E55 hesitation, help please
06-23-2019, 09:06 AM
#1
E55 hesitation, help please
Anyone have a solution for the hesitation/flat spot/ (call it what you want) when the SC clutch engages? You guys that have mods for greater boost know how much worse this gets from stock.
I've searched the forums and spoken to many tuners but apparently no real solution other than drive around it. I'd have thought it could be tuned out?
I've searched the forums and spoken to many tuners but apparently no real solution other than drive around it. I'd have thought it could be tuned out?
06-24-2019, 03:57 PM
#3
Member
It's something we have to get used to on our cars. Only thing you can really do is make sure the pulley gap is within spec (0.35-0.45 mm). Apparently the smaller the pulley, the worse it gets. My stock pulley is out of spec (~0.55 mm) and I get a squeak and a jerk when the SC engages. I have learned to drive it so it engages smoothly, but I'll be pulling the pulley off soon to remove a shim to hopefully get it back within spec and smooth out the engagement
06-24-2019, 08:12 PM
#4
It's something we have to get used to on our cars. Only thing you can really do is make sure the pulley gap is within spec (0.35-0.45 mm). Apparently the smaller the pulley, the worse it gets. My stock pulley is out of spec (~0.55 mm) and I get a squeak and a jerk when the SC engages. I have learned to drive it so it engages smoothly, but I'll be pulling the pulley off soon to remove a shim to hopefully get it back within spec and smooth out the engagement
A bit more detail on what the car actually is. It's a little 2006 AMG SLK55 with its original 7 speed box mated to (effectively) a 2003 AMG SL55 engine I bought at the right price, mainly for it's SC. It turned out to be more difficult than just dropping the engine in because the oil pump in my original engine is located at the rear of the block and the sump is shaped to fit over the cross member. So we fitted all the SL55 components onto my original block just to solve this one issue!. We then modded for greater boost, better intercooling and breathing, all in a car that weighs some 900lbs less than its donor.
To cut a long story short, the car is incredibly fast and fun, (though scary changing from 3rd to fourth with its short wheelbase) but looks and drives like stock if you stay off the loud pedal. It would be perfect (and unique) if I could find a resolution to this issue. I thought about fixed pulley but was warned against it. I had hoped that someone may have managed to tune the problem out. I'll take another look at the clutch clearances first and go from there. Maybe it still has something to do with mating to the 7 speed but other than the SC transition the gearbox appears to work perfectly so I doubt it's adding to the issue.
Thanks again
06-24-2019, 09:00 PM
#5
MBWorld Fanatic!
Thanks, that's helpful (even if it's not what I wanted to hear) and along the lines of what a well respected tuner told me. At times the transition is almost violent in my car and the same tuner suggested I also look at the trq limiter in the gearbox.
A bit more detail on what the car actually is. It's a little 2006 AMG SLK55 with its original 7 speed box mated to (effectively) a 2003 AMG SL55 engine I bought at the right price, mainly for it's SC. It turned out to be more difficult than just dropping the engine in because the oil pump in my original engine is located at the rear of the block and the sump is shaped to fit over the cross member. So we fitted all the SL55 components onto my original block just to solve this one issue!. We then modded for greater boost, better intercooling and breathing, all in a car that weighs some 900lbs less than its donor.
To cut a long story short, the car is incredibly fast and fun, (though scary changing from 3rd to fourth with its short wheelbase) but looks and drives like stock if you stay off the loud pedal. It would be perfect (and unique) if I could find a resolution to this issue. I thought about fixed pulley but was warned against it. I had hoped that someone may have managed to tune the problem out. I'll take another look at the clutch clearances first and go from there. Maybe it still has something to do with mating to the 7 speed but other than the SC transition the gearbox appears to work perfectly so I doubt it's adding to the issue.
Thanks again
A bit more detail on what the car actually is. It's a little 2006 AMG SLK55 with its original 7 speed box mated to (effectively) a 2003 AMG SL55 engine I bought at the right price, mainly for it's SC. It turned out to be more difficult than just dropping the engine in because the oil pump in my original engine is located at the rear of the block and the sump is shaped to fit over the cross member. So we fitted all the SL55 components onto my original block just to solve this one issue!. We then modded for greater boost, better intercooling and breathing, all in a car that weighs some 900lbs less than its donor.
To cut a long story short, the car is incredibly fast and fun, (though scary changing from 3rd to fourth with its short wheelbase) but looks and drives like stock if you stay off the loud pedal. It would be perfect (and unique) if I could find a resolution to this issue. I thought about fixed pulley but was warned against it. I had hoped that someone may have managed to tune the problem out. I'll take another look at the clutch clearances first and go from there. Maybe it still has something to do with mating to the 7 speed but other than the SC transition the gearbox appears to work perfectly so I doubt it's adding to the issue.
Thanks again
06-25-2019, 02:24 AM
#6
Sorry my bad, don't know if it will help me get a resolution though. I love this car and won't give up, so happy to listen to any and all ideas!
BTW, I posted here because there's so many more of you guys running this engine than anywhere else. Useless posting on the SLK forum
BTW, I posted here because there's so many more of you guys running this engine than anywhere else. Useless posting on the SLK forum
Last edited by NazC; 06-25-2019 at 02:28 AM.
06-25-2019, 01:42 PM
#7
Member
Wow a m113k mated to a 722.9...nice work 
If you search around the E55 forums you will find more info on this issue, but unfortunately there's not much you can do. Fixed or clutchless pulleys are an option; many have done it, but I personally would not
If you search around the E55 forums you will find more info on this issue, but unfortunately there's not much you can do. Fixed or clutchless pulleys are an option; many have done it, but I personally would not
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06-26-2019, 10:06 AM
#11
Don't know if this link will work but this clip was taken at Hitech Mufflers who fabricated and fitted the custom exhaust BEFORE the latest engine power mods!
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