Pulley Saver Kit
Pulley Saver Kit
“Pulley Saver”
The next chapter in a Waldig/NeedsWings Design.
After reviewing some of the prior issues Crossfire owners have had with their idler pulley failures, we started to consider the possibilities of an improved design. The real weakness in the design is the idler under the supercharger as it is often the smallest at 60 MM in diameter. With a stock crankshaft pulley of 155MM, the idler is running about 2.6 times faster or 15,500 rpm at our 6000 rpm redline.
The idler pulley is reduced in diameter to allow the stock belt to be used with the 178, 181, and the 185 pulley upgrades. The water pump pulley is also reduced in diameter to ‘free up‘ some additional belt length. This water pump pulley must be smaller in diameter to allow the larger pulley to be installed and does not seem to be an issue overall.
With the larger 185 pulley the idler is now turning at a speed of 3.08 times the engine speed or about 18,500 rpm at full revs. This is excessive and addressed to decrease stress on the pulley and increase its life span. The following design change has been tested on our SRT’s on the street, road trips (Tail of the Dragon, Carlisle Chrysler Nationals), many auto crossing tracks with sustained high rpm operation (4000 – 6000) for up to a minute at a time and over a dozen dyno pulls to date. A Hefty stack of timeslips at the dragstrip and no issues or problems have been detected and all components appear to operate well in this design, the delay in releasing this kit was intentional to gather ample driving time to prove the reliability of the design.
In a nutshell’ the serpentine belt with this kit is replaced with a longer belt to allow for larger pulley to be installed, slowing their rotational speed significantly. The idler pulley is increased in size to 100MM reducing its operating speed to 60% of its previous speed. With the large 185 crank pulley operating at 6000 rpm, the idler pulley is only turning 1.85 times as fast or 11,100 rpm. This is a huge reduction in stress as this pulley carries most of the belt tension and has a 50% wrap which doubles its side thrust load.
Additional improvements include the replacement of the tensioner pulley with another 100mm pulley on the 178 and 181 pulley applications. This allows this pulley to operate at the same speed as noted above and is a 10% reduction from its previous speed. To allow enough belt length to maintain proper tension for the 185 pulley set-up I did not change the tensioner pulley from its original factory 90 MM diameter. A new 90mm pulley is included in the kit for the 185mm customers.
Another improvement feature is the elimination of the TINY grooved idler directly under the supercharger. This poor pulley really gets going due to its small diameter and is a failure waiting to happen. Instead a much larger grooved pulley is located near the alternator on a new grade 8 bolt with a massive ¼” thick stainless steel brace assembly. This brace is the definition of “overkill” and brings everything togather. This larger grooved pulley is turning over relatively slowly and serves to guide and position the belt just prior to it running over the supercharger pulley.
Because of the location of this redesigned groove pulley, the ¼” brace was created to solidly mount this pulley and tie it into the other engine support mounts. The idler pulley is supported on the right (driver side) of this brace providing positive bearing mounts support on both the front and rear sides of these two pulleys as shown in the following photographs. Virtually bulletproof engineering.
It should be noted that the supercharger has an increased amount of belt “wrap” due to the repositioning of the grooved ‘guide’ pulley. This would increase the load handling ability of the belt and in Waldig’s car has prevented belt slippage even though he has been experiencing manifold boost pressures of up to 25 PSIG. The belt wrap increase is helpful as a side benefit, and the improvement is probably in the order of a 10% torque handling capacity.
This improved pulley kit will provide you with additional pulley life and a caged pulley support capable of reducing damage in the unlikely event of a spun bearing caused by an age related failure. The supercharger has additional belt wrap / contact to prevent belt wear due to slippage under severe driving and high boost operation. Overall this kit will materially improve the reliability of your pulley and belt system.
Custom machined stainless steel spacers (thanks MikeR), custom ¼” thick stainless steel water jet brace, 3/8” grade 8 bolt/nut/washers, grade 10.9 metric bolt, 3 new pulleys and new longer belt will be included with the kit. This kit has been going thru testing on 4 different srt6’s to date. We are finally comfortable releasing this kit for the masses. Kit will fit srt6/slk32amg/c32amg vehicles with a 178mm, 181mm or 185mm aftermarket pulley kits.
