| Author | Message | ||
     Reepicheep  |
 Not accusing anyone of anything, just saying that for my "I never fouled the plugs and was never careful" datapoint, that I was actually kind of careful, and avoid high RPM's on a cold engine like the plague. | ||
| Anonymous |
Spatten1, To say the Buells use a very primitive engine control system is an absolute joke. The system is way more advanced than any other manufacturers, with a much higher level ECU...think the equivalent of Pentium as opposed to 386 in other manufacturers' products. The reason the current XBs pass not just 2004 but 2008 California emissions without a catalytic converter is due to the sophistication of the ECU. This ophisticated ECU has high level algorithms along with providing rapid sensor sampling rate and driver rate for the injectors and the muffler valve stepper motor. | ||
| Tank_bueller  |
Sometimes, when I start my bike, I have the opposite happen: It runs rough on initial start-up, but I "crack" the throttle to bring the revs up just a little to "put some heat in", and let go. It smooths the idle, and I let it run for a couple minutes before launch. tank | ||
| Pushrodpete  |
Court - Is that photo recent? As a Kawi triple owner and enthusiast, I'm appalled.....  | ||
| Court |
>>>Is that photo recent? Last Monday. That bikes sits, chained to a pole, in Astoria day in and day out. I keep, like a stray puppy, wanting to save it. Court | ||
| Craigster |
Buell is not the only manufacturer to use Alpha-N for EFI operation. It is simpler than speed density- so I agree w/Spatten1 that it is "basic" EFI, and yes it can not differentiate loaded vs. unloaded operation. But Alpha-N alone will not cause plug fouling on start up. The Buell EFI IMHO is very slick. Problem is the factory hasn't leaked out any info so some folks with the ability, could hack the ECM and provide PC based tuner software. | ||
| Blake |
Not sure there is such a thing as unloaded operation, just relative differences in rate of change in engine speed. Is cruising steadily at 25 mph in 2nd gear loaded or unloaded? And in either case the O2 sensor is more accurate than anything else in ascertaining mixture requirements. Also, why could not the EFI determine relative engine load from simply noting rate of change of engine speed and/or throttle position? Answer, it most certainly could. So Craig, I must disagree with your characterization of the Buell EFI. Why do you need an airflow sensor when intake airflow is 100% governed by throttle position and engine speed? Simpler? In some ways, yes, in others no. Better? Seems so. Ask Triumph and BMW how simple it is to devise a reliable and smooth EFI for a sporting bike that will meets the more rigorous emissions requirements without a catalytic converter. Who else has done that besides Buell? | ||
| Blake |
One other factor to consider about the use of an air flow sensor... What happens if/when the air flow sensor becomes dirty? What effect does that have on the mixture and on the engine in general? | ||
| Cataract2 |
I've been wondering though. Why did Buell go with only 1 O2 sensor on the rear. Why not one on the front? (Message edited by cataract2 on February 01, 2005) | ||
| Craigster |
So Blake, You saying you know for a fact that 20% throttle (or any given %) opening at any rpm regardless of gear will result in the same manifold absolute pressure value? Try this. With alpha-n tell me what % throttle opening in say ...first gear at 2500 rpm results in a manifold pressure of 97kpa. Then tell me what % that is in second gear, then thrird.....think it is the same value for all throttle positions and gears? I'll eagerly wait for your answer! On an Alpha - N systems, rate of change of throttle position is used for accel enrichment. That's about it. In fact, even on a speed density systems TPdot is used for accel enrichment. There does exist a few odd systems that use manifold pressure dot to determine accel enrichment parms but they are somewhat few and far between. Also, remember O2 sensors are used for determining cruise trim to EFI values. They do not apply real time adjustment of fueling. Meaning, you can not replace any sort of intake sensor with an O2. The O2 certainly has a point as it keeps the EFI in check and will constantly trim the efi, but considering the narrow band sensor is only good for operating around 14.0 to 14.7:1 it can never be good for adjusting anything other than cruising operation. The trim values can be applied to WOT but they certainly are not read at that point. If it was true O2 values could be used for real time fueling you would not need an engine temp sense and an intake air temp sensor. Go look at Aarrons testing of the narrow band O2 and see how accurate it is at 13.0:1 then 12.0:1...she's a no so goood! I agree it's a great feature to have, but it does not replace any type of intake sensor. I mearly keeps the system in check. It also usually has a limit on its range of 'trim' before a check engine light is triggered. Also, speed-density uses a Manifold pressure sensor. No air flow sensor involved. Only MAF systems use an air flow (air mass) sensor, so the conversation about including a MAP sensor has no implication of using an air flow sensor. I have already stated that I think the Buell EFI is very slick. They chose an Intel 87C (87C196KD) processor which is specifically designed for automotive industry applications including operation of ABS systems. It's a true 16-bit CHMOS processor with something like 24 or 28 individual interrupts and I believe four or six 16-bit software timers and host of other real slick features. I don’t think it’s a bad system at all. I just wish I could change values to suit modifications. Hey the guys at GM leaked out enough info to make LT1-Edit a reality. Do I expect that the guys at Buell will? Probably not, but folks will tinker, and find away around the the non-adjustable factory stuff. If they didn’t Mr. Buell wouldn’t have gone racing and built his first race bike would he? Like I said I think it's a nice package, but alpha-n is still simple compared to speed density or MAF. I think I can say that with out sounding snotty since the EFI on my Cyclone is currently running in Alpha-N mode. You don't have to agree with me, but may I suggest you check out a copy of Adam Wade’s Motorcycle Fuel Injection Handbook and see what he has to say about the differences in AN vs. SD vs. MAF. | ||
