the same in all gears- 1.2 seconds to full plate open even during upshifts.
It's very clearly a VW programmed slow response.
Whether that is to protect the drivetrain or differentiate performance models, I don't know, but I aim to remove it!
 

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@Qmulus
The car will absolutely begin accelerating sooner if the throttle plate is opened more quickly.
If you think so, then prove it. I say no. Prove me wrong.

Have you called any tuners or gone to the tuner forums? This forum is not the place to find someone who is going to change the basic operation of the engine management system or go in depth on explaining why. I think I know what they are going to tell you, but I think you are going to have to hear it from them. From experience, my guess is they will just tell you "Sorry, we don't/won't/can't change that," and you will need to figure out why. Physics is physics. Contrary to what you may think, just slamming open the throttle will NOT result in the engine accelerating faster. Go drive an old cable throttle Audi A4 1.8T. You can open it instantaneously, but it won't accelerate any quicker than a DBW with its "slow" reacting throttle.

There is a LOT to engine controls, especially on a turbo charged engines. Turbo lag is not caused by the throttle body. I used to also do tuning on older cars. The one thing I found was that the more I learned, the more I learned that there was much that I didn't know that I didn't know. (no typo there). If you want throttle response, go naturally aspirated like on the GMA T.50, It has a dRPM/dt of something like 28500RPM/sec with a redline over 12k RPM, meaning it can rev from idle to redline in less than half a second.

If you really want to learn about engine management and engine controls, Bosch has some great books. You can also go to nefmoto.com (or some of the other places where you can learn) and maybe start learning how to do things yourself. The one thing I will tell you is that while people are helpful, they are not very tolerant of those who just want answers without trying to find it themselves.

This must really bother you, as you have both a pedal commander and a tune. I think now you need to investigate the issue yourself to see just why it does what it does. Maybe you can learn to tune your own engine and end up doing it for others.
 

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OP, I'm surprised the sprint booster didn't help you with this much.

I know this is a touchy subject here, but it's your car so you do what you want to based on your experience.

I've been running the pedal commander for a couple years now. The early version gave me some initial issues, but eventually they updated the software and I've been trouble free for a year or so now. I have also tried the sprint booster, but found the pedal commander gave me the better response I was looking for.

The Pedal Commander coupled with my K04 setup truly transforms the Tiguan. I'll have to see if I still have my dragy snap shots. The pedal commander will help get you from A to B much quicker than just the stock response.

I think you said it best, the problem isn't a power issue like everyone keeps confusing this with. It's the response issue. It's the delay time before you get to your power band. Some people claim you can resolve this by pushing down on the pedal more, but that's just wrong. Even with my K04 setup, the Tiguan was relatively slow. Smash the pedal and the thing was lagging along. Doesn't matter if it's pedal commander, sprint booster, pedal switch 5000 - the take away is that the response time is the issue. I'd prefer there was a tune or factory update to resolve this, but there won't be. So these little pedal gadgets will do for now.

Oh, and I also think this response issue is only in the 2012-2017 Tiguans. No hard proof, but my 2011 K04 Tiguan was much better. Didn't need any pedal gadgets from what I recalled. I've only encountered the problem in my 2017 Tiguan.

Sent from my SM-S908U using Tapatalk
 

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Discussion Starter · #7 · (Edited)
If you think so, then prove it. I say no. Prove me wrong.
I'll be posting the results here. The proof will be time to start raising the RPM, time to peak boost, or time to 60mph as measured from pedal press.
I'm not suggesting the car will be faster 0-60 from rollout, but that it would respond faster from pedal press.

Have you called any tuners ...From experience, my guess is they will just tell you "Sorry, we don't/won't/can't change that,"
I asked APR, and that's what they said. So here I am !

You can open it instantaneously, but it won't accelerate any quicker than a DBW with its "slow" reacting throttle.
Go down to any racetrack and tell the drivers you're going to install a rubber band on their throttle cable that makes it take 1.2 seconds to open, but that their cars won't be any slower as a result. The would laugh you out of the room in about 1.2 seconds!

You can also go to nefmoto.com (or some of the other places where you can learn) and maybe start learning how to do things yourself. The one thing I will tell you is that while people are helpful, they are not very tolerant of those who just want answers without trying to find it themselves.....Maybe you can learn to tune your own engine and end up doing it for others.
That site looks promising! Didn't take long to find a few things to try.
I am trying to hire someone to show me how it works, not just get the result, but no takers yet.
Looks like I'll roll up my sleeves and try it myself..probably on a spare ECU first.
If I get it figured out and the results are good, I'll offer it to others.

@dubGLI05 You get it! It's the response time, not the power.
I was thinking of the K04 or other upgrades but not until I fix this first. How did your trans hold up?

The sprint pedal does what I thought it would- sends higher pedal values to the ECU. I can see how people would say it makes the car 'feel' faster - it does tell the engine to deliver more power for a given pedal position, but WOT is still WOT. I do like that it's adjustable, and I've landed on Green 6 as a good feel.

Thanks!
 

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I know EXACTLY what you want to "fix". The issue here is called "turbo lag". Making a turbo charged engine respond like a naturally aspirated engine has been an issue since turbos were first invented. Basically, turbo charged engines sacrifice throttle response for power. The newest turbo engines with small, efficient turbos and short intake tracts has minimized that with small, light and efficient turbos with short, low volume intake tracts and efficient intercoolers.

The mistake you are making is that you think that opening the throttle faster alone will make the engine respond faster. You are just seeing how the ECU controls the throttle to match the engine. The throttle opening is not what is causing the lag. What is actually causing the lag is the turbo charger spooling up and all the intake plumbing that needs to be filled. Opening the throttle faster would just create a more of a pressure wave, and a nasty stumble and would actually make the response slower. Drive an old turbo car and you will REALLY understand turbo lag, as well as what happen if you just slam the throttle open on a turbo car... The idea is to open the throttle only as quickly as the engine can take the air, and that air is being pumped by the turbo, which has to be driven by the exhaust, and has mass to spin up. All of that takes time, which equals lag. There are anti-lag devices, but nothing that really works well on a street car.

The graph you posted just shows how the throttle responds in the conditions under which you tested it and is a good graphic of turbo lag. It may open faster or slower depending on if the engine can actually flow the air.

Bottom line, you correct in wanting to open the throttle quicker, but first first everything upstream has to be able to enable that. Just opening the throttle quicker will not fix the issue. The only "code" that can help get the turbo spooled up quicker is ant-lag. That is REALLY hard on things, and really only used for racing.
 
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