Technical - Motorcycle Consumer News
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1. The most gradual cam was installed We ve reviewed the G2 system before February 2009 and it makes a noticeable difference Switching back and forth between cams on the SuperDuke revealed a slight advantage to the softer cam profile However mechanical fixes don t get to the root of the problem of throttle snatch which as we illuminate in upcoming installments lies buried within the KTM s EFI Now What If this were a product evaluation we d now turn our attention to what differences both objective and subjective each of these pieces made to our SuperDuke s performance But this isn t that kind of article Our focus here is on fuel injection and what options exist for you as a consumer in your efforts to optimize it 30 JUNE 2012 MOTORCYCLE CONSUMER NEWS Above G2 s throttle cams lock onto the end of their aluminum throttle tube allowing quick modifi more gradually during the first half gation to the speed of the throttle reaction in the first half of twist grip rotation FLY AWAY secondary butterfly that is Because of the multitude of testimo nials on various LC8 related forums and elsewhere advocating secondary butterfly removal as a means of reduc ing on off throttle snatch and the way said snatch seriously detracted from the joy of riding our SuperDuke we began our quest for improved fueling here even though it seemed seriously counter intuitive The procedure was straightf2. NEWS FMF s carbon fiber titanium Apex canisters are very light and not only because of their exotic materials they contain pre cious little to quiet the LC8 s roar for it The long answer involves a discussion of open loop and closed loop EFI designs look for that in a subsequent installment For now you ll have to take it on faith that common modifications to a fuel injected motorcycle s intake tract or exhaust system will likely require mapping changes to maxi mize performance and reliability Although magnificent in many ways KTM s big V twin designated the LC8 across an array of bike models lost some thing in the translation from its original 950cc carbureted form to the current 999cc fuel injected iteration The 950s were known for superlative throttle response with smooth clean fueling from idle to redline The 999s gained a little strength but at the expense of some finesse The LC8 was never a particularly grace ful motor with its ultra light flywheel and tiber punchy power KTM s slogan Ready to Race could have been revised to Ready to Launch for LC8 equipped models Actually make that Ready to Lurch for the fuel injected versions at least in terms of off idle behavior Because our test mule was fitted with several aftermarket accessories by its previous owner we don t know exactly how this particular one behaved when new We have however rid den SuperDukes and other fuel inje
3. duration for that unique combination The white cell is ready good understanding of how each of the possible adjustments to be edited Note This map is from tuning software that will be affected fuel flow at different throttle positions and how to presented in the next installment not from the PC III 26 JUNE 2012 MOTORCYCLE CONSUMER NEWS Stock airbox left MotoHooligan airbox right Compare the little nostrils on the stock airbox s snorkel to the wrap around 4 breathability of the MotoHooligan Which do you think the LC8 s cylinders would prefer a bike s wiring harness These devices can alter the ECU s inter pretation of incoming information from sensors and modify its instructions to the fuel injectors some also include the ability to alter ignition timing coordinate with optional quick shifters traction control add ons and more Some are simply plug and play containing a model spe cific pre programmed map proffered as superior to the stocker perhaps designed for use with the most common airflow enhanc ing mods e g a slip on exhaust canister and freer flowing air filter Others allow for some basic alteration of the fuel mixture such as enriching it to various degrees at the bottom middle or top of the rpm range And some when connected to a computer running the associated software allow for extensive fueling mod ification at a large number of specific throttle position rpm com binations
4. from an additional malady startlingly abrupt on off throttle response not unlike the ultra crisp illu mination of LED brake lights and turn signals regular incan descent bulbs seem to be on dimmer switches by comparison The resulting engine misbehavior is especially problematic for a bike with exceptionally brawny power right off idle and very responsive handling You do not want a SuperDuke bucking hard during delicate throttle manipulations while heeled over in a tight corner The resultant effect is the polar opposite of confidence inspiring Secondly just like the CBR in that jet kit article our test bike has received airflow enhancing modifications that could yield an overly lean mixture without fueling adjustments Or at the very least their potential benefits beyond weight reduction and aes thetic appeal are likely to remain unexploited But wait you might ask doesn t fuel injection do a terrific job of automatically and precisely maintaining optimal air fuel ratios under widely varying conditions for which carburetors would need re jetting such as big changes in altitude Why can t it do the same with intake and exhaust mods The short answer is this Most EFI systems on motorcycles today while capable of detecting and compensating for things like changes in altitude won t notice the impact of intake and exhaust mods on the fuel mixture because they re not looking 28 JUNE 2012 MOTORCYCLE CONSUMER
