AMG55 Scattershield for Supercharger pulley
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From: Santa Clara, Ca
2003 SL55 / 2002 SLK32
Mostly, of course, it has been the smaller aftermarket pulleys failing ... However, it should be pointed out that this is not a blanket indictment of their quality, but rather and understandable (and very low-percentage) outcome that occasionally takes place as a result of the reality of these pulleys spinning faster AND, the springs (which transfer 100% of the power required to compress the air charge) being required to carry a measurably higher work load.
So, while some users (and on-lookers) have expressed concerns about the quality and suitability of these aftermarket SC pulleys (perhaps with a sliver of good reason as there may have been some compromised quality early batches of these pulleys), my feeling is that the very capable and well-intentioned manufacturer has addressed those issues (and I would probably run one of these on my own car if I was not happy with my custom SC pulley that I made)..
MOST IMPORTANTLY ...
Regardless of whether one is running an aftermarket or OE SC pulley, I have always tried to point out how important it is to routinely inspect the SC pulley for signs of cracking on the springs. If everyone did this (and replaced the pulley when signs appear), we would hear very few stories of catastrophic failure and the scattershield would be virtually unnecessary.
For those who like the extra piece of mind, you can purchase a scattershield from forum sponsor Victory Road Performance
I Hope everyone is having the Happiest of holidays
Chris
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Joined: Aug 2015
Posts: 400
Likes: 23
2005 E55 AMG
Yes, I have seen a couple (2) stock pulleys fail (one was on my own 2003 SL55 which was the reason I created the shield).
Mostly, of course, it has been the smaller aftermarket pulleys failing ... However, it should be pointed out that this is not a blanket indictment of their quality, but rather and understandable (and very low-percentage) outcome that occasionally takes place as a result of the reality of these pulleys spinning faster AND, the springs (which transfer 100% of the power required to compress the air charge) being required to carry a measurably higher work load.
So, while some users (and on-lookers) have expressed concerns about the quality and suitability of these aftermarket SC pulleys (perhaps with a sliver of good reason as there may have been some compromised quality early batches of these pulleys), my feeling is that the very capable and well-intentioned manufacturer has addressed those issues (and I would probably run one of these on my own car if I was not happy with my custom SC pulley that I made)..
MOST IMPORTANTLY ...
Regardless of whether one is running an aftermarket or OE SC pulley, I have always tried to point out how important it is to routinely inspect the SC pulley for signs of cracking on the springs. If everyone did this (and replaced the pulley when signs appear), we would hear very few stories of catastrophic failure and the scattershield would be virtually unnecessary.
For those who like the extra piece of mind, you can purchase a scattershield from forum sponsor Victory Road Performance
I Hope everyone is having the Happiest of holidays
Chris
Mostly, of course, it has been the smaller aftermarket pulleys failing ... However, it should be pointed out that this is not a blanket indictment of their quality, but rather and understandable (and very low-percentage) outcome that occasionally takes place as a result of the reality of these pulleys spinning faster AND, the springs (which transfer 100% of the power required to compress the air charge) being required to carry a measurably higher work load.
So, while some users (and on-lookers) have expressed concerns about the quality and suitability of these aftermarket SC pulleys (perhaps with a sliver of good reason as there may have been some compromised quality early batches of these pulleys), my feeling is that the very capable and well-intentioned manufacturer has addressed those issues (and I would probably run one of these on my own car if I was not happy with my custom SC pulley that I made)..
MOST IMPORTANTLY ...
Regardless of whether one is running an aftermarket or OE SC pulley, I have always tried to point out how important it is to routinely inspect the SC pulley for signs of cracking on the springs. If everyone did this (and replaced the pulley when signs appear), we would hear very few stories of catastrophic failure and the scattershield would be virtually unnecessary.
For those who like the extra piece of mind, you can purchase a scattershield from forum sponsor Victory Road Performance
I Hope everyone is having the Happiest of holidays
Chris
Sorry if this sounds dumb, but where exactly should I be looking for signs of wear and what am I looking for? I do know what the sc pulley is but not sure about these springs you refer to.
