VRP 80mm TB & driveability issues
#1
VRP 80mm TB & driveability issues
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.
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.
#2
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!
If the diagnosis is correct the VR ECU tune will likely fix the problem.
Good luck!
#4
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.
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.
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...
#5
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...
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...
#6
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).
#7
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?
My question is why was this effect not so present with the stock TB?
is this a tuning related issue?
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#8
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.
#9
Super Member
Joined: Jul 2007
Posts: 566
Likes: 0
2004 E55 AMG and 2003 C320 4Matic Miss my 993 Turbo above!!
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.
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.
Rocket I run in C mode...
Last edited by higginsbeach; 03-18-2008 at 09:50 AM.
#10
MBWorld Fanatic!
Joined: Jan 2004
Posts: 7,092
Likes: 12
From: Salt Lake City (but not Morm)
2003 E55 & 2014 GL550
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.
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.
Last edited by Jakpro1; 03-18-2008 at 10:01 AM.
#11
Super Member
Joined: Jul 2007
Posts: 566
Likes: 0
2004 E55 AMG and 2003 C320 4Matic Miss my 993 Turbo above!!
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.
Sounds like something is happening during supercharger engagement. Almost like blower is engaging, then it is taking a second to come up to power. Kinda like a slipping supercharger clutch or something.
Could also try clearing tranny adaptations. Dealer can so it in Star or you can try Sneaky ECU reset. Do a search for it. It reset tranny adaptations.
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.
Sounds like something is happening during supercharger engagement. Almost like blower is engaging, then it is taking a second to come up to power. Kinda like a slipping supercharger clutch or something.
Could also try clearing tranny adaptations. Dealer can so it in Star or you can try Sneaky ECU reset. Do a search for it. It reset tranny adaptations.
#13
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).
The supercharger jerking while engaging should feel like a hard shift (at least in my limited experience).
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.
#15
Member
Joined: Sep 2005
Posts: 224
Likes: 0
From: Cary, IL
2003 CL55 Kompressor Horizon Blue Metallic
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.
#17
Super Member
Joined: Nov 2006
Posts: 952
Likes: 9
From: NJ/Greece
2006 CLS55 & 2002 SL55 (R129) Silver Arrow
Does anyone know how to check the bypass valve on the AMG system?
#18
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.
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.
#20
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!)
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!)
#21
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.. )
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.. )
#22
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.. )
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.. )
#24
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.
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.
#25
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.
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.