EO2K contemplates the universe, his rotrex, and why they both fail
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Short answer: Yes. Chances are they will look it up.
Depends on the smog tech, and the sticker. Do an image search for "CARB EO sticker" on google and you will see what I mean. The old JRSC stickers said something like "Honda/Acura/Ford Supercharger Systems" but I have no idea what they say for the CR-Z
It used to be that a lot of them really didnt care. If It looks like a legit CARB sticker and everything appears to be hooked up correctly, they would run it. Unfortunately, CARB has started sending under cover inspectors out to "check up" on the tech stations. Fines and revocation of license are typical for infractions. I've heard that a lot of stations will not even let your car in the shop if you have anything with an EO sticker on it under the hood, simply because they don't want to be responsible for looking up the documentation for the device and then insuring that you have it installed and functioning per the EO description. They would rather continue putting your Moms 2001 Accord on the machine and collecting their $80 and move on with life. CARB EOs are complicated and take time, and that costs them more monies.
Example 1: When I had my NA, it had a MonsterFlow intake (CARB EO D-591) installed and stickered. I had a hell of a time passing the visual part of the inspection because I didn't buy the optional heat shield, and the description on EO D-591 specifically states "heat shield (as applicable)" and all the Miata documentation shows a heat shield.
Example 2: I briefly considered selling my 2000 for a 1999 so I could get a street legal turbo:
When I emailed BEGI and conversed with Stephanie (or Corky, can't remember) they informed me that they no longer sell the extra injector setup, or the powercard controller to control the extra injectors, and that there is no "timing retard device" for the BP4W NB series engines. The RRFPR is actually useless on the returnless NB fuel system unless you install a fuel pump under the hood... etc. The problem is, the underlined stuff in the above CARB EO is IN THE EO DESCRIPTION and any tech worth a damn is going to look this up if someone rolls in with a turbo strapped to their car, rather than "do me a solid" and loose their license.
When I bought these concerns up with Steph, her response was "We have had no reports out of California about people failing smog tests with our kit" or basically "trust us." She then recommended that I buy there $1,495.00 XEDE piggyback so I could retain the stock ECU and thus get OBDII functionality and call that the "timing retard device." To pass visual, I was told to plug a couple injectors into the intake plumbing and install a RRFPR even though they don't do anything.![facepalm](https://www.miataturbo.net/images/smilies/facepalm.gif)
So what did I do? I tried to be legal. I spent a lot of money to try to be legal. The road to hell is paved with good intentions. I bought the kit from Kraftwerks because "We'll get you a CARB EO number once its approved. Its out for testing right now! Trust us!"
IF something happened to this car and someone dropped an insurance check in my lap, I'd buy a 49 state 1999 Miata and a bare bones BEGI-S or Series 1 kit with no turbo (I have a T25 in the garage) for the CARB cert and then run it with my Megasquirt. For visual, I'd do as Steph recommended and install a RRFPR and dummy injectors, and possibly buy one of FMs VooDoo cards. For inspection time, I'd wire the wastegate open, run the stock ECU/injectors/maf/cat w/VooDoo and call it a day.
Depends on the smog tech, and the sticker. Do an image search for "CARB EO sticker" on google and you will see what I mean. The old JRSC stickers said something like "Honda/Acura/Ford Supercharger Systems" but I have no idea what they say for the CR-Z
It used to be that a lot of them really didnt care. If It looks like a legit CARB sticker and everything appears to be hooked up correctly, they would run it. Unfortunately, CARB has started sending under cover inspectors out to "check up" on the tech stations. Fines and revocation of license are typical for infractions. I've heard that a lot of stations will not even let your car in the shop if you have anything with an EO sticker on it under the hood, simply because they don't want to be responsible for looking up the documentation for the device and then insuring that you have it installed and functioning per the EO description. They would rather continue putting your Moms 2001 Accord on the machine and collecting their $80 and move on with life. CARB EOs are complicated and take time, and that costs them more monies.
Example 1: When I had my NA, it had a MonsterFlow intake (CARB EO D-591) installed and stickered. I had a hell of a time passing the visual part of the inspection because I didn't buy the optional heat shield, and the description on EO D-591 specifically states "heat shield (as applicable)" and all the Miata documentation shows a heat shield.
Example 2: I briefly considered selling my 2000 for a 1999 so I could get a street legal turbo:
Originally Posted by D-349-1
CARB EO: D-349-1
EO Date: 2000-12-19
Manufacturer Name: Bell Engineering Group, Inc.
Device: Mazda Turbocharger Kit
Device Type: Turbocharger System / Turbocharger Modification
Remarks:
1994 through 1999 Mazda Miatas The Mazda Turbocharger Kit includes the following: Garrett turbocharger, 10 psi. maximum boost, high flow fuel pump, intercooler (optional), two supplementary fuel injectors, fuel regulator designed to raise the fuel pressure as a function of boost pressure, open element air cleaner, ignition timing retard device, cast iron exhaust manifold, and exhaust connecting pipe. The supplementary fuel injectors are placed in an air tube just prior to the throttle body and are controlled by a boost pressure actuated electronic circuit. The manufacturer recommends 92 octane fuel.
EO Date: 2000-12-19
Manufacturer Name: Bell Engineering Group, Inc.
