| Author |
Message |
    
Werewulf
| | Posted on Tuesday, December 04, 2001 - 07:45 pm: | 
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i put the stock muffler back on and rode it thru deals gap. i was a little disapointed in the power. i remembered it running better than it did. yesterday i took the bike to live oak florida. i couldnt believe how good it ran. it must be the elevation! it ran really strong. i thought that the ddfi would do a better job of compansating for the elevation.
how often does the o2 sensor need to be replaced?
heres a photo of my v-rod if you are interested. http://www.tilleyhd.com/Tilley_Stvl/tilley_prices.htm |
Majicmak
| | Posted on Tuesday, December 04, 2001 - 09:11 pm: |
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Woof,
I checked the book and they dont give a serv. interval for the O2 sensor. Some feel that the stock unit is not the best and the Bosch sensor is a good replacement. I guess if the shop plugs in a scanalyzer and shows N.G. you would replace it then.
Mak |
Blake
| | Posted on Wednesday, December 05, 2001 - 02:37 am: |
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Wulf: The DDFI does compensate for altitude changes; it reduces the amount of fuel to coincide with the reduced amount of oxygen (air) that your engine can inhale in the thinner, high altitude air. All IC engines will lose power with increasing altitude. |
Majicmak
| | Posted on Tuesday, December 04, 2001 - 06:38 am: |
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Sure,
As to my original point, the bike can be tuned for economy and reliability, or for performance. I'm sure you know that most of the high mileage bikes with happy owners are stockers. A guy that wants a racer builds one up and his machine does it's job. But not for as long.
I guess my first responce to the ECM question was simplistic. There may be an accepted parts per million of oxygen in the exhaust that has been agreed to.
Tell me Blake, can you fly? Have you ever seen the mixture control on a small piston powered plane and do you know how to use it? The woman that ran that flight school knew just how much gas it took to get from Detroit to Traverse City and back. And how many hrs. that engine would run to top end overhaul. It was a real good "seat of the pants" experience.
Mak |
Lsr_Bbs
| | Posted on Tuesday, December 04, 2001 - 09:14 am: |
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Yes, Majicmak, there is a proper a/f ratio...14/1. Called stoiometric (if I spelled it right). In theory, what all efi systems attempt to achieve, but as Blake's already pointed out, theory and the real-world of EPA regs aren't necessarily in the same league.
In all fairness, what happens in the plane-world really has no business here (in this discussion). Their design and operating paramaters are so wildly different than a motorcycle, that it's apples-n-oranges. For one thing, you run out of gas on a bike, your don't die like in a plane.
Neil Garretson
X0.5 |
Aaron
| | Posted on Tuesday, December 04, 2001 - 09:22 am: |
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Yes 14:1 is stoic but you'll make more power richer, at about 12.7:1 |
Lsr_Bbs
| | Posted on Tuesday, December 04, 2001 - 11:37 am: |
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Actually, that should be *SLIGHTLY* richer. Your [typically] talking 1-3% changes in pulse width to affect that kind of a/f value (at least in the 4.6L mustang, of which I'm familiar). Which is really the sole advantage that efi has over a carb, it can very accurately meter fuel, whereas a carb [typically] is more difficult to meter this accurately.
But, a carb has a certain elegance in it's simplicity and efficiency of operation. Now that we're totally off topic, anyone seen the details on the R1's new FI system...quite cool. Uses a CV style slide smooth out the abrupt on/off throttle transitions that plague fi systems. Kinda funny that a carb system is superior [in this instance] to all the fancy programming that's been tried to greater-less success to deal w/ this problem.
Neil Garretson
X0.5 |
Aaron
| | Posted on Tuesday, December 04, 2001 - 12:30 pm: |
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Well, since we're correcting each other ...
So you're saying 12.7:1 is only "slightly" richer than 14:1 because it only takes 1-3% more pulse width to get there? I don't follow that logic.
12.7:1 is ~10% richer than stoic.
