What is the point of an EGT gauge?

[TadS]

What the question says. I know several of you have them, so they must be good for something, but what that is, is eluding me. Thanks guys!

[michaels artic frost]

Hope this helps TadS.

I found it googling...it was a good read.

-Michael

Click on the link below to read the entire article.

http://www.bankspower.com/Tech_whyegt.cfm

'The exhaust gas temperature (EGT) pyrometer can be one of the most important gauges on a turbo-diesel-powered vehicle. It can warn the driver of situations that are potentially damaging to the engine, and it can also be used as a guide for optimizing fuel economy.' By C.J. Baker

[TadS]

Good read, sounds like a good addition when going FI. Thanks!

[Mole]

the EGT is useful for the folks who can't make use of the autometer a/f meters.

[808Camry]

What's the ideal EGT temps to shoot for? ANd how do you tune the AFC with it? Do you just aim at keeping in a particular range?

[Mole]

since i am the only one that has one (or currently, or i think i am the only one) i would have no idea what it should be at.

all i know is that there is a lot of activity when i hit the gas (which is expected.)

during idle and sitting in traffic my EGT is stable around 8-900 degrees.

when heavy flooring i've seen at most 15.5 degrees. (this is in the hundreds)

[all_red]

I think JoeB has one installed. From my understanding the EGT tells you if your running lean or rich. If its cooler than usualy, then your running rich. If its warmer then your running lean.

[JoeB]

That's correct, if you are running too rich, the excessive gas cools down the combustion chamber/exhaust out. Too lean it will run hot. The article was great but mostly focused on diesel which is a different principle. My readings are similar to Mike's, at idle it's around 800-900, normal load is around 1200when I'm really getting on it, I see as high as 1300-1400 but never over that. It sounds like diesel might need to run a little cooler than regular gas. The general rule for regular gas is not to excede 1600. Keep in mind this is dependant on where exactly you mount the EGT probe. The further down the exhaust you mount it, the cooler your base reading will be.

Trying to analyze it will drive you mad! The car's ECU keeps the car running at 14.7:1 a/f right? So if I have my a/f tuned to 12.5:1 under load, why would my EGTs go up when I gave it more fuel? The only thing I can think is there is a LOT more energy/power and with that extra power there will be heat. I don't think you can use the EGT as an identical replacement for an a/f meter for this reason. It's great to monitor a/f, don't get me wrong but don't expect to just get 1 reading accross the board. It's still a GREAT tool to watch for dangerous conditions. Especially on the top end! -JoeB

[808Camry]

Where in teh exhaust do you guys have it welded into?

[Mole]

i tap'd the exhaust manifold, about 1.5-2 inches away on the block, front side on the driver's side most pipe.

[SC V6]

for the diesel the more fuel means the hotter exhaust gas.. since there is less air in the cylinder not all the gas/diesel ignites... which makes the exhaust temp more.. I think casue either the gas carries out some of the hot air, im not sure.. but I know that the more gas the hotter the exhaust gas is..

[808Camry]

Would it make any sense to monitor one on the front and one on the rear bank to get both measurements or should they be fairly close?