M4 CRiP: Rotary (13B-REW)

[Carlos Iglesias]

As I understand CRIP, it is the angular distance in degrees (BTDC) from the first REF tooth (after the SYNC tooth lineup) to Cyl/Rotor #1 TDC.

Since the 12-tooth Mazda trigger wheel is mechanically linked without adjustment relative to the rotors, I ASSUME that CRIP values should be the same for ALL 13B-REW engines using the stock trigger wheels and mag sensors. The "Mazda 12 Tooth Mag on Crank" (Diagram T-1T) gives a CRIP of "20" for the '93+ rx-7's 13B-REW. However, I'm seeing a value closer to 10 (BTDC). Is this a mistake on my part or in the MoTeC diagram?

Can anyone please confirm this.

Many thanks,
Carlos

[IDP]

Are you reading the correct edge of the waveform?

Could the polarity of the mag sensor be reversed?

[Carlos Iglesias]

IDP: Thanks so much for your questions.

I've scope the trigger sensors as falling/falling which is in accordance with MoTeC diagram T15's (http://www.motec.com.au/filedownload.php/t15.pdf?docid=1284) recommendation of setting "rEF" mode at 14 (i.e. falling/falling) .

I guess the part I'm really confused about is why my physically measurements for #1 (rotor) TDC is so significantly off from the CRIp setting of "20" in diagram T-15 settings. Since the timing is not mechanically adjustable on 13B-REW rotaries, I'm trying to resolve why am I getting such a substantial difference from MOTEC's documented CRIP setting.

[Carlos Iglesias]

Turns out that my assumptions of how to find TDC on a 13B-REW were wrong. The MOTEC CRiP of 20 is correct. Don't I feel silly!