CHT and EGT Monitoring for CV CARB Tuning

[posplayr]

That's right. The channels could be set-up to run other 5v signal sensors, but there is only one thermo channel.

If you were to want exhaust temps EGT probes would be the most accurate. From my experience with watching CHT it is hard to establish any good metric. It is basically how 'FlyingSteve' interprets what the temps will do. The thermocouples clamped to the down tubes would have a similar affect. One thing you will notice if measuring CHT is the temps will go up or down in regards to jetting changes. Rich AFR it will be lower, Lean will be higher naturally. Never tried 4 CHT thermocouples at the same time, but my guess would be 1 and 4 would be close but different than 2 and 3, which would be similar.

Based on that description I would want to tune for AFR using O2 at the mid pipe (rich side of AFR 14.7) bung then depending on the temperature differential between ave of 1-4 and ave of 2-3 go up the inner cylinder to cool them a little at the expense of a bit more richness. The Fluke 50D will do that for me.

So if you had to pic one TC and where to locate it (the LMA-3 TC input) where woudl you put it? Spark plug of a center exhaust?

On the Speed pick-up there is some split collar set-ups for around $80 in the 3rd Party Products off the Innovate site. I have one. It is just a hall sensor J-B welded to a plastic screw, a resistor, and the collar has 2 magnets 180? apart. I actually pulled the sensor off the end of the screw and J-B welded it to a fabricated aluminum bracket to place it where I needed on another bike. Had to shim the collar to fit the wheel. If you find another set-up that will work please share.

I'll see if the hall sensor has a number on it, and check the resistor. If they are common parts that could be had from a electric supply it might be simple enough to make.


E

As mentioned I got a inductive unit and will have to see if it has mounting nuts or will need a split collar setup or if all else fails JB weld. :-\\\

 

[tejasmud]

Based on that description I would want to tune for AFR using O2 at the mid pipe (rich side of AFR 14.7) bung then depending on the temperature differential between ave of 1-4 and ave of 2-3 go up the inner cylinder to cool them a little at the expense of a bit more richness. The Fluke 50D will do that for me.

In opinion you might go crazy trying to tweak out the temps to be even. It could possibly be done in the pilot circuit, but beyond that needles and the jets should be constants. The temps across the cylinders will trend naturally in regards to AFR and load. At WOT the AFR is most likely going to be in the 13:1 to 12:1 range, where the best pull is observed by the engine. The pilot circuit transition into the needle circuit can be tweaked to run leaner for better fuel economy at cruise. I would stay richer than 14.7:1 for sure. You will begin to see what is going on once you are able to read the AFR, and the feel of how the engine pulls should come intuitively.

So if you had to pic one TC and where to locate it (the LMA-3 TC input) where would you put it? Spark plug of a center exhaust?

Try it on either 2 or 3 then try it on 1 or 4 to see if there is any offset. There should be. I would just place it on 2 or 3 and be done with it.

As mentioned I got a inductive unit and will have to see if it has mounting nuts or will need a split collar setup or if all else fails JB weld.

lol, JB weld has it's uses. It appears from the literature the sensors you picked up have a threaded barrel. May have to buy the nuts unless it comes with.

Yea I'm hoping this works well. After thinking about it for a while the acceleration outputs of the LMA-3 are going to be severely limited since any full power pulls in 1-2 will result in wheelies. Also 3rd gear pulls to redline will be pretty quick.

I'm pretty sure the acceleration will be logged in one of the two axis?s, X or Y, but not both. Last time I programmed the LMA3 there is a selection for either axis. Maybe I missed something. The data for acceleration may have some error in lower gears if the wheel comes off the ground, but not sure. Being the change in horizontal plane would be greater it makes sense it will be skewed.

It is a similar issue with the speed sensor. Mounted to the rear, break the tire loose and the MPH will go up. If mounted to the front pull the wheel up MPH goes down. Just have to find the most reliable data.