Device: Mazda Turbocharger Kit
Device Type: Turbocharger System / Turbocharger Modification
Remarks:
1994 through 1999 Mazda Miatas The Mazda Turbocharger Kit includes the following: Garrett turbocharger, 10 psi. maximum boost, high flow fuel pump, intercooler (optional), two supplementary fuel injectors, fuel regulator designed to raise the fuel pressure as a function of boost pressure, open element air cleaner, ignition timing retard device, cast iron exhaust manifold, and exhaust connecting pipe. The supplementary fuel injectors are placed in an air tube just prior to the throttle body and are controlled by a boost pressure actuated electronic circuit. The manufacturer recommends 92 octane fuel.
When I bought these concerns up with Steph, her response was "We have had no reports out of California about people failing smog tests with our kit" or basically "trust us." She then recommended that I buy there $1,495.00 XEDE piggyback so I could retain the stock ECU and thus get OBDII functionality and call that the "timing retard device." To pass visual, I was told to plug a couple injectors into the intake plumbing and install a RRFPR even though they don't do anything.
![facepalm](https://www.miataturbo.net/images/smilies/facepalm.gif)
So what did I do? I tried to be legal. I spent a lot of money to try to be legal. The road to hell is paved with good intentions. I bought the kit from Kraftwerks because "We'll get you a CARB EO number once its approved. Its out for testing right now! Trust us!"
IF something happened to this car and someone dropped an insurance check in my lap, I'd buy a 49 state 1999 Miata and a bare bones BEGI-S or Series 1 kit with no turbo (I have a T25 in the garage) for the CARB cert and then run it with my Megasquirt. For visual, I'd do as Steph recommended and install a RRFPR and dummy injectors, and possibly buy one of FMs VooDoo cards. For inspection time, I'd wire the wastegate open, run the stock ECU/injectors/maf/cat w/VooDoo and call it a day.
Last edited by EO2K; 11-15-2012 at 02:30 AM.
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You have no idea. I really really try not to cry about it or carry on like a little bitch, but its really difficult at times.
My powercard fuel controller failed, my belt tensioner has failed more times than I can remember, my megasquirt failed twice and now I'm back to stock power. It'll probably stay like this until I get her heiney sniffed in January and then I'll go try for the boost again.
My powercard fuel controller failed, my belt tensioner has failed more times than I can remember, my megasquirt failed twice and now I'm back to stock power. It'll probably stay like this until I get her heiney sniffed in January and then I'll go try for the boost again.
Last edited by EO2K; 11-14-2012 at 08:24 PM.
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mx594m: I know you made 224hp or something on the stock 88mm pulley uncorked, correct? What were you using for management and what elevation were you at? Any chance you still have your timing and AFR tables somewhere?
224hp is not going to blow up my stock block, and I have the intercooler and injectors to support it. Problem is, I'm at sea level. Compound this with the fact that I don't know how to apply data to a compressor map and things may go boom. Though I do have a spare engine now
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Actually, I'd rather just be legal.
Vlad: How do you NOT get hassled DD-ing your builds? Seriously
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TENSION FIX:
OM NOM NOM
![](https://www.miataturbo.net/attachments/supercharger-discussion-38/60312-eo2k-contemplates-universe-his-rotrex-why-they-both-fail-eo2k-15208-albums-eo2k-rotrex-stuff-563-picture-imag0142-2863.jpg?dateline=1353443827)
This is the "notch" that Kraftwerks "machined" into the top of my mounting plate. The hole to the right is the original alignment dowel pin hole from the auto tensioner. The mushrooming you see is due to the incredibly thin wall between the notch and the hole, and me catching the rounded tip of the auto tensioner locating pin on said incredibly thin wall while tightening it the first time. The "notch" allows for significantly more preload on the auto tensioner, thus my 10.5~ish mm preload picture. One of these days I'll drive a piece of bar stock into the hole and get Gesso to tig it up, then I'll file out the mushrooming and make it pretty again.
I'd like to point out that I was told that this is the "official fix" and "would be included in other kits going forward" and was "not something we cobbled together to make yours work."
![](https://www.miataturbo.net/attachments/supercharger-discussion-38/60313-eo2k-contemplates-universe-his-rotrex-why-they-both-fail-eo2k-15208-albums-eo2k-rotrex-stuff-563-picture-imag0143-2864.jpg?dateline=1353443827)
The auto tensioner on the left is as-delivered with my kit, the one on the right is the modified replacement that was delivered with the above "fix." The lower pin has been removed as it no longer lines up with the lower alignment in on the mounting plate. Notice the minor rubbing on the mounting plate in the above picture? I believe that has something to do with them removing too much material from the auto tensioner. It never rubbed before the modification and I may need to stick a 0.005" shim under there when I re install and see what happens.
BELT ALIGNMENT FIX:
Kraftwerks updated the "fixed" idler and its mounting system. I mentioned this in and earlier post but failed to post pics, so here they are.
Please note: that T-Nut, bolt and washer are not stock, I'll explain it in a moment...
