13. To release the main wiring harness from the ECM the release button (top arrow) was pr
A closed loop system can be remapped as well as using add-on modules to modify air:fuel that work in conjunction with the factory ECM in the same way as open loop; tuning will still be limited by the narrow band O2 sensors.
While adding aftermarket wideband oxygen sensors allows a wider range of air:fuel monitoring, the stock ECM will still need remapping for changes in engine airflow, and for optimal performance require expensive and time consuming dyno tuning. Be extremely careful when choosing a dyno tuning technician; treat the situation like real surgery. Because of the relative complexity of EFI there are many hacks that capitalize on misinformed customers. It’s very easy for a tech with little experience to make your bike run terribly, then sell you more parts to try and “fix” what he messed up. It’s easy to get fooled into the next, best, black box, so do your homework and make sure you have referrals. It can get very expensive when your bike doesn’t run right. If you plan on any engine modifications try and have a plan and do the mods all at once if possible. That way each time one part is changed—pipes, airbox, cams, headwork, big bore kit, etc.—you won’t need to get a dyno tune.
14. The main harness connector was cleaned and the rubber gasket (arrow) checked for dama
Another option that largely avoids dyno tuning is the addition of a new ECM that is easily modified and can handle a wide range of performance upgrades. There are several on the market that after engine modifications can tune the EFI and ignition just by riding the bike. Ranges of tuning after performance modification vary by manufacturer but they all provide more and better control over the fuel and ignition system. They’re not for everyone, but if optimal tune and avoiding a lot of dyno time is your goal there is an option.
One such device is the ThunderMax ECM with integrated AutoTune that works in conjunction with two wideband oxygen sensors. Using either a stock or aftermarket throttle body the closed-loop system automatically adjusts fuel and ignition requirements due to performance upgrades such as pipes, airbox, and cams. ThunderMax can also add this same closed loop operation on your older Magneti-Marelli or Delphi systems. ThunderMax works with either throttle-by-wire or cable-operated throttle bodies.
The ThunderMax wideband, five-wire oxygen sensors thread into bungs located near the exhaust port, and are the same thread size and location as stock narrow band sensors used on ’08 and ’09 exhausts. For ’10-12, smaller oxygen sensors were used and located forward of the catalytic converter near the transmission. The ThunderMax sensors must be mounted in the ’08-09 location and on newer machines either new bungs will need to be added to the existing headers in the upper location (with the lower stock sensors removed and ports capped) or ideally order an exhaust system for a 2009 model (fitment is the same for ’10-12 models) and the ThunderMax sensors will install without modification. ThunderMax has all the info needed and detailed instructions and support.
15. The autotune harness plugged into the ThunderMax (arrow) with the logo facing up and
To get a better look at the system and try it we ordered a ThunderMax TBW (PN 309-362) for ’08-12 throttle-by-wire H-D Touring models. The system includes a ThunderMax TBW ECM with integrated autotune module, two wideband oxygen sensors, USB communication cable, TMax tuner software, and ThunderMax TBW quick start guide.
We recently installed a ThunderMax ECM with an autotune module on a 96ci Twin Cam that had only airbox and pipe modifications. The bike ran well beforehand but afterwards the owner said he couldn’t believe it was the same bike. He reported a super-snappy throttle response and a cooler running motor, and while there was no dyno chart (he didn’t need to pay for one) he said the bike had much more seat of the pants torque.
The First Start
After a new module install or interruption of 12-volt power takes place perform the following procedures:
• Turn the ignition switch on and the handlebar switch to run for at least 20 seconds
• Cycle the ignition switch off and on and start the engine
• Let the motorcycle idle on its own for at least 15 seconds
• Turn off the ignition and then restart the motorcycle.
Normal idle speed should be attained depending on engine temperature. The warm-up cycle will have slightly higher idle speed until it reaches operating temperature.
Zippers Performance Products
(410) 579-2828 | Thunder-Max.com