| Author | Message | ||
     Mark_weiss |
I think that I know what the '08s are doing with that extra fuel, cooling the engine. 08Uly's work has made it pretty clear that our '08 models consume significantly more fuel that '06 or '07 model year machines. I wanted to know where that extra fuel was going. One answer could have been, extra power. Some research has shown that there seem to be no significant differences between all three model years. It was difficult to find dyno charts for stock '07s, but I was able to make an acceptable comparison between '06 and '08. They are nearly identical. '08 may have a smoother curve, the differences could easily be attributed to peculiarities of different dynos and their operators. A few charts showed similarly modified '06 and '07 models (Drummer exh and '07 airbox) both look substantially the same. So, if the fuel is not going to extra power, how is it being used? During much of the '80s, I road-raced Japanese multis. On these bikes, with even moderate increases in power output, the inner cylinders ran hotter than the outers. The way to correct this was to run the inner cylinders (or cylinder) with a larger main jet. The extra fuel did not go to increased power output, just improved cooling. When engine components are well matched, intake, cylinder head, cam, exhaust, jetting becomes less critical. On a good engine, peak power will occur over a two to three jet size range. The main effect of changing jets within the "peak" range is to change cylinder head/exhaust temperatures. During much of the '90s I raced vintage BMWs (air-cooled, pushrod, twins). Although the engine remained unchanged, I would run bigger main jets for hot weather races (I'm in the Phoenix area, it gets HOT). The 190 mains that I'd run for a 65 degree February race would cause detonation in a 100 deg June race. On a really hot race day, I'd go to 210s. Dyno runs showed that 190 and 210 produced nearly identical results, at the track however, there was a need to change. As a side note, the only time that I ever ran out of fuel was when running 210s. I could run three practice sessions without needing to refuel with 190 main jets, but found that I could only run two sessions, plus about 3 laps of a third, when running 210 mains. So, cooler running engine, increased fuel consumption. It is all there. This is what I think that Buell has done with the Ulysses. Anecdotal accounts indicate that '08s run their cooling fans much less frequently. If the threshold temperature has not been adjusted, the '08 engines must be running cooler. I am sure that the oil cooler change helps some, but the differences cited for the '08s heat management indicate that there's probably more. Without raw data from Buell, I am not sure how this could be tested. Dyno runs are generally made at full-throttle and under that condition an early Ulysses probably runs the same mixture as an '08. The area where I'd expect to find most of the difference would be in the midranges, every-day riding conditions. This could probably be checked with a load-control dyno. Test two bikes at the same speed, rpm, and with a set load. Check their exhaust composition. Anyone have a load-control dyno and a stock '06-'07 Uly and an '08? Mark in Arizona | ||
| Etennuly |
Interesting observation. I tend to agree with you. I have a stock '06, but not the time or extra funds to ride to Arizona from Tennessee right now.(but I just might if I did) Two other things that might be observable remotely. Are the '08 plugs showing signs of running rich, and could an '06 be reprogrammed to run richer to see if it meets the same standard for temps and fuel mileage as the '08? (Message edited by etennuly on May 01, 2008) | ||
| Mark_weiss |
'08s use different spark plugs. This is another indicator the '08s are designed to run richer. The specified plug is designed to be much more cold-foul resistant than a standard spark plug. '06 and '07 models spec a 10R12A while the '08s get a 10R12X. Size and heat range are the same, the X indicates a foul resistant design. Mark in Arizona (Message edited by mark_weiss on May 01, 2008) | ||
| Chas1969 |
Offical press release for DDFI 3: "New DDFI 3 ECM (Engine Control Module) A new ECM with increased computing capacity. DDFI 3 actively controls and monitors the TPS (throttle position sensor), IAC (idle air control), and timing. DDFI 3 automatically zeros the TPS and adjusts fuel metering for smoother idle, eliminating service intervals and reducing the cost of ownership. A new progressive throttle cam and new throttle cables provide smoother throttle input from stops, and less rotation to full throttle." Very advanced to make an engine run smoothly and so advanced to suck more fuel ... this is unfortunate for the 2008 models, especially for the people that want to tour and XT owners. Dosen't look so "advanced". The extra fuel must be going ... rich A/F ratio. Why, I don't know ? DDFI #3 needs a little spit and polish to debugger it. Service pack 1 patch will out soon. Chas | ||
