Nothing to see here, just project Sisyphus, move along
03-04-2015, 12:46 AM
#904
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Oh yeah, its cake. I just hate dumping trans lube for something silly like this.
Also, I feel like I ordered the wrong gear. Something tells me this one will work for an NA mechanical sender and not an NB electronic one. Oh well, it was $14.
Also, I feel like I ordered the wrong gear. Something tells me this one will work for an NA mechanical sender and not an NB electronic one. Oh well, it was $14.
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03-04-2015, 02:49 AM
#905
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Yes, $14 is the NA mechanical gear, the electronic VSS for the NB is more like $120. Alternately, you can use an Arduino and a bit of code to convert the 3.9 or whatever sender signal you have now into a 3.6 one.
--Ian
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03-04-2015, 11:26 AM
#907
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Yeah, I think I'm just boned if I want the correct VSS. I'll probably post up a WTB and see if one of the euro or aussie bros will sell me one. The NA drive one will probably end up in the classifieds shortly.
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03-04-2015, 11:39 AM
#908
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I'm in for a challenge. It's going to an MS3 right? Can it live with a square wave instead of the variable reluctance signal?
Should be a pretty simple circuit (I hope). We'll add this with the to the traction control circuit.
Should be a pretty simple circuit (I hope). We'll add this with the to the traction control circuit.
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03-04-2015, 11:48 AM
#910
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Its this madness:
Unless Reverant advises me otherwise, I'm probably going to use one of these for the front wheel sensor input when I get around to implementing traction control:
Dual VR Conditioner Board V2.1
Its cheap, easy and tiny
I thought it was worth bumping this thread to post a follow up.
I was curious about the Vehicle Speed Sensor [VSS] output and the speedometer speed output so I put the car on the lift and attached an oscilloscope to the back of the instrument cluster.
I attached CH1 to the output for the VSS, which are pins 2M and 1M.
I attached CH2 to the output of the cluster speedo signal, which is 2L and used the cluster ground 3J.
Here's what I saw:
10mph
20mph
As you can see, the VSS on CH1 is a variable reluctance [VR] sensor that outputs an ugly 0-centered sawtooth-esque signal. Both the frequency and amplitude of the signal depends on the speed, as is common with a VR sensor. I wouldn't feed this into anything expecting a logic-level signal without something like a MAX9924 in front of it. At high speeds I'd bet it would output north of +50V/-50V.
However, the speed output signal is a nice 5V square wave at half the frequency of the VSS, perfect for triggering just about anything.
Another question I had was the confusion between how many pulses per mile various sensors output and the PCM expected. Online it was reported at both 8000 and 4000 pulses per mile, but people were confusing the various signals and outputs.
At ~10mph, the frequency of the speed output signal is 9.76Hz. This gives 3513 pulses/mile. I suspect its actually closer to 4000 pulses/mile but the low end of the speedo is poorly scaled.
At ~20mph, the frequency of the speed output signal is 22.32Hz. This comes out to 4014 pulses, per mile, so exactly what I had expected.
Since this is half the frequency of the VSS, the instrument cluster expects the VSS output to be 8000 pulses/mile. The VSS goes directly to the cluster and no other components interact with it.
The instrument cluster modifies the dirty VSS signal and outputs a square wave at 4000 pulses/mile that the PCM, Cruise control module, and Bose head unit can read.
Hope this helps someone else!
I was curious about the Vehicle Speed Sensor [VSS] output and the speedometer speed output so I put the car on the lift and attached an oscilloscope to the back of the instrument cluster.
I attached CH1 to the output for the VSS, which are pins 2M and 1M.
I attached CH2 to the output of the cluster speedo signal, which is 2L and used the cluster ground 3J.
Here's what I saw:
10mph
20mph
As you can see, the VSS on CH1 is a variable reluctance [VR] sensor that outputs an ugly 0-centered sawtooth-esque signal. Both the frequency and amplitude of the signal depends on the speed, as is common with a VR sensor. I wouldn't feed this into anything expecting a logic-level signal without something like a MAX9924 in front of it. At high speeds I'd bet it would output north of +50V/-50V.
However, the speed output signal is a nice 5V square wave at half the frequency of the VSS, perfect for triggering just about anything.
