Magic Pulleys
#1
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Magic Pulleys
Well I finally got around to having the UPD underdrive pulley as well as the UPD idlers installed. Well, where do I begin. Products are well made and Installation went relatively smooth. Fit and finish is great. So for the performance part. Idlers offer no real performance but should be used more as preventive measure to the plastic stock pulleys. Now on to the underdrive. The car, as expected revs faster and smoother. Breaks traction even easier, that light blinks much more often now. The power gains are quite noticeble. Throttle response is much improved. If I were to guess about the whp gains I'd say 8-15. In all honesty I'd have to say the magic spacers perf gain was more noticeble. But nonetheless I am very happy with the UD pulley mod. Disclaimer, the reason for this thread is more to report on reliability of the underdrive aspect of this pulley not so much on how much gains there are. So with that in mind. I drove the car for about 100 miles today. Mix of highway, city, agressive and just cruising and can report that there were no electrical or power steering or ac issues. ECU didnt go ape shyt or anything. So far so good. Oh, and once again want to give a big shout out and a thank you to Shardul for these great products at great prices.
#4
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Thread Starter
Not dificult but then again I didnt do it myself. Pull the underside covers off, take off the fan shroud and air tubes and you got plenty of access. The underdrive pulley is the reason i had an amg tech do the install for me. Its one of those mods where there is no room for error. Just a side note for anyone who is wondering the ud pulley has no timing marks. Flywheel is locked at 40 deg with special tool thru bell housing. So keep your old pulley to be able to time it in the future.
#5
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Thread Starter
While I'm at it I want to give a shout out to MB Motor-Werkes out of Camron Park Ca for doing the install. They are AMG specialist and one of the very few who were willing to do the install. Like I said no room for error on this mod.
#7
MBWorld Fanatic!
Nice. How long have you had the crank pulley fitted for? 100 miles or more?
If you could, perhaps chime in every thousand or few thousand miles or so to update and keep this as a long-term thread to speak of how it performs over time. I'm sure it will be fine tbh hopefully anyway as this is not a solid pulley and will therefore still help to cancel out a lot of the engine harmonics/vibrations.
It's just a pity that there aren't dyno numbers to go by.
If you could, perhaps chime in every thousand or few thousand miles or so to update and keep this as a long-term thread to speak of how it performs over time. I'm sure it will be fine tbh hopefully anyway as this is not a solid pulley and will therefore still help to cancel out a lot of the engine harmonics/vibrations.
It's just a pity that there aren't dyno numbers to go by.
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#8
MBWorld Fanatic!
Keep an eye on the seals to see if they start leaking oil also.
I'm sure there are gains to this mod but I personally would not touch a crank pulley on this motor.
not sure why companies dont make under drive accessories pulleys and leave the crank as is.
I'm sure there are gains to this mod but I personally would not touch a crank pulley on this motor.
not sure why companies dont make under drive accessories pulleys and leave the crank as is.
#9
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Join Date: Jun 2008
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2012 P31 C63 Coupe Trackrat, 2019 GLE63S Coupe Beast
But but but but I can feel 8.253whp I swear it! Seals are for pussies.
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#10
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#11
Senior Member
Thread Starter
Nice. How long have you had the crank pulley fitted for? 100 miles or more?
If you could, perhaps chime in every thousand or few thousand miles or so to update and keep this as a long-term thread to speak of how it performs over time. I'm sure it will be fine tbh hopefully anyway as this is not a solid pulley and will therefore still help to cancel out a lot of the engine harmonics/vibrations.
It's just a pity that there aren't dyno numbers to go by.
If you could, perhaps chime in every thousand or few thousand miles or so to update and keep this as a long-term thread to speak of how it performs over time. I'm sure it will be fine tbh hopefully anyway as this is not a solid pulley and will therefore still help to cancel out a lot of the engine harmonics/vibrations.
It's just a pity that there aren't dyno numbers to go by.
#12
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Thread Starter
#13
Senior Member
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I will say this, the stock crank pulley is very well thought out and made. It looks exactly like the lightweight pulley I put on my clk550. And the stock clk pulley looks like the UPD pulley but weighs twice as much. Ive had it on the clk for 4 years now i believe and no problems. But that was just a lightweight not an underdrive.
#14
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I think its because the underdrive aspect is only part of the whp gains. Most of the gains come from csp being lighter. Off the top of my head I believe the clk gained 13 whp when I dynoed it 4 years ago, and that was just a lightweight pulley (4-6lbs saved) not an underdrive.
