Pig9r
Living Legend
GPMAZ- Cooler engine at richer a/f ratios is only a side benefit to me, the main reason I tuned for around 13.5 to 1 is for more power. 14.57 to 1 is for emission purposes. The reason you went lean in the higher ranges is that the engine has no way to measure the amount of air entering the engine. If you made intake or exhaust changes more air is going to enter the engine because the intake and exhaust tracts are less restrictive. Therefore you need more fuel. And because it is in an open loop range, there are no trims to correct it to 14.57.
It may not be as noticeable on the Touring models, but on my Classic, until I got a full on dyno tune the throttle was jerky in the mid ranges and small throttle openings. I could also feel a surge more than likely caused by a lean condition.
Doing a PCIII dyno tune I only picked up 6 hp over one of Wayne's canned tunes, but the bike was so much better to ride because of the smooth throttle.
It may not be as noticeable on the Touring models, but on my Classic, until I got a full on dyno tune the throttle was jerky in the mid ranges and small throttle openings. I could also feel a surge more than likely caused by a lean condition.
Doing a PCIII dyno tune I only picked up 6 hp over one of Wayne's canned tunes, but the bike was so much better to ride because of the smooth throttle.
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