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Old 12-17-2009, 11:25 PM   #1
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Default the thread where Savington asks a lot of really, really dumb questions.

I am putting an AEM 30-1710 EMS into my '94 chassis with a 2002 motor on stock sensors. I have a couple of early CASs laying around if I need them as well.

Let's start with the dumbest of the dumb: MAP sensor input, hooks up to 4F, labeled "Spare MAP", right? Or is that for a spare map?

IAT I think I have figured out, I wired it straight to the ECU connector when I did my rewire in the summer.

VVT and the stock wheel is what I'm most confused about. Where do I feed the signal for the stock trigger wheel into the ECU? Through the OEM CAS connector? I've seen Jason's thread on VVT settings. Can I just use an OEM exhaust-side CAS with the VVT stuff and somehow lock the adjuster in place?

I'm using TurboTim's calibration, rescaled for 750cc injectors, so I think I'm in the ballpark for stuff like idle, etc.

Trying to keep it as simple as possible to start out with - I want to try to lock the VVT at zero advance/retard, and if I have to add a couple of "unnecessary" sensors to make things work that's fine with me.

Goal is to get the car running with zero bells and whistles. Get the new motor broken in, rough the fuel in, win the Miata Challenge championship on Sunday, and then pull the head back out for headwork and ECU bells/whistles.

Jason C, Julien, if either of you have some time to hold a baby spoon for me, I'd be eternally grateful. I wish there were more info on basic stuff here.
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Old 12-18-2009, 12:09 AM   #2
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Yes, 4F is your MAP sensor input. Use the sensor wizard to set the config table for whatever MAP sensor you are using. You don't use the MAF input, pin 2O.

I am no help with setting up the CAS sensors for anything other than the 92 style CAS. You will have to change the tooth counts for the fuel injectors and coils. Are your COPs wired sequentially? I assume not cause of the megasquirt. Using your old style CAS should get your car running, but my map as-is has coils 1-4 fired sequentially (not in that order obviously). If you're batch fire, use the standard config/tooth counts in the default maps, or I can get them for you. My fuel injectors also fire sequentially but your '94 should be wired fine.

My injectors are 440cc @ 54psi static. These COPs don't like battery voltage below 12volts. My red top optima is below that when cranking even though the battery tender has been on it forever. It will crank then backfire bigtime. Jumpstarting it works. Anyway...best of luck. I'll help whenever I can.

Last edited by TurboTim; 12-18-2009 at 12:22 AM.
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Old 12-18-2009, 12:22 AM   #3
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I presume you have the 01+ cam (rear of intake cam) and crank sensors.

Yes you can send the signals through the chassis' wiring which is originally meant for the 2 NA motor CAS signals (the CAS has 2 signals). The one with more teeth is the CKP signal.

These will go to the pins for CKP and CMP. CKP is the crank signal, and CMP is the cam signal. Check that this is where it routes to in the AEM schematic/manual.

Load the cam and crank setup variables that I showed in the post I made. I presume you're running COPs. I show a setup for that too.

I would at the least, run the VVT, to run fully advanced between 1500 RPM and 4500 RPM or whatever y8s found was optimal, and retarded outside that. You can use any of the "low side" switch outputs of the AEM and program it to do be an RPM window switch.
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Old 12-18-2009, 12:26 AM   #4
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Use the stock harness to feed the crank position and the cam sync signals. And I guess for the VVT engine as a start the best is to use Jason's setup from here:
https://www.miataturbo.net/forum/t27028/
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Old 12-18-2009, 12:29 AM   #5
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The variables are found in the cam/crank setup page.

The coil setup is in the coil phasing page.

The injector timing setup is in the injector phasing page.

Be sure to check timing before revving the motor and going into the ECU setup -> adjust timing page.
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Old 12-18-2009, 12:30 AM   #6
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Oh and start now and use "boost comp" so that your fuel pulse page appears flat wrt MAP.
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Old 12-18-2009, 12:43 AM   #7
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Quote:
Originally Posted by JasonC SBB View Post
I presume you have the 01+ cam (rear of intake cam) and crank sensors.
Yes, I think - my valve cover did not come with the rear of intake cam sensor, but the one off the front of my '99 valve cover looks mighty familiar. I can't find the part in the comp diagrams, so I'm not 100% sure if it's the same or not.

Quote:
Originally Posted by JasonC SBB View Post
Yes you can send the signals through the chassis' wiring which is originally meant for the 2 NA motor CAS signals (the CAS has 2 signals). The one with more teeth is the CKP signal.

These will go to the pins for CKP and CMP. CKP is the crank signal, and CMP is the cam signal. Check that this is where it routes to in the AEM schematic/manual.
OK, cool. I didn't know the CAS produced two signals.

