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  • Originally posted by gills View Post
    Weird. Pretty sure the M-Factory LSD's are basically copies of the RS. 10 clutch plates per side, coil spring preloading, etc. The washers seem to be there to provide a buffer between the case and the end clutch plates.

    You get a chance to work on your ABS yet?
    Planning to address the ABS this weekend along with a few other things.
    SM 63 KA-t 470hp 480tq G30-660 A2W IC

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    • Sorry there haven’t been any updates. Will post soon.

      Cliffs notes, the abs system is excellent. Blew the engine back at the New Jersey race. Rebuilt for summit point raceway double 9 hour happening now.

      Tune in to a live broadcast: https://www.youtube.com/watch?v=Yvz24SfN7OA

      And our live in-car stream: https://youtu.be/_S1qf9_aC2A
      Core4 Motorsports
      CLICK HERE for Wilwood FSL6R Radial Bracket & Rear Wilwood BBK GROUP BUY
      S14 VQ AER Endurance Racing Team

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      • gills Did you ever contact MFactory about the damage to the 1.5 ramps? Seems like a pretty big design flaw to have that much damage so soon, unless there was some other issue?

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        • Originally posted by ScottSmith View Post
          gills Did you ever contact MFactory about the damage to the 1.5 ramps? Seems like a pretty big design flaw to have that much damage so soon, unless there was some other issue?
          ScottSmith I did and I have never received a response. http://www.synchrotech-transmissions.com/ is who deals with US customer service and distribution. Overall they were pretty good answering my questions, but they had nothing for my findings with the cross-shaft needing to be flipped depending on ramps. It's pretty obvious that is what needs to be done.

          As for other issues, other than likely running the diff for extended time at high fluid temp, no.

          Are you running an M-Factory?
          Core4 Motorsports
          CLICK HERE for Wilwood FSL6R Radial Bracket & Rear Wilwood BBK GROUP BUY
          S14 VQ AER Endurance Racing Team

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          • I'm considering it. It's hard to find many reviews of the metal plate diff; most users of the helical seem happy enough, but they also seem to be in street only applications.
            I really wanted to get the V2 metal plate diff (AFAICT a copy of the Cusco Pro-Adjust RS), but I haven't been able to get any reliable information from either Synchrotech or the MFactory site itself about it. I had a support thread that just kept going back and forth without any real answers (like does it come with all the ramps, or do I buy them separately? If so, how much do they cost? etc).

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            • Also - I wonder if you'd get the right stack height by removing a single clutch from one side. Since you're reducing the lock rate to 60-80%, you could remove a clutch that is adjacent to the same type of clutch without changing lockup; they are only put back in to keep the stack the same size. I know you tried removing end washers but that was too much of a change. I guess it comes down to how much of a change is required and how much slack the preload springs can make up for.

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              • ScottSmith overall the M-Factory provides an excellent value. The go-to BMW racing diff builder in the US (www.diffsonline.com) offers the M-Factory as an option when building a diff (edit: they no longer do!).

                It seems that anything outside of Honda applications, Sychrotech is just winging it. Does M-Factory make their V2 for the Nissan housings yet? Doesn't seem like it looking at M-Factory's website.
                Originally posted by M-Factory
                2nd Generation Design (Application Dependant)
                Through the accumulation of over 8 years of ongoing research and statistical analysis, we are proud to introduce our new v2 Metal Plate LSD applications for BMW (20-Plate) and Honda (16-Plate). A commonly known issue with Plate type LSD's is the associated NVH (noise, vibration, harshness) during low speed manoeuvres, especially noticeable on a daily driver. With the new MFactory v2 Metal Plate LSD, which uses our new 2nd Generation Active Friction™ Type-SS Plates (originally developed for our competition Touring Cars), NVH is reduced by as much as 50%

                If it's just NVH related difference, you could always send all the diff pieces out for REM/WPC treatment which allegedly helps a bunch on that front.


                Their helical is definitely intriguing though. I'm pretty sure the bias ratio on them is more aggressive than your typical OEM unit. You should try to get that info from them. I think I did, I just don't remember.

                And that's a good idea on just removing a single clutch. I will try that next time it's out. Long term I'd like to just order extra end washers and grind them down to achieve the right stack height. But, I still have that messed up 1.5 decel ramp surface on the pressure plates. New pressure plates are almost half the price of the diff itself!

