Exhaust Gas Temperature
Turbo Mini Forums

great stuff - Looking forwards to seeing the results of this one... :)

gosh thats going to be some interesting data paul , well done .

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

No offence but im still not convinced. How will you determine the difference in EGT is not down to the difference of VE.

I would be tempted to fit the widebands before the turbo and use the data, rather than being acurate, but as a balancing tool. doesnt matter what values you get, as long as they are the same. Then read the spark plugs to find if you are fueling lean or rich.

How did they tune engines before the advent of four gas analysers and wide band lambda??

Edited by Sprocket on 29th Mar, 2008.

I do not agree with your VE theory Sprox.

I have a cam with very short duration inlet timing, so the overlap of the two inlet valves is also low. Furthermore, the piston movement through the inlet valve overlap is very small. So small that I do not believe that it will overcome the inertia of the inlet charge that will continue to fill the closing cylinder as the opening cylinder starts to draw.

May be totally different with a high duration cam.

I'm not prepared to risk two wideband sensors at pressure. Even if we did it as you suggest, then you still do not know what is going on at higher boost.

With the data from the EGT/CHT and wideband sensors we can establish if there is a correlation and extrapolate for boost scenarios.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

would the VE on the outer cylinders not be higher due to more effective scavenging of the proper exhaust port?

That sir, is not rust, it is the progressive mass reduction system

http://aseriesmodifications.wordpress.com/

Team www.sheepspeed.com Racing

std 998 A+, g295, MD266, RHF4, 109hp @0.8bar/5400rpm

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

yes I saw that on there site, as I'm using Race Technology Data logger and dash

Team www.sheepspeed.com Racing

mega thread revival...

1340 with SC12 supercharger, the EGT probe is in the exhaust below the join of the two outer pipes of the LCB

First drive after a rebuild and installing the probe and the cheapie gauge was showing me between 300 and 650 celsius

I'll put it on the dyno next week and try to get a bit more scientific data, but I'd like to know, what's a normal range for exhaust temperatures?

thought the egt was measured closer to the head? like 4" or something im probably wrong tho!

Interesting reading all the old stuff. A lot of the above has been superseded by actual testing.

This is a log of data from a test I took in 2009:



Actual range is in the region 500-800 Deg C under load.

In the end, we worked out a way of using dual widebands upstream of the turbo, so there was no real need for the EGT monitoring.

The tests did confirm that the inner cylinder will always read a lot higher. This is due to it giving the average from 2 exhaust pulses, whereas the outer only have one. This was also subsequently confirmed by simulation.

As TT said, the probe needs to be as close to the valve as possible.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

I couldn't decide which pipe to put it on, so I went for the spot that was closest to the head with the most gas going to it

500-800 Deg C would be pretty close to what I got with a foot or so of cooling...

I had to rebuild because my engine had been getting way too much heat, the rings were rooted, the valves had recessed waay up into the head, and one piston had melted a bit. Had done 30,000km, but still was pretty crusty.

Dual wideband would give you a lot more useful information and with a supercharger, the installation would be straightforward.

http://www.jbperf.com/

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will