Occasionally I work with other shops on builds that use my exhaust. Schultz Motorcycle Service in Yuma Az is one of those shops. Don Schultz has done more than a few nice 117 builds that get brought my way for the break in and dyno tune. These Yuma boys roll in the heat! The timing tables have to be spot on or there will be pinging issues at 10.5 compression. I know going in the expectations are high.
Yesterday Don unloaded a nice 2016 water cooled CVO Roadglide with the following parts.
117 top end kit, .030 head gasket.
Stock heads with beehive springs
58 SE TB, 5.3 inj, Ventilator AC
TTS 150 cam, TTS Mastertune Tuner
Fullsac DX Pipe, 2.0 baffle, Techmat
A simple proven cocktail that makes big Torque early and 120/130 every time. Well almost every time and that's what this thread is about. The last 117 Don brought for dyno had the Heavy Breather AC. Rolled out 120/130. Today's bike had the stock Ventilator with a bored backing plate to match the 58 TB. Final pulls were 116 HP and 129 TQ. Don doesn't look too pleased? I suggest we remove the stock CVO Ventilator and make two more pulls. Like Magic, 120 HP and 131 TQ. Once again the simplest part on the bike is working against us. The real point I want to make is the power loss was across the entire RPM range! Not just the top end numbers. The lower in the power band you go the greater the percentage of loss. It's 5 ft pounds at the hit! That's almost 5% torque loss starting at 1800 RPM. Unacceptable. Not sure what AC Don is going to upgrade too, but this is why we use dynos.
Next time you read a thread where it's mentioned the stock CVO AC is just fine. Well just fine if your willing to loose 5% of your low end power. I'm out.
Special Thanks to
Schultz Motorcycle service of Yuma Arizona for using and endorsing our exhaust products and dyno services.
Steve@fullsac.com