                I've been running it in 1.0 way and at the Summit Point race last September I ended up buying a spare diff with a 2 way Kaaz in it from a fellow NRR member (sleepysteve) that came to spectate. The bearings in the M-factory one took a shit at that race and luckily he was willing to part with his diff that he had to remove from his car 1.5 hours away. Anyway, we started running a diff cooler after that. Here's what pitted/failing pinion bearings sound like FYI: https://youtu.be/_S1qf9_aC2A?t=25159

                The Kaaz is only able to run in 2.0 way, but I rearranged the discs to 60-80% mode. Other than the fact that it had the stock 4.083 final in it, the Kaaz performed admirably well for that 9 hour race until the VQ snapped a cam shaft with 15 minutes left!

                Core4 Motorsports
                CLICK HERE for Wilwood FSL6R Radial Bracket & Rear Wilwood BBK GROUP BUY
                S14 VQ AER Endurance Racing Team

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                • Funny you mention BMW diffs, I'm actually using this for a BMW application. I'm only posting here because of what you found out about the MFactory diff. The other indepth review I found on an MFactory Metal Plate diff is clearly sponsored by MFactory/Synchrotech and therefore a bit more biased.
                  New "Ramp Chip" Design for BMW v2 Metal Plate LSD fitments, allowing fully self-adjustable ramp angle customisation
                  I was attracted to the MFactory/Cusco RS setup for ease of adjusting preload and lockup, and potentially for V2 the ability to change ramp angles. Too bad Cusco doesn't have a Pro Adjust for BMW uses.

                  Since this is for road course use, I'm not considering a helical. I used to run a Quaife in my previous RWD car and had issues when I'd lift a wheel. On some forum somewhere (I've been googling this way more than I should) I saw it claimed that MFactory had a 75% bias vs 66% for Quaife, Wavetrac, etc.

                  I thought Kaaz only had 3 pairs of discs per side, so could only be adjusted to 33%, 66%, or 100%? Maybe that's application dependent.
                  Did you find the Kaaz 2.0 to have too much understeer on turn in? It seems odd to me that off throttle engine drag would have that much effect on diff lockup, given how much lower overrun torque is compared to power on torque, but since they sell 1.0, 1.5, and 2.0 diffs it must matter. Even more strange that it matters when braking, since in some of those instances you're actually slowing down the engine with the brakes, thus putting you on the accel ramps!

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                  • FYI Just got off the phone with Cusco USA. Figure I'd share the info in case it's useful:
                    1. The Pro Adjust diff is more finicky than a regular RS diff. The problem is the ramp inserts move a bit - my interpretation is maybe they get banged up a bit. He said it's good for finding what ramps you want.
                    2. He thinks the best setup is 100% lockup but low preload. Also they do custom ramp angles and he suggested an even lower angle than the standard. I'm guessing all that goes together - with slower ramps you can have more lockup since it takes longer to get there. Maybe it gives you more control under throttle?
                    3. He recommends 1.5, not 2.0, "unless you come from Formula Mazda" and are used to a 2.0. He says even with that, the 1.5 is faster.

                    Also I looked up Nissan S14 applications, and it does look like Kaaz has different # discs depending on the application.

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                    • ScottSmith Nice! what chassis BMW and what are you prepping for?

                      I can confirm the the M-factory/RS style diff is definitely easy to setup and mess around with. The preload coil springs make it especially easy to manipulate breakaway torque/preload. Also, even with the many, many hours of racing on my M-Factory, the clutch discs have barely worn (maybe a few thou?). I have yet to replace them.

                      The Pro-Adjust diff is definitely enticing. Sometimes having more options for tuning stuff becomes more of detriment though, especially if you you're solo. Also, ramp angles between manufacturers can sometimes use the opposite reference which can confuse things if you're cross shopping/comparing.

                      I don't recall the number of discs on the Kaaz because I was changing everything on the ground at 1:30am in a stupor. It was definitely 2.0 and the clutch discs themselves were a good deal larger diameter than the M-Factory clutch discs, which is what I remember most. It also uses Belleville springs for preload. All these diffs come from the factory with "100%" lock and high preload and it sucks based on my experience with the M-Factory setup like that so I was destined to change it.

                      The 2.0 Kaaz for the race actually worked very well at Summit Point. There wasn't too much understeer, but it was a bit more than the 1.0 way setup of the M-Factory the day before. Not sure if you're familiar with Summit Point, but the Kaaz felt better through turns 5, 6, and 7 because it required less throttle input to rotate the car at the slower speed. BUT, that was with a shorter final drive also (4.1 vs 3.9).