![](https://www.miataturbo.net/attachments/supercharger-discussion-38/60314-eo2k-contemplates-universe-his-rotrex-why-they-both-fail-eo2k-15208-albums-eo2k-rotrex-stuff-563-picture-imag0147-2868.jpg?dateline=1353443827)
The idler is steel, flat faced and has a single bearing. The bearing is held in by a snap ring and should be user serviceable. I got the NSK part number off the bearing and I now have 2 extras in the tool box. The flat face on the idler lets the belt go where it wants to. The problem with the crowned, plastic idler that origionally came with the kit was that the belt was always pulled to the top of the crown, and the crown was not centered on the blower pulley. This would cause the idler to pull the belt to the front of the pulley and shred the ribs. I'm about 95% sure this is a timing belt idler from some other application, but it has no part numbers on it. I'd source it from Kraftwerks along with the required black spacer. This part is larger in diameter and fouled on my power steering hardline so you may need to do some creative bending of said line. It appears that this part is not usable without the above modification to the auto tensioner, otherwise there just is not enough clearance.
![](https://www.miataturbo.net/attachments/supercharger-discussion-38/60315-eo2k-contemplates-universe-his-rotrex-why-they-both-fail-eo2k-15208-albums-eo2k-rotrex-stuff-563-picture-imag0145-2866.jpg?dateline=1353443827)
It all goes together something like this, also gives a better view of the flat face on the revised "fixed" idler. The black thing is actually a bit of a spacer sleeve. It acts as the spacer to keep the idler off the mounting plate and provides the clamping face for the bolt. It has far more surface area in contact with the mounting plate, so I don't expect there to be any slippage issues. The silver bit on the right is actually part of the original kit. The washer I added because the bolt didn't quite have enough thread. The bolt is also about 1/2" too long.
THE T-NUT
This is something I cooked up out of desperation. Gesso "acquired" a spare T-Nut and then milled it down to fit. The bolt I added from Ace.
![](https://www.miataturbo.net/attachments/supercharger-discussion-38/60316-eo2k-contemplates-universe-his-rotrex-why-they-both-fail-eo2k-15208-albums-eo2k-rotrex-stuff-563-picture-revised-tbolt-2870.jpg?dateline=1353443827)
This is the awesome MS-Pain engineering drawing I cooked up to make this easier for myself because there was no way I could have explained it otherwise. The stud eventually came loose from the T-Nut that Kraftwerks supplied with the original kit and buggerd itself up, so I chose to use a bolt rather than a stud and nut this time around, for the sake of simplicity. I added the pocket in the face of the T-Nut is to capture the end of the adjuster screw and keep it aligned. A small dab of grease in the pocket helped my adjuster bolt turn significantly easier.
This is ugly, but it works. I managed a back-to-back trackday weekend at Laguna Seca plus the 400+ mile round trip drive and track day at ThunderHill on the same belt. (My megasquirt failed, not the rotrex, that's why I had to take the AAA taxi home.) Previously, I couldn't get a belt broken in before it went spaghetti on me.
If anyone has any questions or needs any measurements, please let me know and I'll do what I can to help. I actually have the "fixed" idler assembly and my calipers with me today.
OM NOM NOM
![](https://www.miataturbo.net/attachments/supercharger-discussion-38/60312-eo2k-contemplates-universe-his-rotrex-why-they-both-fail-eo2k-15208-albums-eo2k-rotrex-stuff-563-picture-imag0142-2863.jpg?dateline=1353443827)
This is the "notch" that Kraftwerks "machined" into the top of my mounting plate. The hole to the right is the original alignment dowel pin hole from the auto tensioner. The mushrooming you see is due to the incredibly thin wall between the notch and the hole, and me catching the rounded tip of the auto tensioner locating pin on said incredibly thin wall while tightening it the first time. The "notch" allows for significantly more preload on the auto tensioner, thus my 10.5~ish mm preload picture. One of these days I'll drive a piece of bar stock into the hole and get Gesso to tig it up, then I'll file out the mushrooming and make it pretty again.
I'd like to point out that I was told that this is the "official fix" and "would be included in other kits going forward" and was "not something we cobbled together to make yours work."
![](https://www.miataturbo.net/attachments/supercharger-discussion-38/60313-eo2k-contemplates-universe-his-rotrex-why-they-both-fail-eo2k-15208-albums-eo2k-rotrex-stuff-563-picture-imag0143-2864.jpg?dateline=1353443827)
The auto tensioner on the left is as-delivered with my kit, the one on the right is the modified replacement that was delivered with the above "fix." The lower pin has been removed as it no longer lines up with the lower alignment in on the mounting plate. Notice the minor rubbing on the mounting plate in the above picture? I believe that has something to do with them removing too much material from the auto tensioner. It never rubbed before the modification and I may need to stick a 0.005" shim under there when I re install and see what happens.
BELT ALIGNMENT FIX:
Kraftwerks updated the "fixed" idler and its mounting system. I mentioned this in and earlier post but failed to post pics, so here they are.
Please note: that T-Nut, bolt and washer are not stock, I'll explain it in a moment...
