Opinion on 117" Build

[rmruder]

MIke,

I just purchased a 2003 Road King with a 117". It has originally dyno'd at 122HP and 124T. Compression is stated at 10.8-1. Here' s the set up:

HD 4 3/8" Stroker Crank
Axtell 4 1/8 cylinders
JE Forged 20 degree pistons-reverse hemi dome
SE HTTC CNC ported heads with additional exhaust porting and machining for the JE pistons
S&S 625 geared cams
S&S Roller rockers
SE Rocker cradle
C&A Gapless rings
SE 51mm intake
S&S Super G manifold
Feuling hydraulic lifters
PC III
and..........
Latus Throttle body with interchangeable venturi's.......48mm and 53mm

lots of other little goodies to go with the build.

Questions:

What do you think of the build in general?
Are the numbers good for the build?
Any recommended changes?


Most important........tell me more about the throttle body! Apparently this is a custom job from you. Which size venturi would you recommend? Do you make other sizes besides the 48mm and 53mm? From some of my reading it would suggest a 58mm or larger for this build.......but I know bigger isn't always better.

This is street bike only and has plenty of get up and go. I can regularly get 93 octane gas locally. If I can only find 91 during travels is that still OK?

Thanks in advance!

Rick

[Mike]

Generally a very good build. We prefer to see these tuned with SERT vs PC because of the ability to change tuning constants and other tables PC does not allow. Also allows synchronizing of the IAC motor/table for better idle quality.

The throttle body is a Beta version which is now in production as a cast unit (just ordered first production run). Otherwise no functional differences. Because of the unique venturi design and placement, the throttle body flows more air vs plate diameter than others with the plate placed in the middle of the venturi (we call it the Mikuni affect where Mikuni Smoothbore carbs tend to flow more air in sizes smaller than other larger carbs). Testing has shown that venturi sizes as small as 46 will support up to 144hp (STD/5th gear). Because of similar perceptions to yours, that 54+ is required, we often install larger venturi's to satisfy owners. With a smooth bore, the t-body will be 57mm and we have venturi's of this size available. For best drivability, we recommend the smallest venturi that does not restrict hp, as found via dyno testing.

With good tuning (SERT), 91 should be OK.
Mike