underground Posted June 5, 2007 Share Posted June 5, 2007 Hey Guys, Just wanted to make those of you who are using the AEM EMS for the RB's aware that AEM has released a new aftermarket trigger wheel. Many of you who have experienced issues with this box now have a solution. The CAS fix is a new trigger wheel that goes in the existing CAS housing and they are currently available. This will require some modification to the OEM CAS, so you may want to leave this job up to your mechanic. Quote Link to comment Share on other sites More sharing options...
Careless Posted June 6, 2007 Share Posted June 6, 2007 is it a CAS wheel with less than 360 trigger points? like a divisible number of points, say 30 points or so? I think I saw someone post one in a thread here for a different application, as well as one on the SAU or Calais Turbo threads. There was big RB Engine debate on whether it was the stretching of the cam belt that made the CAS wobble and vibrate at high RPM which would cause the small trigger holes on the OEM CAS wheel to be bounced back and forth in varying degrees as the belt expanded and contracted, so some holes would be re-read by the optical sensor. Quote Link to comment Share on other sites More sharing options...
underground Posted June 6, 2007 Author Share Posted June 6, 2007 Yes, way less points is what I overheard. Apparently, I wasn't supposed to post this up, as this wasn't supposed to slip to the public. But oh well, I'm just glad to see this fix out there, as this has been a problem with every aftermarket ECU I know of on the GTR's. It will be annonced in the next 2-3 weeks from my understanding, and will begin shipping with the boxes shortly thereafter. Quote Link to comment Share on other sites More sharing options...
turbo_fb Posted June 6, 2007 Share Posted June 6, 2007 You have any idea if they will release one for the SR20DET engine also? I have a friend that cant get it to run smooth at all. Quote Link to comment Share on other sites More sharing options...
mannyvig Posted June 6, 2007 Share Posted June 6, 2007 How much? Quote Link to comment Share on other sites More sharing options...
underground Posted June 6, 2007 Author Share Posted June 6, 2007 Place a call to AEM, because they didnt have the pricing info yet released when I called yesterday. Quote Link to comment Share on other sites More sharing options...
Booztd 3 Posted June 7, 2007 Share Posted June 7, 2007 If its going to start shipping with the boxes soon, are the guys that have already purchased the boxes eligible for them? Only would seem fair Quote Link to comment Share on other sites More sharing options...
Careless Posted June 7, 2007 Share Posted June 7, 2007 If its going to start shipping with the boxes soon, are the guys that have already purchased the boxes eligible for them? Only would seem fair it's a nissan CAS problem. the stock CAS wheel has 360 optical points along the disc. they are SO small. take the top off your CAS if you can and take a look. there's 6 varying size holes (per cylinder), and 360 other holes. with belt stretch and vibration, it's no wonder why a lot of people are having that problem at higher RPM. If they do sell it with their boxes, i'm sure they'll make an update to the cost if they're selling them for anything over 100 bucks. me... i'll go to my friend to make one. Quote Link to comment Share on other sites More sharing options...
Administrators RTz Posted June 7, 2007 Administrators Share Posted June 7, 2007 the stock CAS wheel has 360 optical points along the disc. they are SO small. Sure are... When I use the Nissan CAS, I don't bother with the 360 slot row... only the 6 slot row (adding a sync hole for number 1). They've been flawless. Quote Link to comment Share on other sites More sharing options...
Careless Posted June 7, 2007 Share Posted June 7, 2007 Sure are... When I use the Nissan CAS, I don't bother with the 360 slot row... only the 6 slot row (adding a sync hole for number 1). They've been flawless. perfect. you can imagine how easy it would be to miss one or two of those holes, or register even upto 370 degrees on one complete revolution depending on how many times it re-counts a point per complete revolution. the computer gets to the next cylinder in line and goes "61 points...? BUAH!?" or something to that effect. Quote Link to comment Share on other sites More sharing options...
underground Posted June 9, 2007 Author Share Posted June 9, 2007 Yes, the price will increase most likely. So no, the previous guys will not be eligible, as this is not an AEM issue. As mentioned, it's a Nissan issue. Quote Link to comment Share on other sites More sharing options...
