Finally got an rs3 and have tuning questions!

[dbp510]

So i was finally able to pick up a blue 2018 audi rs3 with some mods on it with only 20k miles. (Mods for only 4k).

After driving the car 3,000 miles to get it home and learning all about it I've enjoyed every second of driving it.

I do have some questions about it i can't seem to find a solid answer on.

1) First being the car has a DS1 in it and has a flex fuel sensor. However the sensor wasn't wired in yet. So i wired in the signal wire to pin 15 of the obd2 port, used an add a fuse to a good/tested 12v port, and the ground wire.

After hooking it up i assumed the ds1 would see the signal and automaticlly overwrite the manually set amount of e85 % that i had set. But every time i open up the browser i only see the manual number that i set which is 8% (due to running 92 oct and not full e85 since there are no stations next to me).

Is there something I'm missing? Do i need to somehow clear the manually set amount in order for the flex fuel sensor to tune to the proper fuel mixture?

2) Second being after driving it today in the rain it feels as if the car constantly cuts all power under acceleration even with traction control on, single press for off, or hold for fully off. This is also at freeway speeds. If i roll onto the throttle it will either pull power on and off or kill it completely almost as if you're out of fuel. (Wondering if the flex fuel sensor could be causing this, although it had no issues in the dry yesterday).

As far as i know the car is not spinning the wheels either. Cause at 80mph and pushing on it in 4-5th gear shouldn't cause the tires to break loose.

As for specs this is what is done to the car.

2018 Audi RS3

Mods
IE Full Carbon Intake
APR 4" Turbo Inlet
Unitronic Catless Downpipe
CTS Turbo complete hotside piping
Unitronic Intercooler
APR Throttle Body Inlet
Unitronic 1000cc injectors
Unitronic Stage 2 Trans Tune
Ethanol Content Sensor wired for integration with DS1
DS1 with Pro tune from Darin Dichiara
STG2 Full Flex Fuel
034 Motorsports Front and Rear Subframe lockdown kits
Urotuning Dogbone Mount

If anyone has any good insight on this i'd greatly appreciate it. I do use the search button as well. I'm an avid reader when it comes to searching for info on my vehicles.

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[mtwallace85]

Concerning the flex fuel sensor, make sure you get a good ground spot and that it has a solid connection. Mine didn’t work right away and that was the culprit. Congrats on the new ride!

[o1turbo30v]

also depending on what flex fuel sensor is installed, it will also need a resistor to work properly. https://sillyrabbitmotorsport.com/2-...ensor-kit.html

2. You have a car that makes over 400 WTQ and 500 WHP, depending on the tires, yes it will spin them all day long in the rain, also check the Haldex to ensure not fault codes.

Welcome to the money pit

[tegxsi]

Usually it's a wiring issue...
The ethanol content updates as soon as the signal wire touches.

ds1eth.jpg

make sure you disconnect the factory wire going to pin-15
If you are tapping a signal from a gauge you don't need the 3k pull-up resistor.

[dbp510]

Usually it's a wiring issue...
The ethanol content updates as soon as the signal wire touches.

ds1eth.jpg

make sure you disconnect the factory wire going to pin-15
If you are tapping a signal from a gauge you don't need the 3k pull-up resistor.

Okay see this i was unaware of. All i have right now is the power wire plugged directly into the fuse box and the signal wire i depinned it and used the pin on my new wire, then plugged it back into slot 15.

So i should add a 3k between the power and signal wires?

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[dbp510]

also depending on what flex fuel sensor is installed, it will also need a resistor to work properly. https://sillyrabbitmotorsport.com/2-...ensor-kit.html

2. You have a car that makes over 400 WTQ and 500 WHP, depending on the tires, yes it will spin them all day long in the rain, also check the Haldex to ensure not fault codes.

