Measured Air/Fuel Ratio for Optimization

Status
Not open for further replies.
1up3down said:
hey, thanks for extensively quoting me and then showing where you disagree Dennis

you seem more knowledgable about all this than me

appreciate your input sir
Click to expand...

You cited the other thread and said that it was about horsepower when that wasn't true...you also said that those of us who are discussing methods for solving a problem are operating "seat of pants", because your dyno results are the answer. Sorry, didn't mean to offend you, but your information was wrong. If you are an expert in tuning then explain it, don't attack others because we didn't do it your way.
 
1up3down said:
So, why'd you remove the 02 sensors?
Click to expand...

because they were causing a hesitation off idle

on the newer Triumph EFI bikes, in order to meet Federal emission requirements, these bikes come stock with both air injectors right next to the spark plugs and also O2 sensors in the header pipes.

I removed both air injectors and O2 sensors as they were causing the hesitation and roughness off idle.

The guys on the Triumph online forum say that the O2 sensors effect only the first 6% of throttle opening anyway.

The air injectors poof air into the chambers to lean the mixture coming out the tail pipes, mostly at a steady cruising type throttle opening to meet the standards.

Good riddance to both.
Click to expand...


Those air injectors have no effect on engine performance. (I've owned them since 1986, on several bikes) They are to add POST combustion chamber air meant to further complete burning in the pipes for reduced emissions.
So, what did you do instead of the 02 sensors? Tuneboy?
The hesitation/roughness off idle is usually the lean stumble.
I agree a remap/tune is a great way to improve performance, but the removal of 02 sensors baffles me. My '07 Tiger still has the sensor, with a tuneboy and TOR muffler. Is the Triumph vertical twin an OPEN LOOP EFI system? It can't be, they wouldn't have bothered with sensors. So if it's a closed loop system with fuel trimming capabilities, you had to fool/ignore them somehow... :?: :idea:
 
1up3down said:
by the way, our Commandos don't run on the pure octane rating for the 14.7 ratio you maintain
Click to expand...

For pure octane the stoichiometric mixture is approximately 14.7:1, or λ of 1.00 exactly.

In naturally aspirated engines powered by octane, maximum power is frequently reached at AFRs ranging from 12.5 to 13.3:1 or λ of 0.850 to 0.901.
Click to expand...

Maybe you should look up the definition of stoichiometric.

The 14.7:1 ratio is not mine...it is commonly used as the optimum burn and has been cited by multiple poster's in this thread.
 
Hey Dennis, we did seem to overlap the posts. If I'd seen yours first I would have probably written a little less. Stll, I don't see anything we disagree about. My experience with the O2 sensor system is really limited, but I'm a real fan of it now, and wanted to share with anyone who might be thinking of giving it a try.

I'm posting a couple pictures of it on the MZ below to show what the sensor and display look like. It's certainly temporary, and plugs into the battery charger connector for convenience.

Measured Air/Fuel Ratio for Optimization


This is a closer shot of the display. It has several connections for options I'm not using on this bike, which explains the extra coil of wires beside it.

Measured Air/Fuel Ratio for Optimization


Ken
 
lcrken said:
Hey Dennis, we did seem to overlap the posts. If I'd seen yours first I would have probably written a little less. Stll, I don't see anything we disagree about. My experience with the O2 sensor system is really limited, but I'm a real fan of it now, and wanted to share with anyone who might be thinking of giving it a try.

Ken
Click to expand...

A buddy and I installed one on his Savage Bobber because he put a Mikuni Flat Slide on it and couldn't get it tuned. I like you only have limited experience, but they are pretty cool devices and not that expensive. I think he paid $200 US for the kit. It's how I figured out that the burn varies through out the range. What is interesting is you can see the pilot circuit and transition which can help with tuning more accurately...what you can't really tell with a full throttle plug chop. At some point we may just have these on all our bikes :D
 
Having limited experience with dyno's , the shop where I take my bikes to uses 2 x long copper sniffer tubes up the mufflers and into the headers, if you were to use this method and or the WEGO style with welded bungs, any experienced forum members like to speculate on the optimum distance along the exhaust that the measurement should be taken?
Regards Mike
 
Brooking 850 said:
Having limited experience with dyno's , the shop where I take my bikes to uses 2 x long copper sniffer tubes up the mufflers and into the headers, if you were to use this method and or the WEGO style with welded bungs, any experienced forum members like to speculate on the optimum distance along the exhaust that the measurement should be taken?
Regards Mike
Click to expand...

The manual says the sensor should be placed as close to the exhaust valve as possible. On the bike we installed this on the bung was welded into the top of the down tube as it comes out of the head. Not sure that is the best but it was the only accessible place close to the exhaust port. With the sniffers you are a little less accurate but if they get them into the headers that should work. Someone else might have a better answer.
 
Brooking 850 said:
Having limited experience with dyno's , the shop where I take my bikes to uses 2 x long copper sniffer tubes up the mufflers and into the headers, if you were to use this method and or the WEGO style with welded bungs, any experienced forum members like to speculate on the optimum distance along the exhaust that the measurement should be taken?
Regards Mike
Click to expand...

If you are using a copper tube up the tailpipe then it needs to be at least 24 inches from the end or air will foul the readings.

You will need a pump to draw air from the exhaust and past sensor. Without a pump the readings will be very delayed.

If you mount a wideband sensor too close to the exhaust valve it is likely to overheat under full throttle operation. The readings will then be useless. A wideband has a narrow range of temperatures that it needs to operate at -that is why it uses a heater with feedback to the control it.