| Bigkuri |
I'm sort of with you except where you get to "mid-range" as heavy mileage. I find full throttle to be that. I think so do many others. From nothing more than a guess on riding different year-models, I'd say that the low and mid-range are robbed for the 08, and for anything below those revs the 08s are incredibly rich. | ||
| Desmo900 |
So would it be possible to run a Stock '06 map in a Stock '07 or '08 Uly to gain the gas mileage back? Dos anyone have a 06, 07 and 08 map that they can post for comparison? | ||
| Dennis_c |
If the 08 run richer Then how come my pipes are a lot bluer than the 06 07 | ||
| Windrider |
Mark, The 08s could also run cooler because of a new oil pump, larger oil cooler, different bearing design, etc, etc. There were significant changes to the 08 engine outside of the DDFI 3 ECM. See the Summer 07 Fuell magazine for details of most of the changes made to the 08 mill. It is interesting to note that Buell quotes the same fuel economy numbers for both the 07 and 08 models. I am not sure if they were required to test the 08 model before publishing the numbers? I would like to ride side by side with an 08 Uly so that we could fill up at the same station with the same fuel, ride the same route at the same speeds, then compare numbers. Desmo900, I doubt that you could load an 06 or 07 map into an 08 directly since the computer is different. The plugs could have been changed simply because many 06/07 Uly riders reported fouled plugs. Most reported this after trying to start the engine while cold with throttle or blipping the throttle. My 06 has never fouled the plugs but I start it as per manual: no throttle. | ||
| Towjam |
Anecdotal accounts indicate that '08s run their cooling fans much less frequently. If the threshold temperature has not been adjusted, the '08 engines must be running cooler. Actually, the threshold temperature has been increased which is one reason the fan runs less when riding - but longer after shutdown. I don't recall the exact updated temp but maybe Ratbuell or one of the other BadWeb dealer reps can chime in. Although it's still new, I rarely hear the fan come on when riding my XT. On the other hand, it'll run 10 minutes easy after shutdown. The fans on my '04 and '07 XBs ran almost non-stop in normal city riding but rarely ran more then 4-5 minutes after shutdown. | ||
| Growl |
Mark Weiss: that was an interesting dissertation! | ||
| Mark_weiss |
Windrider, I did consider the oil cooler change, that could very well make a difference but nothing published indicates the change. The increased surface area may only be significant under heavy loading. The oil pump change was reportedly just to be more robust. To improve cooling there would need to be a flow increase. There may have been, I have not been able to find any useful information. Towjam writes that the cooling fan's thermostat has been set higher, so my theory may be all vapor. It would be necessary to monitor engine temperature to find out if there's been a change. Since this is my first Buell, I can only go by what others have reported. Still, the fuel is going somewhere and doing something. I've just passed 3000 miles and have noted that the average fuel consumption is continually improving. Aside from the odd use tank (working a triathlon) I seem to be pretty steady in the very low 40s right now. Mark | ||
| Paul56 |
As a side note, air cooled aircraft engines have used fuel for cooling since at least the 1930's. | ||
| Hughlysses |
The one thing that doesn't computer about this theory is emissions. There is no way that they could deliberately make the engine run rich for cooling purposes and still meet the current emission requirements, certainly not without a catalytic converter (which are only used on European models). I'm still convinced this poor mileage is a result of some problem that hasn't been diagnosed yet, like the automatic TPS reset not working properly. | ||
| Treadmarks |
Maybe the idle air control valve. It is like a regulated intake manifold leak that allows the motor to idle smoother. I'll bet that the ECM has to send extra fuel as it's motor opens. | ||
| Ratbuell |