| Dale |
So how does an xb adjust mixture for altitude changes? | ||
| Smitty  |
One other factor to consider about the use of an air flow sensor... What happens if/when the air flow sensor becomes dirty? What effect does that have on the mixture and on the engine in general? I can answer that . A friend of mine had that problem with his Ford F150. Under load (pulling a 18 foot boat) it would ping he had to run premium to correct. Without the boat it ran fine on regular. So he filled 1 tank with premium and the other with regular and toggled between the two. At the time we couldnt figure it out everything was in speck. He took it to the dealer riding in the truck with the serv tech and laptop hooked in they could hear the ping but the ecu didnt . It showed no faults the MAF was in speck a little on the week side but well within the operating window. The Buell system takes care of the engines needs and is more than good enough at this time. How many bikes can start cold without an accelerator? My guess the next step will be overhead cams dual plugs larger bore and shorter stroke to increase high end power and rpm. Tim (Message edited by smitty on February 01, 2005) | ||
| Anonymous |
Dale, it's really easy for an O2 sensor system to adjust for altitude. If the air density is lower, the mixture will get rich. The O2 sensor sees this, and reduces fuel until the mixture is right. And believe me this happens at an insanely fast pace...remember that at 3000 rpm, the O2 sensor is getting a mixture reading 50 times per second! The O2 sensor system can also adjust for anything else in the engine that might be causing an imperfect burn, which a speed-density or MAP system can't do. Craig, it's really cool to see someone with some background in this area posting. However, I disagree with you regarding speed-density vs. a fast sample rate O2-sensor system. Here's some food for thought, probably enough for you to start getting the concept, but don't spread it around, OK? I kinda like the fact that all these other manufacturers have to add on air pumps and converters... On an engine that is solidly in the center of the adjustment range of the ECU, you can get tremendous accuracy of fueling on an O2 sensor system with a high level ECU and the right sensors. What you need is a processor that is smart enough to check it's full range of sensors. Want to know if it is loaded or not? This ECU knows, can you figure out why? Want to be outside the standard 14:1 mixture under certain conditions? The ECU has all the other sensors to check against...wanna bet that I can't hold it outside that range? I mean, think of it, an air cooled, single-throat throttle body, two-valve large bore engine passing 2008 emissions without any after treatment. Craig, you know enough about this stuff to know we are onto something...Wade's stuff is out of date. | ||
| Dale |
Thanks for the reply. Does the mean the new motor is air cooled? | ||
| Stealthxb  |
That's a silly question!!!  | ||
| Dale |
As long as I am asking questions, how do they make the cracked rods in the V-Rod? | ||
| Anonymous |
Rev them high? | ||
| Davegess |
i love htis stuff. Even though my knowledge of this whole intake, exhaust fuel injections stuff is pretty much limitied to suck, squeeze, bang, blow, I like listening to you guys. | ||
| Smitty |
Davegess Quote} i love this stuff. Even though my knowledge of this whole intake, exhaust fuel injections stuff is pretty much limitied to} suck, squeeze, bang, blow,I like listening to you guys. Suck Bang Blow is a biker bar in Myrtle beach}  }. Tim | ||
| Reepicheep |
Just a sec, let me run out the garage and check... Yup. Mostly, it has an oil cooler also though. (2005 XB9SX, with 3 years in production motor I am QUITE fond of thank you). (Message edited by reepicheep on February 02, 2005) | ||
| Court |
>>>>my knowledge of this whole intake, exhaust fuel injections stuff is pretty much Dave: Ever wonder why Erik never let you and I engineer a motorcycle? | ||
| Whistle |
While we're on the topic of rumors and rubbish and information about Buells... Obviously BMC's relationship with HD sorta helped make this decision and I think that for what the Buell is designed for that our engines are awesome, but what was/is the driving force behind using the sportster based V-twin? Don't anybody jump on me here I LIKE the V-twins we have if I wanted straight-line, go like a batouttahell OMGipissedmypantsagain fast bike I woulda bought a busa and fitted a turbo...but I'm wondering why Buell is using them? Why did they not, for example, choose to use a water cooled inline 3 or a battery w/an elec. motor or fuel cells or whatever? And even if they did use a V-twin why did they choose to use the 45 deg instead of 60, air/oil/fan instead of water cooled, pushrod instead of overhead cams...etc etc. Basically why didn't they simply design their own engine from scratch...($$??) To answer my own question at least a little bit...I think the answer to why they built what they did lies in the purpose of the engine, it's not intended to be a MONSTER 180HP power house where you can do wheelies at 230 MPH. Rather it was designed to be narrow so it would fit in the frame they wanted, be agile in corners with a low CG, be simple (the fewer parts the better-less to break-less weight), and efficient(60mpg out of a 984 cc??? w/2008 CA emissions????!!!! BRAVO!). And low and behold the sportster engine was pretty much what they needed to pull it off...with a few minor tweaks of course... As a continuation of this question does Buell ever want to design their own engine entirely from a blank page? What would be the perfect engine? Too bad I can't sneak into the BMC office in the middle of the night and read a whitepaper discussing all the DETAILS of their design intentions and how the XB would accomplish that. Anything like that posted in the KV??? later guys........... Nick (Message edited by Whistle on February 02, 2005) | ||