I would assume that it only takes *slightly* more pulse width to achieve a 10% change in mixture because the fuel system is under considerably more pressure than the air in the intake tract. |
Robr
| | Posted on Tuesday, December 04, 2001 - 12:49 pm: |
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Neil, in the same way the new Harley F.I. mimics a carb setup by using a vacuum pressure sensor in the intake manifold. It measures actual engine load through intake pressure rather than the calculated engine load used by other fuel injection systems(ie.throttle position vs. engine speed). Rob.
P.S.Blake I beleive you are right on this one. A freind with a stock X1 had the race ECM installed(w/throttle pos.sensor zeroed) and besides a throatier exhaust note, he had noticibly greater midrange torque and exceleration with no carbon buildup that would have indicated a rich condition. |
Blake
| | Posted on Tuesday, December 04, 2001 - 03:49 pm: |
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Good clarification Aaron. I think words are sometimes not perfectly accurate describers of our thoughts/ideas. I'd accept 10% as borderline "slight". 
Mak:
You say... ...the bike can be tuned for economy and reliability, or for performance.
I think your intention was more to say "longevity" rather than "reliability." The difference being, in my mind, that "reliability" implies the ability of a system or component to function failure-free for the it's intended design life, where "longevity" implies the relative length of a system's or component's useful operating life.
Your assertion that performance precludes economy and reliability (again, I think longevity a better term) is very flawed. The major factor that determines an engine's longevity is the operational stress levels it is subjected to. The harder an engine is run, the more stress it sees, the faster it will wear. This is especially pertinent near the limits of an engine's operational envelope, be it heat/temperature, revs, or power output.
A super hopped up high compression, racing engine being run like a racing engine is meant to be run (at the races) certainly sacrifices longevity compared to a stock engine being run like a stock engine is meant to be run.
But, once again, let's keep the discussion on track here okay? We are talking about a race ECM versus the stock ECM on a stock DDFI Buell. You want to save your engine, keep it from wearing, have it last 100,000 miles? The best thing you can do is ride it like an old lady, never exceed 3,500 rpm, never exceed half throttle; run a good grade synthetic oil, perform required maintenance, while running the best dirt catching super duper oil filters and air filters available.
I sure respect your quest for optimum longevity, and I'll ride wichya anytime. Me, I ride my Buell a bit closer to the the edges of it's envelope. If I had a fuelie, I'd be running the race ECM with the race headers, a free flowing muffler, and an aftermarket intake.
Back to the point... So why do you think Werewolf installed the go fast goodies in the first place? For longevity's sake?
You also asked me Tell me Blake, can you fly? No, my arms get too tired. As to airplane engines and their mixuture controls... No I don't fly airplanes (though I am quite good with MS Flight Sim) . I think I understand the principles of mixture controls. In an airplane at cruising speed I would adjust the misture along with engine speed and propeller pitch for optimum efficiency (mpg) while keeping exhaust manifiold temperature within the prescribed safe limit; if I was in a hurry, or during a climb, I might adjust those paramaeters for optimum power/speed. So what's your point? 
The bottom line is that I was merely trying to address Werewolf's questions (Can anyone tell me what a race ECM does that the stock one doesnt? What effect would putting a race ecm on a bone stock engine have?) and questioning what you were telling him (With a stock muffler and air cleaner it would run rich). I would say, "...it would keep it from running lean." |
Lsr_Bbs
| | Posted on Tuesday, December 04, 2001 - 03:51 pm: |
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Ok, ok, ok...Aaron, your right. I implied the wrong thing.
What I was trying to say, was that ~10% richer (which sounds like a lot of extra fuel) doesn't necessarily take huge jumps of 'jetting' (for the reasons you stated - higher pressure in EFI vs. carb). Just got mangled going from my brain to the keyboard.
===================
Actually Robr, that's not quite what I'm talking about, but is an interesting approach to a m/c EFI setup.
