Unitronic Tune

[Dthquazi]

I recently tuned using the Unitronic stage 2 and want to check to see if what I'm experiencing is correct. I am getting a hesitation similar to spark cut during moderate to heavy acceleration in dynamic. It is similar to a boost building features in other tunes (r35 GTR rolling launch feature in ecutec if anyone is familiar). The hesitation then goes away and it accelerates as expected. I haven't hammered on it since I don't have the stage 2 TCU tune yet. I have put around 100 miles on it thinking it might be in a learning stage and go away. It didn't

Additionally, I'm in Washington and we have 92 octane. I was originally running the 91 octane tune. I switched to the 93 octane tune and it is still present. I am thinking it is a feature in the tune but I'm not a huge fan of it. I'd rather have the smooth acceleration.

Relevant upgrades:
Unitronic ECU stage 2
Unitronic TCU stage 1 (will be getting stage 2 this week)
Unitronic catted downpipe
Unitronic intercooler
034 4 inch turbo inlet
Wastegate upgrade line
NGK R7437-9 gapped 24
IE covered intake

[Dimsum222]

I recommend using the Unitronic Beta Data logger. In my experience I've found that the timing advance is quite aggressive with Unitronic tunes and that on pump gas with the appropriate associated octane map, it will still pull upwards of 6-8 degrees of timing in some areas, leading to the feeling of hesitation. In the end, adding a few gallons of e85 with each fill seemed to be the only remedy. This is actually well documented by certain YouTubers, such as Vancity Audi, who recommends running around e20-e30 to eliminate any potential power loss from timing pull.

That being said, I've seen a lot of happy Stage 2 and Stage 3 RS3 owners using DS1. If ethanol isn't easily accessible for you, then you may want to consider them as a possible alternative.

~David

[cseaman]

Don't have a solve for your problem but you're not going to make any friends at Uni when you tell them you're running 92 on the 93 file.

[Dthquazi]

It doesn't feel like pulled timing. Feels like a rev limiter till boost builds. Once it's gone and going, the power is there.

It was only to test. Didn't push it but wanted to see if the problem was with the file or flash. Put the 91 back on after confirming.

[yoffer]

I recommend using the Unitronic Beta Data logger. In my experience I've found that the timing advance is quite aggressive with Unitronic tunes and that on pump gas with the appropriate associated octane map, it will still pull upwards of 6-8 degrees of timing in some areas, leading to the feeling of hesitation. In the end, adding a few gallons of e85 with each fill seemed to be the only remedy. This is actually well documented by certain YouTubers, such as Vancity Audi, who recommends running around e20-e30 to eliminate any potential power loss from timing pull.

That being said, I've seen a lot of happy Stage 2 and Stage 3 RS3 owners using DS1. If ethanol isn't easily accessible for you, then you may want to consider them as a possible alternative.

~David

Most tunes are going to have some form of timing pull. Factory cars brand new will have timing pull. If you think switching to DS1 will eliminate timing pull, I’d hate to be the bearer of bad news….

[John@DEADBEEF_DynoSp]

If anything you often see more timing pull on a DS1 than other tunes because we guarantee to keep the knock sensitivity stock, whereas most of the industry reduce knock sensitivity on VAG tunes. However, we have a map switch for your octane and if you use an ethanol content sensor it auto adjusts. Additionally we make the stock ECU tables that reduce boost with knock retard more aggressive to suit higher boost levels than stock. The user will not feel any of this happening apart from a smooth, safe reduction in performance to protect the engine that is first noticed in logs.

Regardless of any of that, on any tune, if you feel a hesitation even on a first pull, something potentially serious is wrong, you should back out of it and go off logs and data not off feel. Engines get destroyed by people "waiting for things to learn". Hesitation or anything the user can feel wrong in a quality calibration is always something to fix and never something that should be tolerated or left to ideas or wishful thinking. Needs data.

I wouldn't imagine that a Unitronic tune should feel anything other than smooth and there is probably a problem with the car to fix.

[sleepy_rs3]

It doesn't feel like pulled timing. Feels like a rev limiter till boost builds. Once it's gone and going, the power is there.