Logic check:
-Hook the crank sensor signal wire into the OEM harness' Crank input (2E, White wire)
-Hook the cam sensor signal wire (from the valve cover sensor) into the OEM harness' Cam input (2G, Yellow/Blue wire)

Quote:
Originally Posted by JasonC SBB View Post
Load the cam and crank setup variables that I showed in the post I made. I presume you're running COPs. I show a setup for that too.
I've got my coils wired for wasted spark. I can rewire to sequential without a big hassle, but the less I change the better (for now). If I do wire them sequential, I'll just use Coil 3 and Coil 4, 3A and 3B on the AEM's 3rd harness?

Quote:
Originally Posted by JasonC SBB View Post
I would at the least, run the VVT, to run fully advanced between 1500 RPM and 4500 RPM or whatever y8s found was optimal, and retarded outside that. You can use any of the "low side" switch outputs of the AEM and program it to do be an RPM window switch.
ok. My goal with the VVT is to keep my fuel maps as intact as possible - I'm going to attempt to graft the MS fuel map over using datalogs, although I fully expect this to fail in every way possible. When that fails, I have Tim's TT fuel map which should be somewhat close.

As far as boost comp, I want to fiddle with that, but I have plans to try and get some fresh parts and +1 valves into this head, so the less time invested I have into the fuel map the better.

LS = low side?

Is the closed-loop fueling a big ***** to set up, or is it actually decent like I hope it would be on a $2k+ ECU?

Thanks a ton, Jason.
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Old 12-18-2009, 12:46 AM   #8
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For fuel start using the "boost comp" method as Jason already suggested. It makes your life a million times easier, because you don't have to deal with a full 3D map. Very easy to tune the fueling this way.
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Old 12-18-2009, 01:12 AM   #9
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Setup boost comp now, it will make troubleshooting easier.
Translate your old MS maps to boost comp.

Boost comp if setup correctly will multiply the fuel injector on time by MAP.
Warning DO NOT do the "hybrid" setup discussed in the AEM forums wherein the boost comp curve is not as I describe below. That will just confuse you.

Setup the boost comp table like this:

Assuming you have a manifold referenced fuel pressure regulator.

Fuel - advanced - fuel trims - boost fuel - table

For every value of MAP, enter above it, the value MAP-101

For example, if you have an entry for 150 kPa, above it you enter 49
For an entry of 50 kPa, above it you enter -51.
This is important. The reason for this funky equation is that the numbers you enter are interpreted as %fuel to add. Thus at 1 bar of boost (202 kPa), you add 100% fuel as compared to 101 kPa. At 50.5 kPa you add -50%. (subtract 50%)

This will flatten your fuel numbers wrt MAP. The resulting fuel map will only curve as a function of VE (you will see it peak vs RPM, at 5500 RPM or so), and if you want to enrich it in boost, or if you want to deviate from 14.7:1.

Then you take your MS fuel table and correct it to work with a boost comp setup.

What you do is for every fuel pulse width, multiply it by 101/MAP.

For example, if you have 2.00 mS for some RPM, at MAP=50, enter into the AEM fuel map a value which yields 4.04 mS.

Now in the AEM fuel map, you have 3 ways of displaying the numbers. Width, duty cycle, and "raw". Right click to change.

Raw is a number between 0 and 255. This number is multiplied by the variable "microsec/bit" which is found in fuel-advanced-trims-options. The result is the actual on-time. You will want to choose a value for microsec/bit such that the maximum raw value exceeds 100, preferably above 200. This gives you better resolution.

As you can see, the variable microsec/bit is like a gross fuel multiplier which you can change when you change injectors.
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Old 12-18-2009, 01:17 AM   #10
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Yes LS = low side.
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Old 12-18-2009, 01:25 AM   #11
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Another tip. After installing the software for the first time, do Configure-Units and set AFR to gasoline.
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Old 12-18-2009, 01:36 AM   #12
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Quote:
Originally Posted by JasonC SBB View Post
Boost comp if setup correctly will multiply the fuel injector on time by MAP.

Setup the boost comp table like this:

Assuming you have a manifold referenced fuel pressure regulator.

Fuel - advanced - fuel trims - boost fuel - table

For every value of MAP, enter above it, the value MAP-101

For example, if you have an entry for 150 kPa, above it you enter 49
For an entry of 50 kPa, above it you enter -51.

This will flatten your fuel numbers wrt MAP.

Then you take your MS fuel table and correct it to work with a boost comp setup.

What you do is for every fuel pulse width, multiply it by 101/MAP.

