| Author | Message | ||
     Jimincalif |
Folks, I'm running a '97 S3 tuber with some moderate updates: 2004 SB-spec heads cut for 10.5:1 Thunderstorm-domed pistons, 1250 with Axtell barrels, Mikuni 42 carb behind a Forcewinder/K&N. Pipe is still kinda sucky, stock 2" collector headers with a V&H canniser, which is going away soon as I have an old KT Engineering pipe coming  . Cams are stock, same as '96/'97 S1. I've done all upgrades to date myself. Power seems a better than stock overall, though I think the pipe is still holding it back some in the midrange. Still, throttle response is killer and I'm running 45-48mpg consistently. With that kind of mileage and power...<scratches head>...can somebody please explain how FI is better? OK, I can understand the loudness issue, but if you took the Forcewinder and extended it some, made it a double-wall tube, you could clean it up a lot. Emissions? Hell, use more jet circuits, tune it tighter? The carb is SO much easier for me to tweak, maintain or even completely swap on my own. It's a hell of a lot more reliable to boot. What am I missing here? IS the fuel economy and power on tap of FI really that much better than what I've got? Jim | ||
| Ryker77 |
your missing. Sensors. Throttle sensor, 02 sensor, head temp sensor.. lots or wires. an ECU.... All works good when all works good on a stock bike. Throw in a bad wire or a bad sensor. And you'll spend hours with a mulimeter. I pulled that FI stuff off of my x1. HSR42. Never again will I spend hours chasing wires. or replacing expensive sensors | ||
| Jimincalif |
Right...about what I figured. So does anybody make a "downdraft" version of the Mikuni 42 that can be mounted on an XB? Or are us "carb lovers" forever limited to the tube frame? | ||
| Bomber |
lots of downdraft carb available -- as for kits for the Buell, I think you're likely on your own a carb will never be as clean or as precise as a well-engineered FI, sez the guy with a carb on his MaDeuce | ||
| Ryker77 |
but a carb will always be better than a FI system with a faulty sensor, corroded plug, or bad wire. | ||
| Bob_thompson |
On another note, I have experienced it personally that as you go up in elevation and the air gets thinner the computer on any vehicle compensates with less fuel to keep A/F ratio within parameters and engine looses or gains power weather you go up or down. I once drove to the top of a mountain in Rocky Mountain National park, elevation around 14000 feet and my Toyota just about quit running. I was down to second gear and could not get over 2000 rpm's. As I came back down the computer again compensated and all was fine again. Also on a late model Camaro I pick up quite a bit of H.P. when going from here in Utah at 4200 ft. to Vegas which is about 2200 ft. elevation. A carb might run a little rich but you don't loose nearly as much performance. Of course this is not an issue unless you change elevations regularly as on my rides. My rides change elevation by 5000 feet in a few hours of riding. Also I feel I can rejet to meet emissions if necessary, then jet for performance. Eventually the EPA will force carburation to that of the dinosaurs but I'll stick with it for now. Just my experience for what its worth. Bob | ||
| Jimincalif |
OK. Is anybody getting better than 50mpg in any 1200cc+ FI Buell? Anybody? | ||
| Buellin_ri |
Lots of factors contribute to fuel economy. I think people have a better understanding of carbs than FI. Thats why most people tend to lean towards carbs. Granted I work with FI everyday, I find it to be worlds easier to fix (all be it with the proper equipment) and diag. As for which is better both sides will have good arguments. I think it boils down to a personal preference that stems from knowledge of one system more than the other. | ||
| Steve_mackay |
Jim, yes I regularly get over 50MPG on my race kitted '98 S3T. I've seen a high of 56MPG on the way up to appleton for their last "sport bike days". This was keeping pretty sane speeds. 75-80MPH. This is even with a #48/210(iirc) jetting. About 21K on it, the timing cover still has the stock rivits on it  it also got 95HP on the last dyno run. Always runs, always starts great, even in single digit temps. My "regular" city commute MPG is 41 to 44. | ||
| Jimincalif |
Steve: your '98 S3T is a carb model, or FI? I asked about mileage on FI bikes - Fuel Injected. 45-48mpg is what I'm doing on general commutes. What I want to know is, do the FIs do much better? | ||
| Spatten1 |
I'd scrap that electronic ignition and install points while your at it. | ||
| Jimincalif |
Sigh. Gosh darn it! You wanna dis carbs? Fine. What are you getting out of FI that's better? (Message edited by glitch on January 31, 2006) | ||
| Bigblock |
