| Author | Message | ||
     Dktechguy112 |
I noticed that after i removed my inner airbox cover my afv's dropped from 100 and 100 to 89.5 and 94. Is this ok? Should I be worried? | ||
| Thefleshrocket |
Lower AFVs should mean that the engine is running leaner than stock (if you assume that 100/100 is stock). Lower AFVs mean less fuel, which is usually the result of less air entering the motor. Less air and less fuel means less power. Has there been a noticeable power loss? | ||
| Dktechguy112 |
no power loss, i mean i haven't dynoed it, but it still feels like a rocket. | ||
| Easyrider |
Dktechguy112, Put it back if your bike is not tuned, you hurt the engine.. | ||
| Dktechguy112 |
easyrider, what do you mean by "you hurt the engine". I have only had the airbox cover off the bike for 200 miles. Did that harm the engine, or do you mean it will hurt the engine if i leave the inner cover off? | ||
| Easyrider |
Dktechguy112 I mean Both (-: | ||
| Kicka666 |
More air with the inner off will need more fuel, more air less fuel = bad.. Your AFV's dropping means you have a lean running bike. As Easy said if you dont have a tune put the inner back on, cos it will hurt the engine. | ||
| Jasbiz66 |
When you take it off it sounds louder and you don't notice too much a power loss. But when you put it back on after riding it for a while without it you will notice a that it was lacking a little in power. At least I did. Could just be me though..... | ||
| Dktechguy112 |
i thought a lot of people ran the bike with the inner cover off, how could it harm the engine in only 200 miles? | ||
| Cherry_bomb |
i deactivated the 02-sensors and it's running just fine with the afv locked 100%. the oem-fuelmaps on my 062-calibration are good. ecmspy2 (mono) is a fantastic tool... | ||
| Dktechguy112 |
ok, i put the cover back on this morning. I checked in diag mode, with the engine off the o2 sensors are at .2 and .3 volts, and when the engine is on the o2 sensors were all over the place, there were going up to what looked like .7 volts. Is there anyway to reset the afv's without going to the dealer? Or should i just ride it and watch how they change? | ||
| Dktechguy112 |
anybody? | ||
| Easyrider |
Use the search function on the forum (-: | ||
| Dktechguy112 |
easyrider, I did use the search function. In the threads i looked through it seems like a lot of people are running without the cover and i never heard that is hard on the engine. | ||
| Cherry_bomb |
why should this be hard to the engine? maybe it's running lean - so what! engine gets hotter than normal. on a certain point, when it's too hot, the ecm demands soft/hard skip as long as the engine is too hot. this is not ideal but you can change that. lock the afv, disable the o2-sensor, buy yourself one of erik's ecm. so many possibilities... @easy: what and why should taking the inner cover off harm my engine, i'm really keen to hear your explanation. and please don't try to sell me a new costly calibration. | ||
| Dktechguy112 |
thanks cherry_bomb, i had the cover off for only 200 miles, i didn't think that could harm the engine. I would like to hear easyrider's explanation also. | ||
| Kicka666 |
I run my CR with the inner off but I have a tune, O2's disabled & AFV's locked @116. I understand what Easy is saying, a lean running bike will eventually harm the engine, no not after 200 miles. @ Cherry you say maybe its running lean so what... have you seen the damage caused to an engine by it running lean for to long, I have seen many & its not a pretty sight & very expensive, dont rely on an ECM to take care of everything... just my opinion.. | ||
| Cherry_bomb |
...have you seen the damage caused to an engine.... have you? the only thing is, that you won't have all the power, the engine is capable of. if it's running too hot, your ecm is demanding a soft skip first, then a hard skip as long as it is running too hot. and nothing else will happen. nothing. and running them @116% afv is better? i might doubt it. that is far too rich/fat. everything over 105% is too rich. this will harm your engine for sure...and if you (must) run a catalytic converter (like i have to), you'll destroy it in minutes. and have a look on your valves next time you take your engine apart. have fun. btw: i've been running an xb12ss my08 (euro3 specs) for one year with the original setup (no manipulation to the ecm) and it was running on an average afv of 85% all the time. dealers couldn't find out what the problem is and they were fiddling around that bike many times. at last, they told me it's normal (according to emission blablabla) and i've had to accept it. they put new software on as many as 6 times in one year. i've made about 10'000miles with it without any problem whatsoever. i've never seen what this engine was capable of until a good friend came up with a simple solution. this engine is still one of the cleanest i've ever seen and and it's fully ok when we took it apart last winter... and believe me, it was not the first and not only engine i took apart. (Message edited by cherry_bomb on August 15, 2010) | ||
