lean condition when dyno'd

[repoe3]

i would be interested in seeing what the O2 sensor unplugged would do, does that laser race exhaust allow for the O2 sensor or does it require removal? only concern i have with disconnecting the O2 sensor if the added fuel throughout the range may be too much.

bobby, did you ever baseline your sbx? curious what that output was. also why arent you running the laser chip? bbp better suited?

repoe3

[BMW Atlanta]

Unfortunately no,......never did a baseline run. I am now kind of in the tune and document era as before it was a no brainer that I needed to replace the exhaust, filter, chip etc. Would have been nice in retrospect, but now that I am changing performance goodies for other goodies, I like having a point to reference to. As for the BBPower chip, price wasnt as much an issue at wholesale and I really wanted the ability to have a few shots at the best suited mapping. I do notice most of BBPower's dyno charts have a great peak but do suffer a little on the bottom end and do not have as smooth of delivery as the Laser Race chip we had on our Boxer Cup race bike. BBPower recommends removing the O2 sensor given running the bike in Stage 2-5. The O2 sensor only takes pictures of the exhaust occassionally and has little affect on real time tuning via Motronic. Therefore a fixed map can be attained. But I do notice the very very bottom end of the rpm range suffers, but ever so slightly.

As for the wieght reduction with the Ztechnik,,........It is by FAR the lightest system out there. It is amazingly light in comparison to the stock cans and the marketing for the pipes is nothing but the truth I have found. They aren't the only pipe to have, but are definitely the lightest bar none. I was very happy with my system as it was not obnoxious loud but put down the power.

[shovelstrokeed]

Roger,
I bought Bobby's Z-technik system right off his bike. It is easily 15 lb lighter than the stock cans and probably 5 lbs on the cat end when cradled in the hands. The sound is perfect! Nice throaty rumble with no blare, even at WFO. Louder than stock but I cannot hear it at steady throttle, 75 mph, earplugs, Shoei Synchrotec. Grumbles a bit when rolling on to pass the brain dead. My riding partners say it sounds enough better than stock that I'm still allowed to lead. BTW, nice increase in roll on torque according to my finely calibrated SOTP dyno.
Ed

[pmc847]

Bobby & Robert,

Have you done any dyno runs without the crossover pipe? Is it worth while to remove said pipe?

Philip

[repoe3]

why i ask about the stock baseline is more or less to disregard the current peak hp numbers and evaluate what type of increase different setups accomplished from said baseline as there is easily a +/-5hp difference that falls within manufacturer's tolerances. but i have a hard time believing same setups should yield greater than 2-3 hp difference; think that is accounted by the fact that we are not all on the same dyno. maybe i should come back down to atlanta and use your dyno...things do seem better in atlanta

repoe3

to follow up on the O2 sensor, are you saying what i think you are saying, that the motronic does not take input from the sensor continually?

[roger albert]

Thanks Bobby,

I may have to try the Ztechik. A local guy disliked his so much he ended up returning it, but he was running the stock chip, so I wouldnt' anticipate the same. I'll have to keep my ears to the rails to hear the Z setup, and my eyes open for a good deal on them. Tempting, and more affordable than a pair of rims right now.

[BMW Atlanta]

Exactly what I am saying. It is my understanding that the Motronic does not use O2 readings for hard accelleration or decelleration(90% of my commute/riding) It is only really effective during "Cruise" mode going down the highway at a constant speed.

And things are better in Atlanta,..........hehehe

[roger albert]

That is approximately my understanding as well, though I hold that the sensor is still good fine tuning under light acceleration. So, for normal around town or freeway under light throttle loads, dumping the lambda sensor just nets you higher gas bills. Under hard acceleration, it normally does nothing. Pulled, I'm sure the ECU defaults to a somewhat enrichened limp-home mode, so that would likely account for the slightly higher power seen by those doing or advising pulling the 'plug'

[BMW Atlanta]

I am actually getting better gas mileage after pulling the O2,.........go figure. My guess is the chip and the O2 arent fighting each other, so I have a constant map now. Additionally BBPower maps without O2 sensor in place, so to maximize potential,......you must meet the conditions at which it is optimized.

[rob_wijhenke]

I'm almost lost now. Is there a totally scientific theory now that holds in real life, on a real bike on the road?

An be careful with what you say, I might quote you on my site...

[repoe3]

i wish i had answers. but the whole idea of the bike being lean on the dyno seems strange to me. if anything it should have been a tad rich as it was not getting the air volume that it would on the road. don think i will disconnect the O2 sensor as it seems to only kick in a bit and then it does not seem to be such an issue. just for the exercise i do intend to find another dyno to do a run, just for comparison. if the readings are within 1-3hp, then that would at least let me know that they are close, regardless of peak number. this is the problem with the scientific method..so many damn steps to complete to keep everything in check.

repoe3

[roger albert]

Bobby,

Be careful about generalizing. The original BBPower maps were done, per Bernie, with O2 sensing in place. Don't know when that changed, bit it was not the case 2 or 3 years ago.

