e55 baller

Just curious if anyone with the VRP 80mm TB has had any drivability concerns. I thought I had a failing electro magnetic clutch since my car was bucking very very badly. When I went from a gentle cruise to 20-50% open throttle all of the sudden the car would would make a loud thunk and my head would bob forward about 1 foot. This is VERY different than the feel of the S/C engaging. It didn't matter what speed I start at and can happen between 1 and 10 times per day - almost at will but I try to avoid it since it is so abrupt and it really pisses off passengers.

MBenz technician's said that what is happening is that throttle plate is slamming shut for a split second due to increased air potentially not being accounted for with the K2 s/w. Any reality here? Has anyone experienced this issue and is there any know fix to it? Whatever the issue is it sucks and I would really like to fix it. Thanks.

jmf003

That is a bummer. I don't have the problem running the VR 80mm TB with the VR pulley and SpeedtuningUSA's ECU mod.

If the diagnosis is correct the VR ECU tune will likely fix the problem.

Good luck!

ROCKETW19

Just a guess but could it be the supercharger ingaging. In S mode I have a realy bad jerk like you are talking about in C mode its not as bad. what setting do you drive in?

Fleebee

I have the same problem and I have the same mods. Not a thunk but more of a stall. It's as though the fuel/air is shut off for about a second. I try and avoid it by keeping the rpm up. certainly if I'm cruising at less than 1500 rpm and it then plant my right foot my car I will jerk forward out of my seat. It drives me nuts!!!

I did have the problem with the K2 before going to the TB but it wasn't nearly this bad. I'm hoping VRP can tune that away...

ROCKETW19

UMM are you guys not reading my post?

Andy0331

If the car is "stalling" & they are both jerked forward, not pinned to the seat, it's doubtful that it's the supercharger engaging harshly. The way I read the description, it sounds like the car is falling on it's face for a split second.

The supercharger jerking while engaging should feel like a hard shift (at least in my limited experience).

Zod

There is this effect when traveling at low speeds, where the car just feels like you hit a wall or applied the brakes. I believe it was linked to TB closing...
My question is why was this effect not so present with the stock TB?
is this a tuning related issue?

joshd

My car is bone stock and I have always experienced this since buying it used last December. At first I thought it was a transmission jerk, then supercharger clutch, now I'm not sure what it is, maybe the TB closing or the throttle bypass opening/closing has also been suggested. It annoys the hell out of me but of course the two dealers I have taken the car to say it's normal ... I would love to get this fixed if someone can figure it out.

higginsbeach

Was this happening before the VRP Cam install?? Cory at Kleemann just reflashed my ECU for my new mods and everything is PERFECT........No CAMS in my set up. Any cel lights........

Rocket I run in C mode...

Jakpro1

I had one of the first VRP 80mm TB's and have run K2 even longer without a lick of trouble.

Gotta be something else. For you Kleemann guys, Cory does have a newer program that Kleemann customers can upgrade to. Talk to him about pricing and whether or not it can be upgraded at no charge. (newer meaning within 07 I think it came out)

I just don't think it's the Klee program doing it though.

Could also try clearing tranny adaptations.

***edit to remove a lot of rookie info. Forgot it was YOU baller.

higginsbeach

Jim, you weren't suppose to tell anyone about the new Kleemann flash. I lost my edge now....

Jakpro1

Did I say Kleemann?? I meant SCHLEEMANN, yeeeahhh that's what I meant.

ROCKETW19

Yep that what Im talkin about I have the same thing and never knew what the hell it was Adam told me it was the supercharger ingaging. Then when Vadim had my car I told him about it and he drove it and said the same thing its the SC.
It feels like your car just shuts off for a split second and then turns on full blast right? Vadim said daily drive in C mode its less noticable. witch I do now and its alot better than when in S mode.

ChicagoX

Has anyone done any datalogging to see what is really happening with regards to the throttle plate?

mclarenm8d

I second that ... if it feels similar to "dumping the clutch" on a manual tranny car, it could be aggressive torque convertor lockup engagement. I'm of the opinion there are three things that cause the car to buck, SC engagement, TC lockup, and the bypass/throttle interplay.

SamE55

I used to have the same problem as you described. Dealer found out that the car had a faulty fuel pump and after replacing it problem went away.

Tech-Tune

My guess would be the bypass valve is malfunctioning. It does not sound like a software issue to me.

Does anyone know how to check the bypass valve on the AMG system?

Vadim @ FD

On a stock E55, kompressor clutch engagement is barely noticeable. On a car with bigger pulley and more airflow improvement components it is more noticeable. If car has over 40K miles, as clucth wears out, it becomes 'head-bobbing" experience.

This is how car is designed, compressor clutch engages at 30% or higher load or 2900 rpm, whichever comes first.

Solutions:

1. Ask dealer to replace your clutch pack with 2006 revised clutch pack. 50/50 chance, as most SA are not aware of the problem and do not care. Highly dependent on dealer's relationship to you and MBUSA.

2. Put car in Comfort mode. Car takes off in 2nd gear and engagements are significantly smoother. If you have a very high power 55, like Rocket or Jim, with big headers, that will make car a lot nicer to drive around town.

I am looking into load tables and what can be done to make engagement sooner. As always I will post my progress.

Thank you for listening.

chiromikey

i don't believe this is a s/c problem, i think it's a tuning/fuel delivery issue.

Zod

hmm it happens to me when i am in low revs n remove my foot of exalirator.
other thing is when i am driving fast before coming into a turn and the car desides to shift lets say 2-3 and i slow down i get a thumb/ clunking effect.

non of these are realy bad but are noticible
and ah the CEL light I get on n off (will post info on that latter when i am not lazy!)

vrus

Hey Isaac,

Sorry to hear you are still having trouble... There are alot of guys on this board that are running my 80mm TB kit.. I dont think the problem is the TB kit itself unless there is a mechanical failure or a wiring fault.. It is most likely the S/C clutch or it could be something related to the tuning you have in your car.

Is there any chance you can take a video of what happens when you are driving?? I think that would help to get some proper feedback on what the issue is. (Have a friend video tape it from the passenger seat of course.. )

Zod

I will post a star read on mine (what i scan the damn thing )

dsc

I have K2 and VRP 80 mm TB. I'm not experiencing any of the symtems you mentioned.

psk145

mine does the exact same thing with my RT stage 1. I thought it was software at first, but I think its mechanical. If I ease into the throttle holding it in 1st, it will jerk madly at 3500 or so RPM. If I get into it from a stop, it doesnt happen.

Also, my dyno's curves are all weird at the same point, so hopefully its the clutch causing it. Mine is a 2006 with 15K miles in it.

jangy

I'm not sure if it is as much software, although keep in mind that it is an electromagnet and can be controlled.
Charles brings up a great point. What I have always noticed on these cars is that the clutch disengages everytime the car comes to a creep or stop. If you ease into the gas it will begin to slowly put down power. At some point (typically between 1500 and 2000 rpms) the clutch locks in, adding 100hp of resistance to the drivetrain. The car drags then compensates (including you giving gas) which makes it buck.
Now, if you give it a little blip from the start, the centrifugal forces go ahead and release the binding and just hold by magnetics. That way, the clutch kicks in sooner and you feel less difference. Also, if you are under power, dropping 100hp in resistence is not as big of a deal because you are likely putting down more.
Hope that helps.