                      And FWIW, I believe OEM BMW M diffs are actually 2.0 way from the factory. They obviously aren't that aggressive since they don't have many active surfaces and are likely low preload.

                      So, it's funny that Cusco recommends 100% and low preload. The issue with diffs and stated lock % is that everything is very co-dependent. The more active surfaces/clutch discs you have in a diff the shallower the angle acts so it's tough to compare diffs with different numbers of clutch discs and ramp angles. Diffsonline mantra to a properly setup diff is to have it lock the least amount necessary to get the car through the turns smoothly. He would never recommend a true 100% lockup based on my conversations with him.


                      I'm fairly familiar with BMW stuff since I'm surrounded by them in what I race in and my team owns a few (E30, E36, E92 M3). I may as well shamelessly plug that I also offer a BMW wheel stud solution using press-in wheel studs using modified OEM hubs instead of the BMW standard screw-in stud. The screw-in wheel studs are notorious for failing prematurely on BMW cars, especially in endurance racing.

                      Check out my gallery of broken studs: https://www.core4motorsports.com/gal...mw-wheel-studs


                      Core4 Motorsports
                      CLICK HERE for Wilwood FSL6R Radial Bracket & Rear Wilwood BBK GROUP BUY
                      S14 VQ AER Endurance Racing Team

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                      • Built an E46 for NASA ST4. Yes I believe you are right that stock E36 M3 diffs are 45/45 degree ramps with relatively low lockup.

                        I hear you on having too many variables. Especially because while it's easy enough to change the diff once you get it out, it's still a pain to remove the diff, open it up, etc. The E46 non-M diff uses 90mm circlips to hold the bearings in, and you can only access them by destroying the shaft seals, so opening the diff up isn't free.

                        The ramp angle thing seems to be a Japanese vs German thing - ZF, Drexler, etc seem to rate the decel end of a 1.0 as 90 degrees, while Cusco, Kaaz, and MFactory (not Japanese but a clone of Cusco as you say) have the decel end of 1.0 as 0 degrees. And yes, the gripiness of the clutches (along with how many surfaces) affects what a ramp angle really means.

                        Interesting that Diffsonline wouldn't recommend 100% lockup; I thought their most popular diff was a 4-plate. In their world there is no deactivating clutches, you would just order a 2-plate or 3-plate instead of a 4-plate diff.

                        As for high vs low lockup.... well I guess that's why I want an adjustable diff. One thought was to go as weak as possible and then measure wheel slip on track, then go back and add clutch surfaces and repeat.

                        And yes I've sheared wheel studs several times, though recently I've been fine replacing them once a year despite running the 25 Hours of Thunderhill, 3-4 3 hour endurance races, and a season of sprint racing. Your service looks pretty affordable though (as long as I send in my hubs ;-). I'll consider that next time I replace wheel bearings!

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                        • ScottSmith Exactly right on the diff tuning. Pulling the diff to mess with settings gets old real quick unless you have a fancy quick change. Luckily on R200 Nissan diffs there's nothing sacrificial.

                          I think what Diffsonline meant by 100% lock up is basically having a spool, not necessarily a 100% clutch disc configuration. Like we mentioned, how many discs/active surfaces you have with ramp angles determines what the actual dynamic lock % will be. A diff with 10 discs and steeper ramps will give higher dynamic lock % than one with 4 discs and shallower ramps, all discs being active.

                          And if you have time for datalogging, go for it! That would be a fun experiment.


                          Have you ever lost a wheel from losing studs or just noticing missing ones in the paddock? If you have any pictures of busted studs that you can share with me that would be great as well. As you can probably tell, I'm not working with huge margins here so I'm glad you think it's affordable

                          There are a few teams that run in the 25HoT that are on our hubs. HQ Autosport, Moorewood/Kontrolle Engineering, and AR Motorsports to name a few that I can remember. HQ Autosport lost a rear wheel in the 2018 race with 15 minutes to go in first place which prompted their move to my hubs. But yea, if you ever want to consider it, just let me know. Two BMW teams at the AER event at Summit Point last weekend broke studs. One of them was on Rogue Engineering's 14mm screw-in studs conversions to boot.
                          Core4 Motorsports
                          CLICK HERE for Wilwood FSL6R Radial Bracket & Rear Wilwood BBK GROUP BUY
                          S14 VQ AER Endurance Racing Team

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                          • I think ZF had a chart indicating % lockup depending on # of discs and ramp angles; I assume Diffsonline is going off that nomenclature.
                            I'm still not convinced I want 100% in the Cusco RS diff I just ordered but I'll give it a shot.

