Modified E55 (82mm TB, etc) bogging after shifts (1-2 and 2-3)
 

A few months ago, I did some work on my E55: ported heads (from Shardul), OEM SLR McLaren cams, 550 cc injectors, a used OEM 82mm TB (OE snout bored to match) with an adapter plate from VRP, and a RennTech airbox. The car also has shorty headers, but they were installed a long time ago. After doing this work, I am having an issue where the engine seems to bog or cut power for a fraction of a second after shifting (particularly 1-2 and 2-3) during normal (gentle) driving. The severity varies, but it's always noticeable and often bad enough to be very annoying. This is not an issue with the transmission slipping or anything like that: for some reason, the ME is cutting power for a split second. The problem is less severe with spirited driving, and does not seem to exist at full throttle. I suspect it is related to the 82mm TB, but since I did so much work at once, I can't be sure. It is exactly the same as what's described in this video: . I have re-set transmission adaptations (with an SDS) several times. It does seem to make a difference at first, but it's never perfect and after the first drive, the problem returns fully. I have a semi-custom (street) tune from Jerry at EC and he has been unable to make any difference with this issue. I have tried resetting drive adaptations with both gentle and aggressive driving afterwards and it does feel different (but not completely better) for a little while but soon becomes exactly the same. The problem has persisted through several pulley combos, so I don't think it's related to my pulley(s). I'm reasonably sure there are no intake leaks (I replaced all gaskets and smoke tested to verify). I tried swapping out my TCU (Eurocharged tuned at the same time as the other mods) with a stock one from a 2003 E55 with no change. I do plan on getting a dyno tune once I finalize my mods, but I don't see how that will make any difference. I seem to have misplaced my original TB, so I have not tried swapping it back on, but I suspect that swapping it and re-doing adaptation would fix the problem (but loose power). I have no other driveability issues, codes, or any other problems.

Other than the youtube video (linked above), which describes my problem exactly, I have not been able to find other similar complaints. Does anyone have any ideas? (Just to be clear, I want to fix the problem while keeping the 82mm TB: I don't want to switch back to the stock TB; at least not permanently).

Thanks in advance!

Will you even be able to switch back to your stock tb if you had the snout ported?

https://mbworld.org/forums/w211-amg/...ice-e55-2.html

https://mbworld.org/forums/w211-amg/...-hiccup-5.html

Hope these threads help you out.

I don't see why not. There's still plenty of surface left for sealing.

Thanks for the suggestion, but unfortunately, they do not help: my problem is not at all like what is described in those threads. I have no CEL, no codes, no intermittent hiccups, rough running, or anything like that. My only issue is a split-second power cut after every up-shift during gentle acceleration.

I have the same issue, no leaks, no codes, no issues, just a dip in torque after shifts

What mods do you have? Do you think it's related to an 82mm throttle body? Have you had any results trying to get rid of it?

I have this in 1st to 2nd gear change (ONLY UNDER WOT).I believe its either the cars rpms rising too fast and hitting the rev limiter as the car shifts but my main suspicion is that its due to wheel spin at gear change. I think that if the rear wheels are spinning at different speeds outside a certain tolerance it cuts power during shift..I think this coz i can make it not happen if i predict the ass sliding out with the road camber by counter steering a little while accelerating in a straight line. I am installing a limited slip diff soon to see if this helps.

It started happening a lot more for me when i put the 77mm in and the car would rev so much quicker!

do any of you guys with lsd have this happen?

Who tuned your car? I have a bunch of mods, I had this when my car was tuned by Eurocharged. When I changed to RaceIQ, it went away and never returned.

Eurocharged...did you get packetz unresponsive/missing measage from euroflash when applying the tune by any chance?

This is normal, and not an indication of bad flash, the flash process uses checksum, so its all or nothing, if flash is unsuccessful, the car will not start.

- 77mm SC pulley (clutched)
- 82mm TB (from S550)
- Renntech Carbon airbox
- large Injectors (550 cc)
- Belt wrap kit
- Quaife Limited Slip Differential
- Renntech heat exchanger
- additional fan cooled side heat exchanger (from SL65)
- EuroCharged TCU tune.

I had 82mm TB with 83mm pulley for a couple of years and did not notice it. It became most obvious when I installed 77mm and 550 injectors.

However, I am not saying the 77mm caused it, Alex from Legit street cars said the issue went away when throttle was downsized to 74mm.

I am almost thinking about 3d printing a restrictive plate/rig, to put it around the TB neck for non track days, and see if it helps, as my snout is custom made, and downsizing TB requires SC to be removed again, I really have 0 interest in doing that.

I have a RaceIQ tune that did make the issue disappear for the most part, but I preferred the Eurocharged tune top end, and less aggressive gas pedal mapping.

Also Alex is on RaceIQ tune, and the issue did not get resolved for him.