Administrators BRAAP Posted June 10, 2007 Administrators Share Posted June 10, 2007 Been reading this and wanted to put in my $.02 Please don’t take this wrong way, but I’m not understanding how the Nissan CAS that works perfectly fine for the Nissan ECU and other stand alone EMS’s, yet not so well with this AEM EMS, is a Nissan issue? Nissan has been using that sensor with its EFI on several other Nissan engines for several years with no issues, but the AEM is having troubles reading that Nissan CAS on the RB, (and did I read that right that the SR is also having the same issues with the AEM and the CAS?) Based on just the RB issue alone, then doesn’t this seem more like an AEM issue, not a Nissan issue? If I’m missing or misinterpreting this in any way, please let me know and set the record straight for others that will stumble across this thread. FWIW, Similar Nissan CAS wheels are working flawlessly in at least 2 Datsun Z car applications that I am personally involved in, triggering a comparable EMS firing 6 coils, and those CAS’s are being driven off the L-series oil pump drive shaft at that, not the timing belt, (those 2 cars are being driven today and tomorrow to the Datsun/Nissan show in Canby OR). Something to consider when using the Nissan CAS with any aftermarket EMS. Verify what part of the slot in the trigger wheel that the EMS is triggering from, i.e. the leading edge or the trailing edge of the slot itself, (this would apply to the 6 slots, not the 360). I believe, though I can’t confirm this, the AEM, as well as the other plug and play systems, utilize the 6 holes for the trigger, not the 360. And because the Nissan CAS 6 slots are of varying widths, depending on what part of the slot the ECU is triggering from, i.e. the leading or trailing edge of that slot, that would very well affect the timing for those individual cylinders. One way to verify this is using a timing light on each cylinder and verify that the coils are indeed firing exactly 120 degrees apart from each other. If the leading/trailing edge trigger is the issue and it is not an optional setting within the EMS configurations and set up menus, the Nissan CAS can be disassembled and the chopper wheel itself can be flipped over. Just a thought. Quote Link to comment Share on other sites More sharing options...
510six Posted June 10, 2007 Share Posted June 10, 2007 I can remeber getting flamed when I metioned that a friend had several new 12-1 slot wheels for the Nissan and Mitsubishi CAS for AEM systems to reduce timing errors.It was a huge part of the reason I went with a Modified 12 tooth EDIS wheel and a Ford Cam position sensor.As a result (knock on wood) no timing errors.The friend may have some modified wheels left if anyone is interested PM me. Quote Link to comment Share on other sites More sharing options...
underground Posted June 10, 2007 Author Share Posted June 10, 2007 It's an issue with the Nissan CAS. People using the FCON to AEM to PowerFC have all had issues. It doesn't happen 100% of the time, but it's a documented problem. Feel free to read up on the issue on freshalloy.com The issue comes in at High RPM's, typically over 7000+. I'll try to get Henry @AEM to make a post to explain, or perhaps Sean Morris. It's not common to see problems on stock ECU's, as those owners aren't spinning them up past 7500-8000 RPM. Quote Link to comment Share on other sites More sharing options...
Careless Posted June 10, 2007 Share Posted June 10, 2007 Been reading this and wanted to put in my $.02 Please don’t take this wrong way, but I’m not understanding how the Nissan CAS that works perfectly fine for the Nissan ECU and other stand alone EMS’s, yet not so well with this AEM EMS, is a Nissan issue? Nissan has been using that sensor with its EFI on several other Nissan engines for several years with no issues, but the AEM is having troubles reading that Nissan CAS on the RB, (and did I read that right that the SR is also having the same issues with the AEM and the CAS?) Based on just the RB issue alone, then doesn’t this seem more like an AEM issue, not a Nissan issue? If I’m missing or misinterpreting this in any way, please let me know and set the record straight for others that will stumble across this thread. FWIW, Similar Nissan CAS wheels are working flawlessly in at least 2 Datsun Z car applications that I am personally involved in, triggering a comparable EMS firing 6 coils, and those CAS’s are being driven off the L-series oil pump drive shaft at that, not the timing belt, (those 2 cars are being driven today and tomorrow to the Datsun/Nissan show in Canby OR). it's more of a high-rpm issue, if anything. atleast that's what i've read by ppl on the calais turbo and sau forums, regarding ALL ems systems, not just AEM. Some ROM edited Nissan RB ecu's have modifications to get it to run with a modified wheel aswell. it's a belt stretch issue, and was a proven problem with some data graphing which I cant remember about right now. eliminating the amount of holes makes the CAS rely on less holes to calculate it's timing, so the belt doesnt play as big a role. on whatever graph it was, it became apparent that changing it made immediate improvements in the scattering of high and low points on the line, at high rpm. im not talking small improvements either. i'm talking from huge zig-zags covering about double and half the height of the current grid point within the increase of only 10 rpm. that line smoothed out pretty darn nicely when they changed the wheel over and made modifications to the EMS system's way of handling the whole thing. if i wasnt hung-over, i would start searching for the thread, but maybe Ron can explain it better, or who'sa-what'sis name from wherever he's coming from whenever he gets here. but lets put it this way, if it didnt make a difference, i would have no idea what this thread was about, and i wouldnt have bothered reading the other thread from whatever other forum it was on. But i read it, and i know part of what the problem is and why AEM is releasing it. except i can't really say more than it's a high-rpm belt stretch issue =/ Quote Link to comment Share on other sites More sharing options...
