09-22-2016, 08:22 PM
Join Date: Feb 2014
Location: Berkeley, CA
Total Cats: 0
93 Octane MSPNP Gen1 Tune to 91 California Safely
Recently relocated from Texas which was the land of 93 octane, where my miata was tuned to that accordingly with my MSPNP Gen1 ECU back way when. Now, I have relocated to California and the only gas anywhere near me is 91 octane. I have a track day coming up this weekend and long story short didn't take care of this till now (car has been parked with 93 octane in it). I'm going to be towing the car to the track because of CARB and registration non-op reasons.
Question is what are my options to quickly and safely getting the car to run for my event?
I've considered these options:
1) I've looked at Sunoco 260 GTX/GT etc for mixing 91 octane from the pump to make 93 gas
2) Thunderhill Raceway has 100/91 octane unleaded fuel options so I can just top off there
3) Look at changing timing on the ECU table or whatever is suggested to accomplish the change to 91 safely. (to be honest, never have opened up megasquirt software or plugged into the device, it came pre-dyno tuned to 93 from the previous owner)
If anyone can provide any insight into this I'd appreciate it, for now I'm leaning towards just mixing the fuels together at home/track.
I'd like a more permanent solution to where I can live with the few HP I'd lose to go back to 91 octane safely.
Thanks in advance and I hope this question isn't too stupid.