Placement of Single EGT sensor
02-21-2012, 01:13 AM
#1
Honda-Tech Member
Thread Starter
Join Date: Oct 2005
Location: Ft. Hood, Texas
Posts: 752
Likes: 0
Received 0 Likes
on
0 Posts
Placement of Single EGT sensor
For you turbo guys running one egt sensor. Where are you placing the sensor at. I would assume you would want to be as close to the head as possible on the runner to have the most accurate reading but I was also thinking collector to get the average of all 4 cylinders together.
Im leaning towards the runner as close to the head as possible. In all reality in a perfect world, individual cylinder egt's should be fairly close to each other taking into consideration the same amount of air and fuel is being given as well as the same ignition timing. However i know Cylinder 1 is more succeptable to more air flow due to manifold design and so on and when problems start to arise, Cylinder 1 is more likely to show signs before any other cylinder.
So Im thinking single egt on cylinder 1 runner near the head flange would work best.
What do you think and how are you setting yours up?
Thanks
Im leaning towards the runner as close to the head as possible. In all reality in a perfect world, individual cylinder egt's should be fairly close to each other taking into consideration the same amount of air and fuel is being given as well as the same ignition timing. However i know Cylinder 1 is more succeptable to more air flow due to manifold design and so on and when problems start to arise, Cylinder 1 is more likely to show signs before any other cylinder.
So Im thinking single egt on cylinder 1 runner near the head flange would work best.
What do you think and how are you setting yours up?
Thanks
02-21-2012, 03:03 AM
#2
Honda-Tech Member
Join Date: Feb 2003
Location: schooling kids in ny, usa
Posts: 9,813
Likes: 0
Received 9 Likes
on
9 Posts
Re: Placement of Single EGT sensor
I run mine on the #3 runner about an inch and a half from the head. #3 usually is the hottest so I know my other cyls should be equal to or less than that in temp.
Trending Topics
02-22-2012, 03:30 AM
#8
Honda-Tech Member
Join Date: Dec 2005
Location: New York, ny, usa
Posts: 2,124
Likes: 0
Received 0 Likes
on
0 Posts
02-22-2012, 08:38 AM
#9
Re: Placement of Single EGT sensor
Quoted from thread listed above:
There is a gross amount of misinformation floating around about exhaust gas temperatures. I have posted many times explanations to EGT questions. But it seems the search feature here tends to overlook them for whatever reason. I have found an excellent article done by the fine folks over at Simple Digital Systems. It is written in plain English, and is 100% correct. The link is http://www.sdsefi.com/techegt.htm and for those of you that are lazy to click, read below and learn!
There seems to be a lot of mystery and misinformation about using exhaust gas temperatures to tune engines. Claims by many EGT gauge manufacturers about it being the best way to tune an engine must be qualified. The BEST way to tune an engine is on the dyno- PERIOD. What EGT is good for is a reference for where the engine made maximum torque at wide open throttle. Once removed from the dyno, a similar air/fuel ratio can be established a later date by dialing in the mixture to achieve the target EGT. It is really the AFR that is important, not the EGT. Most engines will make maximum power at an AFR of between 11.8 and 13 to 1 however, the EGT may vary from 1250F to 1800F and is dependent on many factors.
It should be mentioned that the target EGT is valid only on the same engine configuration as was used on the dyno. If you change the ignition timing, cams, pistons, headers etc., the optimum EGT may also change. Raising the compression ratio with no other changes will drop the EGT at the same AFR. Retarding the ignition timing will generally raise the EGT at the same AFR. One engine might make best power at 1350 degrees while a very similar engine might be happier at 1500. You can't guess at this or you are simply wasting your money on the instrumentation. Wankel engines have higher EGTs than comparable piston engines due to their lower thermal efficiencies. 1800F is not uncommon here.
Some gauge manufacturers say you should tune to achieve maximum or peak EGT for maximum performance. This is incorrect. Peak EGT generally occurs at an AFR of around 14.7- 15.0 to 1 on gasoline. This is far too lean for maximum power and is dangerous under continuous WOT conditions. Many people think that the leaner you go, the higher the EGT gets. This is also incorrect. Peak EGT occurs at stoichiometry- about 15 to 1 for our purposes. If you go richer than 15 to 1, EGT will drop and if you go leaner than 15 to 1 EGT will ALSO drop. It is VERY important to know which side of peak EGT you are on before making adjustments. It is safe to say that peak power will occur at an EGT somewhat colder than peak EGT.
You can sometimes feel a lean of peak condition as the mixture is hard to ignite and power will be down a bit as well. Once the AFR gets close to 17 to 1 at WOT, generally the engine will start to lean misfire. Most tuners always recommend to begin jetting or programming from a known very rich initial setting and carefully leaning until torque falls off slightly, then going back richer to the point of max torque. Note the EGT at this setting. Be aware that altitude, barometric pressure and ambient air temperature may affect this optimal temperature to some degree.