Welcome to the money pit

I will have to figure out what sensor i have. Unfortunately i don't know at the moment. And yes i suppose you're right about that. 500+hp does make it easy to spin the tires. I just assumed rolling onto it at 80 wouldn't cause them to spin even in the wet. As soon as i have a dry day i will do some harder pulls and see if does the same thing. Over a 3200 mile drive in 4 days it never gave me an issue so i think it's just the rain.

Thank you all for the responses!

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[dbp510]

Okay, something is definitely going on with the car, and I'm not sure what. On dry ground on the freeway, going about 70mph if i throw it in manual in 4th gear and punch it, the car will do 1 of 2 things. About half a second after being floored, the car starts to accelerate, then immediately pulls all of my throttle positioning. This means i can stay floored, yet the car is only showing like 15% throttle. There is no boost, and the car just creeps up in rpm. I'll post a quick screenshot. I just got off of the ds1 log where it happened.

The second thing that may happen is i punched it, and instead of killing all my throttle, the car feels like it's bucking while accelerating. (As if the throttle is on and off over and over super fast). It still feels fast but definitely not as fast as it would during a smooth pull.

In the photo, you can see the throttle dump, yet i haven't let off. You can also see the rpm drop slightly where it pulled and then continue to creep up.

I have another photo showing it pulling all power where it looks like the absolute pressure went past the targeted value. I'm not sure if this is important or not.

Please let me know what anyone thinks. I don't believe it to be a traction issue anymore.Screenshot_20221107_173242_Chrome.jpgScreenshot_20221107_173426_Chrome.jpg

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[dbp510]

Bump, if anyone has any ideas, it would be greatly appreciated. I can't use more than like 25% throttle. Otherwise, it'll start to build boost and then start to shutter under acceleration or cut all my power.

If anyone has any recommendations for tuners i may call or talk to and send logs to, i would greatly appreciate it!

Thanks

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[NapalmEnema]

Until you get a tuner I'd stay out of boost - it sounds to me like some arsehole turned in a modified car and to make a few bucks, took the tune and tuner hardware off it to sell - thereby screwing over the next buyer - you. Stay out of boost and get a tuner on it stat imo - you could also try and figure out all the parts and see if it fits the list for a set tune that is already available that supports those parts. Good luck man

[dbp510]

Until you get a tuner I'd stay out of boost - it sounds to me like some arsehole turned in a modified car and to make a few bucks, took the tune and tuner hardware off it to sell - thereby screwing over the next buyer - you. Stay out of boost and get a tuner on it stat imo - you could also try and figure out all the parts and see if it fits the list for a set tune that is already available that supports those parts. Good luck man

Yeah, this is what I'm attempting to do. After looking over the cars mods, everything seems to be proper as to what was listed. Although i have found a few jank things such as the IE carbon intake with the apr throttle body. Because they don't belong together, someone decided to just cut a hole in the side of the beautiful carbon fiber intake to make room.

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[dbp510]

I'm posting a link share video i took last night. You can hear the shuttering in the video.

https://linksharing.samsungcloud.com/yNGIuwwM4yl2

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[NapalmEnema]

Yeah, this is what I'm attempting to do. After looking over the cars mods, everything seems to be proper as to what was listed. Although i have found a few jank things such as the IE carbon intake with the apr throttle body. Because they don't belong together, someone decided to just cut a hole in the side of the beautiful carbon fiber intake to make room.

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That may impact how that thing works at all - perhaps get a stock air intake and get tuned around that - with the other mods it should be plenty fast - the most concerning bit I saw above is this 'transmission tune' - I'd be worried to drive it for fear of damaging the dual clutch, personally. I've had dual clutch issues on an old Evolution X MR - it was $$$$$$$$$$$$ and that wasn't even an RS3. Good luck and these things are tough but yeah def putter around till you can get a proper look and based on that intake I'd give everything a once over that it is installed properly as well.

