Ecm tuning

    Quote from mac8

    Can ecm be tuned to run 87 octane without knock and maintain current power and performance or is the compression ratio the determining factor?

    My question would be why. I think you could answer your own question just by running 93 octane gas in your 87 octane car for a couple of tanks. It just might surprise you how much better/smoother it runs and the better gas mileage it just might get along with more power.

    Quote from mac8

    Can ecm be tuned to run 87 octane without knock and maintain current power and performance or is the compression ratio the determining factor?

    .

    Although I agree with question ...why ....the simple answer is no... aggressive spark advance and valve timing are where the extra power comes from with premium not so much the CR in this motor ... you can run 87 now without "damage" but the knock sensor will cause the ECM to retard the tuning and cost some power... will you notice is the question ... some can, especially the closer you are to sea level....


    ......... nerd-squared


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    :REDSS: The ghost of SLingshot past ......

    Quote from mac8

    Can ecm be tuned to run 87 octane without knock and maintain current power and performance or is the compression ratio the determining factor?

    I know one owner who ran 87 octane all the time, never changed the 'tune' on his and put over 100,000 miles on his 2016 Slingshot. I personally put in 93 octane most of the time --- unless it's not available --- and than just put in enough to get to some 93... If can't afford the 93 better stay home. (I've put 87,000 miles in the seat since Feb 2015).

    I am like EjFord I run 93 octane non ethanol in everything even the lawn mower except when I am on the road and cannot find the non ethanol. I do not believe all of the B.S. the goverement is putting out on the enthanol in our gas. As to my remark about the difference in the octane. On my 89 firebird I ran a little experiment with just the gas mileage between the two octanes of gas. 16 gallon tank there was a 30 mpg difference with the 93.

    Quote from mac8

    Can ecm be tuned to run 87 octane without knock and maintain current power and performance or is the compression ratio the determining factor?

    You can currently run 87 octane in your slingshot if you want with the stock tune. Plenty of people do it. However, being a high compression engine, you should be running premium. (91 or 93) Octane is one of the main factors that will determine power output and performance. Generally speaking, the lower the octane level, the more the PCM will likely have to pull timing because of knock. In our experience with the Slingshot, the stock tune is about as aggressive as you would want to go if you're going to be running 87 octane.

    ZZPerformance EST 2000 - Go Fast Not Broke

    [quote='FunCycle','https://slingshotinfo.com/index.php?thread/8581-ecm-tuning/&postID=289648#post289648']

    I am like EjFord I run 93 octane non ethanol in everything even the lawn mower except when I am on the road and cannot find the non ethanol. I do not believe all of the B.S. the goverement is putting out on the enthanol in our gas. As to my remark about the difference in the octane. On my 89 firebird I ran a little experiment with just the gas mileage between the two octanes of gas. 16 gallon tank there was a 30 mpg difference with the 93.

    [/quote]

    WOW. That’s a big difference. 🤔



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    Speaking of octane, a few years ago I sent my wife on a full-day racetrack course @ Sonoma Speedway (once Infineon) in her 2011 Porsche 911S cabriolet. We found 100 octane right outside the race track and my wife said her car has never run better, smoother, faster. I just wish I could get 93 on a regular (pun intended) basis.