Make your bike run great in 2008

Dyno Testing All Motorcycles

Expert Tuning American V-Twins


Dr. Dyno hit the pages of American Iron Magazine again in 2006 with some well received articles!
(Look for more in 2008.)

The May, June, July and August 2006 articles are available now - with September to follow.
I've made a couple corrections and clarifications which are in italics.
The two AIM articles from 2003 also remain good current references.

The May issue is an updated reprint of the first "Dyno Dos and Dont's" from  April 2003
The June article details proper dynotuning of carbureted Harleys, including TorqueTuning.
In July I explained why dynos read differently - some reasons legitimate, others purposely faked.
The August article covers the H-D Race Fueler, Dobeck Performance TFI,
Custom Chrome DFO and Kuryakyn Wild Things FI controller. 

The September article details map-based EFI tuning options.
  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.


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.

   
 

V-Rod under Lexan  --  NOW 132 HP @ 8000 RPM   Update 3/7/2005,  140 HP!

  

Dr. Dyno specializes in "Feel the Difference" therapy for Harley-Davidson motorcycles.

Dr. Dyno tests all motorcycles, from Panheads to V-Rods and Sport Bikes, strictly within the owner's constraints.
The rpm and speed YOU ride is where the power counts.

Why pay someone else for an "improvement" that's only on a printout when Dr. Dyno wants to read it by the grin on your face? About half of the V-Twins out there are running 10% to 50% below their potential at the speeds they're being ridden. Every bike is different. Every rider is different. Dr. Dyno takes tuning one step further than the "Mr. Dynos," he moves the power band of YOUR BIKE to where YOU RIDE. That's tuning the bike to the rider and that's the Dr. Dyno difference!
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.
Here are the four areas the doctor uses to make you "Feel the Difference."

1. Air - Assemble and install non-restrictive high flow air cleaners.
2. Fuel - Right-jetting carburetor or Proper-programming PowerCommander, TFI/DFO or Race Tuner.
3. Ignition - "Sweet Spot" timing. For best power and economy, timing is everything.
4. Exhaust - TorqueTuning pipes to cam timing by adding or reducing backpressure to put the power where YOU want it.
 

To those who say you need to jet your carburetor for your pipes I ask, "For what, midrange power or top end?" You won't get both. Conversely, simply tuning the air/fuel ratio on fuel injected Harleys doesn't necessarily result in best midrange power.

Your feedback to comments@drdyno.com is almost always welcome.

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