Well, if you prefer soggy part throttle- response over crisp and snappy, then FI is for you! | ||
| Fullpower |
JIMINCAL: firstly, you are right, carbs work real well, are easy to fix, maintain, and are reliable as atmospheric pressure. second, to ANSWER your question, my XB12 gets 56 miles per gallon running an average 75 miles per hour. | ||
| Steve_mackay |
Jim, my '98 is carbed. hence the statement about the #48/210 jets | ||
| Spatten1 |
If I did heavy mods to an XB I'd actually use a carb too. The FI system can't be adjusted and I'm not happy with the TFI, personally. However, most FI systems have adjustable maps or aftermarket boxes that work well with them. FI adjusts for temp. and altitude where carbs can't. A carb can be perfect at certain RPMs and atmospheric conditions, but will not be perfect elsewhere or if conditions change. An FI system is on the money nearly all the time, dialed properly. The sensors and map enable the system to do the equivilent of constantly changing "jetting" for current conditions. I'm sure you've had to re-jet carbs if you moved to a different altitude or raced at a new track, etc. You just don't need to do so with FI. Also, it atomizes fuel better for a more even dispersion of fuel in the combustion chamber. Also, with flat slides, you need an accelerator pump to keep from bogging with quick throttle opening, hardly an exact mixture. With CV carbs you have less than optimal flow in venturi but no bogging. With FI you have unobstructed throttle body, and no bogging. | ||
| Oldog |
In most cases the EFI system can tell you when a sensor is on the fritz, My X1 "coded" when the cylinder head temp probe went south, wires seldom fail, connectors can, jets and injectors can clog, fuel pumps can fail, ecms' can fail Jim CA has some of the toughest emmisions regs in the us, the S3 was FI, they could refuse to inspect or register your bike (xb?) if it is converted to a carb, also I believe that Al @asb is testing software for re-mapping a standard ecm see the topic in the KV on installing points on a buell why? timing can be adjusted by moving the pickup whats the advantage? vs no moving parts that wear out? if carbs are better why is the xbrr DDFI 3 ? | ||
| Spatten1 |
The point comment was just sarcasm. Sorry for the confusion. | ||
| Djkaplan |
"...but a carb will always be better than a FI system with a faulty sensor, corroded plug, or bad wire." You can't fault the reasoning here, but I think a lot of the issues FI has on Buells will get better as the technology evolves. FI, when it works and is mapped properly, is just better than a carburetor. If there was any advantage to them, believe me, the XBRR would be carbed (it isn't). Remember; carburetors, as simple as they seem, have had over 100 years of development - lots of people understand how they work, but not very many people could design one. That being said, the carburetor was a major factor why I chose an M2 over an X1 in 2000. It was obvious that the FI was still having teething problems back then. | ||
| Buellin_ri |
FI is a relativly "new technology" to motorcycles compared to the auto industry. Djkaplan hit it on the head to me. FI will get better with time, it has so far. I get 50ish mpg on my 9R, I do a lot of stop light to stop light riding. Haven't go a true constant moving mph. | ||
| Jimincalif |
OK. Can we get any reports of mileage on FI 1200cc bikes? | ||
| Easy_rider |
Before the race ECM I got 52 mpg. Now it's closer to 45. I previously owned a '98 carbed S3. If I let off slightly from a constant speed there'd be a "spit" out of the carb. I prefer the silent treatment I get from the FI. Don't need to remember to turn off the choke, either. I'll agree that a carb may be more tunable for the myriad of possibilities we have for heads/pipes/and whatnot and the tunability for FI just isn't available for Buells yet. For my limited mods, FI is the way to go. | ||
| Natexlh1000 |
I average about 52 miles per gallon on my X1. That's of course if I don't flog it too bad. My record was sixty something when I was trying the stock quiet muffler. My friend's XB12 gets better fuel economy than mine now that it's broken in. Mine is at 64000 miles and his is at 16000 now I think. One more thing, Whenever something went wrong with my system, the trouble codes led me right to the problem each time. #1: Error code was "intake temp sensor" problem was: I forgot to hook it back up after I cleaned my filter. #2: Error code was "front injector fault" problem was: wire chafed through on top of throtle body, intermittenly shorting out the front injector. #3: Error code was "oxygen sensor" problem was: exhaust rattled loose and messed with the grounding of the sensor. In other words, It's more easy to figure out what's wrong most of the time. Ryker was dealt a bad hand. His bike was a botched Power Commander installation. He had no SINGLE problem to fix but rather an entire pile of crap all at once. I don't blame him for going carb. Seems like the mos inteligent thing to do in those circumstances. | ||