It was only to test. Didn't push it but wanted to see if the problem was with the file or flash. Put the 91 back on after confirming.

Just throwing this out there - do you have ESC off? And also - definitely good call switching your ECU back to 91 for your 92 octane fuel

[Dthquazi]

Just throwing this out there - do you have ESC off? And also - definitely good call switching your ECU back to 91 for your 92 octane fuel

Nope. I get no flashing light on the dash indicating anything including ESC intervention

[8STTRS]

When I was stage 2 93 on Unitronic, I also experienced what you're describing but, it didn't seem to happen every time. However, if the vehicle was in Dynamic and in automatic, it stood a chance of it doing what sounded like RAL very briefly before actually accelerating. Now, I basically always have the car in manual mode and it doesn't do it anymore but, I'm also on DS1 w/ a custom tune.

My advice is to either keep the car in manual mode and it won't do that anymore or switch to DS1 and get a custom tune.

[sleepy_rs3]

Nope. I get no flashing light on the dash indicating anything including ESC intervention

That could be the problem. ESC/traction light doesn't necessarily flash on the dash when the system intervenes. The motor will literally cut torque to prevent wheel spin, which is why you don't get a flashing ESC light, because the ECU didn't give the wheels enough torque to spin. Many of us immediately put the car in ESC sport when we get in just to avoid this.

Try putting it in ESC sport or completely off (press & hold for a few seconds) and then driving it hard...once the engine is warm, that is

[Dthquazi]

That could be the problem. ESC/traction light doesn't necessarily flash on the dash when the system intervenes. The motor will literally cut torque to prevent wheel spin, which is why you don't get a flashing ESC light, because the ECU didn't give the wheels enough torque to spin. Many of us immediately put the car in ESC sport when we get in just to avoid this.

Try putting it in ESC sport or completely off (press & hold for a few seconds) and then driving it hard...once the engine is warm, that is

OK that's interesting. I'll try this. I called unitronic this morning to talk to them about it. I will be getting logs and sending them the logs. This will be done after upgrading the tcu to stage 2.

I don't want to essentially scrap $1k and buy ds1 so hopefully they can point me in the correct direction. Also seems kinda shitty that I have to drive the car in a specific way to have it work properly.

[sleepy_rs3]

Also seems kinda shitty that I have to drive the car in a specific way to have it work properly.

It's actually just the ESC doing its job, which can be good when you are on slick roads and don't want to worry about tires breaking loose. The ESC simply has to intervene more when the car is making more power due to a tune...

I agree that it's "shitty" when you want to drive hard and don't mind losing a little traction in the process...I believe obdeleven has an app which allows the car to start up with ESC off already, but I haven't tried it out yet because I want ESC on if my girlfriend drives the car

What is even shittier is having to cycle through drive select after startup to get true dynamic...but that's a separate discussion which can be followed here: https://www.audizine.com/forum/showt...errerid=594778

[Dthquazi]

It's actually just the ESC doing its job, which can be good when you are on slick roads and don't want to worry about tires breaking loose. The ESC simply has to intervene more when the car is making more power due to a tune...

I agree that it's "shitty" when you want to drive hard and don't mind losing a little traction in the process...I believe obdeleven has an app which allows the car to start up with ESC off already, but I haven't tried it out yet because I want ESC on if my girlfriend drives the car

What is even shittier is having to cycle through drive select after startup to get true dynamic...but that's a separate discussion which can be followed here: https://www.audizine.com/forum/showt...errerid=594778

So after the stage 2 tcu tune, it is much better. I am still getting a small amount of the issue but of course couldn't getting it while I was logging. I tried it with the ecs limited and with it off. Was still there. I will try to replicate it for logs tomorrow.

[John@Unitronic]

Have you collected any logs of the situation you describe? Our Uni Logger will collect all useful data and allow you to submit to our server. Reach out to me via email for more information - js[at]getunitronic.com

[Dthquazi]

Yes and I submitted them. Was told yesterday when I called that they would be reviewed and contacted after that.