Hey Doug, I beleive it us the other way around. I remember reading on here somewhere that the air boxes flowed better. Met you at the ride to Plant City. I have just installed my Thunder Teardrop and love it .
I have the Kury Pro Hypercharger. Would not by it again. Everytime it rains I am in major trouble about getting water in the carb. Also the F/A is not consistant on a Hypercharger. The faster you go the more air is forced in and thus changing the F/A ratio. I recommend going to a airbox. Also I have noticed that a lot of people that have them the louvers never work properly. This is also the case with mine.
I have to dissagree with Swoop, Its a Hypercharger NOT Ram air, there is a opening on the bottom to allow air to pass through. Also the filter is oiled to collect any rain water, I love mine, I definetly would but it again.
the thunder air kits come with a 210 main jet that will you absoultely need to use. If you have not already rejetted previously then you should get the Dynojet stage 1 kit as you will need the adjutable needle, spring, and clip. The concensus over the last year has been that there is very little performance gain from most air kits but the only measured gains I have seen have come from the Thunder kits. I used this info to make my decision to put on the 7" round and my "seat-of-the-pants" dyno says it rocks as does the other, un-upgraded, 1300 I ride with.
I have an '03 1300S, HK 3"ers with straight-through baffles.
I put on the Thunder 7" round kit with the 210 MJ
e-clip on the 4th notch on the needle and almost 3 turns on the screw
SE Wisconsin ... cool weather right now
about 2 weeks and I have not dyno'd yet to check A/F mixture
Doug, I got the Thunder tear drop from HDL, teh jet kit i picked up at Prefomance in Winter Garden.
I have not dynoed it yet, but it esems to run very well with a 210 main, needle in the 4th slot, with the screw 3 1/2 turns out. Let me know if you need some help. I'll get it to a dyno when i can ride again (about 2 months).