| Jimincalif |
Hmmmmm. Well I was getting some spitting and popping too with the stock CV carb. I'm much more impressed with the Mikuni 42. Some years back I had a '96 S1, all stock motor innards, good pipe and an S&S Super "E" carb. Ran fine but I recall being disappointed with the mileage, down in the 35 - 38 range. Before that I tried an Edelbrock flatslide single-stage jet with no accel pump - Good GOD did that thing suck wind in spades on crack. The Mikuni is a MUCH better carb than any other I've played with. Smooth, fast response, mileage just a hair down from stock. | ||
| Firemanjim |
FI is the way to go,just that the Buell system still needs to catch up with everyone else.I am tired of watching the guys at Bonneville "change jets" with a laptop while I have gasoline running down my wrist working between hot exhaust pipes.My Triumph Sprint has flawless FI and you can get the Tuneboy set-up to make your own changes-- or just go to Triumph dealer for the latest download.The HD FI actually works better than the Buell system at this point.If Al can make his stuff work to hack the stock box and the race ecm it will be a step in the right direction. And don't think carbs don't have their own set of problems that go with them,sticking floats,clogged jets,bad diaphragms,heck I had the needle break on my S-2's Quiksilver.Try to find that hidden glitch. | ||
| Cataract2 |
Works better how? In that you can upload new maps from the computer for tuning. In that case yes. In just normal running form my understanding is the Buell system is way more advanced and runs way better. Hopefully the software to reprogram the ECM's will be released soon and that can all change. | ||
| Spatten1 |
"In just normal running form my understanding is the Buell system is way more advanced and runs way better." We had some heated discussions on this board about this about a year ago. Annony and other Buell loyalist insisted the XBs have the best system going. There was plenty of dissent on this point, but all the technical reasons for the dissent were brushed aside in group attacks. In fact, that may have been the beginning of the end of Craigster's participation on the board, which I think is a great loss, as he owns a bike dyno shop, has desingned and worked with FI systems for years, and had excellent information. In fact, that very discussion was probably the last argument I tried to participate in, as there were heated personal attacks on all those that did not state how advanced the Buell system is. I got my first and only STFU for stating a technical FACT. I am just stating how it went down from my point of view. I also love this board and think the participants are great people and very helpful. However, sometimes when people state that everything about the Buell is "way better" than every other brand I think the brand loyalty of the source should be considered. | ||
| Al_lighton |
Well, now that we have access to the map (or will VERY soon, anyway), I'll take FI over carbs any day. I hate removing carbs, ripping them open, changing jets, reinstalling, all to find out it wasn't the right change and to do it over, and over, and over, again. I'd much rather poke numbers into a computer. Whether the Buell DDFI system is the best or not, I'll leave to others to debate. Fact is, I think it is a very good example of simple sophistication. I like simple. It's one reason why I like Buells so much. And, early 99 examples notwithstanding, it works very well in getting the engine the right amount of fuel and spark at the right time across lots of changing conditions. All 100% IMHO. | ||
| Djkaplan |
"I hate removing carbs, ripping them open, changing jets, reinstalling, all to find out it wasn't the right change and to do it over, and over, and over, again." I can see your point Al, but I'd never complain about the one carb on a Buell after spending countless weekends over a row of Mikunis! | ||
| Ryker77 |
once we get to live maps the ECU.. in a cheap and easy format then the FI will be the best option. For the orginal poster changing from a carb to FI would be expensive and not worth it. Getting a new XB with pipes and airfilter properly live mapped on a dyno--- near perfect I had a BMW r1100sa with bosch FI and 6speed trans. Low speed surges and terrible fuel milage. never more than 36mpgs.. | ||
| Ted |
I never even thought of owning a carb'd I4. After year3 the hassle & maintenance would be nuts. FI on a I4 makes sense to me. On a vtwin... maybe not. |
