AIM Fuel Milage
#1
Racer
Thread Starter
AIM Fuel Milage
I'm replacing my MXL Pista with an MXL2 and looking forward to using the math channels.
Has anyone looked at using a fuel level sensor and math channel techniques similar to those in the Corner Vmin and Straight Vmax discussion to estimate gallons/lap, or miles/gallon?
I was thinking about something like = (fuel (@fiinish) - fuel(@start))/(@finish-@start) with the appropriate conversions, where @start and @finish is similar to the turn1/turn2/etc. math channels. (Sorry for the math channel shorthand)
Also, is there a list and description of math channel functions in RS3?
Thanks!
Greg
Has anyone looked at using a fuel level sensor and math channel techniques similar to those in the Corner Vmin and Straight Vmax discussion to estimate gallons/lap, or miles/gallon?
I was thinking about something like = (fuel (@fiinish) - fuel(@start))/(@finish-@start) with the appropriate conversions, where @start and @finish is similar to the turn1/turn2/etc. math channels. (Sorry for the math channel shorthand)
Also, is there a list and description of math channel functions in RS3?
Thanks!
Greg
#2
Rennlist Hoonigan
which cost no drachmas
Lifetime Rennlist
Member
Rennlist
Site Sponsor
which cost no drachmas
Lifetime Rennlist
Member
Rennlist
Site Sponsor
That should work, but it will only be by the lap. But then you could export the channel report and take the average of the averages or pull out green flag mileage, yellow flag mileage, etc.
Most times fuel consumption is done by the ECU based on the injector flow rates and duty cycle plus a fudge factor.
RS3 is only for setup of the MXL2, MXS, MXG, Evo4s, and Evo5 units. All analysis is still done in RS2 Analysis.
Most times fuel consumption is done by the ECU based on the injector flow rates and duty cycle plus a fudge factor.
RS3 is only for setup of the MXL2, MXS, MXG, Evo4s, and Evo5 units. All analysis is still done in RS2 Analysis.
#3
Rennlist
Basic Site Sponsor
Basic Site Sponsor
Join Date: Jun 2008
Location: Durham, NC and Virginia International Raceway
Posts: 19,150
Received 3,329 Likes
on
1,891 Posts
Hopefully, RS3 Analysis may add more flexible and powerful features, similar to MoTeC i2 and Dash Manager, which allows this computation now, without segment data or building a spreadsheet.
__________________
-Peter Krause
www.peterkrause.net
www.gofasternow.com
"Combining the Art and Science of Driving Fast!"
Specializing in Professional, Private Driver Performance Evaluation and Optimization
Consultation Available Remotely and at VIRginia International Raceway
-Peter Krause
www.peterkrause.net
www.gofasternow.com
"Combining the Art and Science of Driving Fast!"
Specializing in Professional, Private Driver Performance Evaluation and Optimization
Consultation Available Remotely and at VIRginia International Raceway
#4
Rennlist Hoonigan
which cost no drachmas
Lifetime Rennlist
Member
Rennlist
Site Sponsor
which cost no drachmas
Lifetime Rennlist
Member
Rennlist
Site Sponsor
You'd need to calculate this for each track and it would vary according to lap times (percentage WOT over the lap). Never tried to do it without calculating consumption data, first.
Hopefully, RS3 Analysis may add more flexible and powerful features, similar to MoTeC i2 and Dash Manager, which allows this computation now, without segment data or building a spreadsheet.
Hopefully, RS3 Analysis may add more flexible and powerful features, similar to MoTeC i2 and Dash Manager, which allows this computation now, without segment data or building a spreadsheet.
We normally just pump out after the session and that gives us very good results.
#5
Rennlist
Basic Site Sponsor
Basic Site Sponsor
Join Date: Jun 2008
Location: Durham, NC and Virginia International Raceway
Posts: 19,150
Received 3,329 Likes
on
1,891 Posts
The ICM fuel level sender (specifically for AiM loggers) after being set up as a custom sensor for some BMW's works very well. The extensive MoTeC database for Cup cars and now GT4 CS cars is quite accurate.
#6
Rennlist
Basic Site Sponsor
Basic Site Sponsor
Join Date: Jun 2008
Location: Durham, NC and Virginia International Raceway
Posts: 19,150
Received 3,329 Likes
on
1,891 Posts
Here are the current options for ICM's fuel level sensor. Their second gen has a microprocessor for more accurate and stable readings. It's about $175.
#7
Addict
Rennlist Member
Rennlist Member
The math channel is easy to do but from a purely practical application perspective, I have never gotten this to work given the unreliability of the stock fuel level sensor for the 987.1 Cayman. I ended up weighing the car before and after a session to determine the actual fuel consumption and found out that the scale set-up used at most PCA Club Races is totally unreliable to do this as well. I then resorted back to the "go out with a full tank and then top it back off after you return" methodology as the only true reliable way to calculate fuel consumption.
Given that I am absolutely fanatical about carrying around as little weight as possible for a race I would love to figure out a truly reliable way to make this work. I took note of the better sensors now available.
Given that I am absolutely fanatical about carrying around as little weight as possible for a race I would love to figure out a truly reliable way to make this work. I took note of the better sensors now available.
Trending Topics
#8
Rennlist Hoonigan
which cost no drachmas
Lifetime Rennlist
Member
Rennlist
Site Sponsor
which cost no drachmas
Lifetime Rennlist
Member
Rennlist
Site Sponsor
If you want accurate measurements of consumption, then you have to find a way to pump your tank dry after each session. Then you can measure what you put in and take out, divide that by the miles you ran, and have a real number. You still have to control for drives to the grid, pace laps, etc. And remember to go by weight not volume.