Another question I had was the confusion between how many pulses per mile various sensors output and the PCM expected. Online it was reported at both 8000 and 4000 pulses per mile, but people were confusing the various signals and outputs.
At ~10mph, the frequency of the speed output signal is 9.76Hz. This gives 3513 pulses/mile. I suspect its actually closer to 4000 pulses/mile but the low end of the speedo is poorly scaled.
At ~20mph, the frequency of the speed output signal is 22.32Hz. This comes out to 4014 pulses, per mile, so exactly what I had expected.
Since this is half the frequency of the VSS, the instrument cluster expects the VSS output to be 8000 pulses/mile. The VSS goes directly to the cluster and no other components interact with it.
The instrument cluster modifies the dirty VSS signal and outputs a square wave at 4000 pulses/mile that the PCM, Cruise control module, and Bose head unit can read.
Hope this helps someone else!
Dual VR Conditioner Board V2.1
Its cheap, easy and tiny
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03-04-2015, 11:55 AM
#911
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Ahh, someone already built it, thank you. Wish those VSS sensors weren't so damn expensive, I really want one to run the speed signal to the data system, the existing is sketchy, although it's stopped flaking out when I step on the gas.
And yes, I think you can install without dumping the gearbox oil. Even filled I don't know that the fluid line is up as high as the sender. Even if it is, you have to lift the passengers side to get to it, which should make that the highest point and leak free(ish).
And yes, I think you can install without dumping the gearbox oil. Even filled I don't know that the fluid line is up as high as the sender. Even if it is, you have to lift the passengers side to get to it, which should make that the highest point and leak free(ish).
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03-04-2015, 12:04 PM
#912
Maybe I'm late to the conversation but why not use a hall sensor on your wheel hub and calibrate the MS3 accordingly? I used to sell the Haltech red sensor to this company building these little GSXR powered race cars a couple of years back. In fact I'm now using one as my crank position sensor.
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03-04-2015, 12:41 PM
#913
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Because I'm not smart? 
Can we build some sort of electronic trickery to make the speedometer read correctly? Probably, but what happens when it stops working and I'm 240 miles from home at Thunderhill? (Yes, I know speedo is not critical)
Can I use some other sensors for crank and cam signal pickup? Sure, but now I have to mod my wiring harness to supply them power or make them work or whatever. More points of failure and more permanent modification.
Could I have built an MS? Yes, probably but I chose to buy one from Rev because his units just work and I won't have to pull out what's left of my hair trying to troubleshoot the damn thing.
Could I have built my own motor? I believe I could have done it, but I decided to pay someone for expertise so I have a better chance of not ruining a grand worth of forged hardware.
Could I conceivably build my own manifolds? They would look worse than Leafys but yes, I could probably do it but ARTech makes pretty things so I paid him.
The more custom your setup becomes, the fewer people can help you troubleshoot it. I learned an incredibly valuable lesson when my ignition system went out at Thunderhill back in 2012 and I had to spend 5 hours in a AAA flatbed with an insane tow truck driver on the way home. Whenever possible, I prefer to use as many stock things as possible because stock things tend to just work. Then when they don't work its much easier to roll into a FLAPS and get (or order) another CPK rather than try to go hunt down some obscure sensor. I could also conceivably bum one off a local so I could get home. This is why I hoard stock parts and only modify things that are modular or easily swappable/replaceable.
My car also has to be able to be returned to stock when the time comes. I don't think you guys who live in other areas realize how much of a restriction this actually is. As it sits currently, I can put my car back to stock in a matter of hours. Once the built motor goes it, its more like a weekend but it can still be done. I need as few permanent modification as possible.
Can we build some sort of electronic trickery to make the speedometer read correctly? Probably, but what happens when it stops working and I'm 240 miles from home at Thunderhill? (Yes, I know speedo is not critical)
Can I use some other sensors for crank and cam signal pickup? Sure, but now I have to mod my wiring harness to supply them power or make them work or whatever. More points of failure and more permanent modification.
Could I have built an MS? Yes, probably but I chose to buy one from Rev because his units just work and I won't have to pull out what's left of my hair trying to troubleshoot the damn thing.
Could I have built my own motor? I believe I could have done it, but I decided to pay someone for expertise so I have a better chance of not ruining a grand worth of forged hardware.
Could I conceivably build my own manifolds? They would look worse than Leafys but yes, I could probably do it but ARTech makes pretty things so I paid him.