5. just outline the arguments here and relay a really surprising claim made by many posters on internet forums removal of the secondary butterflies and their shafts reduces on off throttle snatch not only for fuel injected LC8 s but other makes and models too We can imag ine that a secondary ectomy might improve top end horsepower because of improved airflow especially given how the Super Duke s don t quite open all the way to vertical but we can t come up with any explanation for reduced snatch off idle if anything it ought to make snatch worse See page 31 to learn what we actually experienced when we tried it While not contributing to any airflow impedance the Sec ondary Air Injection system SAI or SAS a solenoid controlled collection of hoses that helps the catalyst finish burning any fuel that snuck through the combustion process unspent by adding fresh air to the exhaust tract adds complexity and plain old ugli ness to the breathing apparatus Switching to a non catalytic exhaust system makes the SAI unnecessary for engine function and another candidate for removal At this point a disclaimer is in order We cannot recommend that readers modify their motorcycles in ways that may violate legal mandates And we appreciate that some may not want to alter anything that could make their bikes less environmentally friendly Nevertheless we re well aware that a multitude of motorcyclists make minor intake and exha
6. serves no purpose with the catalyst removed so it was jettisoned as well Right Removing the SAI isn t a free mod you ll need Moto Hooligan block off plates for the locations where it used to enter each cylinder head throttle cables almost instantaneously limited only by the speed of a rider s wrist the ECU may intervene by easing open the secondary butterflies more slowly Theoretically this results in smoother throttle response prevents the hesitation of a momentary lean condition and maintains optimal airspeed through the throttle body Detractors say that when it comes to airflow more is always better provided adequate fuel is available They want as little as possible getting in the way of incoming air and they sure don t want a computer deciding how suddenly they re allowed to go wide open These folks insist that removing the secondary butter flies results in a noticeable increase in power and attribute that to more air flowing less turbulently through the throttle body Sec ondary butterfly defenders counter that this modification only cre ates the sensation of more power because it makes throttle response more sudden something we certainly don t want on this bike at low rpm where the secondary butterflies have their biggest impact We could probably do a whole article on this debate collect ing objective data about this modification in isolation and draw ing a definitive conclusion Instead we ll
7. to KTM machinery after all it s an LC8 s fueling that we re trying to perfect But the majority of our attention will be spent on how to under stand and employ some examples from the rapidly expanding range of gadgets available to the home mechanic in pursuit of EFI nirvana Perhaps mechanic would seem a less appropriate term here than programmer But don t be intimidated just because you re not a computer engineer It turns out that this end user technology doesn t require any more expertise in electronics and software than those jet kits required in the area of fluid dynamics maybe even less This had been loaded with Dynojet s easy to use Read about it in the next installment advanced map for SuperDukes with aftermarket exhausts and air filters An Akrapovic full exhaust system and a BMC air filter are specified in this map but it was the closest match for the bike s mods given what few pre set options Dynojet offers It could reasonably be expected to get this SuperDuke s fueling well within the ballpark One other mod bears mentioning In his attempt to tame the Super Duke s abrupt throttle response at very low rpm through a purely mechanical intervention the previ ous owner had replaced the stock throttle tube with G2 s Throttle Cam System allowing for exchange of the stock profile to others that ramp up of throttle rotation offering the rider more control within that range