Are EGT gauges better than AFR meters? Conventional narrow band oxygen sensors and digital LED meters are not the best devices to measure AFR in the richer ranges but they certainly warn of a too lean condition immediately and obviously, without translation by the driver and they are affordable. Meters combined with wide band sensors are laboratory quality usually, highly accurate and useful but very expensive and sometimes bulky. EGT gauges have the limitations above and are generally priced between the other two. I would suggest that the two types are complimentary. EGT gauges have the advantage of working long term with leaded fuel which will clog oxygen sensors. EGT gauges are widely used to set mixture on engines used for steady state high power applications where operation has been carefully documented such as in aircraft. The choice would depend on the application. Both are better if you can afford them.
All this is courtesy and copyrighted by Simple Digital Systems EFI http://www.sdsefi.com
Once of the best, simple explanations of EGT's I have found.
Blaze
02-23-2012, 01:50 PM
#10
Honda-Tech Member
Re: Placement of Single EGT sensor
so why do people use a single exhaust temp. sensor? i could see if 1 was to use one on each runner to allow the computer to fine tune the pulsewidth. but why use 1 sensor? if you know your a/f ratio is where it's supposed to be.....then having 1 temp sensor really doesn't matter?
what would really be sweet, is to have 1 lambda sensor for each runner.
what would really be sweet, is to have 1 lambda sensor for each runner.
02-23-2012, 05:45 PM
#11
Honda-Tech Member
Join Date: Feb 2003
Location: schooling kids in ny, usa
Posts: 9,813
Likes: 0
Received 9 Likes
on
9 Posts
Re: Placement of Single EGT sensor
my wallet isnt fat enough to run individual egt lol. i also dont try to tune off the egt, thats pretty much what i use the wideband for. the egt is helpful for prolonged periods of high load or rpm letting me know when the temp is creeping up, as well as for some 5th gear boost i occasionally do, showing me when i need to let off.
if you stay in the throttle for too long even a properly tuned engine will have excessive egt and let go
if you stay in the throttle for too long even a properly tuned engine will have excessive egt and let go
02-24-2012, 03:29 AM
#13
Honda-Tech Member
Join Date: Dec 2005
Location: New York, ny, usa
Posts: 2,124
Likes: 0
Received 0 Likes
on
0 Posts
Re: Placement of Single EGT sensor
Mmmm... Try this originally posted by Vapor Trail - https://honda-tech.com/forums/showth...EGTs+explained
Quoted from thread listed above:
There is a gross amount of misinformation floating around about exhaust gas temperatures. I have posted many times explanations to EGT questions. But it seems the search feature here tends to overlook them for whatever reason. I have found an excellent article done by the fine folks over at Simple Digital Systems. It is written in plain English, and is 100% correct. The link is http://www.sdsefi.com/techegt.htm and for those of you that are lazy to click, read below and learn!
There seems to be a lot of mystery and misinformation about using exhaust gas temperatures to tune engines. Claims by many EGT gauge manufacturers about it being the best way to tune an engine must be qualified. The BEST way to tune an engine is on the dyno- PERIOD. What EGT is good for is a reference for where the engine made maximum torque at wide open throttle. Once removed from the dyno, a similar air/fuel ratio can be established a later date by dialing in the mixture to achieve the target EGT. It is really the AFR that is important, not the EGT. Most engines will make maximum power at an AFR of between 11.8 and 13 to 1 however, the EGT may vary from 1250F to 1800F and is dependent on many factors.
It should be mentioned that the target EGT is valid only on the same engine configuration as was used on the dyno. If you change the ignition timing, cams, pistons, headers etc., the optimum EGT may also change. Raising the compression ratio with no other changes will drop the EGT at the same AFR. Retarding the ignition timing will generally raise the EGT at the same AFR. One engine might make best power at 1350 degrees while a very similar engine might be happier at 1500. You can't guess at this or you are simply wasting your money on the instrumentation. Wankel engines have higher EGTs than comparable piston engines due to their lower thermal efficiencies. 1800F is not uncommon here.
Some gauge manufacturers say you should tune to achieve maximum or peak EGT for maximum performance. This is incorrect. Peak EGT generally occurs at an AFR of around 14.7- 15.0 to 1 on gasoline. This is far too lean for maximum power and is dangerous under continuous WOT conditions. Many people think that the leaner you go, the higher the EGT gets. This is also incorrect. Peak EGT occurs at stoichiometry- about 15 to 1 for our purposes. If you go richer than 15 to 1, EGT will drop and if you go leaner than 15 to 1 EGT will ALSO drop. It is VERY important to know which side of peak EGT you are on before making adjustments. It is safe to say that peak power will occur at an EGT somewhat colder than peak EGT.
