Originally Posted by blk-betty
FWIW...when I installed the SEPST and downloaded the map for aftermarket exhaust and airfilter it did not run all that well during the first few SmartTune runs. This was a year ago and I don't remember everything but what I remember the most was that during hard acceleration beginning about 3500 rpm it literally felt like I was dragging an anchor...motor took forever to rev up to 5000 rpm. I inquired about this on the HTT site and was informed that was a function of the SmartTune feature......again don't remember the details but something about the way the ECM delivered fuel for data collection while in SmartTune mode I was told to run it a few more times in SmartTune and allow the software to "remap" after every run. Sure enough it got better and better with each download and run. I think I did about 5 or 6 runs.
The software instructions claim the VCI can store up to 15 minutes of ride time but I had several runs up to 40 minutes and have heard claims that it will store up to 45 minutes of data.
I never actully rode it with just the SEPST download map so I don't know how it might have run and the poor performance I got was due to running in the SmartTune mode.
I am absolutely certain that a dyno tune would give more performance and efficiency than the SmartTune as a dyno operator will not only adjust air fuel ratio but also spark advance, acceleration and deceleration mixtures at numerous throttle positions and rpm ranges. The only thing SmartTune changes is fuel air mixture. The software allows you to make changes in spark advance etc. if you want to but the concensus was "leave that to a professional dyno tuner". I din't make any of those changes, just a/f ratios.
In my opinion, the beauty of the SmartTune is that the engine tunve can be individually "refined" after a download to a state much closer to ideal than with something like a piggy-back style fuel controller that just adds fuel, without the need for an actual dyno tune.
If one was doing more than just mufflers and air-filter, say a cam and/or headwork I would strongly recommend an actual dyno tune over the SmartTune feature.
Thanks for the info. Nice to have real world feedback! I plan to install the tuner and a/c soon, just haven't had time to get to it yet. The Pro-Pipe, SE a/c, and SE tuner are all I have planned at the moment, but I may upgrade cams later. Probably get a professional dyno tune at that point. This is my second FI Harley, but the first one I have modified. My first one was a '01 RKC which had the old Marelli FI system. Ran it with the stock map and a set of V&H Longshots for 30K miles before I sold it. With the torque of this new 103 in stock form I couldn't resist uncorking it a bit with the tuner.