Still though, it does require extensive programming to try to minimize/avoid abrupt throttle transitions...which won't be as evident on a BT as it would a F4i spinning @ 10k. That's the cool thing about the R1 EFI as it eliminates all that complicated programming...it just lets physics do the work naturally...plus it will altitude compensate better due to the same effect...another failing of motorcycle EFI systems.
I'll bet dollars to doughnuts that when the mags start testing the R1, there will be no complaints about the throttle abruptness on it's fi. Sometimes it pays not to be the first on the block.
For a 100+ yr/old hunk of metal, it's amazing how well a carb actually works. Simplicity at it's best.
Neil Garretson
X0.5 |
Majicmak
| | Posted on Tuesday, December 04, 2001 - 04:03 pm: |
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Great,
Now that we are all here and this is cooking lets go back a step. No question that a Race ecm makes the bike run stronger. With the full kit better yet. But at what cost in engine wear?
How do you feel about my pos. that a lean running engine, that is not detonating,running next to an identical bike that is set up to burn more fuel will go farther down the road?
Mak |
Lsr_Bbs
| | Posted on Tuesday, December 04, 2001 - 06:59 pm: |
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If we're talking the difference between 14:1 (stoic = lean) vs. 12:1 (slightly rich)...I'd hazard the guess it won't have one whit to do w/ engine longevity. Now, if it's so rich it's washing the oil off the cyl. walls...then that's just poor jetting/setup. World's apart in my book.
Lastly, there's a big difference between the [detrimental] effects of a lean engine at 3,000 rpms and 6,000 rpms. At higher revs, there's more heat, and if it's detonating, even more. To my knowledge, most airplane engines spend the vast part of their operational life at cruising speed (or roughly 1/2 rpms)...whereas the typical motorcycle, car, hotrod, what have you, sees a more varied rpm life...and especially my bike, sees more high rpms. Hell, I cruise between 3-4,000 rpms, anything less is no fun.
Neil Garretson
X0.5 |
Werewulf
| | Posted on Wednesday, December 05, 2001 - 05:51 am: |
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after my trip to florida, im convinced that the race ecm is a good thing and will keep it! the stock muffler is louder than it used to be and seems to what i need at the moment. i will repack the v&h and keep it on hand if i ever want to change back. i just bought the factory race air cleaner for a s-3 and will use the asb tank accents. do you think i need to install a catch can with this filter? |
Az_M2
| | Posted on Wednesday, December 05, 2001 - 08:47 pm: |
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Unless you route the breather lines into the backplate of the race air cleaner, you will probably want a catch can. |
José_Quiñones
| | Posted on Wednesday, December 05, 2001 - 09:09 pm: |
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We have some very interesting data for the corresponding fuel curves for the stock ECM and the BPS ECM, we should have these posted in the next week or so. Basically, the stock unit is very lean until about 1500 RPM's, then goes into open loop mode and gets VERY rich. The BPS unit starts out a little richer but stays pretty flat (leaner than the stock ECM) throughout the the whole RPM range. Charts to follow.
Brad, any updates on this tease? |
Blake
| | Posted on Wednesday, December 05, 2001 - 10:24 pm: |
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Don't make sense do it? |
Lsr_Bbs
| | Posted on Thursday, December 06, 2001 - 09:25 am: |
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Well, sort of. I seem to remember that the EPA testing is of the silly variety. Like they only check at a certain RPM or something like that. If so, I'd guess that explains the super lean of the stocker. The over-rich in open loop might have been a [poor] choice to account for the vast majority of owners who were going to ditch the pipe before it left the dealer...a bit on the rich side to ensure you don't blow it up.
Still to this day I'm baffled that BMC has squandered the [suppossed] flexibility of their software. Suppossedly there is a tremendous amount of programability in the software...it just doesn't leave the BMC factory. A shame. Would have been the biggest selling accessory for the 2 EFI models, hands down.
Neil Garretson
X0.5 |
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