If you have an aftermarket ECU, you can calculate fuel burn by injector size and duty cycle, but that is not most people.
#9
Rennlist
Basic Site Sponsor
Basic Site Sponsor
Join Date: Jun 2008
Location: Durham, NC and Virginia International Raceway
Posts: 19,150
Received 3,329 Likes
on
1,891 Posts
Actually, the V2 ICM conditions the output to reduce the variations, IIRC.
The directions to calibrate the initial custom sensor curve from the ICM involve starting with an empty (I mean, REALLY empty) tank, going through progressive addition of specific quantities of fuel and notating the sensor value. Once the curve is set, there is no reason to continually pump down to know what you have. But that's not specific to consumption.
Most pro teams do what Matt has described. Measure weight of fuel added from empty before session, measure weight of fuel removed at end of session, divide by miles run. Add the positive fudge factor (for pace and cool down laps) and you're set.
The directions to calibrate the initial custom sensor curve from the ICM involve starting with an empty (I mean, REALLY empty) tank, going through progressive addition of specific quantities of fuel and notating the sensor value. Once the curve is set, there is no reason to continually pump down to know what you have. But that's not specific to consumption.
Most pro teams do what Matt has described. Measure weight of fuel added from empty before session, measure weight of fuel removed at end of session, divide by miles run. Add the positive fudge factor (for pace and cool down laps) and you're set.
#10
Racer
Thread Starter
Thanks Matt/Peter,
I understood that is would per lap on a per track basis, but if I setup the Vmin/Vmax it shoud be relatively easy to add it. I should have added that it is an older car, 944S2 in SP3, with the AIM sensor.
We have the ability to drain the tank with the fuel pump to get every last drop that would get picked up, so our plan is to add a gallon at a time and take a reading to setup the custom sensor.
A concern I have is will the sensor be precise enough using less than a half gallon per lap, and how much smoothing will be needed to get the noise out of the data. By taking the average I'm hoping it will be useful, so when the team asks me how much fuel I want for a 14 lap race, I'll have a better answer than "i don't know, 10 gallons?". And know with some confidence if I can make it to the end of a 90 minute enduro.
It would be cool if I could do it in the dash.
Greg
I understood that is would per lap on a per track basis, but if I setup the Vmin/Vmax it shoud be relatively easy to add it. I should have added that it is an older car, 944S2 in SP3, with the AIM sensor.
We have the ability to drain the tank with the fuel pump to get every last drop that would get picked up, so our plan is to add a gallon at a time and take a reading to setup the custom sensor.
A concern I have is will the sensor be precise enough using less than a half gallon per lap, and how much smoothing will be needed to get the noise out of the data. By taking the average I'm hoping it will be useful, so when the team asks me how much fuel I want for a 14 lap race, I'll have a better answer than "i don't know, 10 gallons?". And know with some confidence if I can make it to the end of a 90 minute enduro.
It would be cool if I could do it in the dash.
Greg
#11
The Penguin King
Rennlist Member
Rennlist Member
Thanks Matt/Peter,
I understood that is would per lap on a per track basis, but if I setup the Vmin/Vmax it shoud be relatively easy to add it. I should have added that it is an older car, 944S2 in SP3, with the AIM sensor.
We have the ability to drain the tank with the fuel pump to get every last drop that would get picked up, so our plan is to add a gallon at a time and take a reading to setup the custom sensor.
A concern I have is will the sensor be precise enough using less than a half gallon per lap, and how much smoothing will be needed to get the noise out of the data. By taking the average I'm hoping it will be useful, so when the team asks me how much fuel I want for a 14 lap race, I'll have a better answer than "i don't know, 10 gallons?". And know with some confidence if I can make it to the end of a 90 minute enduro.
It would be cool if I could do it in the dash.
Greg
I understood that is would per lap on a per track basis, but if I setup the Vmin/Vmax it shoud be relatively easy to add it. I should have added that it is an older car, 944S2 in SP3, with the AIM sensor.
We have the ability to drain the tank with the fuel pump to get every last drop that would get picked up, so our plan is to add a gallon at a time and take a reading to setup the custom sensor.
A concern I have is will the sensor be precise enough using less than a half gallon per lap, and how much smoothing will be needed to get the noise out of the data. By taking the average I'm hoping it will be useful, so when the team asks me how much fuel I want for a 14 lap race, I'll have a better answer than "i don't know, 10 gallons?". And know with some confidence if I can make it to the end of a 90 minute enduro.
It would be cool if I could do it in the dash.
Greg
#12
Racer
Thread Starter
Greg
#13
Rennlist
Basic Site Sponsor
Basic Site Sponsor
Join Date: Jun 2008
Location: Durham, NC and Virginia International Raceway
Posts: 19,150
Received 3,329 Likes
on
1,891 Posts
Bigger sample, better info.
The V2 ICM has improved this issue substantially, AFAIK.
The V2 ICM has improved this issue substantially, AFAIK.
#14
Rennlist Member
The Iron Canyon works great. Have it running in a few cars. Very simple reliable and accurate. Just took reading at full and move sensor to empty and built simple curve for a sensor in AIM. Now we show gallons left on display. seems dead accuarate.
#15
Rennlist
Basic Site Sponsor
Basic Site Sponsor
Join Date: Jun 2008
Location: Durham, NC and Virginia International Raceway
Posts: 19,150
Received 3,329 Likes
on
1,891 Posts
And the V2 is even better!