![](https://www.miataturbo.net/attachments/supercharger-discussion-38/60314-eo2k-contemplates-universe-his-rotrex-why-they-both-fail-eo2k-15208-albums-eo2k-rotrex-stuff-563-picture-imag0147-2868.jpg?dateline=1353443827)
The idler is steel, flat faced and has a single bearing. The bearing is held in by a snap ring and should be user serviceable. I got the NSK part number off the bearing and I now have 2 extras in the tool box. The flat face on the idler lets the belt go where it wants to. The problem with the crowned, plastic idler that origionally came with the kit was that the belt was always pulled to the top of the crown, and the crown was not centered on the blower pulley. This would cause the idler to pull the belt to the front of the pulley and shred the ribs. I'm about 95% sure this is a timing belt idler from some other application, but it has no part numbers on it. I'd source it from Kraftwerks along with the required black spacer. This part is larger in diameter and fouled on my power steering hardline so you may need to do some creative bending of said line. It appears that this part is not usable without the above modification to the auto tensioner, otherwise there just is not enough clearance.
![](https://www.miataturbo.net/attachments/supercharger-discussion-38/60315-eo2k-contemplates-universe-his-rotrex-why-they-both-fail-eo2k-15208-albums-eo2k-rotrex-stuff-563-picture-imag0145-2866.jpg?dateline=1353443827)
It all goes together something like this, also gives a better view of the flat face on the revised "fixed" idler. The black thing is actually a bit of a spacer sleeve. It acts as the spacer to keep the idler off the mounting plate and provides the clamping face for the bolt. It has far more surface area in contact with the mounting plate, so I don't expect there to be any slippage issues. The silver bit on the right is actually part of the original kit. The washer I added because the bolt didn't quite have enough thread. The bolt is also about 1/2" too long.
THE T-NUT
This is something I cooked up out of desperation. Gesso "acquired" a spare T-Nut and then milled it down to fit. The bolt I added from Ace.
![](https://www.miataturbo.net/attachments/supercharger-discussion-38/60316-eo2k-contemplates-universe-his-rotrex-why-they-both-fail-eo2k-15208-albums-eo2k-rotrex-stuff-563-picture-revised-tbolt-2870.jpg?dateline=1353443827)
This is the awesome MS-Pain engineering drawing I cooked up to make this easier for myself because there was no way I could have explained it otherwise. The stud eventually came loose from the T-Nut that Kraftwerks supplied with the original kit and buggerd itself up, so I chose to use a bolt rather than a stud and nut this time around, for the sake of simplicity. I added the pocket in the face of the T-Nut is to capture the end of the adjuster screw and keep it aligned. A small dab of grease in the pocket helped my adjuster bolt turn significantly easier.
This is ugly, but it works. I managed a back-to-back trackday weekend at Laguna Seca plus the 400+ mile round trip drive and track day at ThunderHill on the same belt. (My megasquirt failed, not the rotrex, that's why I had to take the AAA taxi home.) Previously, I couldn't get a belt broken in before it went spaghetti on me.
If anyone has any questions or needs any measurements, please let me know and I'll do what I can to help. I actually have the "fixed" idler assembly and my calipers with me today.
Last edited by EO2K; 11-20-2012 at 03:54 PM. Reason: clarity
#153
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Crossposted my above litany to M.net and got some good feedback. It turns out the bearings in the steel idler are just as bad as the ones in the original plastic idler.
Miata GT (Mark) posted up this image:
![](http://forum.miata.net/vb/attachment.php?attachmentid=152773&d=1353502300)
And I had a real WTF/FACEPALM moment when I figured out what that was... Its a Miata timing belt pulley
I don't know why the hell I didn't think of that. 60k mile bearings sound good to me! I ordered one from Rosenthal
I also found a thread in the S2KI forums with some guys who were also eating belts and bearings on their rotrex kits. One of the guys posted this image:
![](https://www.miataturbo.net/attachments/supercharger-discussion-38/60763-eo2k-contemplates-universe-his-rotrex-why-they-both-fail-failedtensionerpulley008.jpg?dateline=1353983448)
And that appears to be my steel idler bolted to an auto tensioner. I would suspect it would have the same high speed bearing issues that Miata GT saw, but at least it should work. I also noticed that the S2k guys get a 6 rib belt. Makes sense, too bad I'm stuck with the 4 rib on the Miata.
These S2k guys are crazy, they are talking full ceramic bearings for this stuff. Of course, they are also talking about grinding down the idler pulley because apparently it will contact the crank pulley in the S2k application. And I thought I had it bad! They posted a bunch of alternate part numbers and other bearing related information that I'm trying to track down, but I guess its good to know I'm not alone with this.
I'm also going to try to hunt down this 6203 bearing and see whats up:
![](http://www.s2ki.com/s2000/uploads/gallery/album_19090/gallery_50964_19090_20966.jpg)
I'm going to pull apart my old auto tensioner and see if I can get the bearing sizes off of it, and maybe read up on some additional bearing tech. I doubt I'll have any worries with the Miata timing belt idler, now I'm worried about the single bearing tensioner.
I also found this guy Godard on S2000.com who is apparently freeking nutbar. He cut up a C30-94 and mated it with the compressor of some giant fricking Borg Warner combine turbo, filled it with $500+ worth of ceramic aircraft bearings and is making something like 550hp with it in a S2k. He ALSO has complete disassembly pictures of a C30-94 blower in his flicker. He also claims to be in touch with "the biggest rotrex dealer in north america" and has some not exactly flattering things to say about how Kraftwerks was doing business. There are apparently some pretty huge issues with the traction fluid volume and cooler size supplied by KW. I'm going to do a bit more reading and see what I can find.