| Mikej  |
Nick, The history is buried on the site here and on sites such as davegess.com and dcbrag.org . Basically, per my understanding, Erik worked at Harley as an engineer. Erik also roadraced bikes on the track. Erik wanted to start building his own bikes. The first direction he went, a square-four two-stroke (I believe), died on the vine for a few reasons. He still had friends at Harley. Harley had some unsold race engines. Erik and Harley got together and made a deal. The rest, as they say, is history. What may come tomorrow, or in March or May, is unknown, but for now things are what they are. Good or bad is up to the viewer's discretion and opinion. I kind of like it, but then I kind of limp at times too. As always, YMMV. | ||
| Blake |
Craig, "You saying you know for a fact that 20% throttle (or any given %) opening at any rpm regardless of gear will result in the same manifold absolute pressure value?" No. I'm not saying that at all. What I thought I said was that a MAP sensor is not required to determine engine load. "Try this. With alpha-n tell me what % throttle opening in say ...first gear at 2500 rpm results in a manifold pressure of 97kpa." Why do I give a damn what the manifold pressure is? The ECM can determine engine load without it. That was my point. ECM no need manifold pressure to determine engine loading. But if I did want to answer your question, you would first need to specify WHEN wrt cam position you want the manifold pressure to be 97kpa. Intake manifold pressure is not constant, it is highly transient. As I am completely unfamiliar with such systems, I ask silly questions like that, where others more familiar might know that a certain time or averaging method is implied. I don't though. "Then tell me what % that is in second gear, then third.....think it is the same value for all throttle positions and gears?" At the same engine speed and constant throttle position, maybe, probably pretty darn close. I don't know. What is your point? Again, if the ECM knows engine speed wrt time and thus engine acceleration along with throttle position, it can also determine the engine load effect upon fuel requirements, given proper ECM programing of course. "I'll eagerly wait for your answer!" Hey, I've answered your questions. You didn't answer mine though.  You offered that you need a MAP sensor or speed density system in order to determine engine load and that since Buell does not utilize one their EFI system was inferior and prone to fouling in some cases (you may not have stated exactly that, but it was implied based on the discussion prior). I disagree. I am claiming that all the ECM need know (sense) to perform proper fuel adjustment wrt varying engine load is: 1. Engine speed 2. Rate of change of engine speed (acceleration) 3. Throttle position 4. The proper look-up table and/or empirical formula in the ECM. No MAP or MAF sensor is required. Agreed? And apparently the O2 sensor output is all that is needed once the bike is warmed up. Even better! Simple is better. (Message edited by blake on February 02, 2005) | ||
| Court |
>>>And low and behold the sportster engine was pretty much what they needed to pull it off...with a few minor tweaks of course... Not only is it PRECISELY what Buell needed, but thanks, in large part, to the Elves at Buell, you can now buy a better Harley-Davidson Sportster than anyone had ever dreamt would be made. I can not speak for Erik buell. Were the decision, taking all instant facts as they exist, mine...i would follow the rule that all good jugglers follow....have as few balls in the air at a time as absolutely necessary. Buell MAY someday show us an engine. Ask yourself this....in the transition from tube frame to an ENTIRELY new platform would you change the motor if you didn't need to? Buell was already using well over 1,000 parts for the first time ever. Me?...I'd hedge my bet by using essentially the same motor that left in the last 1.5 million Sportsters. Just one view.... By the way....don't think for one moment that Buell Engineering can not "clean sheet" an engine that would have the moto world gasping. | ||
| M1combat  |
"By the way....don't think for one moment that Buell Engineering can not "clean sheet" an engine that would have the moto world gasping." And it's my humble belief that they probably are... But I'm VERY happy with my "sportster lump" . | ||
| Mikej |
A little ancilliary(sp?) reading: http://www.castsolutions.com/archive/05_feature_article.html | ||
| Budo  |
"By the way....don't think for one moment that Buell Engineering can not "clean sheet" an engine that would have the moto world gasping." I don't doubt for a moment they could build something really stunning. However I am convinced that HD want's to keep the sporster derived motor in the Buells so they may point out the connection between the Buells and the Harleys. Have we not already established that Buell is designed (in part) to get younger riders into the Harley family? | ||
| Tripper  |
Whistle; spend a little time at the Buell web site and watch the videos. You will hear Erik explain most of the philosophics. | ||
| Dale |
But it is time for four sloppy cams spinning in drip oil to go. |