As a side note, when we removed our 30k mile OEM belt we noticed a great amount of cracking in the stock belt and were relieved to be installing a new belt at that time. 4 of the 6 ribs were cracked on our belt in several locations. All components of this kit are readily available now and in the foreseeable future.
We have no problem warranty’ing the parts in the kit with a 1 year unlimited mile coverage but we will NOT put a blanket warranty on the engine/vehicle, USE AT YOUR OWN RISK! (See our disclaimer on our website for further details). We are planning on making very little off these kits if we even do recoupe the r&d/parts/materials, this kit was designed by Waldig, tweaked by us and should help keep the SRT6’s turning heads on the road or track!
www.needswings.com/pics/psk1.jpg
www.needswings.com/pics/psk2.jpg
www.needswings.com/pics/psk3.jpg
www.needswings.com/pics/psk4.jpg
www.needswings.com/pics/psk5.jpg
www.needswings.com/pics/psk6.jpg
www.needswings.com/pics/psk7.jpg
www.needswings.com/pics/psk8.jpg
The next chapter in a Waldig/NeedsWings Design.
After reviewing some of the prior issues Crossfire owners have had with their idler pulley failures, we started to consider the possibilities of an improved design. The real weakness in the design is the idler under the supercharger as it is often the smallest at 60 MM in diameter. With a stock crankshaft pulley of 155MM, the idler is running about 2.6 times faster or 15,500 rpm at our 6000 rpm redline.
The idler pulley is reduced in diameter to allow the stock belt to be used with the 178, 181, and the 185 pulley upgrades. The water pump pulley is also reduced in diameter to ‘free up‘ some additional belt length. This water pump pulley must be smaller in diameter to allow the larger pulley to be installed and does not seem to be an issue overall.
With the larger 185 pulley the idler is now turning at a speed of 3.08 times the engine speed or about 18,500 rpm at full revs. This is excessive and addressed to decrease stress on the pulley and increase its life span. The following design change has been tested on our SRT’s on the street, road trips (Tail of the Dragon, Carlisle Chrysler Nationals), many auto crossing tracks with sustained high rpm operation (4000 – 6000) for up to a minute at a time and over a dozen dyno pulls to date. A Hefty stack of timeslips at the dragstrip and no issues or problems have been detected and all components appear to operate well in this design, the delay in releasing this kit was intentional to gather ample driving time to prove the reliability of the design.
In a nutshell’ the serpentine belt with this kit is replaced with a longer belt to allow for larger pulley to be installed, slowing their rotational speed significantly. The idler pulley is increased in size to 100MM reducing its operating speed to 60% of its previous speed. With the large 185 crank pulley operating at 6000 rpm, the idler pulley is only turning 1.85 times as fast or 11,100 rpm. This is a huge reduction in stress as this pulley carries most of the belt tension and has a 50% wrap which doubles its side thrust load.
Additional improvements include the replacement of the tensioner pulley with another 100mm pulley on the 178 and 181 pulley applications. This allows this pulley to operate at the same speed as noted above and is a 10% reduction from its previous speed. To allow enough belt length to maintain proper tension for the 185 pulley set-up I did not change the tensioner pulley from its original factory 90 MM diameter. A new 90mm pulley is included in the kit for the 185mm customers.
Another improvement feature is the elimination of the TINY grooved idler directly under the supercharger. This poor pulley really gets going due to its small diameter and is a failure waiting to happen. Instead a much larger grooved pulley is located near the alternator on a new grade 8 bolt with a massive ¼” thick stainless steel brace assembly. This brace is the definition of “overkill” and brings everything togather. This larger grooved pulley is turning over relatively slowly and serves to guide and position the belt just prior to it running over the supercharger pulley.
Because of the location of this redesigned groove pulley, the ¼” brace was created to solidly mount this pulley and tie it into the other engine support mounts. The idler pulley is supported on the right (driver side) of this brace providing positive bearing mounts support on both the front and rear sides of these two pulleys as shown in the following photographs. Virtually bulletproof engineering.
It should be noted that the supercharger has an increased amount of belt “wrap” due to the repositioning of the grooved ‘guide’ pulley. This would increase the load handling ability of the belt and in Waldig’s car has prevented belt slippage even though he has been experiencing manifold boost pressures of up to 25 PSIG. The belt wrap increase is helpful as a side benefit, and the improvement is probably in the order of a 10% torque handling capacity.
