In choosing a Dyno...
- Be especially wary of the one-size-fits-all selling approach at a dyno.
- All air cleaners are not power-robbing dirty, nor are all spark plugs bad!
- About half the fuel injected Harleys DON'T need an EFI tuning device.
- Insist on two matching baseline runs. Otherwise "gains" can be faked.
- Dr. Dyno doesn't sell any parts or labor the bike doesn't actually need.
PowerCommander vs SERT
I prefer PowerCommander because tuning is done live (without shutting the bike off).
It's like all the traffic lights turning green when you come to them.
SERT tuning requires continual down-shifting and stopping, and then accelerating again.
In effect all the lights turn red just as you get to them.
Considering a full tune may involve 30-50 runs (traffic lights, each 40 seconds if red), the
PowerCommander tuning "trip" I can complete in an hour may take three hours with a SERT.
If you do have a SERT and want further tuning, you need (1) the black interface,
(2) the interconnect cable, and (3) a copy on disk of the current map in the bike's ECM.
I recommend asking your dealer for a backup copy when they modify an H-D download.
Dual Air/Fuel Testing
The second Air/Fuel Ratio Module I added for 2007 allows simultaneous measurement and display of A/F curves on both cylinders on V-twins . This has reduced the number of dyno runs needed to complete individual cylinder tuning on EFI models from 45-50 to 25-30. That's easier on the bike, easier on the wallet and let's me fully tune more bikes On carbureted models it allows best overall jetting of one carburetor for both cylinders. TorqueTuning can be better optimized when different A/F ratios between front and rear cylinders result from right-angle air cleaners (such as D&M) and unequal length exhaust systems.