deekay11

With piggyback, the ECU doesn't know what's "true" because it's not mapped to specific conditions, and just reads what the sensors are outputting. The sensors cause the ECU to input more/less power based on how much the JB4 limits the input/output of the sensors. So because of this, the ECU doesn't know how much "time" it needs to clamp down. With a tune, the ECU knows exactly how much air/fuel ratio creates combustion, which then makes everything else in the power train system act accordingly. This is why tunes in general can achieve higher HP and TQ values, because it does more than "fool" the ECU using stock mapping.

HyperS4

I vaguely remember you but not so much. I definitely didnt use that word to describe you, Im certain of that, but hey, if thats what kept you up at night.....

Theres many people with Audi's, driving with tunes and mods WAY more aggressive than mine, and they are having no issues. I am going to stand by my original assessment that these cars are built much stronger than people assume. I had over 550hp going to the DSG in my S6's without ever having any issues(granted, slightly different DSG). If I am having an issue with a slipping clutch, it is not due to the mods, but that I have a weaker than normal transmission(or some other issue). It is most likely an isolated incident, not that these transmissions are incapable of handling more power.

HyperS4

Fair enough. I like your thought process.

ErikM

I've only owned my 2018 for a few months, but I've found that from a stop the car does not like having the pedal mashed all the way down. It reminds me in some way of my BMW K1200S MC.. apart from having a top redline, think it was 12K.. The bike also had a bottom redline below about 3K it just did not really launch; at about 3K hold the eff on.. It was a locomotive then in every gear (145 and I chickened out )

I notice my Audi is the same way, kind of.. If I'm in regular drive it idles about 750 rpm and it needs to be eased up the rpm's until about 1500 then it'll will rip. In Sport it idles at 1K and and gets in the power quicker. BTW the slow power uptake is great in the snow.. kinda like the soft acceleration curve then..

HyperS4

2 things: 1. Where in Lawrenceville are you? 2. The situations Im experiencing are always when Im at speed, never stopped. Majority of the time its when Im going around 45-50 and merging onto a highway. This one happened to be around 15 mph.

vkamnyev

Did you have to pay for the clutch replacements since those are not covered under warranty (unless of course your are within the first year or 12K miles)... I sure hope Audi reimbursed you once they determined it was the master cylinder.

SDakota

Everything was covered under warranty, but I was at 10 months and 6,000 miles. The complete story was a little more involved. One day I noticed that it seemed like I had to push the clutch pedal down farther than normal while shifting for the clutch to fully disengage. It wasn't obvious, but the clutch pedal felt a little different. After parking the car and coming back a few hours later to start it up, I pushed the clutch pedal to the floor and it stayed there - it didn't spring back at all. The engine wouldn't start because I assume the sensors indicated that the clutch was still engaged. Thankfully I could force the gearshift into neutral and turn the wheel to get it onto a tow truck - the electric power steering even worked with the engine off.

The dealer replaced the clutch and told me after test driving it that everything was fixed. After driving away, I experienced the clutch slipping in second gear while accelerating with about 50% throttle - moderate acceleration, but not too aggressive. I took it back to the dealer and demonstrated the problem, which was easy to replicate. They kept it for a couple of weeks and troubleshooted the possible causes with help from Audi corporate. Eventually they determined that the master cylinder was leaking onto the clutch and causing slippage, so they replaced the master cylinder and the clutch (for the second time).

I still don't know if the two problems (dead clutch pedal and slipping clutch) had the same cause, or if maybe the master cylinder or some hose was damaged when they replaced the clutch the first time and that's what caused the slipping. Of course now I pay close attention to the behavior of the clutch, but everything seems to be working like new. For the three weeks it was in the shop I tried to figure out what I would replace it with if it turned out to be a lemon, but I couldn't come up with anything now that the A4 and 3 series are automatic only. I probably would have ended up with a 2 series or Golf R, but I'm glad to have the A4 back.

vkamnyev

ErikM

I'm in Lawrence Green.. Off Federal City... Apart from taking it to the dealer.. I'd make sure you're using a Top Tier fuel and of course Premium. Depending on Mileage I'd also run a tank of fresh fuel with a bottle of Techron added, and I'd check the air filter, replace if needed.. Other than that, it's a trip to the dealer.

HyperS4

Nice, Im in Woodmont off Franklin Corner. Always Top Tier 93. Air filter is aftermarket. Not sure what those things would have to do with the transmission though. Im going to monitor this and see if it happens again under similar circumstances or if its random.