This improved pulley kit will provide you with additional pulley life and a caged pulley support capable of reducing damage in the unlikely event of a spun bearing caused by an age related failure. The supercharger has additional belt wrap / contact to prevent belt wear due to slippage under severe driving and high boost operation. Overall this kit will materially improve the reliability of your pulley and belt system.
Custom machined stainless steel spacers (thanks MikeR), custom ¼” thick stainless steel water jet brace, 3/8” grade 8 bolt/nut/washers, grade 10.9 metric bolt, 3 new pulleys and new longer belt will be included with the kit. This kit has been going thru testing on 4 different srt6’s to date. We are finally comfortable releasing this kit for the masses. Kit will fit srt6/slk32amg/c32amg vehicles with a 178mm, 181mm or 185mm aftermarket pulley kits.
As a side note, when we removed our 30k mile OEM belt we noticed a great amount of cracking in the stock belt and were relieved to be installing a new belt at that time. 4 of the 6 ribs were cracked on our belt in several locations. All components of this kit are readily available now and in the foreseeable future.
We have no problem warranty’ing the parts in the kit with a 1 year unlimited mile coverage but we will NOT put a blanket warranty on the engine/vehicle, USE AT YOUR OWN RISK! (See our disclaimer on our website for further details). We are planning on making very little off these kits if we even do recoupe the r&d/parts/materials, this kit was designed by Waldig, tweaked by us and should help keep the SRT6’s turning heads on the road or track!
www.needswings.com/pics/psk1.jpg
www.needswings.com/pics/psk2.jpg
www.needswings.com/pics/psk3.jpg
www.needswings.com/pics/psk4.jpg
www.needswings.com/pics/psk5.jpg
www.needswings.com/pics/psk6.jpg
www.needswings.com/pics/psk7.jpg
www.needswings.com/pics/psk8.jpg
Re: Pulley Saver Kit
Taaaa freaking Daaaaaa.
I have been working on this upgrade since last fall. The idler issues and speeds were becoming an issue and I thought that there had to be a better way. A longer belt is added to allow the bigger pulleys and preserve a nice adjustment range on the factory tensioner.
The writeup above describes it all, if you have questions please just ask and Rob or I will get you more answers.
I have done lots of dynos, autocrosses this season and last fall, plus road milage at the dragon and carlisle. Seems stable on the car without any downsides.
Hope you enjoy the improved design, more coming.....
W
DY
I have been working on this upgrade since last fall. The idler issues and speeds were becoming an issue and I thought that there had to be a better way. A longer belt is added to allow the bigger pulleys and preserve a nice adjustment range on the factory tensioner.
The writeup above describes it all, if you have questions please just ask and Rob or I will get you more answers.
I have done lots of dynos, autocrosses this season and last fall, plus road milage at the dragon and carlisle. Seems stable on the car without any downsides.
Hope you enjoy the improved design, more coming.....
W
DY
Last edited by waldig; 08-11-2009 at 07:58 AM.
Re: Pulley Saver Kit
has anyone come up with a bracket that includes barrel spacer (like bracket for original idler) for the DIY belt wrap?
I had picked up a piece of steel plate to use and found the threads in the adjacent piece that I will be attaching to is a different size(smaller) and is not parallel with face of new pulley. I need to hit a proper hardware store to find a nice barrel spacer to make up the difference. I just thought that since the DIY has been out there for awhile that someone had already mocked up a proper support bracket, that others could use .
Sorry to be off topic, this will be great when I trade up from the Code3 to a crank pulley. Thanks for the R&D.
I had picked up a piece of steel plate to use and found the threads in the adjacent piece that I will be attaching to is a different size(smaller) and is not parallel with face of new pulley. I need to hit a proper hardware store to find a nice barrel spacer to make up the difference. I just thought that since the DIY has been out there for awhile that someone had already mocked up a proper support bracket, that others could use
. Sorry to be off topic, this will be great when I trade up from the Code3 to a crank pulley. Thanks for the R&D.
Join Date: Jun 2009
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Re: Pulley Saver Kit
Originally Posted by goodgenes79
has anyone come up with a bracket that includes barrel spacer (like bracket for original idler) for the DIY belt wrap?