I've always done my pulls in a higher gear similar to how it would be done on a dyno at WOT. Rolling start, quickly getting into either 4th or 5th then from about 2500-3000 RPM hitting WOT and letting it climb until over red line once the main jets are correct.

Once hooked up you will begin to get the feel of it. It is really nice to see the measurement. I usually just tuck the LM1 in the clear map pocket of my tank bag. Being able to see the display of the unit is what makes tuning the AFR so simple. A quick burst at WOT, turn around, back to the garage, adjust mains if needed, and then repeat until the AFR is close. Once close find the designated "plug chop run" one uses, and make a pass at WOT and log the run. Head back to the garage, evaluate, and tweak if needed.

On the other throttle positions I've usually just held them constant by watching the tape on the throttle housing. Tape that is marked, but a pin with a little ball pushed into the grip for an indicator. Then try to remember the log sessions when I get back to the laptop.

I think it will be a little different with CVs, might need to get the MAP to become consistant during the log session. I've only run with mechanical slide carbs. Now I will not have to remember the throttle position given I added a string pot for TPS. I'm excited to see how this works out.

I bet you will wonder why you have not been running the DAQ until now. You will learn, but it will be fun too. At least for me it is fun. Once you are comfortable with measuring the variables you have now, the thought may cross your mind, "What else can I measure and log?" Gear position? Or, suspension travel? It goes on and on.... Next thing you know you have $5k worth of stuff monitoring this and that..

One thing you might concider is a LC1 with a DB gauge set-up. Once you have all the tuning done with the LM2 and tired of carrying it with, it is nice to see the AFR.

E

 

[posplayr]

In opinion you might go crazy trying to tweak out the temps to be even. It could possibly be done in the pilot circuit, but beyond that needles and the jets should be constants. The temps across the cylinders will trend naturally in regards to AFR and load. At WOT the AFR is most likely going to be in the 13:1 to 12:1 range, where the best pull is observed by the engine. The pilot circuit transition into the needle circuit can be tweaked to run leaner for better fuel economy at cruise. I would stay richer than 14.7:1 for sure. You will begin to see what is going on once you are able to read the AFR, and the feel of how the engine pulls should come intuitively.

That all sounds good. Just need to get the unit installed.

I'm pretty sure the acceleration will be logged in one of the two axis’s, X or Y, but not both. Last time I programmed the LMA3 there is a selection for either axis. Maybe I missed something. The data for acceleration may have some error in lower gears if the wheel comes off the ground, but not sure. Being the change in horizontal plane would be greater it makes sense it will be skewed.

Measuring acceleration on a car in the X and Y direction makes sense as the car is not as likely to wheelie. Also the car does not bank in a turn.

On a motocycle the bike leans in the turns and it is not obvious that it is at a roll angle consistent with the turn radius. If you remain in the saddle and dont lean out it is probably pretty close however. All that means is the force is straight down in the body frame (i.e. the gravity and centriptal forces are balanced to keep the bike at a constant roll angle).

For a motorcycle getting both axis in the vertical plane (or the X-Z plane of the biek) woudl be best.

It is a similar issue with the speed sensor. Mounted to the rear, break the tire loose and the MPH will go up. If mounted to the front pull the wheel up MPH goes down. Just have to find the most reliable data.

I've always done my pulls in a higher gear similar to how it would be done on a dyno at WOT. Rolling start, quickly getting into either 4th or 5th then from about 2500-3000 RPM hitting WOT and letting it climb until over red line once the main jets are correct.

I'm figuring the rear wheel is less likely to spin than the front wheel coming off the ground.

I'll not be going to redline in 4th anywhere near my house and much less likely in 5th. Redline in 3rd is all I'll venture on the 101 FWY

Once hooked up you will begin to get the feel of it. It is really nice to see the measurement. I usually just tuck the LM1 in the clear map pocket of my tank bag. Being able to see the display of the unit is what makes tuning the AFR so simple. A quick burst at WOT, turn around, back to the garage, adjust mains if needed, and then repeat until the AFR is close. Once close find the designated "plug chop run" one uses, and make a pass at WOT and log the run. Head back to the garage, evaluate, and tweak if needed.

so you still do a plug chop santy check? At what throttle positions?

