The documentation I found so far says that initial timing at idle is 5 degrees ATDC for the leading coil, 20 degrees ATDC for the trailing coil. That makes sense, the leading plug fires, gets the fuel lit and the trailing plug cleans up what's left.

I have a lot of experience with auto engines, and ignition is usually roughly 10 degrees BEFORE tdc. They ignite the fuel before TDC and then the piston rolls over center and starts downward, the 10 degrees gives the fuel time to ignite and start building pressure. And advance continues to be more before TDC for the same reason as RPM increases, usually around 34 degrees BTDC at 5000 rpm.

So the 13B starts ignition AFTER TDC, huh? As RPM increases, I would expect timing to move over to the BTDC side and be advanced more. Also, when under boost, I would expect timing to retard 1 degree per lb of boost, like a piston engine, right?

I have this in an aircraft using an aftermarket ECU, its hard to get back there and watch while that prop is turning!

Thanks

 

Probably you're referring to the timing when ignition is locked as it is described in the workshop manual (G section). I think there is no definite knowledge as to what are the exact factory ignition timing values on 13B REW. From what I've could find out it is believed that Power FC timing base maps are closest to the factory ones, so you can have a look at them. And generally your observation is right that timing advances as RPMs increase and retards as the boost increases.

 

I’m far from a tuner. But I think you have to be careful translating typical timing from piston to rotor. The shape and surface areas involved are so dissimilar. And I think porting will also affect what is appropriate timing.
And of course tolerance to knock is MUCH less on the rotary so timing tends to be conservative.

 

from what I have been told over the years..toss the piston tuning stuff and learn the NEW Rotary tuning stuff.
It's not the same and frankly scared me so much that I didn't want to jeopardize my investment and hired a tuner to travel down to my house and tune the car.
Funny I could fix v8's when I was a kid,then got into Rotary at 45...now I don't know **** about piston engines any more!