And yeah repoe, I too would think a dyno run (vs road) would register rich, assuming it was mapped accurately for the correct mixture at road speed.

Yeah, science is a *****.

The higher mileage w/o sensor thing is sure puzzling. The way the software works, there is not real opportunity for the chip and sensor to work against each other. They, by definition, work in tandem, the sensor providing a bit of info to the chip. Doesn't mean it's not happening, but I just don't buy that explanation. Don't have a better one yet though

How big of a sample did you have to base that on Bobby? No chance of mileage going up with the motor breaking in? Other exhaust or system changes, or riding styles?

The only obvious opportunity for pulling the sensor to make mileage better, is for the map in question to be so insanely rich that the default sensor-failed mode is leaner. I've seen that mode leaner on a very very few cars, but it goes against all knowledge of this system.

Then again, software is damn easy to change, so maybe Bernie is doing something differently now.

???

wish I had the answers too.

[BMW Atlanta]

Well strange thing, we went to install a couple BBP chips and the instructions now say to remove the O2 Sensor for stages 3-5. I never ever recall seeing that in older instructions. Both our Master tech and myself have removed the O2 sensor all together and have a much smoother pulling bike, he also runs a Laser Race exhaust. As for my gas mileage. I ran with the Laser exhaust for over 1500 miles with O2 hooked up. I have done 3 tanks now without the O2 sensor and am getting another 10-15 a tank at least. I have noticed a very smooth pull through the RPM's where as before I had a noticeable drop/hesitation at around 5200 RPM's. That hesitation is all but a memory now, however I have yet to verify I retained my peak horsepower, still trying to get to the dyno.

[roger albert]

Hi Bobby,

Interesting feedback. Thanks. Confirms, or at least further implies that the BBP chips' programming and requirements have changed. Definitely was not in the old instructions, though a couple listers as far back as a year or so ago were told by Bernie to disconnect. Looks like the printed instructions have caught up. Not sure if I like that method. That means that the computer goes from having minimal capability from responding to airflow changes (indirectly, via lambda readings) to none. Otoh, if it works, it's hard to argue with. Very much would like to see A/B withO2/without)2 runs. Hope you can do so. I may have to drop Bernie a line. It goes much smoother if you talk to him directly and bypass english He's always been quite helpful when there is a very specific question.

[Joe]

Roger

I made many runs both ways some posted here last year............
Chip ..vs...Pressure Reg. I tried all stages w & w/o O2 connected nil difference on graphs below 8.5k.





BTW just put the K12 reg back in with BBP stage 3 much better pull up top but seems rich (not as crisp response lower range) I 'm going to set the chip to stage 2 and test.

31,000 miles
TBR exhaust system/ Welds cleaned up on headpipe
SanJose Powerfilter/Snorkel
BBP chip
K12rs reg
Bad attitude

[roger albert]

Interesting yet again

BBP=3 and K12 reg is the same Rob is running, and he's also planning on trying back to 2. With the stock regulator, mine likes stage-3, even though my exhaust is not as uncorked as yours (stock except for cat elim)

I'm thinking about trying a bit of dyno time as my current rear tire nears it's useful end of life. I'm definitetly going to compare BBP stages 1, 2, and 3, and maybe 4. May also look at a Ztechnik if I can work out a return-if-dissatisfied policy.

[Joe]

Maybe someone can tell me why I needed to run the BBP chip at stage 5 with no engine work to get the bet pull but lousy gas milage..............(maybe chip remapping is needed)


Here's a graph with Blue line is standard. Green is stage 3. Red is stage 5. all with O2 sensor connected.

[roger albert]

Good question. I'd call Bernie directly on that one.
Still, the red and green are just about identical except when thrashing, yet I bet green/3 gives better mileage. I'd be hard pressed to select 5 other than maybe at track days.

How did 4 and 5 compare? I have to believe 5 is so rich that you're gaining a bit of perf, but are then air limited. BBP documentation would certainly point you to level 3 with that config, so it's kinda strange.

Darn good question. The worse news is, that now I'm broke again. Someone just made me a stonkin' deal on a Ztechnik system. So much for buying new trans rebuild tools this month. That puts one of the airheads a month behind schedule. The immediate gratifcation for the S was too much to resist. sigh...

[repoe3]

so finally got the print out from the last dyno run and she wasnt running lean afterall. didnt get a composite comparison printed out, so here is an overlay showing power, torque, and air/fuel mix. torque improvement is great, power is obviously linear and bumped nicely. makes me kinda want to do the sprockets and then leave it alone...really. still think the dyno used is reporting figures a bit low...but oh well.



repoe3

[roger albert]

Well, you did take the tennis balls out of the exhaust after the last washing, right?


Seriously, thanks for sharing the curves.
The important thing is the relative improvement. I'd not sweat the numbers

Roger