I'm looking to finally get rid of my stock AFM on my '91 N/A, so I decided that I want to go the Megasquirt route. I plan on using the Megasquirt version 1, as it only controls fuel. I know that they haven't fully figured out the whole Leading and Trailing timing yet for rotaries, so I don't trust using the Megasquirt's ignition (just yet).
So, what's my best option for controlling my ignition then? I want to take advantage of using zero timing split. I plan on using either the 12A or 13B GSL-SE distributor in place of my crank angle sensor, but I want "direct fire"/ something more powerful than a stock distributor. Would it be best to use the 13B GSL-SE distributor and do the DLIDFIS mod, which I believe uses the 2nd coils (?). (I don't quite remember). I'm also thinking of running an MSD as well.

If anyone has any suggestions and/or experience with this, please let me know.

(I would like to finally take advantage of the large intake/ exhaust porting that I've done, as well as having a header, presilencer, etc. and I know that my AFM is my most restrictive part now.)

Brian

 

Actually, leading already works, and trailing works on the oscilloscope. I'm going to test trailing soon (~2 weeks or so, depending on tofuball) and then post results. There's no reason not to go with the stock ignition on that car.... the code for leading is rock solid on tofuball's 'vert... that's with several hundred miles on the car... with megasquirt controlling stock leading, and I'm confident that trailing will work fine when we wire it up sometime in the next couple of weeks.

 

Well, in that case, I'm really looking forward to the "finished" product!!! I haven't ever seen the Megasquirt software before, so I have to ask:
Is the timing split adjustable between leading and trailing?

If timing split were to be set to "ZERO", what's the accuracy/ precision of the ignition?? Would there be a possibility of the Trailing firing before the Leading??

I know that Microtech's ignition accuracy is: 0.25 +/- of a degree, so it's well suited for the task of ZERO split. Haltech's ignition accuracy, however, is not as precise, and therefore cannot run ZERO split due to the fact of the possibility of the Trailing firing before the Leading, thus causing detonation.

I'm REALLY looking forward to it!!

BTW, what is the cost of the fuel/ ignition (megasquirt II) un-soldered computer kit for an RX7??

Regards,
Brian

 

It's adjustable... there's a 6x6 table.

By looking at the code, it's impossible for the trailing to fire before the leading. The trailing is always scheduled right when the leading fires... which means it can't possibly fire before the leading because it won't have been scheduled yet.

You don't want megasquirt II, it's not what we're using to do rotary ignition. In fact, there's no code there to allow you to do rotary ignition in megasquirt II

What you want is the megasquirt kit ($140), a dual lm1815 vr sensor conditioner circuit (~$20 in parts if I remember correctly), and a few extra resistors for things like replacing the bias resistor for air temperature, and for adding pull-up resistors to allow ignition to work. I'm working on a complete "how-to" on modding the megasquirts to work with rotarys... but I'm not going to post it until leading + trailing is tested. Oh yeah, and you need to upgrade your firmware to the latest msns-extra firmware... I think I have 025e on the megasquirt I'm using for testing right now.

Regards,
Brian[/QUOTE]

 

I'll definitely be looking out for your thread on installing and running megasquirt on a rotary!! I'll put off buying it till then so that I know what to buy (extras and all). In the meantime, I'll be getting accustomed to Megasquirt and it's software, etc. My RX7 is my daily driver, so the more I know about megasquirt before-hand, the better off I'll be when I'm installing it
Thanks for the update!!

Regards,
Brian

 

Damn, I'm trying to sort out all this stuff and a guide would be VERY useful.

And I'm not even going to be running trailing!

 

I'll get a guide together soon... but like I said, a lot of people do want trailing, so I'm going to wait until I'm convinced it's working 100% before posting a guide... leading works perfectly, but trailing, while it works ... still has a couple of problems at about 0 - 3 degrees of split that I'm working with the author of the code to figure out.

 

Alright, we'll see which comes first: Trailing ignition or us getting the motor broken in on the stock computer