You can sometimes feel a lean of peak condition as the mixture is hard to ignite and power will be down a bit as well. Once the AFR gets close to 17 to 1 at WOT, generally the engine will start to lean misfire. Most tuners always recommend to begin jetting or programming from a known very rich initial setting and carefully leaning until torque falls off slightly, then going back richer to the point of max torque. Note the EGT at this setting. Be aware that altitude, barometric pressure and ambient air temperature may affect this optimal temperature to some degree.
Are EGT gauges better than AFR meters? Conventional narrow band oxygen sensors and digital LED meters are not the best devices to measure AFR in the richer ranges but they certainly warn of a too lean condition immediately and obviously, without translation by the driver and they are affordable. Meters combined with wide band sensors are laboratory quality usually, highly accurate and useful but very expensive and sometimes bulky. EGT gauges have the limitations above and are generally priced between the other two. I would suggest that the two types are complimentary. EGT gauges have the advantage of working long term with leaded fuel which will clog oxygen sensors. EGT gauges are widely used to set mixture on engines used for steady state high power applications where operation has been carefully documented such as in aircraft. The choice would depend on the application. Both are better if you can afford them.
All this is courtesy and copyrighted by Simple Digital Systems EFI http://www.sdsefi.com
Once of the best, simple explanations of EGT's I have found.
Blaze
Quoted from thread listed above:
There is a gross amount of misinformation floating around about exhaust gas temperatures. I have posted many times explanations to EGT questions. But it seems the search feature here tends to overlook them for whatever reason. I have found an excellent article done by the fine folks over at Simple Digital Systems. It is written in plain English, and is 100% correct. The link is http://www.sdsefi.com/techegt.htm and for those of you that are lazy to click, read below and learn!
There seems to be a lot of mystery and misinformation about using exhaust gas temperatures to tune engines. Claims by many EGT gauge manufacturers about it being the best way to tune an engine must be qualified. The BEST way to tune an engine is on the dyno- PERIOD. What EGT is good for is a reference for where the engine made maximum torque at wide open throttle. Once removed from the dyno, a similar air/fuel ratio can be established a later date by dialing in the mixture to achieve the target EGT. It is really the AFR that is important, not the EGT. Most engines will make maximum power at an AFR of between 11.8 and 13 to 1 however, the EGT may vary from 1250F to 1800F and is dependent on many factors.
It should be mentioned that the target EGT is valid only on the same engine configuration as was used on the dyno. If you change the ignition timing, cams, pistons, headers etc., the optimum EGT may also change. Raising the compression ratio with no other changes will drop the EGT at the same AFR. Retarding the ignition timing will generally raise the EGT at the same AFR. One engine might make best power at 1350 degrees while a very similar engine might be happier at 1500. You can't guess at this or you are simply wasting your money on the instrumentation. Wankel engines have higher EGTs than comparable piston engines due to their lower thermal efficiencies. 1800F is not uncommon here.
Some gauge manufacturers say you should tune to achieve maximum or peak EGT for maximum performance. This is incorrect. Peak EGT generally occurs at an AFR of around 14.7- 15.0 to 1 on gasoline. This is far too lean for maximum power and is dangerous under continuous WOT conditions. Many people think that the leaner you go, the higher the EGT gets. This is also incorrect. Peak EGT occurs at stoichiometry- about 15 to 1 for our purposes. If you go richer than 15 to 1, EGT will drop and if you go leaner than 15 to 1 EGT will ALSO drop. It is VERY important to know which side of peak EGT you are on before making adjustments. It is safe to say that peak power will occur at an EGT somewhat colder than peak EGT.
You can sometimes feel a lean of peak condition as the mixture is hard to ignite and power will be down a bit as well. Once the AFR gets close to 17 to 1 at WOT, generally the engine will start to lean misfire. Most tuners always recommend to begin jetting or programming from a known very rich initial setting and carefully leaning until torque falls off slightly, then going back richer to the point of max torque. Note the EGT at this setting. Be aware that altitude, barometric pressure and ambient air temperature may affect this optimal temperature to some degree.
Are EGT gauges better than AFR meters? Conventional narrow band oxygen sensors and digital LED meters are not the best devices to measure AFR in the richer ranges but they certainly warn of a too lean condition immediately and obviously, without translation by the driver and they are affordable. Meters combined with wide band sensors are laboratory quality usually, highly accurate and useful but very expensive and sometimes bulky. EGT gauges have the limitations above and are generally priced between the other two. I would suggest that the two types are complimentary. EGT gauges have the advantage of working long term with leaded fuel which will clog oxygen sensors. EGT gauges are widely used to set mixture on engines used for steady state high power applications where operation has been carefully documented such as in aircraft. The choice would depend on the application. Both are better if you can afford them.
All this is courtesy and copyrighted by Simple Digital Systems EFI http://www.sdsefi.com
Once of the best, simple explanations of EGT's I have found.
Blaze
Thread
Thread Starter
Forum
Replies
Last Post
