Here's a history of my 103 buildup which I thought might help out others with less cash to waste than I have spent. I got one of the very first 03 SERKs in August 2002. The Race Tuner kit came out that same month and I was the first person in or around my dealership to purchase it. In addition, it came with no 103 maps and there was no Stage I module out for the 03 SERK. No one there knew or wanted to know anything about it or the 103 motor at that point. So first, I had to find people on the Net to help me with the EFI tuning concepts and then work with my dyno guy to tune the SERK and design a 103 map. We changed to Wild Pig exhausts, a bigger than SE air filter and SE split tip spark plugs. The end result was 103 HP and 114 ft lbs of torque. I was extremely happy considering the limited amount of the investment.
After a year, I decided that I needed more, so I installed an SE 258 cams with no head change. End result after another $800.00---105 HP and 121 ft lbs, but I lost low end power which was noteable. My tuner said that compression ratio was too low for the SE 258 cam. In addition, the gas mileage dropped a few miles per gallon (about 41) and my tuner suggested upping the compression ratio and adding Rineharts. the next step was to change out the SE performance heads, which have the same valves and porting as our stock 103 heads, but without the hemi chamber. The tighter chamber ups the compression to 10.5 to 1. That also required compression releases. The bike felt like it had a lot of power, but due to work, I didn't get to the dyno for a month. About that time, one of the baffles in the Wild Pig started rattling so I decided to install Rineharts. With another $631 spent, I headed to the dyno to build a new map. After two hours of dyno time, we finished up with 110 HP and 116 ft lbs of torque. It makes less power at the bottom end than before the exhaust and head change and all gains in HP are above 5200. Needless to say, I feel like a dumbass now and I have to say that other than the true dual effect of the Rineharts sound, I liked the sound of the Wild Pigs better. This is not to criticize the Rinehars, but is just a pesonal opinion. However, the dyno doesn't lie and I wouldn't reccomend purchasing them with the idea that you are going anywhere with a power increase.
The lesson to be learned here is that we are driving heavy baggers and need the low end. The stock cam does a great job providing that. After spending a lot of money and taking a lot of advice, I gained 7 HP in a range that I never drive end, lost 5 ft lbs of torque and don't have as much low end as I did a year ago. Ain't life grand?? Learn from my mistakes. [smiley=confused5.gif]
SERK03