OK, so here’s what’s going on a at least two local Harley-Davidson dealers: You buy a new bike. They offer you a discount on items included in either the sale of the bike or within a certain period after the sale. Common items are exhaust and air cleaner upgrades (aka Stage 1). Dealers are telling people they need Harley’s Super Tuner to tune their bike for the Stage 1. While it’s true that you will need to have the bike tuned (really tuned, on a dyno with a certified Dyno operator) in order to correct the extremely lean EPA satisfying emissions standards, you DO NOT have to buy the $470 tool they want to sell you. The dealer may say you need the Super Tuner so he can “Smart Tune” the bike. Smart-tuning” consists of plugging the Super Tuner into your bike then riding it around so it can “learn” what the bike needs and theoretically make its own corrections. This is a whole lot like pissing up a rope and I’ll tell you why. Although a good idea if it worked, the “Smart Tune” feature of the Super Tuner is limited by the ability of your narrow-band O2 sensors to actually make adjustments. Simply because of their design, they can only adjust ONE TENTH OF ONE AIR FUEL RATIO. That means if your bike is currently real lean at 15 parts air to 1 part fuel (common for Harleys and dangerously lean!), the Smart Tune can only change the ratio to 14.9:1. That’s it! That’s as far as it can go. And without running it on the dyno, they can’t tell you what your actual Air/Fuel Ratio is. Only the dyno can do that! What you need is to get the Air/Fuel Ratio (AFR) to somewhere around 13.8 parts air to 1 part fuel at idle and down around 13:1 at high throttle positions. Without a device such as the Thundermax, which is THE ONLY REAL auto-tuning device on the market, THIS CAN ONLY BE DONE BY ACTUALLY TUNING THE BIKE ON A DYNO WHERE MANUAL CHANGES ARE ENTERED INTO THE FUEL MAPS. Most HD dealers don’t want to do this because it’s time consuming and because they don’t have Certified Dyno Operators. They do a poor job at best and cost you a lot of money in Dyno time. So I ask you…Why buy a Super Tuner from your dealer when they’re never going to tune your bike? It’s a $470 paper weight! If your dealer tells you it was dyno tuned, they should have presented you with three graphs of your bike’s results. One graph shows the horsepower and torque. A lot of tuners just print this for you because everyone gets excited about their power numbers. What’s more important is to be able to see the individual Air/Fuel graphs. That’s right, there should be one for each cylinder! On these two graphs, you will see with your own eyes whether the dyno operator did his job or not. What I mean is that if the AFR graphs look like tsunamis or EKG waves, your dyno operator didn’t do his job. Those two AFR graphs should be smooth, straight, and real damned close to the target AFR which I mentioned above. If you did not get a printout with your bike’s results, it didn’t get Dyno tuned. If it didn’t get dyno tuned, you didn’t need to buy that $470 tuner. Now then, to give credit where credit is due: Harley’s Super Tuner is a great tool. There are several other real tuners on the market that are just as good and better in some aspects. All of them are $100 less than the Super Tuner. If you want to get the best technology available, you can go for the Thundermax which is a REAL auto-tuner using wide-band O2 sensors capable of changing the AFR up to two full ratios (15:1 down to 13:1) with just some basic setup. It’s pricey but it does what others falsely claim and it virtually eliminates the expense of Dyno time.
This article was written by Admin