Thread Starter
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Joined: May 2009
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From: Santa Clara, Ca
2003 SL55 / 2002 SLK32
To answer your questions, I will first briefly go into a little bit of SC pulley basics.
The SC pulley consists a few simple components.
It has the grooved portion that engages the belt, a bearing so that the assembly can spin independently of the supercharger (when the supercharge is not "turned on"), 3 springs (shaped somewhat like dog-bones) attached to the grooved portion of the pulley by (3) rivets that work in unison to both transmit the power from the grooved pulley to the pressure plate AND retract the pressure plate from the magnet (when the supercharger/magnet is NOT "turned on"), and finally the pressure plate which is attached to the springs by (3) rivets.
Spinning at a speed determined by engine RPM and SC over-drive ratio (engine RPM X CP size / SC pulley size = SC pulley RPM), the SC pulley freewheels on the snout (input shaft) of the supercharger (while the SC coasts/turns because of air being drawn through it). When the SC is "turned on" by the ECU energizing the magnet), the SC pulley is, for all practical purposes (theoretically, barring SC clutch slip) locked to the Supercharger input shaft. Now, no-longer freewheeling, (SC pulley bearing stops spinning, inner race relative to outer race, at this point), all of the power (potentially, over 60 HP) required to spin the supercharger and compress the air charge, is transmitted from the belt to the supercharger through the above mentioned components, the springs (dog-bones) being the weakest links.
The goal is to regularly inspect the point(s) where the 3 springs are secured to the pressure plate (by their 3 rivets, respectively) ... as well as give the rest of the pulley a look over (it is not entirely unheard of to have the smallest diameter SC pulleys separate into 2 pieces by splitting on a groove where it passes over the thinnest part of the pulley (thinned by counter-bore for internal bearing).
The pictures that I have included are not necessarily typical, but I think they are useful for illustrating the issue and areas to focus attention on.
The fist pic shows 2 of the 3 springs already broken and exhibiting signs of having already beat their outer edge(s) flat from "weed whacking" near-by components... this was clearly spotted too late. At 13,000 plus RPM, this can do damage quickly.
The second and 3rd pic show an OE pulley caught right at the point of failure (prior to any collateral damage). The progression of failure in this case would seem to be ... 1) edge of rivet cracked off creating stress riser .. 2) "dog bone" broke at point of stress riser.
The 4th pic is another aftermarket pulley that was caught right at the point of failure .
My hope is that with regular inspection, members can spot the beginnings of a crack (prior to the progression shown in pic 4, for example) AND/OR a compromised rivet .... and then immediately take their pulley out of service.... hopefully avoiding any and all damage.
Hope that helps!
Cheers,
Chris
Last edited by latemodel21; Dec 28, 2016 at 01:58 PM.
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SL55, ML500 & Acura TL
^ Nice write up Chris. Allow me to add that for this very reason, many of us remove the front plastic cover and run without it so we can easily and routinely inspect the SC pulley. I pop the hood every other fill up and have a peek at the SC pulley, the counter pulley, and the belt.
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2017 G63 Edition 463, 2008 G55k
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WTB 2005 E55
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2003 SL55 / 2002 SLK32
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2004 e55
Buy this part. My clutch went all buzz saw and this shield is all that kept me on the road. Best money spent so far. You can see the broken do so g on the lower left of the pulley. Actually 2 of them went.
Adam T.
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From: Santa Clara, Ca
2003 SL55 / 2002 SLK32
Worth pointing out (to all, with or without a scattershield)
There is NO substitute for periodic inspection of the sc pulley. More details here https://mbworld.org/forums/w211-amg/...ml#post7007207
Happy holidays to all,
Chris
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Joined: Oct 2015
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From: SC
2005 E55 AMG
Wow. That was some force to bend up the stainless steel like that.
Havent seen you in here in a while Chris. Good to see you posting
What is the second version like? Pic and details please.