The more custom your setup becomes, the fewer people can help you troubleshoot it. I learned an incredibly valuable lesson when my ignition system went out at Thunderhill back in 2012 and I had to spend 5 hours in a AAA flatbed with an insane tow truck driver on the way home. Whenever possible, I prefer to use as many stock things as possible because stock things tend to just work. Then when they don't work its much easier to roll into a FLAPS and get (or order) another CPK rather than try to go hunt down some obscure sensor. I could also conceivably bum one off a local so I could get home. This is why I hoard stock parts and only modify things that are modular or easily swappable/replaceable.
My car also has to be able to be returned to stock when the time comes. I don't think you guys who live in other areas realize how much of a restriction this actually is. As it sits currently, I can put my car back to stock in a matter of hours. Once the built motor goes it, its more like a weekend but it can still be done. I need as few permanent modification as possible.
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03-04-2015, 01:32 PM
#915
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Actually, I went a little insane with that response, please to be forgiving 
For the front wheel speed, I've got an NB ABS hub, sensor and complete spindle assembly that will be going in the car. We have a lot of guys who can fabricate things on this board so going custom is a pretty common solution, but its not something I want to deal with. The stock ABS parts fit because they are designed to fit so I don't have to reinvent the wheel or fabricate a bunch of insanity. The little JBPerf board will take the signal from the stock ABS sensor and turn it into something (0-5v square) the MS3 can read. Its already been implemented by a bunch of folks so the hard part is done. Easy peasy!
Nothing I'm doing is new or unique. My entire build is just taking things I've seen other people do and reconbobulating them in a way that I like
For the front wheel speed, I've got an NB ABS hub, sensor and complete spindle assembly that will be going in the car. We have a lot of guys who can fabricate things on this board so going custom is a pretty common solution, but its not something I want to deal with. The stock ABS parts fit because they are designed to fit so I don't have to reinvent the wheel or fabricate a bunch of insanity. The little JBPerf board will take the signal from the stock ABS sensor and turn it into something (0-5v square) the MS3 can read. Its already been implemented by a bunch of folks so the hard part is done. Easy peasy!
Nothing I'm doing is new or unique. My entire build is just taking things I've seen other people do and reconbobulating them in a way that I like
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03-04-2015, 06:01 PM
#916
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Can you just use any universal speedo modifier. Doesn't scenturion have one he uses for his JDM clusters. For VSS just adjust the pulses per mile accordingly.
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03-04-2015, 10:07 PM
#918
Not so white here now , was able to get out and experience some boost again this afternoon . Keep forgetting how fast the Miata is , especially when it's only +4*c . And your welecome , I'll get that shipped out this weekend. My wife wishes I'd clean out some of my other precious spare.....
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03-09-2015, 01:19 AM
#919
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Thanks Fred! I've recently started clearing out LOTS of stuff I'm not using so I feel you there. It kinda gets to be fun after a bit. Also, the tracking number hasn't gone live yet, but Ill check back on it in the AM.
On a related note, the diff is IN! Zero drama with removal or installation and now its bathed in SVG 75W-90. I'd imagine my 4.1 torsen will eventually find a home in the Exocet. Something I didn't notice until Gesso pointed it out was how much beefier the 3.63 pinion is when compared to the 4.1 pinion, and how thin the 3.63 ring is compared to the 4.1 ring. I mean, it makes perfect sense but I wasn't expecting it to be so dramatic. Also, you wouldn't necessarily expect it but dropping 370+RPM from 65+MPH cruise really makes a difference in interior noise. We'll see what kind of effect it has on gas mileage here in the future.
The 3.63 was definitely an all around good decision
On a related note, the diff is IN! Zero drama with removal or installation and now its bathed in SVG 75W-90. I'd imagine my 4.1 torsen will eventually find a home in the Exocet. Something I didn't notice until Gesso pointed it out was how much beefier the 3.63 pinion is when compared to the 4.1 pinion, and how thin the 3.63 ring is compared to the 4.1 ring. I mean, it makes perfect sense but I wasn't expecting it to be so dramatic. Also, you wouldn't necessarily expect it but dropping 370+RPM from 65+MPH cruise really makes a difference in interior noise. We'll see what kind of effect it has on gas mileage here in the future.
The 3.63 was definitely an all around good decision
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