For example, if you have 2.00 mS for some RPM, at MAP=50, enter into the AEM fuel map a value which yields 4.04 mS.

Now in the AEM fuel map, you have 3 ways of displaying the numbers. Width, duty cycle, and "raw". Right click to change.

Raw is a number between 0 and 255. This number is multiplied by the variable "microsec/bit" which is found in fuel-advanced-trims-options. The result is the actual on-time. You will want to choose a value for microsec/bit such that the maximum raw value exceeds 100, preferably above 200. This gives you better resolution.

As you can see, microsec/bit is like a gross fuel multiplier which you can change when you change injectors.
easiest way to change my map for injectors is to change said microsec/bit. EDIT: Sorry I see JasonC said that in his last line.

There's also a feature that rescales the entire map such that your max ms value entered (assuming you entered ms values when viewing ms values, not bits when entering bits) gets set to 255 (or so) and the microsec/bit gets set accordingly, so your ms values are close to what you entered. It automatically sets the resolution as good as possible. My max bit is 212 so you can see I haven't done this in a while. You boost past 18psi so you'll have to rescale your breakpoints.
EDIT: right click the fuel map, select "rescale fuel map". I just did it, it rescaled my fuel map so the max bit is now 245 @ 65 microsec/bit instead of 212 @75.

I do not know if this feature would work with the boost comp method of setting up your map without thinking about it which isn't going to happen at the moment. I don't use boost comp, after seeing it demonstrated at AEM and trying it on my car, I prefer the standard map layout where a higher load row has a higher ms (bit) value in it, and keeping my boost fuel correct table zeroooooo. While it could give you significantly higher resolution (needed?), I don't see how it makes tuning simplier, other than a single change in the boost fuel correction table will scale an entire load row. I don't know when i've ever had to do that, and if I did, I would just highlight the entire load row in the fuel map and hit the "+" key. If you need to adjust the fueling in one specific cell you still need to do that in the fuel map, not in the boost fuel correction table.
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Old 12-18-2009, 02:14 AM   #13
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It will work with boostcomp.
All the rescale function does as you point out, is change usec/bit and the "raw" values.

It makes tuning easier bec for a given VE and a given target AFR, the value in the fuel table doesn't change with MAP.
So if you have the same AFR target say at 50 kPa, and at 80 kPa, the curve across RPM will be the same ... and when you examine the fuel map in 3D view, you can easily spot bumps and dips. Your fuel map only changes by maybe 2:1. Without boost fuel comp, your fuel map goes from 0.5 mS, to 15 mS, a change of 30:1, and so you can't see a 1 mS dip which is a 50% dip in a 2ms region, when your scale goes to 15 mS. With a boost comp map, the dip is pretty much 50% of full scale, easily visible.

Last edited by JasonC SBB; 12-18-2009 at 02:44 AM.
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Old 12-18-2009, 02:28 AM   #14
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Makes sense. My head isn't quite into the tuning, but I will definitely be reading that tomorrow. Thanks a lot, guys.
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Old 12-18-2009, 11:20 PM   #15
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Two more questions:

-Where do I plug the VVT solenoid into the ECU?

-Jason, what did the marks on your '01 cam gears look like for setting the timing? There is a couple of marks and a dot on the exhaust side, and a mark and a dot on the intake side.
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Old 12-18-2009, 11:46 PM   #16
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Hmm, I marked them with some paint, but didn't take pix, and it's at my machinist now.

VVT solenoid, use any LS (pulldown) output that isn't being used.
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Old 12-19-2009, 12:48 AM   #17
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I think I figured it out. It's tricky because the VVT cam only has those two marks. No clue what the dot is for, but I aimed the line at the black "e" mark on the plate behind the gears and the cams seem to be actuating at a logical point. Exhaust opens after TDC, then it closes right as the next TDC comes up, then the intake goes for half a stroke then closes up for the compression. Mi logic iz gude.

Jason, assuming I can just set that output in the software no matter which one I use?

Also, does anyone know what the size and thread pitch is for the VVT oil feed banjo bolt at the back of the valve cover?
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Old 12-19-2009, 06:57 PM   #18
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Jason, I am not going to have time to deal with tuning around the VVT. Is there a way to default lock it to 0 degrees advance/retard?
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Old 12-23-2009, 11:35 PM   #19
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So, how did this go?
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Old 12-24-2009, 12:12 AM   #20
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Discretion is the better part of valor. I came down with a sinus infection while I was doing this work and didn't make my deadline, so I took a break for the holidays. I will probably end up pulling the head and having it built before I fire everything up, so it may be a couple of months before anything comes to fruition.
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