Se pro 103 performance upgrade kit
Ultimate HDF Member
Joined: Aug 2008
Posts: 5,413
Likes: 17
From: eastern oklahoma
those 259-E cams have great lift, and the whole combo works great. the 255 cams are good cams but they run out of steam before you really get the motor wound out. yes, the 58mm throttle body is too big for the 103 motor. remember you have to establish and maintain port velocity, and if the exhaust or intake are too big, then that port velocity goes down and your volumetric efficiency suffers. for a bike that runs very high speed all the time, like a drag bike, then you could use the opened up intake and exhaust, but on a bike you're going to be using as a daily driver, it'd be too finicky to work with. by the way joe98 and cigarcritic, the 27544-10 kit was designed for the new harley trikes because they're so heavy that they have a tough time getting out of their own way. we discovered that the kit really makes exceptional torque and horsepower, and at usable rpm's. some builds can make power at high rpm's and feel flat below that. there are others that can build power down low, but suffer at high rpm's. it's all about getting a balance throughout the rev range. i am really impressed with the kit i used. sure, an S&S 106 or fuelmoto 107, or other kits can do more, but for me, i can't see the need for more power. in a way, it's comfortably scary, but designed to be dependable in the long run too, so longevity won't suffer. good luck guys.
Road Warrior
Joined: Apr 2010
Posts: 1,529
Likes: 8
From: Central Fl.
Just to throw another option in there, my build (2 months old)
98"
Hillside stage II heads
Hillside bored TB
Andrews 37 cams
9.9:1 compression
111 tq 106hp 104tq @2500rpm. std
108 tq 104hp 104tq @2500rpm. sae
Tuned by Doc.
98"
Hillside stage II heads
Hillside bored TB
Andrews 37 cams
9.9:1 compression
111 tq 106hp 104tq @2500rpm. std
108 tq 104hp 104tq @2500rpm. sae
Tuned by Doc.
Cruiser
Joined: Jun 2010
Posts: 227
Likes: 0
From: Jersey
A word to the wise like someone else posted already anything above stage 2 isn't warranty. All kits stage 3and 4 are covered for 90 days according to harley davidson. If the dealer is willin to cover after the time expires good for for u. I have a stage 4 103 kit with 260 cams. When it was running it was a beast. Now I'm fixing the motor cause it wasn't installed properly by the dealer and with new pistons and cylinders I guess if u ride it like u stole it something is gonna give sooner or later. Good luck with ever u choose.
Road Warrior
Joined: Jun 2009
Posts: 1,943
Likes: 3
From: NYC
I looked at the fuel motto stuff and the one thing I don't like about it is the nickel plated cylinder walls as opposed to iron sleeve insert Harley uses. How the heck would you ridge cut and bore to use oversize rings on nickel plated stuff?
Road Warrior
Joined: Oct 2010
Posts: 1,332
Likes: 34
From: Michigan
Pretty sure Fuel Moto just bores your stock HD cylinders.
i just installed this 103 pro kit in my new streetglide 103.....i wasn't overly impressed so far....but i haven't been able to get into the throttle either....bike is brand new and trying to baybe it till it gets some miles on it....then i guess at 1,xxx miles i'll get it dynoed and tuned.....hoping it pulls harder than im thinking it does....but like i say.....haven't had it over 3xxx rpms....
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Ultimate HDF Member
Joined: Aug 2008
Posts: 5,413
Likes: 17
From: eastern oklahoma
if your new motor is going to have the 10.5 compression ratio, the se 259 cams are just right. the 255's are for basically stock compression and will build too much compression if used with the high compression pistons. i know i made the right choice when going to the 10.5 cr forged pistons and the 259-E cams. the kit i used is hd part#27544-10. i don't know where joe 98 got the wrong numbers, but this is the current number in the 2010 screamin eagle catalog. not in the thick harley parts and accessories catalog, but in the screamin eagle one. it comes with the sepst, which is a fine tuning device when dynoed properly. i'd suggest using a se compensator to give your starter a chance. with yours being a new bike, if it doesn't have compression releases, it'll sure need them with that 10.5 compression ratio. i'm using the manual ones, they're easy to use, and you can remove and clean or replace them if necessary. it'd be a pain in the *** to service the automatic ones.