Miata GT (Mark) posted up this image:
And I had a real WTF/FACEPALM moment when I figured out what that was... Its a Miata timing belt pulley
![CRX](https://www.miataturbo.net/images/smilies/pissed.gif)
I also found a thread in the S2KI forums with some guys who were also eating belts and bearings on their rotrex kits. One of the guys posted this image:
![](https://www.miataturbo.net/attachments/supercharger-discussion-38/60763-eo2k-contemplates-universe-his-rotrex-why-they-both-fail-failedtensionerpulley008.jpg?dateline=1353983448)
And that appears to be my steel idler bolted to an auto tensioner. I would suspect it would have the same high speed bearing issues that Miata GT saw, but at least it should work. I also noticed that the S2k guys get a 6 rib belt. Makes sense, too bad I'm stuck with the 4 rib on the Miata.
These S2k guys are crazy, they are talking full ceramic bearings for this stuff. Of course, they are also talking about grinding down the idler pulley because apparently it will contact the crank pulley in the S2k application. And I thought I had it bad! They posted a bunch of alternate part numbers and other bearing related information that I'm trying to track down, but I guess its good to know I'm not alone with this.
I'm also going to try to hunt down this 6203 bearing and see whats up:
![](http://www.s2ki.com/s2000/uploads/gallery/album_19090/gallery_50964_19090_20966.jpg)
I'm going to pull apart my old auto tensioner and see if I can get the bearing sizes off of it, and maybe read up on some additional bearing tech. I doubt I'll have any worries with the Miata timing belt idler, now I'm worried about the single bearing tensioner.
I also found this guy Godard on S2000.com who is apparently freeking nutbar. He cut up a C30-94 and mated it with the compressor of some giant fricking Borg Warner combine turbo, filled it with $500+ worth of ceramic aircraft bearings and is making something like 550hp with it in a S2k. He ALSO has complete disassembly pictures of a C30-94 blower in his flicker. He also claims to be in touch with "the biggest rotrex dealer in north america" and has some not exactly flattering things to say about how Kraftwerks was doing business. There are apparently some pretty huge issues with the traction fluid volume and cooler size supplied by KW. I'm going to do a bit more reading and see what I can find.
#154
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I have ordered a timing belt idler to replace the supplied steel idler on my new bracket.
I got to thinking about belt speed and pulley RPM's. The stock crank pulley is 130mm. The idler pulley is 55mm. So, at 7200 engine redline, that idler pulley is doing 17k RPM. I'm surprised the resin idler pulleys lasted as long as they did, frankly. If one is using a 150mm overlay on the crank pulley, the max idler RPM jumps to 19.6k. That's fast. I can see where a resin pulley might simply explode, or how extended high-rpm usage could destroy the stock grease in the pulley in short order.
I'm sure the S2K guys have it even worse since their engine goes so much higher.
Hopefully the timing belt idler will do the trick. It appears much more robust, and the OEM application it was designed for is pretty severe. But, the RPM it sees with the timing belt is much lower.
I wish had kept my old pulleys when I did the timing belt 4 years ago, so I could disassemble it. Who knew.
I got to thinking about belt speed and pulley RPM's. The stock crank pulley is 130mm. The idler pulley is 55mm. So, at 7200 engine redline, that idler pulley is doing 17k RPM. I'm surprised the resin idler pulleys lasted as long as they did, frankly. If one is using a 150mm overlay on the crank pulley, the max idler RPM jumps to 19.6k. That's fast. I can see where a resin pulley might simply explode, or how extended high-rpm usage could destroy the stock grease in the pulley in short order.
I'm sure the S2K guys have it even worse since their engine goes so much higher.
Hopefully the timing belt idler will do the trick. It appears much more robust, and the OEM application it was designed for is pretty severe. But, the RPM it sees with the timing belt is much lower.
I wish had kept my old pulleys when I did the timing belt 4 years ago, so I could disassemble it. Who knew.
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I know exactly what you mean. I also sat down and did the math and the RPMs are outrageous, and like you say even worse in the S2k application. This actually really, really pissed me off. This seems like such an elementary oversite on the part of KW. I understand that bearings are wear items, but OEMs manage to get 100,000 miles out of an idler or an alternator all the damn time, but it probably has something to do with NOT buying $4 Chinese bearings. I think another big part of the problem is the belt misalignment. From what I've read, these bearings are not designed for sideloads, they are designed for single axis loads IE:straight up and down. With the crowned resin pulley constantly trying to center the belt, its no wonder these things explode.
A quick google search of "NACHI 6301NSE C3" turned up japanesebearings.com/VXB Ball Bearings and these specs:
6301-2NSE Nachi Bearing 12x37x12:Sealed:C3:Japan
Grease Lubrication: 16,000 RPM
That's the KW supplied bearing. It's just barely adequate for the application... and its a $6.88 bearing. I've seen them on alibaba for $3-4 in bulk![Bang](https://www.miataturbo.net/images/smilies/bang.gif)
6301ZZE Nachi Bearing 12x37x12:Shielded:C3:Japan
Grease Lubrication: 20,000 RPM
That's slightly better, but its still a $6.88 bearing and its probably the exact same bearing as above but with less sealing ability. I'm not sure if a shielded or sealed bearing is appropriate for an under-hood application.
