Zipper's Smarter Fuel Injection

Getting To The Next Level Of Performance EFI Tuning-Automatically!

Here's what you get in the Thundermax with AutoTune kit (# 309-360) and it's ready to install on Big Twins already equiped with Delphi fuel injection and oxygen sensors, mostly '07 models. Older Big Twins with Delphi systems without the sensors can use this once sensors are added. If your bike is equipped with an earlier ThunderMax module, you can contact Zipper's for info on the oxygen sensor add-on kit and any firmware upgrades that might be necessary to upgrade to closed loop. (EFI Sportsters need kit #309-365.) Any bikes that don't already have bungs in their exhaust pipes will also need the weld-in bung kit #272-200 (See sidebar).

Once the kit is unpacked, to install it on a dresser as we are here, the next move is to remove the side cover and take out the fuse marked ECM Power from the fuse block, which is located in the top right of the picture. (This procedure is a bit different than it would be on Dynas, Softails, or Sportsters, but the ThunderMax instructions are clear for any application). Then unplug and unscrew the factory ECM; you won't be needing it anymore.

Plug the ThunderMax module into the factory harness jack, but do not mount the module yet. There's a bit more messing about to do first, like neatly routing wire harnesses from the sensors to the ECM and such.

On machines that already have O2 sensors, it's pretty much a matter of routing the sensors wires-as per the stockers-which you remove as you install the Zipper's wide-band equivalents. Unless you have a better idea, that's usually the simplest way. If you have custom pipes where bungs have been installed in non-standard locations or on early models where they've been added it's more a matter of trial and error. Just make sure there's no stress, strain, chafing, or heat getting to any wires anywhere once the sensors are plugged in.

Once that's all happy and cozy, you plug the AutoTune portion of the ThunderMax into the factory data port socket.

Move on to installing the wideband oxygen sensors by adding a little anit-seize to the (clean!) threads and hand starting them into the bungholes.

Final torque (and believe me, you don't want to just reef on these things) is best accomplished with a special tool like this one, available from most automotive tool sources. The alternative, naturally, is an open end metric wrench, but you'll have to go slowly here and be cautious not to "wound" the flats on the sensor-you might just have to service/replace it someday, after all!

You'll need to run the wire harness plugs for each sensor to junction with the ECM harness. In the interests of clean routing, heat avoidance, and secure installations, zipties can certainly be of help here!

Once you've got that handled, the next step is plug the respective (and clearly marked) O2 sensor leads into their respective sockets on the ThunderMax harness.

After the remaining wires are tidied up, bundled, and ziptied, you bolt up the module. It should look something like this.

Computer time! Take the Zipper's software CD and slap it into the PC of your choice to install the program(s). There's a free demo of how the rest of this process should go down on the disc as well. So if you're not too excited to bother (and you shouldn't be) it's worth watching a time or two before you start "networking" with your motorcycle.

It takes awhile for the software to do its thing, but after that few minutes, and dealing with any prompts and particulars peculiar to your PC or engine,you cable up to the ECM's USB.

Fire it up, then wait until the screen shows an engine temperature of more than 245 degrees (operating temperature). The software is creating virtual IAC (Intake Air Temperature) steps, which affect how the engine drops back to idle (among other things), then correlat es it all to the target IAC maps in your chosen base map, a fairly important aspect of this whole auto tuning deal when you stop to think about it. That's really about all there is to it, unless by some remote and weird chance you need to override anything, like air/fuel, in which case you can go to another instruction area on the CD and do some manual tuning with the software. Not bloody likely-but nice-if you ever need it.

The biggest pointer we can offer is to select a base map from the files that are as close to the specs of your machine as possible! Though the system works pretty well, it helps the auto-adjusting aspects of the AutoTune system, to tune that much quicker and better if it's damn close inthe first place. The filtering process in making the selection more goof-proof leads you through several decision tree types of screens, asking you to select engine type first, then throttle, exhaust, and so on. Once you load a base map, there's some configuring to do as the software prompts you move through a few more screens, refining the base map settings and calibrating the speedometer, among other things What's important to remember is that you must choose closed loop operation for the system to work with the O2 sensors. Next, initialize the ECM by turning the ignition switch to the on position, but don't start the engine. Instead, cycle the switch on and off three times for 30 seconds each time in each position. Once that's over with you finally start the bike, but only twice and only about 10 seconds each time. Then shut it off, but stay linked. Go back to the Smartlink software and move through a couple more screens to get things ready to fire up under closed loop operation.

