ck279

How does one know how to interpret an EGT guage? Is the temp readout the same for all cars? By that I mean is 1600 degrees on an Audi 1.8T have the same meaning as on a 3SGTE as on a turbo B18C1? I would assume so, but is this the case? Where does a person go to find out what temperatures designate: rich, a little rich, barely rich, stoich, barely lean, a little lean, very lean, etc??? I think it would be great if there was a complete chart showing which temp's corresponded to their given air/fuel meanings.


Carl


Modified by ck279 at 4:44 AM 8/13/2003

Disco Stu

TTT I'm interested as well. If two seperate cars had a perfect 12:1 AFR at every rpm (using this only for example) would the exhaust gas temp have to be the same? I would think that there would be differences obviously, but would those differences come from being two different motors all together or more from designs in the exh. mani, exh. piping, etc.? Maybe different materials used in the engine?

Bailhatch

From searching on here..ahem...i found that the best way to utilize an EGT guage is to find out what your particular motor puts out for temp at the desired A/F ratio. Generaly, if you are working from a 'good' temp/airfuel base then higher temps mean your lean and lower mean rich. The problem is that you can also have high temps when you are really rich. This is way it is important to get a base-temp to work from.

Also a single temp can not be used for each car because of where the sensor is located in respect to leanest cylinder and how far downstream from the exhaust ports it is.

So, like many questions here on honda-tech, it is anwsered with "Dyno It". I, still am interested in non-dyno, street tuning so if anyone can help educatd us budget tuners please do. I wanna be able to get my afc hack 95% of the way there on the street. blue wire mod and EGT possibly??

ck279

Thats what I'm saying.....how do you get a baseline for a particular engine?

I'm also wondering if the temp is the same regardless of power. I mean....If I am making 400 WHP from turbo or 180WHP....if the air/fuel ratio is the same at a given RPM, load, etc....will the cars produce the same temp exhaust gas??

I recently bough a 91 MR2 Turbo. I need a boost guage and I want to monitor basic engine performance (hence air/fuel ratio). People always rag on the Autometer air/fuel guages...saying they don't tell you anything. However....regardless of the EXACT air/fuel ratio percentage...I can ascertain from the Autometer a general idea. I mean...if I see it pinned in the red I know something is up. If it is almost always in green....I know something is up. I don't know an exact number....but I know the important stuff. Its time to inspect the engine/get something serviced.

The EGT I know can tell me more. But for those who profess as to their advantage in accuracy.......how do you know what temp equates to what level of air/fuel ratio, where did you find this info, is there a difference between cars (engines) engine types (NA vs FI) and is the temp reading power dependent (150WHP on stock engine vs 300 on boosted engine)??????

I think there is more than a few people who would be interested in knowing what the deal is with this.


Carl

ck279

TTT