Boca Bearing Company :: Ceramic Bearing Specialists carries 8 different options for a 6301/12x37x12. My favorite is a Stainless 440C Race/Ceramic SI3N4 ball hybrid sealed bearing SMR6301C-2RS/C3 #3 MG2 that is rated at 27,000 RPM, but they are also $54 each. My Miata idler was $39![Giggle](https://www.miataturbo.net/images/smilies/gay.gif)
So there are some real options for the 6301.
(Quick plug for Boca Bearing: This guys know how to build a site. You can search bearing by dimensions! I'll be shopping here more often, thats for sure)
The above picture of the GMN HY-6203-P43 supplied by the S2k guys may be a wild goose chase. That 6203 is a 17x40x12 bearing and ours is a 6301 12x37x12 bearing. Maybe the auto tensioner? I still need to check this. Got busy last night and didn't make it out to the garage.
Remember: I burned out the bearings in my original twin bearing resin idler pulley and auto tensioner in less miles than I generally see in an oil change interval. I'm sure part of this was sideloading due to the belt misalignment, but I'm sure the quality of the bearings was a big part as well. I'd gladly spend $100 with Boca on some decent bearings to prevent that from happening again, rather than spend another $100 for more shitty bearings from KW.
AND the TrackDog Racing has been using these with their updated JRSC/MP45/MP62 Belt Tensioner for quite some time with very very few complaints. The PD blower boys pretty frequently use the 150mm overlay as well. I think Miata GT hit the nail on the head with that one.
A quick google search of "NACHI 6301NSE C3" turned up japanesebearings.com/VXB Ball Bearings and these specs:
6301-2NSE Nachi Bearing 12x37x12:Sealed:C3:Japan
Grease Lubrication: 16,000 RPM
That's the KW supplied bearing. It's just barely adequate for the application... and its a $6.88 bearing. I've seen them on alibaba for $3-4 in bulk
![Bang](https://www.miataturbo.net/images/smilies/bang.gif)
6301ZZE Nachi Bearing 12x37x12:Shielded:C3:Japan
Grease Lubrication: 20,000 RPM
That's slightly better, but its still a $6.88 bearing and its probably the exact same bearing as above but with less sealing ability. I'm not sure if a shielded or sealed bearing is appropriate for an under-hood application.
Boca Bearing Company :: Ceramic Bearing Specialists carries 8 different options for a 6301/12x37x12. My favorite is a Stainless 440C Race/Ceramic SI3N4 ball hybrid sealed bearing SMR6301C-2RS/C3 #3 MG2 that is rated at 27,000 RPM, but they are also $54 each. My Miata idler was $39
![Giggle](https://www.miataturbo.net/images/smilies/gay.gif)
So there are some real options for the 6301.
(Quick plug for Boca Bearing: This guys know how to build a site. You can search bearing by dimensions! I'll be shopping here more often, thats for sure)
The above picture of the GMN HY-6203-P43 supplied by the S2k guys may be a wild goose chase. That 6203 is a 17x40x12 bearing and ours is a 6301 12x37x12 bearing. Maybe the auto tensioner? I still need to check this. Got busy last night and didn't make it out to the garage.
Remember: I burned out the bearings in my original twin bearing resin idler pulley and auto tensioner in less miles than I generally see in an oil change interval. I'm sure part of this was sideloading due to the belt misalignment, but I'm sure the quality of the bearings was a big part as well. I'd gladly spend $100 with Boca on some decent bearings to prevent that from happening again, rather than spend another $100 for more shitty bearings from KW.
AND the TrackDog Racing has been using these with their updated JRSC/MP45/MP62 Belt Tensioner for quite some time with very very few complaints. The PD blower boys pretty frequently use the 150mm overlay as well. I think Miata GT hit the nail on the head with that one.
Last edited by EO2K; 11-27-2012 at 03:21 PM.
#156
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Good research. I think the side, thrust loads are entirely to blame. These bearings are designed for a thrust loading of zero. If an idler pulley is having to serve a dual purpose as a belt centering device then something else is completely hosed. As we have realized.
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LOL! 6203 is the idler ![Bang](https://www.miataturbo.net/images/smilies/bang.gif)
![](https://www.miataturbo.net/attachments/supercharger-discussion-38/60839-eo2k-contemplates-universe-his-rotrex-why-they-both-fail-eo2k-15208-albums-eo2k-rotrex-stuff-563-picture-imag0154-2905.jpg?dateline=1354083250)
The savvy among you will also note this is an NTN 6203LU bearing. Its greased rated to 18,000 RPM. Who wants to calculate the bearing RPM for me? There is too much blood in my alcohol system right now for math to work properly.
The pulley is marked DAYCO & 00039, but apparently that is lies because 00039 is not a valid part number. Somehow it magically translates to:
![](https://www.miataturbo.net/attachments/supercharger-discussion-38/60840-eo2k-contemplates-universe-his-rotrex-why-they-both-fail-eo2k-15208-albums-eo2k-rotrex-stuff-563-picture-dayco-89003-2910.jpg?dateline=1354083250)
...DAYCO 89003. Dimensions on the manufactures website back this up, mostly. There is no listing for a 00039, so dimensionally the 89003 is a match if you look at the width between the flanges rather than the width of the pulley. That's my story and I'm sticking to it. My experience with these polymer jobs indicates that attempting to press the bearing out usually destroys the pulley. I need to see if Gates or one of the other manufacturers has an equivalent part with a better bearing, otherwise this may be as good as it gets. These are $13 on Amazon so its probably worth it to toss a couple in the "track spares" box for "just in case."
