INS1GNIA

No problem here with the tune. Most of the time though, the real problem seems to be operator error .

bluejae

i agree some of the time it is user error but i doubt this particular issue is...

Jasonoff

I see this from 3-4 at partial throttle. Doesn't always happen either, depends on %throttle and load.

TIR

I've noticed this too. For me its when you go full throttle and then ease off to 75% range that you see this. Feels like it doesn't know if it should shift or stay in higher rpm range then all of a sudden shift

bluejae

back when i had v3, i didn't have this specific issue that usually happens from a stop...

but i did have a slight hesitation that happened only when the car wasn't fully warmed up and this would happen usually entering a highway and picking up speed. it would happen between 5-6 or between 6-7... once the car was warmed up, it wouldn't happen again...

after upgrading to v4/v5, i haven't had that issue happen again... but now it's this bogging/hesitation between 1-2 or 2-3... and it's much more pronounced when it happens since it's a lower gear... when it happened up top, there was barely a jerk, but you felt it... but when this happens, it's enough to pull my back off the seat and then jerk back...

ritalin

Exactly.

Jasonoff

I thought my clutch packs may have been starting to slip but it was fine after flashing back to OE.

medamullet

what fuel do you run? Sometimes a bog in the tune is related to too much fuel? I know these guys know how to tune but every car reacts to an off the shelf tune. Maybe your maf sensors aren't scaled properly for the parts you have on your car and it's getting too much fuel? Vacuum leak can also cause a bog situation. Fouled plugs/gap too big can do it?

BLKROKT

How is a tune that doesn't touch your TCU going to affect your shift quality? Not being a fanboi here, just a serious question. Maybe the tune - where they are just adjusting fuel and timing really - isn't the problem.

xxaarraa

You ask a legitimate question, but the shift bog issue is real. Even if TCU isn't touched, shifting in an auto box is impacted by throttle position and RPMs (among other factors) both of which are impacted by a tune?

EC should weigh in, but they often tend to go radio silent when criticism is raised. Anyway, I am not long for this forum, so don't mean to cause heart ache. I won't be back for a few years till I can afford a 2017 C63 coupe.

thesaintusa

FWIW I put a EC v5 tune on my car quite shortly after getting my C63.

I have noticed this intermittently (even on the same tank of gas). Mainly from a stop. No rhyme or reason.

I put it on a 507 C63, so the gains are not as impressive versus other versions of the c63. The tune reminds me of my own results of tuning on my RX-7, with overly rich maps, and bogging, until I sorted things out. haha.

deadlyvt

My bet is it has to do with the tune adjusting throttle inputs and the transmission coding being in the upper limits before shifting
By bogging you are meaning it's in too high of a gear and the acceleration is reduced right? Or do you mean the car is cutting timing and the gear is correct but the throttle isn't being responsive?

ritalin

Im in no way saying it is definitively the tune.
I have thought for almost a year now that the tranny really doesnt like the power and i would just adjust how i drive as no symptoms are present in manual mode. The shop foreman at the local benz dealership lived w my car and seems to think that because the dme communicates with the tcu and thinks that if it sees too much torque before a shift, it is going to pull power as a safety... not sure if this is the case. I still feel like it's tranny related.....either way, not the end of the world.

Jasonoff

No, but it does hurt my feelings a little...

ritalin

Lol. I have some vagisil if you need it.

avery.whss

Do you have headers or any cat delete? If you have either make sure the tuner disables the 02 sensors otherwise you car will bog hard. I had this same problem 2 years ago ..had the tuner disable the 02 sensors due to being catless and no issue since, I had the same issue with just 2nd cat delete too until i had the sensors disabled

bluejae

o2 sensors are disabled. if you don't disable it then you would have a CEL.

avery.whss

have you tested your fuel pumps or purge valve? it's one of those 2 if the sensors are disabled...do you ever get low fuel rail pressure CEL? Next time it bogs down, don't let off..WOT it and a CEL will probably come up with low fuel rail pressure

bluejae

how do you test the fuel pumps or purge valve?

i've never gotten any other type of cel before.

avery.whss

you wont with fuel pumps you'll just feel it, and you'll need MB to test them

the only way a CEL should come up is on WOT when you get that "bog" ...the car will probably feel like it's going to blow up but it won't

bluejae

here are some video examples of my shifting issue. the ones in the video are not as bad as when it happens unexpectedly when i'm giving it more throttle. the abrupt hesitation between the shift can make your head jerk forward and back. kind of like slamming on the brake and then slamming on the throttle back to back. this issue happens randomly but all these videos are from one trip.

video 1 - happens at :05 and :25
https://drive.google.com/open?id=0B-...VVQM0kzbVlGNjA

video 2 - stopped at the next light. happens at :07
https://drive.google.com/open?id=0B-...zhfd2dHOS16VTg

video 3 - this was taken from my cell phone which coincides with video 2. it happens between the 2-3 shift. if i could sync video 2 and 3 together, it would have been better.
https://drive.google.com/open?id=0B-...2hYNEsyT09UdUU

SuperFastYo

That reply took awhile... lol

bluejae

very true. this happens so randomly and the few times i've tried to record the gauge cluster, it never happens when i'm wanting it to. i have no idea what makes it happen. but yesterday it happened twice in a row so at the next light i started to record with my phone and i got it. so i was a little more determined this time.

Jasonoff

Slipping clutch pack or maybe a fluid blockage.