There's an IAC on every XB (and every EFI vehicle made). I had to plug Smiley1eye's back in after he looped his bike and had an error light with poor-to-no idle. The IAC is a plunger on an air bleed to the throttle body - the engine can't breathe past a closed throttle plate, so the bleed (IAC) is installed and computer controlled to allow idle breathing, but the computer closes it as soon as the throttle opens so there is an accurate airflow quantity for the computer to work with. My theory (and it's a THEORY) is this: everybody (and I mean EVERYBODY) complained about "too much heat" coming off the XB bikes. "Right thigh BBQ", "Buell Leg", etc. Buell finally does something about it. People bitch again, but for a different reason. Ya picks yer poison....granted, it doesn't help that fuel consumption appears to be up in these times of expensive fuel. You want heat? Come ride one of my tubers in traffic. Then hop on your XB and see how it feels. You'll thank me, and your XB will feel like an air-conditioned Caddy. I promise. Another factor to consider: everybody has been riding 08s in cold weather so far. Cooler operating temps plus cooler ambient temps equal longer coldstart-loop run times. Coldstart loop (a.k.a. "computer-choke"  equals richer conditions. Let's see how they do in warmer weather. | ||
| Chas1969 |
"Another factor to consider: everybody has been riding 08s in cold weather so far. Cooler operating temps plus cooler ambient temps equal longer coldstart-loop run times. Coldstart loop (a.k.a. "computer-choke" equals richer conditions. Let's see how they do in warmer weather. " Very excellent point!!!! Chas | ||
| Bobr |
My XT is still averaging 45mpg commuting on I-75 between 75 and 85mph with hard acceleration getting on the slab just for fun. Not bad for a 500lb bike that performs well. I've got a bit over 3000 miles on it. My '03 XB9SL started out averaging 48mpg. Somewhere around 10K it started getting 50-60mpg depending on where and how I rode it. When I traded it at 27K it had been consistently averaging 52mpg for several thousand miles doing the same commute I do on the XT. That bike weighs over 100 lbs less and is over 200cc smaller than the XT. During a recent e-mail exchange with Kevin Drummer he said that the new FI is way better. I don't think there is anything wrong with the new system. | ||
| Stevem123 |
I leave in the mornings during the coldest part of the day and go from 400 ft elevation to 1800 ft elevation then back down to sea level within a 28 mile commute. On the straights I'll average 80-90 MPH and sometimes bucking a headwind. Tailwind going home and slower speeds but the same elevation change. It's about half twisties and half slab. I average 38-42 MPG with this commute but I've seen near 50 MPG on the slab at normal hwy speeds. My bike is an early 06 model with race ECM, factory race muffler, and a modded airbox with race filter. All bags all the time and I'm a heavy 300 pound dude flogging it hard. I can't complain at all! BC Steve | ||
| Treadmarks |
There's an IAC on every XB (and every EFI vehicle made).  I'm hip to the IACV function, but when I rebuilt my 06 uly I didn't see one. Might you be kind enough to point me to it, because if I have one-me and it are gonna have a nice long talk.  | ||
| Crusty |
When I first got my '06 Uly, my fuel mileage was around 40 MPG. After 4 or 5 thousand miles, it gradually improved to almost 50 MPG. My wife has an '08 Lightning Long (Ss) with about 1500 miles on it, and she got 43 MPG on her last tank full. That's an improvement over the 40 MPG she was getting on the first couple of fill-ups. I think the biggest reason that the '08s aren't getting the mileage of the '06s and '07s is that they haven't accumulated enough miles yet. | ||
| Crusty |
OH, my wife's fan runs a LOT less than my Uly's. Not that it matters, 'cause LOUD FANS SAVE LIVES! | ||
| Jwnsc |
After getting no better than 35 mpg on my '08 Uly in the 2500 miles on 89 octane while riding around town and on the interstate, imagine my surprise when I got 45 mpg on a tank of regular doing 155 miles of mountain roads in north GA, western NC and eastern TN! I thought my low fuel light was broken. After I had replaced the 3.4 gallons of regular that was used, I conveyed my amazement to a confidential source (in a position to know) who replied that during the Buell Badness in March, whenever the demo bikes needed fueling they were filled with regular. Well, I always knew mountain air was invigorating! | ||
| Tipsymcstagger |
