Harley Davidson tuning

Why do Harley's cost more to Dyno tune?

How can such a simple motor be more money to tune over a 4 cylinder Japanese bike?  The answer is simple.  We are basically tuning two separate motors, the front and back cylinders, have completely different fuel requirements, as well as timing.  The front cylinder is up front in the air stream and gets a good opportunity to cool off.  The back cylinder is not quite so lucky, where the temperature can vary as much as 120° from the front cylinder.  This significantly changes how each cylinder wants to be tuned.

 

 

Generally, Here is what we are doing and how we get the results we get. We'll are 4 gas analyzer with a very long metal probe. And with a flash light will make sure it goes into the rear exhaust pipe. At the point we will do a step test through the RPM range and throttle % range. Stopping every 500 to 1000 rpm range. Looking at the 4 gas and at what throttle opening and rpm on the power vision dash. I'm able to dial the fuel requirement in to a 1% range instead of 6 or 7 %. Making for a smooth even power that runs cooler and gives you better fuel mileage to boot. When we're done with tuning the rear we move the probe to the front and repeat.  When you go through that you cant help to have a good running Harley.  

 

Depending on the motor modifications, this process can take a couple of hours per cylinder.  But generally when we are done, we have a Harley-Davidson that runs absolutely flawlessly.  It runs smoother, cooler much better throttle response and usually better fuel mileage.  Finally, if you were to look at the maps between the before and after tuning, you would swear they were two separate motors.  Actually you would be right!! Below is a typical dyno graph for a Harley tune. The customer was saying it didn't run that bad. He just had no idea how good his Harley could could run..... If you have any questions please feel free to call and talk the Chad of if I'm available me. We're here to help. Thanks for taking the time to read my little articular and I hope it helped.