How does a Power Commander work?

Inside the computer of fuel injected motorcycles is a “fuel map”. At given throttle positions, RPMs and other factors like air density and temperature the computer uses the fuel map to tell the fuel injectors how much fuel to spray into the engine. When changes are made to the motorcycle that effect the amount of air the engine uses (like an aftermarket exhaust or air filter) then changes to the fuel map need to also be made. A Power Commander intercepts the signal going from the computer to the injector and modifies it to add or subtract the right amount of fuel to make the appropriate air / fuel ratio.

What is Tuning Link and how does it work?

Tuning Link is a software program developed by Dynojet for use with their dynos to tune their Power Commanders. While the bike is being run on the dyno at different RPMs and throttle positions the air / fuel ratio is constantly being computed. Changes to the Power Commander are made automatically by the Tuning Link software while the bike is running! Before Tuning Link the motorcycle would be run through the RPM range on the dyno at a given throttle position. Then the air / fuel ratio is calculated by the dyno operator at different RPMs of the run. Those calculations are then entered by hand into the Power Commander. Another run is then done at the same throttle position and differences noted. That cycle continues until the dyno operator is satisfied with the “tune”. Tuning Link is a quicker and more exacting tune!

Do I need a custom map?

There are a lot of downloadable Power Commander maps. Just as off-the-rack clothing of the same size may not fit just right, custom tailored clothing is made exactly to your size. Every bike is a bit different so not every map fits every bike. Even with a map that was made on the same bike with the same equipment there is always room for improvement.

Does dyno tuning hurt the motorcycle?

No more than riding it on the road does.

Why are dyno readings between dynos different?

Horsepower is a computed figure based upon how much torque an engine produces. The torque of the motor is measured on a dyno by how quickly it can rotate a drum of a given weight. Several variables like wear, lubrication, temperature, etc can effect how easily or hard the drum can be rotated thus skewing the torque reading of different dynos or even the same dyno on different days. An eddy current dyno produces more repeatable and consistent results by controlling the speed of the drum that the motorcycle is turning. The DynoJet 250i also samples air pressure, temperature and humidity within the room. It uses this data to apply a “correction factor” to the computed data. Since engines generally run better in cooler air with less humidity the motorcycle run at different times could show different output readings. The correction factor ensure that the operator is comparing “apples to apples” when looking at runs from different times.

Do "auto tuners" work?

Short answer: Yes. Long answer: “A tool is only as good as the person using it.” Being given an auto-tuner is almost like being given a dyno. It’s just a tool but it takes training, knowledge and experience to use it correctly. Examples: what air / fuel ratio will you be tuning to? What’s too lean? Too rich? What ratio gives your bike the best horsepower without “hurting” it? How can I get rid of a hesitation or jerkiness? These are all questions that are answered during the creation of a custom map. Once that map is made there is really no reason to change that map (the bike compensates for temperature and pressure changes) unless changes are made to how much air is being passed through the bike (e.g. new type of air filter, full system instead of a slip-on, head porting).

What do I need to do to my bike before I bring it in for a dyno?

Most important is to have the bike in the configuration it’s going to be run in for a while. If you’re going to take off the slip-on and get a full system in a few months that would require a completely different map. It would be better to wait until you have the full system.

Ensure your air filter is new or clean. If we tune it for a dirty, clogged air filter it will run great as long as you continue to have a dirty filter.

We’ll give your bike a safety check when it shows up looking for things like: dangerous chains, oil or coolant leaks, severely worn tires, etc. Bikes that we wouldn’t ride on the street: we won’t ride on the dyno! Luckily you’re at an awesome bike shop!

  • Labor Rate = $90.00 an hour
  • Bikes 10 years or older = $94.00 an hour
  • Licensed Racers = $86.00 an hour

Wanna Go Faster?

Contact Us To Schedule Your Dyno Run!

How To Read A Dyno Sheet

We normally have 3 lines on our dyno sheet: horsepower, torque and air/fuel ratio.
This sheet shows three dyno runs from the same motorcycle. The motorcycle was run in 4th gear at 100% throttle position.

This graph shows the difference between the first and last run of a motorcycle after tuning. The red lines being before and the blue lines being after a custom Power Commander map was created.

The taller lines in the upper chart indicates horsepower (upper left vertical scale) at given RPMs (across the bottom scale). This is commonly called the “power curve”. The other lines in the same graph are torque and are measured in foot / pounds at given RPMs.

The lower graph shows the air/fuel ratio as the motorcycle goes through the RPM range. The red dotted line indicates a target air/fuel ratio of 13.2 to 1. Below the line indicates a rich condition and above the line a lean condition.

As you can see by the “before” air/fuel ratio line, the bike was originally running in a very lean condition. After tuning to the proper air/fuel ratio, the changes equated to nearly 9 more HP and over 3 ft/lbs of tourqe!

Our Dyno In Action

Every bike I have owned since I’ve moved to the area has been serviced at MarMo. Quality, detail-oriented mechanics, and a history of supporting all levels and kinds of two-wheel racing. I am honored and humbled to be able to run their stickers on my race bike.

Ed Eberhart

Well, I have been coming to this shop for 5 years now. Guess it’s finally time I give it a review…I’ll never go anywhere else. The people here literally taught me to ride on the track and a few years later I raced in my first pro race. Out of all the times I have raced and been on the track, I’ve only had ONE mechanical DNF and it was because of a faulty fuel pump plug. They disassemble and build my race bikes, suspension, motors, and dirt bikes from the ground up every year. I never have to worry about the safety or ability of my bike while I’m riding and that’s definitely worth a few seconds.

Anne Roberts

Hey MM I want to take a min and brag on you guys. Over the years I’ve been coming to you for service and tuning service and tuning tuning and more service tuning tuning tuning and well there is a reason why I won’t use some of the other guys livingood,huff,caylor, to do my work. I only have 1 life and when it comes down to who I trust with working on my bike it will be MM for life. You guys will take the time to explain what is happening and such and most the time I’m just nodding saying uhh hmm but I’m just shifting gears in my head with the high rpm sounds of my 2012 zx10. I love you guys and love the fact that I always get fed on Saturdays. Sheer coincidence I always show up at 11sharp..I think not.. huey Selena Skinny you guys are amazing. Don’t change anything about how you guys do things. I’ll keep referring you guys to everyone I know as long as you keep me the fastest guy in Atlanta. How fast do i wunna go???? I want to go as fast as possible and I believe you’ve created a monster Huey.

Josh Booth
Rates For Dyno Testing

dyno_jet_approvedThe rates for dyno tuning vary based on the type of testing and the motorcycle.

Please contact us with any specific questions, a quote for your motorcycle, and to schedule a time to get on the dyno.

Fun Run HP Only

  • Bike is run until max HP is reached Full printout of your bike’s horsepower

Fun Full Run

  • Bike is run until max HP/Torque reached Full printout of your bike’s horsepower, torque, and air/fuel ratio

Full Custom Tune

  • Custom maps for your Power Commander (3 USB/5) or Bazzaz Personalized map created focusing on: peak performance rideability usability

Aftermarket ECUs

  • Updated MAP for your EmPro, YEC, Kit Kawi, etc Bike is run until max HP/Torque are reached Full printout of your bike’s horsepower, torque, and air/fuel ratio

Rejet Carburetors

  • 1 hour + 1 hour per cylinder (e.g. 4 cylinder = 5 hours) X Our labor rate. Full printout of your bike’s horsepower, torque, and air/fuel ratio

Yamaha ECU

  • Re-Flash your R6/R1 ECU Read More