Miata engine management system

[Prof. Chaos]

With the allowance of ECUs in the GCR, I was wondering if something like the Electromotive Tec-GT is legal for an 1.8L Miata in ITA. The GCR says you can only use a crankfire ignition system if the car was fitted with one from the factory. The Electromotive system uses its own crank sensor you install.

Does the 1.8L Miata have a crank sensor? Am I talking about the same things or am I confusing definitions?

My overall question, however: Would something like the Electromotive Tec-GT be legal on the 1.8L Miata?

[tnord]

With the allowance of ECUs in the GCR, I was wondering if something like the Electromotive Tec-GT is legal for an 1.8L Miata in ITA. The GCR says you can only use a crankfire ignition system if the car was fitted with one from the factory. The Electromotive system uses its own crank sensor you install.

Does the 1.8L Miata have a crank sensor? Am I talking about the same things or am I confusing definitions?

My overall question, however: Would something like the Electromotive Tec-GT be legal on the 1.8L Miata?

1.8L miata does not have a factory equipped crank fire ignition system.

[Prof. Chaos]

Thanks. I think I was confusing a couple sections of the GCR...but regardless, if the car doesn't have a crank sensor then I can't add one. Thanks for the help.

[C. Ludwig]

The Electromotive systems only use the 60-2 trigger wheel. Since you can't add the wheel and sensor under the rules the Electromotive systems are out...you already figured that out.

There are a number of other systems that can work with the stock sensors. We're doing plug-in patch harnesses using the Haltech E8/Sport 1000 for the 1.6 and 1.8 cars now.

[Greg Amy]

Since you can't add the wheel and sensor under the rules the Electromotive systems are out...you already figured that out.

But...since the crank angle sensor is probably nothing more than a Hall Effect sensor...and the distributor innards are free...what keeps you from tricking the Electromotive into thinking that the distributor Hall Effect sensor ain't nothun' but a high-falutin' crank angle sensor...?

(Don't mind me, I'm jes brain-stormin'...besides, Tristan's supposed to be ignorin' me and all...)

[Prof. Chaos]

But...since the crank angle sensor is probably nothing more than a Hall Effect sensor...and the distributor innards are free...what keeps you from tricking the Electromotive into thinking that the distributor Hall Effect sensor ain't nothun' but a high-falutin' crank angle sensor...?

(Don't mind me, I'm jes brain-stormin'...besides, Tristan's supposed to be ignorin' me and all...)

This sounds all too smart to me...I'm having trouble just understanding the GCR.

[C. Ludwig]

If you can convince an Electromotive ECU that the 4+2 cam sensor is a 60-2 crank trigger and that the OE Hall sensor (read: square wave output) is a VR sensor (read: sine wave output) you're better than most.

[Greg Amy]

ANYTHING is possible, Chris. I don't know anything about the Electromotive system, buts bits is bits, and programming is programming.

Personally I'd buy a MegaSquirt and be done with it. But if you've got The Big Love for Electromotive, "if there's a will..."

GA





(P.S. - disregard the "edit" in Chris' post above; I accidentally hit the "edit" button instead of the reply button, and didn't notice it until it was too late. Fortunately, I was able to recover his response to me without any changes. Damn you, moderator superpowers!!!)

[shwah]

I thought DIYautotune.com had put together a plug and play package for the Miata already, based on megasquirt.

[jlinfert]

Yes DIYautotune has a P-n-P for Miatas. The price is very fair and Megasquirt is a pretty decent system. MUCH easier to work with than an AEM and it uses the same basic tuning algorithms as Electromotive (VE tables).

[Chip42]

ISC Racing in Florida also has a PnP ECU, though I don't know anythgin about tunig it other than it uses a "smart card". It is very small.

There's a lot of guys who have figgured out how to hook up a motec without removing the factory ECU case from the loop (old rules) in RX7s, so there's got to be a relatively easy way to hook them up, too.

can the Tec-GT be used with the factory ignition? BTW - the cam angle wheel in the OE distributor could be replaced with an Electromotive style 120-2-2 and the sensor either swapped or made to look like a sinusoidal output with the appropriate addition of Rs and Cs. don't know how well that would work, or if it is indeed worthwhile, but it is "possible".

[seckerich]

We ran the Electromotive on our Production Spitfires for years with the 120 tooth wheel inside the distributor with no problems. Not as accurate as crank mounted unless you have some very new drive gears but it will work. I would call ISC as he has one wicked fast setup. Why invent the wheel?

[JeffYoung]

Based on trying to follow, and failing, Kip and MIke in their ITS Miatas the last two years, I have to say: do as they do......

[Andy Bettencourt]

I am running the same system as Mike and Kip. We developed them independently of each other a couple years ago. It works well!

I think this is a case of someone trying to utilize something they have - or have access to for real short money.

[IPRESS]

Jerry with DIYAutotune has it down pretty well. He did a great job on my miata before ARRC. The MegaSquirt is perfect for us .....uhhh... challenged sort.