Once the Smartlink software boots, and the ECM is communicating with the PC, the instructions will lead you through some preliminary steps to get to the base and settings.

All that's left is to unplug, button up, and buff down as Steve and Bob are doing, then get it off the lift and go! Later, after a few hundred miles of riding to let the system do its AutoTune thing, you'll need to merge the maps. Soon enough, you'll see the benefits of a system that's not stuck with fixed, static, inflexible engine management and its limitations, no matter how finely mapped. Instead, you get a machine that will constantly adjust to how you ride, where you ride, and what you've done (or do) to your ride. Whether it's cruising in the thin air above timberline, running hard below sea level in Death Valley heat, or anywhere and anything in between with any combination of hot-rod goodies in the motor, this EFI system's got you covered. It's also important tonote that this system will create offsets from your base map to maintain proper AFRs. In addition, with the system functioning, you can record a riding session in a monitor log, and replay the session on your computer. This will allow you to watch the AFRs under normal riding operation. This can help reveal issues like a clogged fuel filter or an intake manifold seal leak. We strongly suggest you bring the engine to normal operating temperature, then review and log the values using the Engine Monitors and Monitor Logging functions of the software. These values are vital in troubleshooting a problem that may be keeping the engine from operating properly. With the new Monitor Logging feature, youcan log an operating session and email the data to Zipper's Technical Support for review.

The process starts with the bungs themselves, naturally. There are several kinds, but all of them take your basic 18mm x 1.5mm threads, those being the standard for O2 sensors. This is the package of bungs (with plugs in place) supplied by Zipper's for our ThunderMax AutoTune install. Note the design, which has rather deep shoulders oriented towards pocketing the bung deeply into the pipe in a perpendicular (90 degree) position from the pipe wall.

Meanwhile (as we'll see much more clearly later) some others (like these, from S&S;) are still for perpendicular installations, but are a lot shallower and have a contoured surface, rather than a flat one, where they meet the metal.

As you see here, there are also angled bungs, such as these - used on plenty of exhaust systems designed with them in mind - for 2007 and newer (factory closed loop) applications. Mind you, one can make any of these designs do the job, but some might be better suited to certain pipe bends.

Like this one! It's a real challenge to get an oxygen sensor tucked in right and out of sight with a header radius this tight. Several of the true dual styles are this...tough.

Once you've made your choice of both pipes and bungs to fit them, you need to carefully contemplate where they will fit. Take your time here, and if possible, make up a tool like this: An old, junky O2 sensor with the tip cut off. (If you can't quite manage that, second best choice would be an old spark plug or something close to the same dimensions as the sensors you plan to use in your closed loop conversion.)

Place the tool in any potential location you think will work for your exhaust. Try at least a few (but not this one) to be sure there's room for bung, sensor, and wires to be installed (and someday removed for routine replacement). Optimal placement also means a location between four and 12inches from the exhaust flange on any pipe, and not less than three inches downstream on the Factory Y-pipe rear header. Even though they're pretty well shielded, keeping the wires away from excessive heat is a good plan too. Once you're satisfied, mark the spot with a Sharpie. It might be a good idea to outline the bung, then remove the sensor part of the tool, and dot the center.

Getting it right results in a perfectly good set up like this, in even the tightest of locations. But let's not get ahead of ourselves...

Repeat the whole process forboth front and rear head pipes before you remove Anything from the bike. Check everything as often as you need to be comfortable with your mounting locations. Then it's time to pull one of them, stick it a vise, and punch a mark for drilling the pilot hole.

Eventually, you'll need to make this 1/4-inch hole in the header large enough to accept the tip of the oxygen sensor. But you've gotta start someplace and a 1/4-inch is big enough to get this tool in there and hog the hole out until it's just large enough for a snug slip-in fit (about 3/4-inch) then pull the bung back out, de-burr and clean the area around the hole, then stick the bung back in as preparation for welding! (Okay, right here we should mention a couple of things, namely that this particular pipe isn't chrome-it's been coated by Performance Coatings and it needed a lot of prep and weld to get that coating off around the hole so we could weld the Zipper's bung in properly.) get this tool in there and hog the hole out until...'s just large enough for a snug slip-in fit (about 3/4-inch)...

