I am considering buying a Moates 2-timer, so I can have easy access to 2 bins while driving. One for unleaded and one for super unleaded. I know, with a stock tune that my truck will audibly ping and knock when using regular gas while under load. When I run super I get no audible ping, and I maintain boost under load so I know I must not be getting much if any KR. I just changed my fuel pump (which was causing alot of knock retard and lean AF ratio's under load), and I have not logged any data since to know for sure, but it holds boost now so I know the ECM isn't pulling it for KR.

What I want to know, is there any real performance difference between a proper tune under boost using 89 octane vs a proper tune under the same boost level using 93 octane??

Should I just tune for 89 and if I choose to run 93 it would be like a margin of safety? Or would I be giving up power by not tuning to 93's full potential? Right now I really dont care to buy super unleaded due to the price, but if it can gain some more power using it I can just buy the 2-timer and have it as an option with the flip of a switch.

Has anyone done any testing like this?

 

Yes.
No.
Yes.



I've been doind a fair bit of work on running 87, and then running alky injection when in boost. With 87 you can run several degress less timing in low load conditions. In boost, there's a difference of 4-6d difference.....

I have a rather large Front Mount Intercooler, but even with just a whisper of alky makes all the difference. FWIW, I'm using the alkycontrol.com set-up.

 

Well, I guess I will look into one of those 2-timers. I know I want it to be able to make max power, but at the same time I want it to be safe if my wife drives it and with 87 in the tank not knowing to drive easy with that octane level.

Thanks