e10 vs 98
Posted: Fri May 20, 2022 9:41 am
Assuming the engine isn't knock limited, the torque should be pretty similar between e10 and 98? perhaps a touch lower with the ethanol but more or less the same?
I had a few people comment in a FB post that I should be tuning for 98 over 91 or e10 as there's a whole lot more power available even just by swapping fuel - even in a low compression (8.8:1) engine without knock sensor.
So I tried it. Dyno runs on e10 and 98 showed absolutely no difference in torque or HP.
Then I started adding timing. Ended up with around 15% more torque in most of the rev range and room possibly for more. This wasn't the case with e10, any more timing rolled the torque off. No detonation was heard through a knock sensor & headphones.
So what's going on? Where is this extra torque coming from? Maybe I'm not hearing detonation in the e10 tune? Does 98 burn more effeciently? AFR's were about 0.1 to 0.2 richer with the 98. Any theories?
I had a few people comment in a FB post that I should be tuning for 98 over 91 or e10 as there's a whole lot more power available even just by swapping fuel - even in a low compression (8.8:1) engine without knock sensor.
So I tried it. Dyno runs on e10 and 98 showed absolutely no difference in torque or HP.
Then I started adding timing. Ended up with around 15% more torque in most of the rev range and room possibly for more. This wasn't the case with e10, any more timing rolled the torque off. No detonation was heard through a knock sensor & headphones.
So what's going on? Where is this extra torque coming from? Maybe I'm not hearing detonation in the e10 tune? Does 98 burn more effeciently? AFR's were about 0.1 to 0.2 richer with the 98. Any theories?