...then pull the bung back out, de-burr and clean the area around the hole, then stick the bung back in as preparation for...

...welding! (Okay, right here we should mention a couple of things, namely that this particular pipe isn't chrome-it's been coated by Performance Coatings and it needed a lot of prep and weld to get that coating off around the hole so we could weld the Zipper's bung in properly.)

The same operation on a regular chrome pipe, using an S&S; bung, went differently-so much so that re-chroming after welding was not required.

Here's the end result on the Performance Coatings chromex-coated pipe as the threads on the bung are being cleaned and chased with an 18mm x 1.5mm tap.

Here's the end result on the Performance Coatings chromex-coated pipe as the threads on the bung are being cleaned and chased with an 18mm x 1.5mm tap.

Anyone with a fuel injected Harley should be paying close attention: Quite simply, it is not only far better when EFI systems are controlled by actual feedback directly from the engine (via sensors) it is also easier.

Older, open loop EFI systems, while more efficient than carburetors, also involve a lot more effort to be any more effective. Or it did. With the advent of so-called closed loop EFI on 2006 Dynas, H-D has made a giant stride in precision engine management. Trouble is, all the Factory system manages, in fact the reason for the whole EFI thing, is emissions compliance. The deal boils down to something like this: Narrow band oxygen sensors and an ECM/ECU that lock into lean 14.7 air fuel ratios on cruise. In effect, all the tools but no intention to offer true performance.

Zipper's Performance ThunderMax system, on the other hand, builds on this firm foundation by providing the exact set-up required to turn closed loop EFI into the high-precision, high-performance system it should be! Swapping the stock ECM for the ThunderMax unit and switching to Zipper's wide-band O2 sensors is pretty much a plug and play operation on '07 and newer Harleys (as well as '06 Dynas) but the real beauty of it is that folks with older, open loop factory fuel injection can update and upgrade as well by adding oxygen sensors bungs to the exhaust. (See the sidebar for more information on doing that correctly, courtesy of Bob at R and R American Cycle).

Once you install the ThunderMax with Autotune EFI along with the O2 sensors, you not only get fuel injection that can be tuned close to a stoichiometrically erfect 13-13.5 to 1 air/fuel ratio for bestpower from any combination of hop-up arts, but does it all automatically! To betechnically accurate it's more of an auto adjusting capability than actual auto tuning, since certain other parameters must be base-lined and a decent preliminary map must be installed, but we'll get to that...right now

Taking On Oxygen
It's All About The Bung HolesOk, you can stop laughing now! I know the terms are a crackup, but the process is serious-adding the mandatory oxygen sensors for closed loop EFI. The fact is, it's no big deal for those of us with '07 and later models, since almost all exhaust systems made for those applications already have bung holes (that is the proper term, dang it-stop giggling)! But adding closed-loop so-called automatic tuning types of EFI upgrades to older Harleys means adding O2 sensors to exhaust pipes that were never designed with them in mind, so putting them in place-the correct place-means measuring twice or even three times before doing any cutting, drilling, or welding. It has mostly to do with getting the sensors somewhere close to the right distance from the exhaust valves and plain old clearance issues. For instance, try an install on a Heritage Springer. The space available between the tight curve of the cross over header, behind the barrel, over the tranny top, across the primary and in front of the oil bag leaves minimal room for a sensor, to be kind about it. But if you yank that header off, slam in a bung, pop the pipe back on and find out that the sensor won't screw in, or hits something in those tight confines, you will not be a happy Harley, you'll get to do it all over again!

The point is, installing the bungholes in your existing exhaust is arguably the make-it-or-break-it part of the exercise for upgrading to autotune EFI. It'd be real nice to supply you with a foolproof technique for adding these necessary evils, but fact is, there ain't one! This is one arena of endeavor where there just is no good substitute for logic, experience and caution. All we can do (and will, courtesy of Bob Robinson at R and R American Cycle) is show the best starting point, some tips, and point to a good strategy and some useful tactics to help ensure a successful mission.

Now, let's watch how it's (supposed to be) done...

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