These test stand numbers are from a production NR Speed 13 purchased from Buddy at SMT Distributing LLC, at www.smtdistributing.com
We will be posting more info as it is available.

BTW, we are also testing coupler material provided by patternpilot1, seems to be working very well so far. Thanks, Scott.

The first numbers are with a Hatori 650 pipe, also being tested are the old Mac's "flat back" pipe, Mac's Muffled Tuned Pipe, the NR pipe and Mac's Quiet Pipe. We are attempting to make the runs when atmospheric conditions are similiar, not easy in central AL this time of year.

1. NR Speed 13 production engine w/10mm carb, PowerMaster 10/22 fuel, NR plug as supplied with the engine, NR straight header, APC 11x7 prop, Hatori 650 long chamber pipe, 16 5/8" to first baffle: rpm 15,800 peaked.

2. The same Speed 13 w/10 mm carb, Cool Power 15%, NR plug as supplied with the engine, NR 1" rise header, APC 11x7 prop, old Mac's flatback pipe at 14 3/4" to beginning of convergence: rpm 15,700 peaked. Humidity and temp slightly higher than Hatori data.

3. Same Speed 13 w/10mm carb, Cool Power 15%, same NR plug that came with the engine, NR 1" rise header, APC 11x8 prop, Hatori 650 long chamber pipe at 17 1/4" to first baffle: rpm 14,800 peaked. This set up seems to duplicate what Dave P. saw with the NR 50400 pipe and NR 2" rise header, both systems set with slight gap between header and pipe. More Rs may be available, but this is major power, with no trial and error necessary.