Havent seen you in here in a while Chris. Good to see you posting
What is the second version like? Pic and details please.
Thread Starter
MBWorld Fanatic!
Joined: May 2009
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From: Santa Clara, Ca
2003 SL55 / 2002 SLK32
Cheers,
Chris
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From: Colorado, USA
E55 C63
wow! Good thing you had the shield! Send us a PM and we will get you sorted out with one of our pulleys (we use thicker springs)
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2006 E55
Solid Product
My Eurocharged 84mm sc pulley failed on me after 3 years and about 8K miles. Fortunately the scatter shield saved me and completely negated all damage although it got destroyed in the process. I would highly recommend this product. Also shout out to Jerry at Eurocharged for hooking me up with a replacement 84mm pulley at a major discount.
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From: DownEast Maine
CLS 55 AMG E500 ML320
I had Chris extend the tab on mine and add another one to the bottom I drilled through the tabs and through the post and dropped a cotter pin through on the drivers side. Hasn't been tested yet, but I fully expect it to keep the shield from being pushed out of the way, and my cover still fits.
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Joined: May 2007
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From: Hudson Valley, NY
2005 E55 Black, 2007 GL450 Carneol Red
Just installed latemodel21/Chris's Scattershield, and very impressed! Very quick response from order to shipping, and the attention to detail matches Gottlieb Daimler's motto "The best or nothing at all", even to adjusting the cover's mounts with a few washers and another tiny machined plate with welded nut. (The underside of the front left is pictured).
Last edited by Kropf; May 10, 2018 at 12:26 AM. Reason: Removed embedded youtube link
Thread Starter
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From: Santa Clara, Ca
2003 SL55 / 2002 SLK32
You can buy it from forum sponsor VRP speed, or directly from me. If you have any questions, email me at latemodel21@yahoo.com
Cheers,
Chris
Cheers,
Chris
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2024 c300 , 2006 E55, 2005 e320, 2007 gl450, 2025 glc300, 2025 e450
AMG55 Scattershield for Supercharger pulley
As everyone has likely seen in https://mbworld.org/forums/w211-amg/...ed-my-car.html Urbamworm posted pics of the serious damage that his Supercharger pulley did to some vital surrounding components when it came apart recently. Many chimed in with first-hand and second-hand stories of similar failures on E55s and other AMG55s. I, myself, had the OEM pulley come apart similarly (though I caught it before it went catastrophic).
While opinions vary as to the core cause (aftermarket part quality keeps coming up), the bottom line is that some are failing. I suspect the actual failure is a direct result of increased load. I am told, the 55 superchager uses north of 50 hp to compress air ... spin it faster and, more to the point, increase the load thru the creation of higher boost and the load may approach and/or eclipse 75 HP ... that is a lot of work for 3 little straps (the "dog bones") that are only .045" thick less than a 1/2" wide and secured with a 5mm rivet! While the problem seems to be more common for those using smaller SC pulleys, in my case it was on an OEM SC pulley that was loaded slightly more by a 168mm Crank Pulley. So, while I rebuilt my SC pulley with thicker dog bones (.050" thick), I still wanted more protection.
And, while inspecting your pulley periodically (specifically, the dog bones where they are secured to the pressure plate and taking it out of service at the first sign of a crack) will likely save you from a big repair bill.... I have always sought to improve the safety of my cars, be it on the street or on the track (I could tell ya about the time I did a cartwheel down the front straight at chowchilla speedway ... fixed the car under yellow ... and then came all the way from 19th to 5th before the race ended ... that was a safe car design that I was proud to drive : )
In any case, having already made a scattershield solution for the V6 AMG (info and pics here https://mbworld.org/forums/w211-amg/...ml#post6302678), I was already thinking of creating a solution for my SL55 ... when I was asked by some on the forum to make some extras (as I did in the case of the V6 scattershield)...
So, I finished the prototype this morning and wanted to share a few pics. As the viability of making extras at a great price is directly related to how many extras I have the need for and make (economy of scale), I thought it useful to make it known that this will be available and invite anyone to contact me if they have questions or interest.