Administrators RTz Posted June 12, 2007 Administrators Share Posted June 12, 2007 maybe Ron can explain it better... First, admittedly this is a bit of conflict in interest, so I'll do my best to keep to the facts. That said, If anyone feels this post inappropriate I'll remove it. Second, and mostly moot... my specialty has been primarily L-series. I use the Nissan CAS exclusively in those applications and have tested to 7500 rpm, with no trigger errors, period. However, as I mentioned previously, I'm opting to read only the 6 slot row. Third, I've only recently been submersed into the RB installations so specific personal experience is limited. For this reason, I contacted Steve Taylor, owner of Wolf3D, to get a broader scope. In short, Wolf's plug-N-play's use both rows, counting how many slots are within each of the 6, to determine where cylinder one is. The implication is that the actual timing is a function of the 6 slot row. I couldn't say if the strategy (including the unspoken strategy) is any different than AEM. However, I have his assurance that Wolf has proven to be consistently reliable to 10,000 RPM, with a properly functioning, untouched CAS. Fourth, 'reading between the lines', he defended AEM to some degree, with the statement that these CAS sensors and their wiring are getting old and the *occasional* issue should not be a surprise. Quote Link to comment Share on other sites More sharing options...
Careless Posted June 20, 2007 Share Posted June 20, 2007 Hey everyone, dont buy it from AEM. it's like 30 bucks here. http://wolfems.cart.net.au/details/106320.html Quote Link to comment Share on other sites More sharing options...
Administrators RTz Posted June 21, 2007 Administrators Share Posted June 21, 2007 Hey everyone, dont buy it from AEM.it's like 30 bucks here. Stirring the pot, eh? I'm not in a position to guess if that count and geometry will work with AEM... maybe someone can confirm/deny. Also, functionally, its the same as the one I posted previously... punching a .100" hole yourself saves $30. The hardest part of this mod is getting the wheel out. If its anything like the Z32 CAS, you have to drill out the tamper resistant screws, press out the bearings to remove the disk, re-tap, and re-assemble.... If you're capable of that, you're capable of punching the requisite hole, me thinks. Quote Link to comment Share on other sites More sharing options...
Careless Posted June 21, 2007 Share Posted June 21, 2007 Stirring the pot, eh? This is from the Twin VL RB30 head swap information page, found on google. Pick an RB25 engine that has a removable rubber grommet in the centre of the crank angle sensor. This denotes a crank angle sensor that can be disassembled to allow replacement of the trigger disk. This feature may be required if you plan to use a programmable ECU. Of course, I picked the wrong bloody engine didn't I, so it cost me another $150 for a crank angle sensor from an RB20 that 'could' be disassembled. Above:This is the unit that can be disassemabled easily. Instead of the collar, there are a couple of screws clamping the disc in place. Use a big hammer to punch out the pin (circled in photo) that holds the drive adaptor onto the shaft, then press the bearing off to gain access to the screws that clamp the rest of the shaft onto the trigger disc. Below: This shows the crank angle sensor that can't be disassembled easily. You can see the collar that was pressed down holding the disc in place - there was a bearing on top of that. There is no easy was of holding the collar or getting leverage under it without damaging the disc or collar. Quote Link to comment Share on other sites More sharing options...
Administrators RTz Posted June 22, 2007 Administrators Share Posted June 22, 2007 From what I can tell, that one is built identically to the Z32 CAS. Quote Link to comment Share on other sites More sharing options...
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