| Kicka666 |
Good for you, it dont take much to stir the pot & I have seen the damage caused working on many bikes over the year as a tech, I set mine up using wide bands & @ 13:1a/f ratio if thats to rich I will donate a white rabbit to the orphanage. AS I SAID my opinion yes the are like a/holes we all have one... I wont waste my time commenting or offering advise in future as there are far to many sooky lala's ...  | ||
| Zac4mac |
I burned a dime-size hole in a piston once, courtesy of a pinhole in a CV carb diaphragm. Rebuilding that engine was the best 4 days of a 30 day leave, so I have no real regrets... lean is bad. Z | ||
| Bextreme04 |
Detonation destroys engines, not rich or lean. Detonation is almost always caused by the timing being too advanced or by the AFR's being too lean. That being said the values at which a specific engine makes the most power and doesn't detonate can vary widely. As a general rule though the closer you can get to stoic(14.7:1) the more efficiently the motor runs and the more power you make but also the hotter the motor runs and the closer you are to detonation. On turbo'ed motors for instance we almost always tune to about (12.6:1) because it is the point where we get the most power without detonating. Too rich will make the motor run "dirty" and can foul plugs and o2 sensors but too lean will put holes in pistons and possibly break rods and cranks. Personally i would rather be safe than sorry and run just a little bit rich. | ||
| Jng1226 |
Bextreme04 - very interesting thanks for the information. | ||
| Bextreme04 |
Oh and the lower AFV doesn't mean he is running leaner. The AFV is how much difference there is between the stock map and what the computer actually had to put in to get the AFR's to the target amount. Therefore at 100 AFV the computer is using the exact amount of fuel that the fuel map said it should. At 105 AFV it is using 105% of the fuel the map said it should(because it was running leaner). The computer is always striving for that stoic position and all it is telling you is your motor needed less fuel at a certain point than the stock fuel map said it would... still not good but the bike is actually running richer for some reason so the computer leaned it out to keep it at the target AFR. This means that while the AFV's can be used to tell you if there is a larger problem it doesn't actually tell you that it is running richer or leaner, just how much the computer added or removed fuel compared to the stock map to get it to the target AFR. And all Kicka666 is doing by locking his AFV's at 116 is removing the stock map from the equation so that it doesn't interfere with his aftermarket tune. As long as he is tuned the AFV doesn't really matter because his aftermarket tune is actually giving the bike the amount of fuel he wants at a specific point. Oh and back to the main point... i would look into why the motor was sucking in less air with the inner airbox off than with it on... in everything i read about the inner airbox removal your AFV's should have gone up from you pulling in more air at low speeds not down... there might have been another problem from something else that got touched when you removed it. | ||
| Kicka666 |
Great explanation Bextreme04, thats exactly what I did, removing the stock fuel & spark maps & setting up with widebands to get my AFR @ 13:1 or there abouts. Changing the AFV values ie: 105 to 106 changes the air/fuel value by about 0.2:1. | ||
| Firemanjim |
Guys, the 85% means that somewhere in the "learned fuel" area the bike is now running rich by 15% and has cut the fuel map everywhere by this amount,giving you an AFV of 85.The problem with that is you can now be very lean in some area of your map now,and over time that can cause engine damage. | ||
| Cowboytutt |
Jim, thanks for weighing in on that! Its Andy from Laguna Seca here (I was going to say from the Love Shack but that sounded so BAAAAD!  Anyhow, it sounds to me like the stock Buell airbox might actually be good for something (at least in certain applications!) Jeez, Erik Buell is an honest-to-God Engineer who knows about "resonant chambers" and such. Imagine that. Good Luck at Bonneville! Hope to hear about it and your turbo GSXR 750! -Tutt aka Andy Tuttle aka the fool on the hot rod Harley Street Bob. | ||
| Bextreme04 |
But if it adjusts the whole AFV for one spot being very rich wouldn't it adjust it up for one spot being lean? I know on my turbo'ed SRT-4 the computer will detect detonation and pull timing as well as adjusting for the AFR. Not to mention the fact that you can feel it getting leaner. If the bike was running lean enough to detonate and cause engine damage i would think you would feel it as well as hear the pinging from the cylinders. Also i heard something about Erik Buell Racing cutting the front half off of the inner airboxes and running them like that... something to do with heat. Personally i think it's more trouble than it's worth and i would just keep the airbox on but i doubt it is gonna damage your engine to run without it. |