If you decide to do that, please let me know how it goes, but I doubt it will help. This issue happens (at least for me) only under part throttle when the TB is mostly closed, anyway. I don't think a restriction will make any difference at that point. I'm assuming the issue has something to do with how the different TB reacts to what should be an un-noticeable power cut during the shift; I'm assuming there is supposed to be some amount of power cut during the shift (to make it less harsh) which should be immediately reversed as soon as the shift takes place (rather than a half second after the shift, like in this case). The larger throttle body will be open less during normal driving, so if the power cut is a percentage of throttle position (I don't know if that's true... just guessing), it would be excessive with the larger TB. I would think it would still end immediately after the shift, but perhaps the ME notices something odd and keeps it closed longer, for some reason. Unless this is actually a defect with the TB (which seems unlikely), it seems that someone should be able to completely tune this out. (But I guess there aren't enough people with this problem and the platform is too old for anyone to bother investing any serious time in fixing it.)

I'm thinking about trying an 80mm SL55 throttle body if I can find one inexpensively. Hopefully the power difference will be minimal and it will fix the problem. (I already happen to have a snout for one.)

Torque is lowered to smooth the shift by means of changing ignition timing, I am not aware of TB angle changes

<br />I too have the same issue with my SL55 with the same mods basically.

Anthony Lawshee Race IQ tune

I don't know if someone already stated it, but I just had identical problems. Thought it was the trans, so i threw in a conductor plate, valve body updates, a new tq converter, vaccum leak tests, all new sensors and top end reseal, spent a bunch of money on trying every other sensor as well. Threw some brand new upstream 02's in just because they were the only thing that hadnt been replaced yet, and that solved all of my problems. Worth a try for 100 bucks. Keep in mind I had no CEL for bad 02 sensors or any erratic voltage readings either. Just decided to try them and it fixed all of my shifting problems, it worked for another guy as well.

You had a split second power cut after each shift? Other problems too, or just that? What mods did you have? I can't find them any cheaper than $75 each (OE Bosch on Amazon and FCPEuro) but that's still definitely worth a try.

I have dual widebands and haven't noticed anything abnormal with the afr, but as far as I know, my O2 sensors are original, so I might as well git it a try (it's a lot cheaper than an 80mm TB).

(Just for the record, I also have a new conductor plate, although not for this reason. I had to replace a solenoid so I figured it was worth doing while I was in there. Didn't make any difference with the hesitation.)

I sure did, and over time(period of 5 months) it got worse. Hesitations got longer, eventually idle got rough and started misfiring.. still with no codes. Here is my thread, if you change the 02s let us know how it turns out. One thing the forum could really use is a troubleshooting sticky. The description of my issues in my thread were after a few months of the same type issues your dealing with right now.

https://mbworld.org/forums/w211-amg/...lems-help.html

Once again, if your car modified? I dont think we're talking about the same issue here, despite symptoms being similar on paper.

In my thread, included in my last reply, it is stated that it was occurring with both 77mm clutched pulley on stock injectors and on the 72mm clutched pulley on 550s.I am running a stock 74mm Tb. Other mods included meth, long tubes, 3000 stall, shift kit, sonnax valve body updates. Just sharing info and giving a suggestion if you run out of things to try, it fixed shift hesitation for another member that did not have the same symptoms as me. Good luck.

The input is certainly appreciated, and worth a shot for sure, I was just saying the issues may be different because the issue we observe comes with mods, and goes away with them

Mine appeared when I installed 82mm TB (83mm clutched pulley was already installed), and became very apparent with 77mm + large injectors.

Others reported being fine with all mods, until 82mm throttle was added.

I replaced both upstream O2 sensors and (not surprisingly) it had no affect on the shifting issue. I sill appreciate the suggestion, Kyle, and it's great that it solved your problem, but it didn't work for me. I just passed 100k miles, anyway, so a new set of O2 sensors, while not completely necessary, certainly isn't a bad thing.

Does anyone have a line on a used 80mm throttle body from an SL55? I'd hate to have to have to buy a new one from MB, especially if it doesn't fix the problem.

We're back to square one,

I was hoping it would work, against my better judgement

Keep suggestions coming guys though, I am personally willing to test anything to be honest

2003 S55 AMG
77mm clutched
.580 blower
Ported runners
90mm tb
550cc injectors
DTK TCU
Intake
3" exhaust (stock headers)
1.8L/min water injection

My car does the same exact thing. It'll do it part throttle and under WOT. I've noticed its worse when cold outside. I thought it was a problem with the TCU, so I bought a DTK TCU but it didnt change anything. The other night it was ~36° out and a -1400DA and it was the worst it's ever been. I mean it was VERY noticeable. Then, other cold-ish nights (~50°) it may get one shift in thats perfect. May be an ECU issue with the board... Dunno

It did 11.95 @120 on the street with street tires shifting like an old man puts on socks though!