8. 63 www fmfracing com Above Secondaries removed main butterflies open the view down through the throttle bodies is clean and uncluttered Linkage at bottom is controlled by the throttle cable and rotates the main lower butterflies Upper linkage transfers movement from the servo controlled rear secondary butterfly to its forward mate The upper linkage as well as the servo motor and its TPS will all be removed the ECU to address these issues but that ll have to wait until the next installment So what did we notice with the secondary butterflies removed There really was a small but definitely noticeable im reduction in the jerkiness of W on off throttle transitions Under close scrutiny this w seemed to be mainly a matter f of less dramatic engine braking r during the on to off transition 1 the bike no longer felt quite so much like it d been caught by a tail hook The off to on transi tion didn t seem to be any dif ferent or at least the difference was so small as to likely be the product of suggestion But it certainly wasn t any worse either and worse 1s what we would have expected So given the lack of any apparent penalty for their removal and the like lihood that at least high rpm performance would be enhanced by cleaning up the intake tract we left them off As it so often turns out less is more Power Commander III USB model 925 411 399 95 Dynojet Researc
9. A select few with the addition of auxiliary wide band oxygen O2 sensors can even learn how to massage injector instructions to achieve individually specified air fuel ratios for each one of those combinations with separately tailored maps for each cylinder and each transmission gear and user defined fueling adjustments for different speed temperature and air pressure ranges But most are much simpler whew In sharp contrast to hours of carb dis and re assembly custom tweaking of EFI sounds too good to be true Simply connect your laptop execute a few well chosen mouse clicks and key strokes and voila you re done Not only is this worlds easier and quicker than swapping jets and needles it can be much cheaper too As we ll show you later in this series it s possible to significantly improve some bikes EFI performance with hard ware that costs less than the price of the average single cylinder jet kit And keep in mind that when you hire a tuner and or buy dyno time to gather hard data for the dialing in process the meter would also be running during all that carb R amp R You might recover the entire cost of your EFI mods in saved tuner dyno charges compared to what you d spend on those pro services for carb tuning Instead of jets and needles then the aspiring fuel injection tuner will have to manipulate numerical tables that influence how much fuel the injectors force into the airstream entering the engi
10. Reprogramming Fuel El gd One Orientation b 1 i r i on a 5 P In the fuel necia age this is a uning is tone No more iets and needles just grids and keyboards The Times They Are A Changin ACK IN May of 01 I wrote a lengthy article comparing B four jet kits and two dynamometers used in assessing their performance The test mule was a Honda CBR600F4 with a bank of four CV carburetors Before starting that project Pd fiddled with a couple of dirt bike carbs and installed one four cylinder jet kit sticking to the recommended settings that came with it But d never done any systematic tuning or made use of dyno charts I was emboldened to take on that project by the fact that I d be working with two tuning experts who would walk me through their respective methodologies for extracting the best possible performance out of each jet kit The impetus for testing those kits was the installation of an aftermarket exhaust system and air filter on the CBR each of which would theoretically allow it to breathe more freely with two potential results First without carb tuning the mixture might have been too lean compromis ing performance and possibly causing the engine to run hotter And second with carb tuning improved performance might be achieved as the increased volume of incoming air could then be paired with more fuel which if correctly balanced ought to generate more power when ignited During th
11. cted LC8s of this vintage in stock form and read and heard numerous owner accounts We ve concluded that it s pretty common for these bikes to suffer from not only abrupt off on throttle response but also some surging below 4000 rpm as well as a little hunting at steady highway speeds none of which is all that unusual for a fuel injected bike In addition to these EFI related fueling glitches SuperDukes inhale through a seemingly small and restrictive airbox We haven t measured its volume or flow but we find it hard to imag ine those two big cylinders gulping at high rpm being fully sat isfied by what could squeeze through that airbox s dainty snorkel And SuperDukes exhale through an enormous and very heavy catalytic converter cleverly tucked under the seat with two rather quiet read stuffy canisters Hidden from view inside each throttle body that part of the fuel injection system that goes where the carburetor used to be are another set of obstructions some argue deserve removal the secondary butterfly valves metal disks that flip open and closed like a traditional choke and their shafts These are now common on many fuel injected bikes and are supposed to smooth power delivery by modulating the rate at which air flow into the engine changes They re operated by the ECU via a servo motor Whereas the twist grip can yank open the main butterflies via the Above The Secondary Air Injection plumbing