Here is the auto tensioner:
![](https://www.miataturbo.net/attachments/supercharger-discussion-38/60845-eo2k-contemplates-universe-his-rotrex-why-they-both-fail-eo2k-15208-albums-eo2k-rotrex-stuff-563-picture-imag0155-2906.jpg?dateline=1354083250)
Here are the interchange numbers:
016-029 - Tensioner, Belt, $50.00 @ KW
AKA: Dayco 89325, $31 @ Amazon (throw away pulley that comes with this tensioner)
016-387 - Pulley, Flanged, Smooth, 76mm, $36.75 @ KW
AKA: Dayco 89003 $13 @ Amazon
016-429 - Shim, Ring, 18x25x.5mm, $0.59ea @ KW
These are shims... lol I didn't look them up. They go together like this:
![](https://www.miataturbo.net/attachments/supercharger-discussion-38/60846-eo2k-contemplates-universe-his-rotrex-why-they-both-fail-eo2k-15208-albums-eo2k-rotrex-stuff-563-picture-imag0156-2907.jpg?dateline=1354083250)
Tensioner at the bottom, then washer, then shims. The thickness of this shim/washer stack is 4.46mm or 0.1755". My original auto tensioner came with 3 shims, the replacement unit came with 4.![Dunno](https://www.miataturbo.net/images/smilies/dunno.gif)
Then the pulley:
![](https://www.miataturbo.net/attachments/supercharger-discussion-38/60847-eo2k-contemplates-universe-his-rotrex-why-they-both-fail-eo2k-15208-albums-eo2k-rotrex-stuff-563-picture-imag0157-2908.jpg?dateline=1354083250)
Because of the thickness of the stack, that leaves 2.65mm or 0.105" of "nipple" to support the bearing! The rest is left open
Then the bolt:
![](https://www.miataturbo.net/attachments/supercharger-discussion-38/60848-eo2k-contemplates-universe-his-rotrex-why-they-both-fail-eo2k-15208-albums-eo2k-rotrex-stuff-563-picture-imag0158-2909.jpg?dateline=1354083250)
That's a HUGE amount of unsupported space under the bearing.![](https://www.miataturbo.net/images/smilies/eek.gif)
I'm not going to waste a lot of time trying to find an interchage for the $31.50 "016-475 - Pulley, Tensioner, 2.2in, 37mm," AKA "fixed idler" because I think the timing belt idler is probably going to end up being superior unless you upgrade the KW unit with a $40-50+ bearing. Now your up to $80+
Check this out:
![](https://www.miataturbo.net/attachments/supercharger-discussion-38/60849-eo2k-contemplates-universe-his-rotrex-why-they-both-fail-eo2k-15208-albums-eo2k-rotrex-stuff-563-picture-imag0153-2904.jpg?dateline=1354083250)
You can see where the auto tensioner is already skooging its grease out. I'm not sure I like this.
I need to do some more reading on S2ki and S2000 and see if I can find alternate parts for the auto tensioner and the auto tensioner pulley. I'm about 80% sure KW just reused all the parts in different configurations with their kits. If the honda boys solved the high RPM bearing issues already, and the parts are interchangeable, I see no reason to reinvent the wheel.
I'm glad that I'm finally getting some of this sorted out, but disappointed that I have to do so.
I somehow missed this earlier. New bracket? Do tell!
![Bang](https://www.miataturbo.net/images/smilies/bang.gif)
![](https://www.miataturbo.net/attachments/supercharger-discussion-38/60839-eo2k-contemplates-universe-his-rotrex-why-they-both-fail-eo2k-15208-albums-eo2k-rotrex-stuff-563-picture-imag0154-2905.jpg?dateline=1354083250)
The savvy among you will also note this is an NTN 6203LU bearing. Its greased rated to 18,000 RPM. Who wants to calculate the bearing RPM for me? There is too much blood in my alcohol system right now for math to work properly.
The pulley is marked DAYCO & 00039, but apparently that is lies because 00039 is not a valid part number. Somehow it magically translates to:
![](https://www.miataturbo.net/attachments/supercharger-discussion-38/60840-eo2k-contemplates-universe-his-rotrex-why-they-both-fail-eo2k-15208-albums-eo2k-rotrex-stuff-563-picture-dayco-89003-2910.jpg?dateline=1354083250)
...DAYCO 89003. Dimensions on the manufactures website back this up, mostly. There is no listing for a 00039, so dimensionally the 89003 is a match if you look at the width between the flanges rather than the width of the pulley. That's my story and I'm sticking to it. My experience with these polymer jobs indicates that attempting to press the bearing out usually destroys the pulley. I need to see if Gates or one of the other manufacturers has an equivalent part with a better bearing, otherwise this may be as good as it gets. These are $13 on Amazon so its probably worth it to toss a couple in the "track spares" box for "just in case."