                            I do have data logging. I have wired the wheelspeed outputs of my MK60 ABS so I can record them (and so I can have traction control with my aftermarket ECU). I look forward to analyzing the results when the car gets sideways. Hopefully I can find a cause/effect.

                            No pictures of broken studs. One failure was in the heel of the boot at Watkins Glen. I tried to turn right, my wheel went left and I went straight-ish. That was 17+ years ago. Luckily some local crew was able to fix my car so I didn't waste my trip to the East coast. The rest have been detected before causing car-nage. One happened when I went to torque the wheel. It just kept spinning!

                            Amazing a 14mm stud failed! That's a lot more metal than 12mm. We've run 10+ 25 hours and had one stud failure during the event; I forget the circumstances behind it. Driver came in with a "vibration." Bimmerworld (was racing their E9x M3) helped us repair it by welding random bolts onto the remains of the stud! We didn't lose much time (actually I think we won that year!)

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                            • ScottSmith, if you email or call Diffsonline and ask about what % lockup, you'll see that you'll get a "it depends" answer if you talk to the owner (Dan).


                              Can you go into more detail about what you did to log the MK60 wheelspeed outputs? What about the pressure sensor outputs? Not sure you've saw in this thread, but I've retrofitted MK60 ABS on my S14 so any CANbus related stuff is not available for me, but I would love to get the pressure information. Pretty sure I can just tap into the pressure sensor wires, but the wheel speed sensors are digital and likely can't be tapped into the same way?


                              Too bad you have no in-car video from that Watkins event! Would've been perfect to add to my gallery. The 14mm does add quite a bit more cross-section and clamping force, but they still have the same fundamental stress risers at points of peak stress being a screw-in stud that needs to bottom out on the hub. That's the third incident I know of that's been shared with me of a 14mm failing in less than a years span.

                              What was your team name? And FYI, if a press-in stud ever breaks, all you need is a hammer and a punch to get it out and a basic wheel stud installer tool and lug nut to pull a new one in.

                              Core4 Motorsports
                              CLICK HERE for Wilwood FSL6R Radial Bracket & Rear Wilwood BBK GROUP BUY
                              S14 VQ AER Endurance Racing Team

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                              • El Diablo Motorsports.

                                For pressure sensor, yes you can just tap into the signal wire. I'd put something like a 1k-10k resistor in line just in case the wiring to the data does anything wacky. Don't want to lose ABS over anything stupid. I did design my own circuit that reconditions the circuit for the data acq to account for ground shift between computers; I don't know how important that is in practice though.

                                For wheel speed, the MK60 outputs all four as digital signals so you don't need to tap into the sensors. You need to pull the line up somehow; most data acq and aftermarket ECU have a way of enabling a pull up resistor on digital inputs. The frequency is pretty high if you have a 38 tooth ring; for the Link ECU I use I had to build a frequency divider circuit to reduce it 4x.

                                The wiring diagram for E46 M3 shows two of the wheel speed outputs; I figured out the other two from a friend. p8=RR, p10=RL, p12=FR, p14=FL.

                                I thought about trying to use canbus to get wheelspeeds. The problem is you need to get the ABS talking first. I have a sequence of 4-5 CAN messages that seem to do that, but I don't know what other effect it has on the ABS (does it make assumptions on throttle or RPM?). In the end using digital outputs is easier. Also MK60 doesn't output pressure over CAN - for that I think you need the MK60E5. It also integrates the pressure sensors into the ABS unit itself. Also I've seen some posts from some Porsche racers who mentioned you can send messages to the MK60E5 to tell it your wheel diameters and get different braking characteristics. I'd love to be able to code a different tire traction coefficient to eliminate ice mode.

                                And yes I saw you were doing an MK60 swap in this thread. I'm going to help a friend get wheel speeds in his E36-ti rally car so he can get traction control and we may use the newer MK60-based sensors since they're easier to get a hold of, and he already has an MK60 swap in his E30. I've made a mental note on your comment about orientation of the rear sensors and already told him to look at that. So I've learned two things from you on this thread!

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