[dbp510]

That may impact how that thing works at all - perhaps get a stock air intake and get tuned around that - with the other mods it should be plenty fast - the most concerning bit I saw above is this 'transmission tune' - I'd be worried to drive it for fear of damaging the dual clutch, personally. I've had dual clutch issues on an old Evolution X MR - it was $$$$$$$$$$$$ and that wasn't even an RS3. Good luck and these things are tough but yeah def putter around till you can get a proper look and based on that intake I'd give everything a once over that it is installed properly as well.

Ill have to give this a shot, i have noticed that the transmission shifts insanely hard/fast. So much so that i would actually prefer going down a stage if possible. I also posted a video if you wanna listen to it.

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[o1turbo30v]

Log the duty cycle of your fuel pump(s)

[dbp510]

Log the duty cycle of your fuel pump(s)

So i just flashed the stage 2x 980cc ots tune, and the car is no longer giving me any issues. I think it has something to do with the pro tune from darin. This is most likely due to me only having access to 91/92 oct, whereas the previous owner only ever ran full e85.

All i did was switch the map to 91 from 93 and put 92 octane fuel in it. (And set Ethanol properly) For some reason, the car wasn't happy about it. That's what led me to try the ots tune.

I got the flex sensor working properly as well, and it is now updating Ethanol % on the dash.

Thank you for the input!

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[NapalmEnema]

So i just flashed the stage 2x 980cc ots tune, and the car is no longer giving me any issues. I think it has something to do with the pro tune from darin. This is most likely due to me only having access to 91/92 oct, whereas the previous owner only ever ran full e85.

All i did was switch the map to 91 from 93 and put 92 octane fuel in it. (And set Ethanol properly) For some reason, the car wasn't happy about it. That's what led me to try the ots tune.

I got the flex sensor working properly as well, and it is now updating Ethanol % on the dash.

Thank you for the input!

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Awesome outcome man! Yeah running a safer tune for the fuel you're running was a good call.

[dbp510]

Awesome outcome man! Yeah running a safer tune for the fuel you're running was a good call.

Thank you again. Hopefully, if anyone else sees this, it may give good input as well. Also, if the pro tune gets modified, I'll update the thread on that outcome as well.

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[tegxsi]

I find it odd that switching back to OTS map fixed things...
A proper datalog will narrow things down but at least it's running good now.

[dbp510]

I find it odd that switching back to OTS map fixed things...
A proper datalog will narrow things down but at least it's running good now.

I was surprised myself. Once i get ds2 I'll take some more data logs on this current ots tune and see what it shows.


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[dbp510]

I find it odd that switching back to OTS map fixed things...
A proper datalog will narrow things down but at least it's running good now.

Well, another update. I took the car out for another spin and pushed on it pretty hard. I was able to get it to shutter. It's drastically less than what it was doing. Also, it did throw a CEL on the way back to the garage. I think they're related to the cats, but i haven't had time to dig into them yet.

Back to square one... Screenshot_20221108_203133_Gallery.jpg

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[tegxsi]

Well, another update. I took the car out for another spin and pushed on it pretty hard. I was able to get it to shutter. It's drastically less than what it was doing. Also, it did throw a CEL on the way back to the garage. I think they're related to the cats, but i haven't had time to dig into them yet.

Back to square one... Screenshot_20221108_203133_Gallery.jpg

Unmodified OTS maps won't disable catalyst codes but that's probably not your issue. The 24367 is probably the same.

I'm not sure what 17138 is... bad oxygen sensor?

[dbp510]

Unmodified OTS maps won't disable catalyst codes but that's probably not your issue. The 24367 is probably the same.

I'm not sure what 17138 is... bad oxygen sensor?

Tomorrow, when i get up, I'll start digging a little more to find out what those fault codes are most likely cause by.

Thank you

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[tegxsi]

Is there an o2 spacer on the secondary o2?

[dbp510]

Is there an o2 spacer on the secondary o2?

That i am unaware of. I'll have to ask the previous owner. I didn't get these check engine lights until putting the ots tune onto the car, so i wouldn't be surprised if it was all related to the cats. Hopefully, I'll have the pro tune back in the car soonish.