Here is the auto tensioner:
![](https://www.miataturbo.net/attachments/supercharger-discussion-38/60845-eo2k-contemplates-universe-his-rotrex-why-they-both-fail-eo2k-15208-albums-eo2k-rotrex-stuff-563-picture-imag0155-2906.jpg?dateline=1354083250)
Here are the interchange numbers:
016-029 - Tensioner, Belt, $50.00 @ KW
AKA: Dayco 89325, $31 @ Amazon (throw away pulley that comes with this tensioner)
016-387 - Pulley, Flanged, Smooth, 76mm, $36.75 @ KW
AKA: Dayco 89003 $13 @ Amazon
016-429 - Shim, Ring, 18x25x.5mm, $0.59ea @ KW
These are shims... lol I didn't look them up. They go together like this:
![](https://www.miataturbo.net/attachments/supercharger-discussion-38/60846-eo2k-contemplates-universe-his-rotrex-why-they-both-fail-eo2k-15208-albums-eo2k-rotrex-stuff-563-picture-imag0156-2907.jpg?dateline=1354083250)
Tensioner at the bottom, then washer, then shims. The thickness of this shim/washer stack is 4.46mm or 0.1755". My original auto tensioner came with 3 shims, the replacement unit came with 4.
![Dunno](https://www.miataturbo.net/images/smilies/dunno.gif)
Then the pulley:
![](https://www.miataturbo.net/attachments/supercharger-discussion-38/60847-eo2k-contemplates-universe-his-rotrex-why-they-both-fail-eo2k-15208-albums-eo2k-rotrex-stuff-563-picture-imag0157-2908.jpg?dateline=1354083250)
Because of the thickness of the stack, that leaves 2.65mm or 0.105" of "nipple" to support the bearing! The rest is left open
Then the bolt:
![](https://www.miataturbo.net/attachments/supercharger-discussion-38/60848-eo2k-contemplates-universe-his-rotrex-why-they-both-fail-eo2k-15208-albums-eo2k-rotrex-stuff-563-picture-imag0158-2909.jpg?dateline=1354083250)
That's a HUGE amount of unsupported space under the bearing.
![](https://www.miataturbo.net/images/smilies/eek.gif)
I'm not going to waste a lot of time trying to find an interchage for the $31.50 "016-475 - Pulley, Tensioner, 2.2in, 37mm," AKA "fixed idler" because I think the timing belt idler is probably going to end up being superior unless you upgrade the KW unit with a $40-50+ bearing. Now your up to $80+
Check this out:
![](https://www.miataturbo.net/attachments/supercharger-discussion-38/60849-eo2k-contemplates-universe-his-rotrex-why-they-both-fail-eo2k-15208-albums-eo2k-rotrex-stuff-563-picture-imag0153-2904.jpg?dateline=1354083250)
You can see where the auto tensioner is already skooging its grease out. I'm not sure I like this.
I need to do some more reading on S2ki and S2000 and see if I can find alternate parts for the auto tensioner and the auto tensioner pulley. I'm about 80% sure KW just reused all the parts in different configurations with their kits. If the honda boys solved the high RPM bearing issues already, and the parts are interchangeable, I see no reason to reinvent the wheel.
I'm glad that I'm finally getting some of this sorted out, but disappointed that I have to do so.
I somehow missed this earlier. New bracket? Do tell!
#158
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Sunnovabitch!
Car died while I was out getting lunch. I went around a corner and... nothing.
It cranks but nothing happens. I can't hear the fuel pump kick on when I crank, so that's most likely the culpret. I walked the mile home and grabbed my fuel line disconnect tool and had our part time intern pick me up and drive me back to the car on his way in. I disconnected the fuel at the hardline under the hood and cranked while he watched. He didn't get soaked in tasty CA91 so its either the pump or the relay.
I'll get a ride home from the girlfriend, build a jumper and see if I can bypass the realy. I SHOULD be able to jump the white/blue and red/blue in the relay harness and get fuel, right? I'll probably post this in "General Miata Chat" and see if I get an answer. Its far more frequently visited than the Thuperchurger section.
Car died while I was out getting lunch. I went around a corner and... nothing.
It cranks but nothing happens. I can't hear the fuel pump kick on when I crank, so that's most likely the culpret. I walked the mile home and grabbed my fuel line disconnect tool and had our part time intern pick me up and drive me back to the car on his way in. I disconnected the fuel at the hardline under the hood and cranked while he watched. He didn't get soaked in tasty CA91 so its either the pump or the relay.
I'll get a ride home from the girlfriend, build a jumper and see if I can bypass the realy. I SHOULD be able to jump the white/blue and red/blue in the relay harness and get fuel, right? I'll probably post this in "General Miata Chat" and see if I get an answer. Its far more frequently visited than the Thuperchurger section.
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Dude, the gremilins have been after you this year.
Nothing to tell, really. Rather than send my bracket in, I bought the new revised one. Along with a new autotensioner, idler, etc. Basically all of the mounting hardware.
I somehow missed this earlier. New bracket? Do tell!
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I know. It should be fun driving my gas guzzling 2wd 1973 F-250 again while we are just starting in on the first big storm of the season. Drum breaks FTW! Thank god I put decent tires on it last year.