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Engine basics => Engine set up tips => Topic started by: Matt Colan on May 24, 2009, 05:23:55 AM

Title: What a difference a different fuel will make
Post by: Matt Colan on May 24, 2009, 05:23:55 AM

For the longest time, my grandfather and I have been using 5% Sig Champion fuel and our motors ran well, but today I tried 10% Red Max fuel in my Ares, which sounded like an echo chamber when the other fuel is in it.  When I took off, the echo chamber sound was gone and that motor ran better.  Even other motors that had the 5% nito in it, when we switched to 10%, they ran better.  Is it because of the extra nitro?

Title: Re: What a difference a different fuel will make
Post by: phil c on May 24, 2009, 04:04:13 PM

Most likely the nitro.  You get the most benefit from the initial percentages of nitro.  5% is much better than 0%,  10% is better than 5%, 15% is better than 10%, etc.  When you get up to 25% or so the improvement in power gets less and less with each addition.  In addition to more power, more nitro gives the fuel a bit broader ignition range, so it tends to run smoother and it more tolerant of how the motor is set up.  0% nitro requires some pretty specific tuning of the motor to get it to run right- exactly the right squish band clearance, closer control of the head volume, the correct plug.