Racepak/AIM/etc in an NA Miata - How?

It's a straightforward question with what I assume is a slightly complicated answer. I'm guessing it is possible to run one of those really cool race car dashes with the stock ECU, right? Is it just a factor of getting the right sensors and programming the dash? What about speed? Since it's mechanical in the NA, does the unit just use GPS or would it require some sort of wheel speed sensor adaptation?

I feel like it has to be known how to do this as I think I've seen Spec cars with it but when I try searching online, most everything references MS or another standalone system.

Anything is possible with enough time and money. Much easier with OBD2 cars; for OBD1, you need to wite in a sensor for just about everything. I have an Aim MXL, the GPS does very well for speed/distance. 

This will only get you halfway but there's a company called Speedometer Solutions (http://speedometersolutions.com/) that sells a digital signal converter that screws onto the factory takeoff point in lieu of the cable. It's not on their website so you'll have to email them. Looks like this:

It's a small, self-contained trigger wheel and Hall Effect sensor. Feed it power and ground and it outputs a 16 pulse/revolution square wave signal. I use one on my RX7 for vehicle speed input to my ECU, which then goes to a RacePak IQ3 display via CAN. Since it works on my RX7 it'll work on your Miata assuming stock transmission. You have to figure out integration with your display of choice. 

The AIM systems can log CAN data but I dont think anything pre 94 will work (no 1.6's).  However if you have a Megasquirt PNP you should be able to get it to talk to the AIM. 

The AIM systems use a GPS input for MPH.  

No need to get a custom part, an NB speed sensor will plug right in to the NA transmission to give you a pulsed signal. If you've got GPS for the track analysis, that's the super-easy solution.

You can pull some of the information for the race dash off the stock cluster wiring itself. Tach, coolant, fuel, oil pressure (or switch). The race dash will have internal accelerometers and a standalone GPS antenna, so there's your driving analysis done. Iron Canyon Motorsports sells an adapter to feed a properly tweaked fuel signal from the stock sender if your dash of choice can't make it work. 

What else do you want on the dash? Come up with a list of data and we can figure out how.

Kendall_Jones said:

The AIM systems can log CAN data but I dont think anything pre 94 will work (no 1.6's).  However if you have a Megasquirt PNP you should be able to get it to talk to the AIM. 

The AIM systems use a GPS input for MPH.  

No NA Miatas have CAN on board in stock form. The 1996-97 OBD-II implementation is not CAN AFAIK. Don't believe the NB ever got it either. The NC has some CAN. They really weren't up-to-date cars until the ND came out, it's always been a little behind on the tech front.

Keith Tanner said:

No need to get a custom part, an NB speed sensor will plug right in to the NA transmission to give you a pulsed signal. If you've got GPS for the track analysis, that's the super-easy solution.

You can pull some of the information for the race dash off the stock cluster wiring itself. Tach, coolant, fuel, oil pressure (or switch). The race dash will have internal accelerometers and a standalone GPS antenna, so there's your driving analysis done. Iron Canyon Motorsports sells an adapter to feed a properly tweaked fuel signal from the stock sender if your dash of choice can't make it work. 

What else do you want on the dash? Come up with a list of data and we can figure out how.

Thanks, I was really hoping you'd chime in. Honestly, right off the top of my head, a dedicated low oil/pressure warning is all I can think of but I'm pretty religious about looking at oil pressure in the Miata we run currently. Eventually I expect to be running boost so that would be the only addition to that basic list I can think of. 

Also thanks to everyone else for the tips. 

I don't think I care too much about data acquisition in terms of the car systems, I really see this as a very cool replacement for the gauges. Telemetry would be cool to have so I suppose that complicates things with throttle and brake integration but I certainly don't need it displayed on the dash in real time. It would be great to have lap times displayed as well. Anyone have suggestions as to which unit(s) I should be looking at?

The dash will use internal accelerometers to record braking and acceleration, so no need to bring that data to the dash unless you want to see actual brake pressure and throttle position. Pretty much all of them will do lap times without any input from the car, that's all GPS.

