My last resort is data logging on a dyno and sending it to EC to see what they can do, but I wanted to see if anyone from EC or with a EC tune has fixed this.

My buddy's e55 does the exact same thing. It bucks when rolling into throttle at low rpms.

Yes a fsp will fix that. Outside of that, no.
It sounds like the supercharger clutch engaging

Most think that it is the sc engaging which is not the case. If you have a boost gauge the car will still be in vacuum when this happens and if you log the tps you will see it open to 97 percent and close back when the hiccup occurs.

So how do you fix this?? Mine has been doing it more and more, recently...

Interesting Shardul, did not know that. I however, never had that problem when I had the fsp. That being said, its back with my 77mm clutched pulley though not as severe or as often as with the 84mm or stock supercharger pulleys

I used to have the dreaded hiccup, now it is barely noticeable. Some tuning by the experts was all it took for me.

The ~2500 hiccup is quite unpleasant with my box EC tune, and goes away when flashed back to stock. Which tuner helped you eliminate the hiccup?

Speedriven did mine.

Do we have a sponsor from Eurocharged on here that can chime in on this? This isn't just happening to one person.

Just data logged a number of gentle starts from standstill (which is when these violent jerks consistently occur on my car) using dash command and the numbers corroborate throttle position suddenly opening from 6-7% to 96+% momentarily around 2K RPMs.

I have always dismissed this as SC engagement but after seeing the evidence I will definitely be requesting EC to fix the tune.

Which obd2 reader did you use to link up to the dash command? Im looking at buying it. Is that the easiest way to data log?

I forget the brand or exactly where I purchased it but you need a Wifi version if using iOS, otherwise Bluetooth will work (and cheaper) for Android devices. May want to avoid the 'low profile' or 'shortie' OBD readers as one I purchased could not extend far enough to make contact with the OBD port.

A wireless OBD reader coupled with Dash Command for Android or iOS was the simplest solution and interface, otherwise you could connect with a laptop but try using that while driving

Thanks for posting your findings. As I started previously in the thread it is not the SC engaging.

Shardul is correct and the afrs will spike tremendously and I suspect that this issue that some have had may have contributed to the motor popping since the driver unsuspecting accelerated and went very lean and popped. Sometimes it may just shake at idle like a misfire after it does it and if you are monitoring the afrs you would see they are very lean until key is cycled then it goes back to normal. Only happens to a very small percentage of cars especially when they go bigger tb

Does reflashing back to stock fix the issue? I may go back to stock and see how the drivability is for me

I am stock and still get it...not all the time but have noticed it lately.

Yes, I've experienced this with several stock E55s.

How are we sure this isn't at least a consequence of SC clutch engagement? If the throttle closes (as it appears to do, reading TPS), a boost gauge would read vac...even if the magnet is engaged. Wonder if the boost bypass is somehow involved.

Obd is usually too slow to capture the split second change in tps , must be hard wired to see it

mine is pretty violent when it happens. Almost like i tapped the brakes. The sound doesn't make it any better as well. Frankly its so embarrassing that when people are in my car ill do whatever I can to avoid that rpm range

My car does this too...a severe "bucking" at part throttle...usually I have to let off the gas then get back in it...It's been going on for a long time, but getting tired of it lately. Maybe I'll contact Jerry @ Eurocharged to see if he has any updated tune. Has anyone else contacted them about this?

haven't had the time all week but will email EC this weekend, with my data logs. Prob won't hurt if they hear from multiple customers with the same issue.

I have a box EC tune on my 2005 E55 and it does the same thing (bucking). My car did not do it before the tune.

Most of all of us had this issue or still have this issue with the bigger TB. The tune fixed mine a bit but still there at times, I gave up on it and just live with it. But soon will get retuned and hopefully address the issue..

Same here, whichever mode C/M/S... I usually have to let off and ease the accelerator thru it.