While I have designed and am the sole manufacture of other products (the popular AMG55 Paddle Converter Module, the R170 Paddle integration kit, V6 AMG Belt Wrap Kit, V6 AMG Scattershield, Porsche paddle conversions, etc) that I sell either thru forum sponsors or exclusively on other forums ... I was hoping that I would not ruffle any feathers if I sold a few of these directly.
Being that this is a Safety Item, it makes sense that it should be priced low enough that it is within the budget of anyone who feels the need to get one.
I will do a run of these out of Stainless Steel. They will be done on a regular production floor which generally translates into a 4 week lead (but the good news is they wont have any of the tool-marks, etc that you see on my proto).
I am hoping to keep the price under $100 and should have a more definite idea of the price next week.
Anyone who is interested in one feel free to send me an PM.
Cheers,
Chris
As everyone has likely seen in https://mbworld.org/forums/w211-amg/...ed-my-car.html Urbamworm posted pics of the serious damage that his Supercharger pulley did to some vital surrounding components when it came apart recently. Many chimed in with first-hand and second-hand stories of similar failures on E55s and other AMG55s. I, myself, had the OEM pulley come apart similarly (though I caught it before it went catastrophic).
While opinions vary as to the core cause (aftermarket part quality keeps coming up), the bottom line is that some are failing. I suspect the actual failure is a direct result of increased load. I am told, the 55 superchager uses north of 50 hp to compress air ... spin it faster and, more to the point, increase the load thru the creation of higher boost and the load may approach and/or eclipse 75 HP ... that is a lot of work for 3 little straps (the "dog bones") that are only .045" thick less than a 1/2" wide and secured with a 5mm rivet! While the problem seems to be more common for those using smaller SC pulleys, in my case it was on an OEM SC pulley that was loaded slightly more by a 168mm Crank Pulley. So, while I rebuilt my SC pulley with thicker dog bones (.050" thick), I still wanted more protection.
And, while inspecting your pulley periodically (specifically, the dog bones where they are secured to the pressure plate and taking it out of service at the first sign of a crack) will likely save you from a big repair bill.... I have always sought to improve the safety of my cars, be it on the street or on the track (I could tell ya about the time I did a cartwheel down the front straight at chowchilla speedway ... fixed the car under yellow ... and then came all the way from 19th to 5th before the race ended ... that was a safe car design that I was proud to drive : )
In any case, having already made a scattershield solution for the V6 AMG (info and pics here https://mbworld.org/forums/w211-amg/...ml#post6302678), I was already thinking of creating a solution for my SL55 ... when I was asked by some on the forum to make some extras (as I did in the case of the V6 scattershield)...
So, I finished the prototype this morning and wanted to share a few pics. As the viability of making extras at a great price is directly related to how many extras I have the need for and make (economy of scale), I thought it useful to make it known that this will be available and invite anyone to contact me if they have questions or interest.
While I have designed and am the sole manufacture of other products (the popular AMG55 Paddle Converter Module, the R170 Paddle integration kit, V6 AMG Belt Wrap Kit, V6 AMG Scattershield, Porsche paddle conversions, etc) that I sell either thru forum sponsors or exclusively on other forums ... I was hoping that I would not ruffle any feathers if I sold a few of these directly.
Being that this is a Safety Item, it makes sense that it should be priced low enough that it is within the budget of anyone who feels the need to get one.
I will do a run of these out of Stainless Steel. They will be done on a regular production floor which generally translates into a 4 week lead (but the good news is they wont have any of the tool-marks, etc that you see on my proto).
I am hoping to keep the price under $100 and should have a more definite idea of the price next week.
Anyone who is interested in one feel free to send me an PM.
Cheers,
Chris
Thread Starter
MBWorld Fanatic!
Joined: May 2009
Posts: 1,187
Likes: 239
From: Santa Clara, Ca
2003 SL55 / 2002 SLK32