12. e course of testing many different combinations of needles needle heights mixture screw settings and jet sizes I grew nauseatingly familiar with that brace of carbs We did dozens and dozens of dyno runs making adjustments between most of them Numerous seat of the pants adjustments were made too Remember all those changes involved doing the same thing to four carbs By the end I could remove disassemble reassemble and replace those carbs blindfolded well almost ey f listen and feel for signs of a lean or rich mixture And I learned how dyno testing can inform the tun yy ing process including the auxiliary use of exhaust gas analysis to monitor and evaluate the actual x air fuel ratio being delivered by the carbs at any given engine speed Still I d never ever want to do it on that scale again 7 As I write this I feel a strange uneasiness like 8 when I catch myself using the word album while discussing music or film in a conversation about photography two domains the digital revolution has radically changed forever I don t want to think of myself as someone so old that I can recall a truly fea bygone era and we re not quite yet at the point where discussions of carburetors must be accompa nied by an explanation of what those ancient con traptions were but the day is coming Computerized fuel injection EFI is no longer a novelty in the motorcycling world it
13. e twistgrip are visible closed beneath them certain points along the way and required considerable force they finally surrendered with no harm done m Finally the holes left by the WE shafts had to be plugged We used Wpro a some plastic automotive trim M panel fasteners with a wide cap Ji that would prevent them from MAW being sucked in by those huge pistons at 9500 rpm and wrapped E them in Teflon tape to give just h the right interference fit Then we F buttoned everything back up The whole process is easily reversible Baa but doing so involves resetting the removed TPS which is a pain see the factory service manual Note that removal of the sec ondary butterfly TPS will pro duce an error message and turn on the EFI warning light the ECU will detect its absence As the ECU has a set of maps devoted to operating the secondary flies and assumes they re part of the equation its calculations for the main butterflies will be thrown off even if only the plates are removed There s a way to turn off the secondary butterflies in SOURCES Motobox with K amp N Air Filter 348 49 SAS Blockoff Kit with resistor 34 95 LC8 Secondary Butterflies 24 95 MotoHooligan Performance 1210 Commerce Court 4 Lafayette CO 80026 720 371 6747 www motohooligan performance com Apex Slip on Exhaust Canisters 1099 99 FMF Racing 18033 South Santa Fe Avenue Rancho Dominguez CA 90221 310 631 43
14. f This required after market block off plates also MotoHooligan pieces to seal the openings on each cylin der head where the SAI had been con nected The ECU will turn on the EFI warning light and generate an error code unless it s either tricked into thinking the SAI is still functioning by bridging the now unplugged electrical connector with a resistor or by disabling the SAI circuit in the ECU see next installment Alternatively the plumbing and wiring could have all been left in place and the hoses simply plugged To address the lean condition that might have resulted from these intake and exhaust mods and in the expressed hope of remedy ing the stock fueling flaws our SuperDuke s previous owner had also installed Dynojet s Power Commander IJI USB PC III an add on module that modifies the ECU s instructions to the injectors Above Dynojet s PC III is a tidy add on that s The mods listed above are merely exemplars the most common types of performance oriented accessories installed by average motorcy clists They set the stage for our explo ration of what ordinary folks can do to re mix a bike s fueling in the post carburetor era In upcoming installments we ll show you what s involved in using a PC I as well as two alternatives with attention to how to maximize your DIY capabilities and when to get pro fessional assistance A small portion of what we ll discuss is specific
15. h Inc 2191 Mendenhal Drive North Las Vegas NV 89081 800 992 4993 www dynojet com G2 Throttle Cam System 109 95 G2 Ergonomics 1008 East Commercial Street Lyndon IL 61261 815 535 3236 www g2ergo com Note Check online for substantially lower prices on all but the MotoHooligan items Visit us at WWW MCNEWS COM JUNE 2012 31