I had picked up a piece of steel plate to use and found the threads in the adjacent piece that I will be attaching to is a different size(smaller) and is not parallel with face of new pulley. I need to hit a proper hardware store to find a nice barrel spacer to make up the difference. I just thought that since the DIY has been out there for awhile that someone had already mocked up a proper support bracket, that others could use .
Sorry to be off topic, this will be great when I trade up from the Code3 to a crank pulley. Thanks for the R&D.
I had picked up a piece of steel plate to use and found the threads in the adjacent piece that I will be attaching to is a different size(smaller) and is not parallel with face of new pulley. I need to hit a proper hardware store to find a nice barrel spacer to make up the difference. I just thought that since the DIY has been out there for awhile that someone had already mocked up a proper support bracket, that others could use
. Sorry to be off topic, this will be great when I trade up from the Code3 to a crank pulley. Thanks for the R&D.
I know I'm in for one.
Re: Pulley Saver Kit
Originally Posted by qzomak
Is there any noticeable change in the feel of the car when driving? Does this pulley saver system improve performance? Oh and how much to ship to Toronto. Thanks
it "could" possibly improve performance due to the added belt wrap but i dont think it would be anythign noticable unless you are slipping already. its deisgned to be a safety part more so then a performance part.
to canada would be $17 additional
Re: Pulley Saver Kit
I have this kit on the Aero and I did have belt slipping prior to installing. No slipping since I installed it. It also cleaned up minor squeaks I had been hearing. As Woody said, it put the tensioner in a good position to have good flex in both directions. I'm happy with how it performs.
Re: Pulley Saver Kit
[rcompart]Why would you want to even do the DIY belt wrap? You're not getting away from the small diameter pulleys and it's spinning them at ridiculous speeds.
I used the DIY belt wrap because I had slippage with the Code3, now I don't and have better performance. The only pulley that is spinning faster is the S/C pulley so not concerned with that. If and when I add a crank pulley then I can change my set-up.
Although this would be a bit safer on long-term for all setups.
I used the DIY belt wrap because I had slippage with the Code3, now I don't and have better performance. The only pulley that is spinning faster is the S/C pulley so not concerned with that. If and when I add a crank pulley then I can change my set-up.
Although this would be a bit safer on long-term for all setups.
Last edited by goodgenes79; 08-11-2009 at 11:33 AM.
Re: Pulley Saver Kit
Originally Posted by goodgenes79
[rcompart]Why would you want to even do the DIY belt wrap? You're not getting away from the small diameter pulleys and it's spinning them at ridiculous speeds.
I used the DIY belt wrap because I had slippage with the Code3, now I don't and have better performance. The only pulley that is spinning faster is the S/C pulley so not concerned with that. If and when I add a crank pulley then I can change my set-up.
Although this would be a bit safer on long-term for all setups.
I used the DIY belt wrap because I had slippage with the Code3, now I don't and have better performance. The only pulley that is spinning faster is the S/C pulley so not concerned with that. If and when I add a crank pulley then I can change my set-up.
Although this would be a bit safer on long-term for all setups.
Re: Pulley Saver Kit
We know Rudy...but running a crank pulley before this mod has now come alone was more risk than I wanted to take. The only thing spinning faster right now on mine is the Code 3...the rest is MB engineering, who have a pretty good track record. I haven't had an problems with any other pulleys, including the idler...I am happy with my set up, and I don't run a belt rap, I just run a new belt , all the time, and a new one in the trunk, just in case... I now may move up to a 185, put the stock SC pulley back on, and do this mod...we shall see...
Re: Pulley Saver Kit
I think I'm being misunderstood. My biggest beef with the DIY is the flat side of the belt on the ribbed pulley. I know all the other pulleys spin the same speed with the C3. What I'm saying is if you can get all those little guys spinning a little slower, you run less risk even than stock of one failing and when you put another pulley in the equation you have a lot more stress on the load bearing side of those pulleys, much more so than they were ever intended to see. As for running a larger crank pulley, this shouldn't even be considered an add-on but rather a no brainer and should be on your list of things to get done like yesterday. If you're gonna run a belt wrap kit, this should be the one to do it with I guess is what I'm saying. Not because NW is selling it but because no one else makes one like this.
This isn't pointed at anyone individual either, I think between me misunderstanding what other were saying and maybe me being unclear about what I was saying caused the confusion.
This isn't pointed at anyone individual either, I think between me misunderstanding what other were saying and maybe me being unclear about what I was saying caused the confusion.