Oil pressure is pretty easy, you can either program an alarm for if the pressure drops below a certain value or you can add a factory oil pressure switch (from a 1996+) on a tee and have that trigger a light. I do the latter with my car.

I've used AIM on a couple of cars. They're pretty solid pieces and made to survive the environment of a race car, but you will struggle with the programming and analysis interface. Haven't any experience with the Racepack or others.

Having spent a few years playing with data using an AIM dash on my M3, the built-in GPS and accelerometers will get you 75% of the way there.  After that, IMHO the most useful data channels are the driver inputs -- TPS, brake pressure, steering angle (in that order).  Add in RPM and you've got 95% of the data I ever look at.  (there are another couple dozen in my system, but they are pretty specialized.  Individual wheel speeds from the ABS, for example).

For "dash" functionality you really want oil pressure, oil temp, coolant temp, so that it can turn on "pit now" warnings.  If you're going to delete the stock dash cluster you'll also want to interface it to the fuel gauge.

I really appreciate all the feedback. 

It seems like the Racepak unit I'd be looking at is 250-KT-IQ3SGPS. That's a kit that comes with much of what I'd need. It's probably an issue on my end but the AIM website(s) seem clear as mud as to which  dashes fit the need and its even more difficult figuring out pricing. 

I'm probably 6 months out at this point but if anyone can solve the mystery of which AIM compares to the Racepak I'm looking at, that would be super helpful. 

I don't have time to check out the Racepack - on the road - but you'll be looking at the AIM MXL or MXL2. Most of the others are for karts. 

Just out of my own curiosity, why go through all that on the stock ECU? A nice standalone could get you some decent gains (supposedly) and it would make the whole dash thing much easier. If it is for a classing restriction though, I totally get it.

Edit: I run a "Perfect Tuning Gauge"(linked below) with my Miata that runs on MS3Pro and it can display everything the ECU knows to include Ethanol content, etc . It's very discreet and I can keep the stock looking gauges. I even have it mounted in the glovebox so I can hide it to keep the interior looking nice.

https://www.diyautotune.com/product/perfect-tuning-universal-gauge-ms3pro-ms3-ms2-microsquirt/

In reply to JAdams :

That's a totally fair question and I suppose my initial answer is that it makes it simpler to get the car running, on track and have a baseline. I never said it makes sense to run one of these with a stock ECU, just that it would be damn cool to have. 

I'm also guessing that if at some point I move to a standalone, switching over the dash to capture data from there would be relatively easy. I'm pretty sure both STL and STU allow for a standalone. 

In reply to Keith Tanner:

Much appreciated. 

Keith Tanner said:

I don't have time to check out the Racepack - on the road - but you'll be looking at the AIM MXL or MXL2. Most of the others are for karts. 

The MXS works great in race cars, that's what I have in my M3.  Yes it's smaller than a traditional car dash, but realistically the only thing you have time to look at while you're on the the track are the shift lights so the difference between it and the MXL is inconsequential.  You use programmable alarms to worry about temperatures/etc.  If you're going to mount it on the steering column then something the size of an MXL or MXG may not be fully visible behind a smaller diameter racing steering wheel.

If the car is used on the street then that may be a different story.

What do we need to do different for an OBD1, 1990 Miata? Would like to use an Aim MX in place of the current dash and instead of a separate timer. 

nbowers said:

What do we need to do different for an OBD1, 1990 Miata? Would like to use an Aim MX in place of the current dash and instead of a separate timer. 

None of the NA/NB Miatas have a stock ECU that can talk to the AIM dash (no CAN bus til NC), so they're pretty much the same in terms of what it takes to set them up.

nbowers said:

What do we need to do different for an OBD1, 1990 Miata? Would like to use an Aim MX in place of the current dash and instead of a separate timer. 

Short version - you'd need to wire the sensors that originally fed the stock dash its signals to the AIM dash instead. I am not sure if the AIM has internal signal conditioners or needs an external module for this.