16. hich may have to be negated in order for an aftermarket module to work its magic Visit us at WWW MCNEWS COM JUNE 2012 27 The stock catalytic converter forms the Y pipe connecting the 2 into 1 header with the two slash cut canisters It s gorgeous ly sculpted but terribly heavy and sounds very sedate Of course the question remains How can we tell what num bers should go in all those cells to optimize performance And how exactly do we go about changing them These and other questions will be addressed in future installments But before we get into solutions we need to understand the problems good prescriptions are based on good diagnoses To illustrate various EFI issues we ll be using a lightly modified 2007 KTM 990 SuperDuke actually 999cc The Problem Child Beauty and Beast Our SuperDuke presents two kinds of challenges First there s the stock map Just like most fuel injected motorcycles this one came from the factory with less than ideal mapping Although engineers may start with a map that maximizes engine perfor mance achieving compliance with emission and noise regula tions along with goals for fuel economy can require distortions of that original schema The same is true for carbureted bikes A jet kit or a revised ECU map can undo such distortions and allow even an otherwise unmodified bike to run better But unlike carbureted bikes most fuel injected motorcycles suffer to varying degrees
17. ing up however because several show the secondary butterfly servo doing its thing When viewing the throttle bodies from the left you ll see two linkages that move with each blip The lower controlling the main flies moves abruptly while the upper for the secondaries lags fluidly On the other side of the combustion chambers the stock cata lyst and canisters were replaced with FMF Apex slip ons These carbon fiber titanium units save a lot of weight complement the SuperDuke s origami styling with their sharply angular geome try and allow exhaust gases easier exit The cost of these bene fits in addition to their lofty purchase price is noise Even with the supplied inserts small conical tubes that are supposed to reduce the decibels these cans are obnoxiously loud even to those who would otherwise appreciate their raucous basso pro fundo voice We ve heard about a fix for this perforated sheet metal custom welded across the insert openings and hope to try it out we d love to be able to retain the Apex cans but they re way too loud for street use If we succeed in quieting them down Visit us at WWW MCNEWS COM JUNE 2012 29 we ll give you a full report For the purpose of the current project though we re confident no other slip ons would threaten to lean out air fuel mixtures more than these AS mentioned earlier removal of the cata lyst allows for removal of the SAI too and ours had been taken of
18. is steadily advancing across product lines Of course it took over the entire auto motive realm long ago For better or for worse we re in the midst of a mass carb ocide So What s a Poor Tuner to Do At first glance it might seem that the carbure tor s extinction may leave shade tree tuners with no option but to either accept their bikes factory dictated digital scripts or pay a tuner for his sophisticated under standing of the electronics involved and the use of his expen sive specialized equipment Regardless of how well a lay person might comprehend the fueling process it s no longer possible to translate such knowledge into performance gains with a few hand tools and an assortment of jets and needles EFI tuning requires the ability to tap into the black box brain of the motor cycle its Engine Control Unit ECU This means having certain hardware and software and knowing how to read and write the digital maps that have come to replace physical needles and jets in managing fuel delivery It turns out things really aren t so bad More and more companies are making electronic modules that simply plug into PETER T PRA R TE PRRERPRRERRERRSE at Along the top are TPS values as open Along the left side are Although this was an excruciatingly tedious process I m lit rpm points Where each column and row intersects is the injec erally shuddering at the memory of it I certainly developed a tion
19. ne While this may seem intimidating to the uninitiated it s actually more straightforward than tuning carbs in some ways and is definitely within the reach of many perhaps most home mechanics I m speaking as one who had even less prepa ration for this project than I had for the jet kit comparo The only fuel injection tuning I d ever done before was to confirm the calibration of my old Suzuki TL1000S s Throttle Position Sensor TPS a task that I vaguely recall as requiring only a 2 Phillips head screwdriver and the ability to read LCD numbers on the bike s gauge cluster So I admit that embarking on this mission called to mind those Messin with Sasquatch commercials see YouTube if you missed them I worried I might thoroughly confuse the bike s brain and possibly even do irreversible damage to its electron ics or worse the motor itself overly lean mixtures can cause overheating and piston damage But even if my foolish tinker ing could provoke terrible consequences the idea that I might accomplish far more than I did with those carbs just by tapping a keyboard was irresistible And rather than having to under stand stuff about the fluid dynamics of venturis needle tapers and jet orifices all I had to focus on was a single variable the length of time an injector was open during the intake cycle This is the beauty of digitalization everything s reduced to 1 or 0 on or off The end produc