#15
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#16
Senior Member
Thread Starter
A Guess is not a claim. The only claim was from a dyno done 4 years ago on my clk. Car does rev faster and is a bit more jerky. I see a bill for my mich 275's coming sooner rather than later.
#17
Senior Member
Thread Starter
Ok I drove the car some more today and noticed a few things. For starters the gains in power and respose are down low, we're talking idle to 4k. So for city driving and a dig you're golden. Here's the problem, the pedal. This pulley drastically changes the throttle feel. Its very touchy now, too sensitive. And the more I drive the more I'm having mixed feelings about it. Its getting a bit too jerky and while driving on freeway its damn near impossible to keep at a steady speed. Lots of up and down on speedometer. You have to barely touch pedal. Think of it like a sprintbooster on roids. Im thinking the underdrive is doing exactly what it was meant to do, steal early hp from accesories and help deliver it to the wheels. But its doing something that i wanted to avoid, its erasing the middle ground. Meaning Its turning the driving experience into *****foot or ballstothewall only. This is the reason I tried for a while to find one of those old eurocharged lightweight pulleys that were stock diameter just lighter. I'll report back every so often just for updates.
#18
MBWorld Fanatic!
Ok I drove the car some more today and noticed a few things. For starters the gains in power and respose are down low, we're talking idle to 4k. So for city driving and a dig you're golden. Here's the problem, the pedal. This pulley drastically changes the throttle feel. Its very touchy now, too sensitive. And the more I drive the more I'm having mixed feelings about it. Its getting a bit too jerky and while driving on freeway its damn near impossible to keep at a steady speed. Lots of up and down on speedometer. You have to barely touch pedal. Think of it like a sprintbooster on roids. Im thinking the underdrive is doing exactly what it was meant to do, steal early hp from accesories and help deliver it to the wheels. But its doing something that i wanted to avoid, its erasing the middle ground. Meaning Its turning the driving experience into *****foot or ballstothewall only. This is the reason I tried for a while to find one of those old eurocharged lightweight pulleys that were stock diameter just lighter. I'll report back every so often just for updates.
#19
MBWorld Fanatic!
Without wanting to sound like we're trying to knock you down or anything, the gains surely can't be that pronounced on the car. Hell, if the throttle response really opens up that much down low, then this would be a superb mod for most of us on here. I'm surprised that you don't like this...most people usually want more of this when they get a box tune...
also....for what it's worth, the gains should be all over the powerband but mostly felt in gears 1 and 2, with a taper off in third and then nothing meaningful in 4th.
also....for what it's worth, the gains should be all over the powerband but mostly felt in gears 1 and 2, with a taper off in third and then nothing meaningful in 4th.
#21
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Thread Starter
Its not so much as too much power or gains or nothing like that. I'm saying that when you barely touch the pedal the car goes. Im talking minuscule, barely putting tip of your toes and curling with the slightest pressure and it goes, not rockets down road but just goes, slightest pressure off and your completely off the throttle. Which is awsome for city/spirited driving. On highway driving I try to keep it at a steady 80. 10-20 seconds later it creeps up 5-7 mph. Tried to slow down and pulled back slightly and I was completely off the throttle. And it did this the entire trip yesterday. Cruise controll will be used a lot more from now on, thats for sure. All I'm saying is I've never had pedal/throttle control problems and ive had this car for almost a year. I'll do a reset this morning and see how that goes.
#22
MBWorld Fanatic!
Sounds like the ECU is trying to compensate for the rpm difference and is raising the TPS on you.
what is your TPS % at idle in park fully warmed up and what is it in drive with the foot on the brake?
what is your TPS % at idle in park fully warmed up and what is it in drive with the foot on the brake?
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#23
Senior Member
Thread Starter
Without wanting to sound like we're trying to knock you down or anything, the gains surely can't be that pronounced on the car. Hell, if the throttle response really opens up that much down low, then this would be a superb mod for most of us on here. I'm surprised that you don't like this...most people usually want more of this when they get a box tune...
also....for what it's worth, the gains should be all over the powerband but mostly felt in gears 1 and 2, with a taper off in third and then nothing meaningful in 4th.
also....for what it's worth, the gains should be all over the powerband but mostly felt in gears 1 and 2, with a taper off in third and then nothing meaningful in 4th.
#24
Senior Member
Thread Starter
Thats what seems like. As far as giving you an exact number. If I knew how I'd tell you.
#25
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