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[NapalmEnema]

Stay out of boost - get a tuner looking at it - you're on a more stable tune but you're crazy romping it lol - Good luck!

[dbp510]

Stay out of boost - get a tuner looking at it - you're on a more stable tune but you're crazy romping it lol - Good luck!

Lol, yeah, i know. I honestly thought it was fixed, then felt it happen twice. Going to be getting logs looked at tomorrow. Or asap

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[tegxsi]

Try switching to map 4 and run that... it's supposed to "stock like" but IMO it's probably slower.

[dbp510]

Try switching to map 4 and run that... it's supposed to "stock like" but IMO it's probably slower.

I figured this whole thing may have started because i switched from 93 map to 91 while on a custom tune.

But on the ots i will definitely try this.

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[tegxsi]

I figured this whole thing may have started because i switched from 93 map to 91 while on a custom tune.

But on the ots i will definitely try this.

If the difference is 91 and 93 octane then it should not be the cause of throttle closures. I don't know how the map switches are setup on your custom tune.

Personally, I only have 91 and E85 available so I don't have any use for higher octane map switches. I setup my map for different boost request.

[dbp510]

If the difference is 91 and 93 octane then it should not be the cause of throttle closures. I don't know how the map switches are setup on your custom tune.

Personally, I only have 91 and E85 available so I don't have any use for higher octane map switches. I setup my map for different boost request.

Me neither. I'm not sure how the custom one is set up either. So after switching to the ots, i figured it'd help. Maybe im having an issue with overboosting. While driving across the country, i was hearing a fluttering noise during acceleration, which i thought was coming from the diverter valve around 3500-500rpm.

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[dbp510]

Hey, i pulled the top panel off the engine and found that this line was not connected to whatever it's supposed to be. Does anyone know if this could be causing the shuttering issue? I'm not sure what this even is. I'd like to do some due diligence prior to running the car again. Does anyone have any ideas?

Thanks for the input20221109_135728.jpg20221109_135952.jpg

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[tegxsi]

Hey, i pulled the top panel off the engine and found that this line was not connected to whatever it's supposed to be. Does anyone know if this could be causing the shuttering issue? I'm not sure what this even is. I'd like to do some due diligence prior to running the car again. Does anyone have any ideas?

Thanks for the input

Valve for PCV fresh air supply

[dbp510]

Valve for PCV fresh air supply

Damn. So it needs it but probably not my issue.

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[dbp510]

So i got an updated file from darin that has been adjusted for 91 oct. Unfortunately, I'm still getting the shuttering. I haven't had it pull all my throttle like previously. I'm still trying to figure everything out. Hopefully, i can update this with good news soon...

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[o1turbo30v]

So i got an updated file from darin that has been adjusted for 91 oct. Unfortunately, I'm still getting the shuttering. I haven't had it pull all my throttle like previously. I'm still trying to figure everything out. Hopefully, i can update this with good news soon...

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Just for fun, flash the TCU back to stock and see if the stuttering remains.

[dbp510]

Just for fun, flash the TCU back to stock and see if the stuttering remains.

Will i have an issue doing this with 1000cc injectors in it?

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[mtwallace85]

Will i have an issue doing this with 1000cc injectors in it?

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Not if you flash just the TCU back to stock. The stock injectors would need to be installed for a stock ECU flash.

[dbp510]

Not if you flash just the TCU back to stock. The stock injectors would need to be installed for a stock ECU flash.

Oh my bad, i thought he was saying Flash Stock ecu and not tcu. I'll give that a shot.



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[dbp510]

Sent logs into ds1 and responded with a question on if i have replaced plugs and coils in order to get rid of the misfire. So it is indeed misfiring.

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[dbp510]

Swapped out plugs and coils packs. The plugs looked fine. But it was the coil packs. Cylindars 2 and 3 were misfiring, and afterward, the shuttering went away.

Did a compression test as well, and all cylinders were within 5psi of each other, so luckily nothing was hurt.

Thanks for everyones input!

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