Quint,
Your statement about altitude and air density would be more accurate if you had a vehicle that didn't have a closed loop system constantly adjusting the fuel to maintain a 14.7:1 AFR. Less oxygen, system cuts fuel back to match. So, you folks at higher altitude don't get a free ride, you still have the same lean mixture & hot running issue as everyone else. Even the older EFI systems without O2 sensor feedback could approximate the same thing, through air pressure readings.
Jerry
Jerry
Thanks for the information - that is extremely helpful. Given that the HD closed loop system maintains the AFR at 14.7:1 regardless of altitude, does that also mean it will maintain the same AFR if I switch to V&H slip-on mufflers? Here's my thinking. If I spent another $2,000+ getting a true dual exhuast, SERT, installation and dyno time, my better half would have an apoplectic seizure, particularly given that I still need a different windshield, a more comfortable seat for her, etc. That's why I was thinking of installing the V&H slip-ons myself, and then at the 1,000 mile service, get it dyno tuned with the SERT. The reason for this is that I'm sure the stock HD exhaust is "reasonable" in that it is decent quality and will deliver enough horsepower for me - I don't need to be in the 110 HP club with this Harley - I have a 167 HP BMW sportsbike that gives me my speed thrills. Given that the bike is going to run at 14.7:1 anyway, I'm not really making matters any worse, am I?
Don't get me wrong: I completely understand that HD has the bike running way too lean from the factory, and this leads to excess heat, pre-detonation, less that stellar power, and jerky throttle response. I also understand the need for properly tuning it. But this stop-gap solution might give me the sound that I like with 95+% of its performance potential, without making any significant difference to the way the bike runs now, until I get it tuned. I'm just looking for facts rather than opinion. Again, your comments are most welcome...