A welded bung at about center-line of the crank -give or take a few inches works very well. Jim
 
I guess I have not used a WEGO brand sensor. I wonder what they do different.

I do have two LM1's, an LC1 and a PLX wideband. All of them caution against mounting too close to the exhaust valve. They even sell a copper heat sink to go under the sensor if it needs to be mounted "within 10 inches of the head or if overheating is experienced". The Innovate sensors will set an error code. Jim
 
According to Daytona sensors forum the reading will not be correct at temps over about 1350 degrees.

According to Bosch the element temp for a LSU 4.2 sensor as used by Daytona and Innovate must be maintained at 750C. Temps above or below will result in erroneous readings.

I think I would want it a few inches at least from the head for dyno runs. Jim
 
drones76 said:
acotrel said:
Pete, it is NOT rocket science. If you want the best performance from a commando , you use standard ignition timing and lean off the mixture carefully right across the whole range of throttle openings until you get signs that the motor might destroy itself, and check that you've got excellent response under all riding conditions. If you then change the fuel or the weather changes a lot, you need to adjust for the change. I think you will find that most commandos are set too rich to cater for lazy bastards who just ride the bike fairly mindlessly - the average commuter.
Click to expand...


Is that like turning a bolt in the head until it strips, then back off half a turn?
Click to expand...

Surely you can tell when the cauretion is too lean without doing damage? If it is in the mid throttle, the motor will cough - you simply lift the needles or if that doesn't cure it drill one though out of the jet and lower the needle until it coughs again and raise it one. You set the mains to plug colour, and the black band should there in the plugs,unless you are wealthy. You won't usually do damage by running the mid throttle too lean, it will just be a pig to ride, and on most circuits you are not on the mainjets for long, however take care on the big stuff.
 
comnoz said:
According to Daytona sensors forum the reading will not be correct at temps over about 1350 degrees.

According to Bosch the element temp for a LSU 4.2 sensor as used by Daytona and Innovate must be maintained at 750C. Temps above or below will result in erroneous readings.

I think I would want it a few inches at least from the head for dyno runs. Jim
Click to expand...

Jim,

Your experience says something isn't right here. I think your correct that the sensor should be at least a few inches from the outlet of the exhaust because the potential to exceed the recommended temps of the sensors is possible particularly at high RPM. I think the Wego manual might not be clear. They are saying "as close as possible" because they want you to avoid placing the sensor in a position where back pressure might disrupt the flow. It certainly could be placed further down the pipe as you suggest without problems. The one we installed in the top of the pipe has been working fine, but the bike has not been on a dyno so hard to say what would happen.

Dennis
 
acotrel said:
You won't usually do damage by running the mid throttle too lean, it will just be a pig to ride, and on most circuits you are not on the main jets for long, however take care on the big stuff.
Click to expand...

What if the mid throttle turns out to be the normal cruising RPM for the particular bike? Talking normal riding here, not racing.
 
dennisgb said:
acotrel said:
You won't usually do damage by running the mid throttle too lean, it will just be a pig to ride, and on most circuits you are not on the main jets for long, however take care on the big stuff.
Click to expand...

What if the mid throttle turns out to be the normal cruising RPM for the particular bike? Talking normal riding here, not racing.
Click to expand...
A lean mixture at LESS THAN WOT is not likely to cause catastrophic engine damage because the engine, at only 50% (for example) power output, has a surplus of cooling capacity, and poor drivability will cause the rider to lose his cool long before the engine poops.
 
concours said:
dennisgb said:
acotrel said:
You won't usually do damage by running the mid throttle too lean, it will just be a pig to ride, and on most circuits you are not on the main jets for long, however take care on the big stuff.
Click to expand...

What if the mid throttle turns out to be the normal cruising RPM for the particular bike? Talking normal riding here, not racing.
Click to expand...
A lean mixture at LESS THAN WOT is not likely to cause catastrophic engine damage because the engine, at only 50% (for example) power output, has a surplus of cooling capacity, and poor drivability will cause the rider to lose his cool long before the engine poops.
Click to expand...

Yes your probably right about this...but for me it would be an uncomfortable situation. Only because I have fried engines with lean buring and it isn't pretty.
 
Ok. I have just drilled holes in my header pipes 10" down from the head. Now what?
 
comnoz said:
pete.v said:
Ok. I have just drilled holes in my header pipes 10" down from the head. Now what?
Click to expand...

JCWhitney -chrome tape.
Click to expand...
Is it a nice shiny chrome tape or just gray? Can you get it with a tint of blue?

Thanks for playing along, Jim.
Peter
 
At lower rpm like most street bikes live in, the headers can back wash by the sonic and mass flow reflections all the way back out carb throat so O2 sensor not that good but near WOT. Highest EGT Peel produced was 1375'F measured by temp needles in each header 10" from exhuast ring bolt. If Canaga could get O2 to help dial in touchy over carbed engine then maybe us lessor experienced can too. The one wire type will heat by exhaust only as C'do's owners not that worried to heat up enough for cold start EI fueling by using the polarity sensitive 3 wire type, nor likely must spare electric current to heat it much anyway. Its takes a fairly long study to see what's up with all the little to big factors to rely on O2 sensors of various types. Color tune plug kit likely more useful for low down rpm dial in, if not just going by ear and feel as traditional.
 
Status
Not open for further replies.
Back
Top