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Dyno Tuning the FJR

After installing the Power Commander III/USB (PC3) and the D&D Exhausts, I knew that the FJR needed a chance to strut its stuff. The best way to do that is by a little quality time on a dyno machine. Jim at Sabin Performance Cycle in Dallas, Texas was nice enough to open up on a Monday (when they are normally closed) to accommodate my schedule. Three hours later, we had run through at least 3 passes for each testing range and the custom fuel map for the PC3 was done. I took the long way home and am happy to report that throttle response is much smoother and no matter what I tried, I couldn't cause the EFI to feel like it was hunting for a proper setting (low load, 2500 rpm's).

Please note: I understand that a "complete" dyno test of the FJR would require a baseline run in its stock configuration. Even a so-called "complete" dyno test of this FJR would still be argued and hashed to death by those pointing out that this FJR (and dynomometer) is somewhat different than every other FJR due to manufacturing tollerances and other issues. That wasn't my intent. My goal was to tune the FJR to this new configuration to optimize its performance. There are plenty of other sources available that have already tested the FJR in its stock configuration. I have included links to some of those resources as a way for the reader to have a reasonable comparison.

I'll report later after I've had more time and miles with the new setting on things like overall performance and fuel economy.

The process is pretty straight forward. Like anything else, it's always easier if you have the right tools. They pull your bike up onto the dyno stand,

hook it up to their computer system,

and then run several passes as they DynoJet 250 updates the "map" in the PC3.

I could hear audible irregularities during the first pass in any given band. The 2nd pass would be smoother. The third pass would be "perfect" (to my ears at least); no bobbles or hesitations as the motor accelerated up to its target speed.

Jim explained, in detail, each step and was more than patient with any questions I had, as I tried to follow along. What is happening is that the first pass (using the PC3 "zero map") is doing nothing to the OEM EFI mapping. After that pass, the dyno "learns" where improvements can be made and uploads corrections to the PC3. Those corrections are used in the second pass and corrections are again made to the PC3 map by the dyno computer. On the third pass the PC3's map is fined tuned again if needed. The final results are stored in both the PC3's memory and on a file in the dyno computer. Jim then gave me a floppy disk with the map file and the charting data to take home with me. DynoJet has a free viewer that you can download to view the data file(s). You can view them in an uncorrected graphic format or use any of several correction factors that take into account temperature, humidity and barometric pressure (these help standardize the results for different dyno tests in different cities or on different days).

The whole process was very trick. The results were "sick" (in the good sense of the word).

Historical Tests From Other Sources

MCN reports their results (chart) for a stock '03 FJR as: 120.7 hp, 87.6 lb/ft


Wally's Dyno Run of a stock '03 FJR with PC3 installed shows: 119.25 hp, 86.29 lb/ft


Micapeak's European Dyno Chart of a stock '02 FJR reports: 127.1 hp, 90.4 lb/ft

Tests At Sabin Performance

Jim Fortner's '04 w/OEM cans, air filter, PC3=N/A or zero map (blue): 119.9 hp, 85.3 lb/ft
Mine w/D&D cans, OEM air filter, PC3=zero map, O² disconnected (red): 129.5 hp, 90.8 lb/ft


Tuned: My '03 (as above) after the dyno tune and PC3 mapping update: 131.24 hp, 91.36 lb/ft

Download Onethumb's Map: M409-MJ82
Download Wally's "Smoothness" Map: M409-WK008



All material on this site (c) Mark Johnson February 17, 2004 - 2011. All rights reserved.