UEGO or EGT?

[grimpuppy]

I am looking into getting either a AEM UEGO air fuel ratio gauge or Computech Exaust Gas Temp gauge setup for the truck. Anyone have any experiance with either one? The UOEG will provide a digital readout of the exact air fuel ratio via a wide band O2 sensor. It is suppose to be accurate to .1 percent. The other option is the Exaust gas tempature setup. Any opinions on which would be the better setup? They both run about the same price. Only down side is I run C12 leaded fuel. Any input on how long you think the O2 sensor will last with the leaded fuel would be appreciated.

[s10rodder]

I don\'t have experience with either one, but personally, I\'d go with the UEGO. An EGT gauge will help tell you if the motor is running lean or rich and when it\'s time to shut it down, but I\'d think a wideband O2 meter would be a much more valuable tuning tool.



Another point is that some cylinders will be running hotter than others. The EGT gauge will only be able to tell you how hot/cold one cylinder is running. If you put the sensor any farther away than a couple inches from an exhaust port it won\'t be very responsive and won\'t be as accurate. You can\'t really put the sensor in the collector or something and expect it to really tell you what\'s going on in the cylinders.



I\'d go with the wideband.

[spacecadet]

Air fuel ratio meter would be good but I have to agree, with s10rodder. The wideband O2 would do a better job. The a/f meter only knows whats going into the engine. The 02 would read the exhaust and tell you what is coming out. You can adjust the a/f ratio accroding to what the truck actully uses.

The only down flaw is the fact that you are using leaded fuel. It may not last long enough to make it pay for itself. I think the lead ash will interfere with the accuarcy of the readings.

Space.

[grimpuppy]

I don\'t think I stated what the 2 systems do very well. I will try and clafiry it.



The EGT system reads exhaust tempature. Two probes are threaded into a bung that is welded in each collector. This system will take exhaust tempature readings for each bank. Typicaly to hot is lean to cold is rich. A typical exhaust should be between 1250 and 1500 degrees. The system comes with a computer that ties into the tach and trans brake. It will start taking temps when you let go of the trans brake button. It takes temp and rpm reading during the run and stores them for viewing in the pits. This is exhaust temps not engine coolant temps. The exhaust temps should stay realitivly consistant throughout the run. If not you have a lean or rich condition at the rpm the readings vary significantly.



The UEGO uses a wideband Bosch O2 sensor also mounted in a bung that is welded to one colector. This system has a gauge with a digital display of your actual air fuel ratio. I believe this system will be easier to interput vs trying to figure out why a temp is lower or higher. But this system also has the wideband O2 sensor that may not like my leaded gas. I could live with replacing the sensor once a year, but do not want to change it any more often then that. Last time I looked sensors were around $100 I think.

[eigthmile]

Grim,I have an egt which has really helped on my tuning. I agree with others go with the a/f meter. The egt is good but they change within 50 degrees of every run for me. I ran 112 fuel for a year before switching to alcohol and never hurt my sensor.

[jeremytkoontz]

ok so here is my stupid question about this: If you use an Air/fuel ratio monitor system with an 0xygen sensor, won\'t it only be accurate for the bank of cylindars that corresponds with the header that you have the sensor welded into????

[ZZ4Blazer]

The AEM wideband is supposed to be a decent unit. I know a few guys from other forums that use it, and love it.



I don\'t know how well it would work with leaded fuel though. I think it kills O2\'s.



https://www.rpmoutlet.com/ezRetail/search/view.php?msg_id=1769



Cheapest I\'ve found the AEM kit.

[s10rodder]

I understand the difference. For an EGT gauge to respond quickly and be accurate, the sensor can\'t be more than 2 inches or so from an exhaust port. If you put the sensors in the collectors, the rpm you notice a change at won\'t necessarily be the actual rpm the lean or rich condition is happening. The farther away from the exhaust port you move the sensor, the less accurate it becomes. Also, you\'re right, generally, a high temp means lean and cold means rich, but that is not always the case. It\'s not a set in stone rule. Just a general rule of thumb to follow. A wideband O2 meter is a much more accurate way of telling where your A/F is at.



I installed an EGT gauge in my WRX, because I didn\'t need the total accuracy of a wideband for tuning, I just wanted to know when it would be good to back off and let the engine cool and if and when I might be running dangerously lean. I\'m not using it for a tuning tool, just an indicator of when I might be pushing it to hard. I chose the EGT gauge because I didn\'t thnk the extra money for a wideband O2 was necessary, since I\'m not using it for tuning purposes. BTW, I researched to find which is normally the hottest running cylinder in those cars and drilled and tapped the exhaust manifold runner for that cylinder to insert the probe. It\'s only about an inch and a half away from the exhaust port, so it\'s readings should be fairly accurate.



I still vote UEGO.

[gdmclnh]

I know some people that have forced induction systems that use the EGT as the setpoint for the rev limiter. They usually set at about 1625 deg. The wide band heated O2 sensors are better for tuning.

[grimpuppy]

On 2006-01-20 07:18, jeremytkoontz wrote:

ok so here is my stupid question about this: If you use an Air/fuel ratio monitor system with an 0xygen sensor, won\'t it only be accurate for the bank of cylindars that corresponds with the header that you have the sensor welded into????



That is true, but as long as you don\'t have a mechanical problem with the motor both banks should be pretty much the same. If you are lean on one side and rich on the other bank, carb adjustments are not going to fix that. The racers that need every ounce of HP possible do measure every cylinder.Then they do manifold, carb and head mods to ensure each cylinder is doing the exact same thing. For the average guy this is imparactical.



I believe I will go with the UEGO. I am more intrested in the tuning aspect of this. I am not really worried about the overall state of my motor or if it is being pushed to the limit. I shift and go through the lights 1000 rpm less than what is optimal and what the motor os capable of now. It saves a lot of wear and tear on parts. I just hope the sensor last for a year.

[350-s-10]

i bought a kit from daytona twin tech. It has a data logger which logs RPM, AF and another 0-5 v input. It was $350 shipped! I think it is the best deal out there. checkout the website:



Daytona Twin Tech (http://www.hutterracing.com/Performance%20Center/WegoII/wego.htm)

[grimpuppy]

On 2006-01-21 17:23, 350-s-10 wrote:

i bought a kit from daytona twin tech. It has a data logger which logs RPM, AF and another 0-5 v input. It was $350 shipped! I think it is the best deal out there. checkout the website:



Daytona Twin Tech (http://www.hutterracing.com/Performance%20Center/WegoII/wego.htm)



<font size=1>[ This message was edited by: 350-s-10 on 2006-01-21 17:25 ]</font>



That would be a great setup, but I can not run any type of data aquisition product in my class. Playback tach is the only recording device allowed.

The EGT system I was looking at may not pass tech either, thats another reason I will go with the UEGO system.