On the other throttle positions I've usually just held them constant by watching the tape on the throttle housing. Tape that is marked, but a pin with a little ball pushed into the grip for an indicator. Then try to remember the log sessions when I get back to the laptop.

Was figuring on that, but also with MAP I should be able to tell what the throttle setting was that goes with different data sets.

I think it will be a little different with CVs, might need to get the MAP to become consistant during the log session. I've only run with mechanical slide carbs. Now I will not have to remember the throttle position given I added a string pot for TPS. I'm excited to see how this works out.

I bet you will wonder why you have not been running the DAQ until now. You will learn, but it will be fun too. At least for me it is fun. Once you are comfortable with measuring the variables you have now, the thought may cross your mind, "What else can I measure and log?" Gear position? Or, suspension travel? It goes on and on.... Next thing you know you have $5k worth of stuff monitoring this and that..

One thing you might concider is a LC1 with a DB gauge set-up. Once you have all the tuning done with the LM2 and tired of carrying it with, it is nice to see the AFR.

E

I have studied instrumented flight data for years so the fascination of instrumented Moto tuning will become familiar quickly I'm sure. However my primary goal is improved and reliable tuning and not gadgetry.

Suspension tuning would probably be done best with track lap times v.s. trying to do trajectory reconstruction so I'm not sure how much value there is in that.

Thanks for you detailed response. I'll let you know how the prox gauge works.

 

[tejasmud]

so you still do a plug chop santy check? At what throttle positions?

Yes. I normally check the plugs at idle, and also check them a time or two at WOT. Have found two points helps establish the AFR is reading accurately and then the rest usually falls into place. I'll do fresh air calibration on the O2 sensor periodically depending how far off any reading appears to be. Just to be positive.

A good example would be where I was getting 20:1 at the LM at idle on the initial start-up a few weeks ago. I could smell it was too rich from the exhaust fumes. Quick enough it was discovered the Bosch O2 sensor was not tightened down. It was hand tight. Checking the plugs confirmed the circuit was rich. Tightening it down solved the problem with the reading.

This example also gives a good indicator of how sensitive the O2 sensor is to any air leaks. My guess is this is a similar issue Katman was experiencing with the lean reading using the end clamp in the pipe. Any leakage at the midpipe connection or pulse of the exhaust where it can suck air back in to skew the sensor will normally show lean readings or a large variation in readings. Noise. Plug chops and sensor calibration helps give confirmation.

To be honest just measuring the AFR alone is priceless. Especially when working with aftermarket/non-stock configuration carburetors, and not having any base to work from on the jetting. I plan on tuning in the VM29s, then later play with the VM33s, and I have a few slingshot sets lying around, although I'm not too keen of CVs.

Any info I can help with just ask. Not a problem. If I have had any experience with the question I don't mind relaying my observations. If I don't know the answer I'll say so, but that usually has me try to look it up to seek the answer. Any info I can find, will post the source. The Innovate forum doesn't have a ton of info on bikes, but still there is a ton of relevent info. I weed through there every once in a while.

I hear what you are saying on the "gadgetry." Once in tune, I pull the equipment off and put it back in the boxes. I'll run a LC1 w/gauge to keep tabs on the AFR, but that's about it afterwards.



E

 

[posplayr]

Here is a quick update of what I have been up to. Still working out the bugs but have some data collected. See below.

Problems with a pdf to show the setup; later

 

[posplayr]

Interim Final results of getting the Innovate stuff to work and then using it to tune my carbs. It has been a learning experience.




http://www.thegsresources.com/_forum/showpost.php?p=1303763&postcount=12


my trials and tribulations getting the LMA-3 SPEED and RPM to work properly. They are almost flawless now.

http://www.innovatemotorsports.com/forums/showthread.php?t=12410