20. orward After removing the airbox lifting the throttle bodies assembly intact out of _ their rubber boots and stuffing rags in the intake tracts to keep out debris the first step was to remove the screws holding the disks to their shafts For some reason KTM opted to make these screws out of wax and weld them in place Okay not really But they re almost impossible to remove without rounding out Some internet posters stopped here leaving the shafts in place and saving them selves most of the work Others replaced the stock circular disks with more elliptical ones from MotoHooligan that allow more flow in the closed position We decided to go all the way and remove everything This involved unplugging the electrical connection and remov ing the screws that hold the servo motor in place along with its TPS separate from the one for the main flies and pulling the combo away from the throttle bodies Small pieces tried to fall out and get lost be warned Next we removed the circlips on the right side shaft ends and slid the linkage assembly with shafts attached away from the throttle bodies on the left side This was a bit nerve racking as the shafts proved very hard to budge at Above The computer controlled secondary butterflies are seen here partially open Even fully open they re not quite vertical creating what would seem to be a significant obstruc tion to incoming airflow The main butterflies controlled by th
21. t of all the ECU s calculations is how long an injector will flow fuel an event that occurs for mere milliseconds Basically each injector is a solenoid operated valve with pressurized fuel on one side and the bike s intake tract on the other When the ECU commands the injector to open it opens completely when instructed to close it closes completely The only variable for controlling mixture is how long it stays open And rather than having to figure out how to blend transitions from a carb s idle circuit to its needle taper to its main jet size there s just a grid of numbers with engine rpm along one axis and throttle position along the other Cells in the grid represent all possible combinations of these variables and contain numbers that define injection duration for each of those combinations True an ECU may take into account other variables too such as atmospheric pressure air and engine temperatures O2 sensor readings etc each of which contributes a map of its own to the calculation process For example a cold engine temp bumps mixture instructions toward the rich side lengthening injection duration making an airflow restricting choke obso lete But tuning at the level described here isn t concerned with all those inputs and calculations It s only concerned with the ultimate output the injection duration grid that s what gets tweaked The only exception is the signal from the O2 sensors if present w
22. ust mods of exactly the sort we re about to describe If you re concerned about the legality of such modifications consider this series relevant for closed course track use only If it offends your environmental sensibilities consider it applied science As mentioned earlier this particular SuperDuke came to us already sporting an assortment of typical interventions and accessories Those affecting the engine were as follows Starting with the intake tract the stock airbox had been replaced with a beautifully crafted and accordingly priced billet aluminum piece by the aptly named MotoHooligan Perfor mance an outfit devoted to fixing the quirks and enhancing the performance of KTM s infamous hooligan machine see their website for applications of these parts to other LC8 equipped bikes and even Harley V Rods Sandwiched between the machined aluminum plates is a free flowing K amp N air filter The whole setup looks like something that would be at home under the hood scoop of a 1960s era American muscle car and it adds an invigorating honk to the music emanating from the engine bay during heavy breathing Note You can find YouTube videos just search for Moto Hooligan wherein owners have tried to capture this wonderful noise but just as with any rich motorsport sound recorded with less than studio quality audio equipment what comes through is only a tiny slice of the aural spectrum The videos are still worth look
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