Anecdotal accounts indicate that '08s run their cooling fans much less frequently. I don't have any basis for comparison because I've only owned an '08, but if the '08 fans run less frequently while riding than previous model years, that must mean the fans on previous model years run all the time because the fan on my '08 seems to run at least 75% of the time. Non scientific numbers based on listening to my fan run while I'm riding. Tipsy | ||
| 08uly |
The fan on my '08 almost never runs while underway. If it gets hotter 80F+ and I'm in stop n go traffic then it will kick on but under normal riding conditions it waits until I kill the engine, then runs for approx. 5 mins. | ||
| Gs1100gk |
"There's an IAC on every XB (and every EFI vehicle made). I had to plug Smiley1eye's back in after he looped his bike and had an error light with poor-to-no idle. The IAC is a plunger on an air bleed to the throttle body - the engine can't breathe past a closed throttle plate, so the bleed (IAC) is installed and computer controlled to allow idle breathing, but the computer closes it as soon as the throttle opens so there is an accurate airflow quantity for the computer to work with. My theory (and it's a THEORY) is this: everybody (and I mean EVERYBODY) complained about "too much heat" coming off the XB bikes. "Right thigh BBQ", "Buell Leg", etc. Buell finally does something about it. People bitch again, but for a different reason. Ya picks yer poison....granted, it doesn't help that fuel consumption appears to be up in these times of expensive fuel. You want heat? Come ride one of my tubers in traffic. Then hop on your XB and see how it feels. You'll thank me, and your XB will feel like an air-conditioned Caddy. I promise. Another factor to consider: everybody has been riding 08s in cold weather so far. Cooler operating temps plus cooler ambient temps equal longer coldstart-loop run times. Coldstart loop (a.k.a. "computer-choke" equals richer conditions. Let's see how they do in warmer weather." Nice post Joe! I'm with you on this.  | ||
| Growl |
LOUD FANS SAVE LIVES! Crusty - you don't realize how true that actually is! The fan is a true deer alerting device. | ||
| Growl |
% of time fan is on seems to vary from bike to bike: Mine is on a lot ('06 Uly) and I have a friend with identical bike. When we ride together at same speeds his is on much less... I suspect manufacturing variances in heat sensor as a possibility. | ||
| Hughlysses |
There's an IAC on every XB (and every EFI vehicle made) That should read every 08 XB. Earlier XB's did not have an IAC. Treadmarks- that's why you didn't find one on your 06. | ||
| Ratbuell |
I may stand corrected.... | ||
| Adrian_8 |
Fuel Injections are :"wonderful, fuel efficient, don't require a choke, adjust for altitude"...bla..bla...bla...give me a ULY with a carbureator....then it will run as good as my 99 Dyna... | ||
| Ratbuell |
My (bone stock) Uly runs better than my S1W, my S2, or my FLHP. By "better" I mean more consistently, with less fiddling, less begging for attention, etc. My carb bikes are dialed in, I'm VERY familiar with my toolbox and its contents, and the EFI system has already proven itself to me hands down. I still love my carb'd bikes...but the Uly? Virtually idiot-proof. Key on, starter button, go. Simple. | ||
| Jwnsc |
In my case going from mid 30's to mid 40's with a tankful of regular got me thinking about some real mpg-reducing variables which are maybe seen more with Ulys farkled with big windshields and heavy loads seen in long distance touring. Although the RPM range was nearly identical on the interstate and in the twisties (3K-4K), gear selection (5th vs. 3rd), and therefore speed was not. This would seem to point toward aerodynamic drag as being a significant factor on the interstate, not to mention the extra HP needed to carry the weight of camping equipment, tools, spares, clothes, etc. Anybody like to offer a theory that it was really the altitude (2K-5K vs. sea level) and/or ambient temps (50-60 deg. vs. 70-80 deg) that gave me 45 mpg in the mountains? | ||
| Bigkuri |
Drag - I use a pretty standard plus 2" screen, so no great difference there. No side bags or top box, although occasionally on long trips I use a 10 litre strap on tail pack. Altitude - no real difference, maybe less than 1-2 mpg? I've just been to a trip in Luxembourg and Switzerland, and days up around 1,500m to 2,000m have not resulted in any real change consumption. Temps - it has been -5 to +25 (Celsius) so far, and again no change, although that's no where near as hot as some parts of the States for you guys! (Message edited by bigkuri on May 05, 2008) | ||
| Electraglider_1997 |
http://www.joe-ks.com/archives_may2004/GasSiphon.g if |
