I would recommend the following, having had great results on my own SERK.
1) The stock air cleaner system is very restrictive and has to go. The Screaming Eagle
unit is fine, I went with the Arlen Ness Big Sucker, as it has a better contour into the
throttle body and an internal (hidden) breather system.
2) The stock mufflers have to go. There is nothing wrong with the stock dual/shared pipe
arrangement, they actually work pretty darn good. The real problem is the mufflers, they
are too restrictive. I would run the SE mufflers you listed (do not get the newer SE II
mufflers, as they do not perform as well), or a Kerker or Vance & Hines slip-ons. I went
with the Vance & Hines Ovals; great look, sound and performance. But again, everyone
has an opinion. The V&H Ovals were a new release at the time, and when I was
investigating, the company rep told me they had higher flow values and would work
great with the 103 engine.
3) Obviously with the improvements on engine throughput, you will have to modify your fuel
and ignition maps. Yes the new "cartridge" or factory download will help, but as the
MOCO is installing it on a street machine, it still has to be politically correct (read EPA
friendly). The fuel maps will be leaner, and the ignition curves slower as it still has to be
"street legal". You will not get the same performance on a factory download as you
would with a canned map from the Screaming Eagle Race Tuner. These fuel and ignition
maps are much more aggressive, and your bike will perform much better. Plus, it is easily
modified for any changes you make to the bike later. I would put the money you would
spend for a new catridge or factory down load towards the price of a SERT. You can buy
SERTs on EBAY for $350 all day long.
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