Max EGT? Options

[technicalninja]

The title is the question.

I know what to look for with water-cooled stuff.

I have no experience with air-cooled stuff yet...

What say you?

Is there a normal range?

A never exceed number?

Anyone ever use 4 thermocouples?

Was there any noticeable difference (#3 is of concern to me)?


Thoughts, tips, any data would be greatly appreciated!

[technicalninja]

CHT is first in my air-cooled book. I have never used one on a water-cooled build
AFR is second.
EGT is way down the list of important logging data for me.
It's still important enough that I prefer to log it.

I know of no other way to set individual injector pulse widths...

Most of the available aftermarket ECUs have the ability to individually tune each injector.

Has anyone adjusted individual injector pulse widths WITHOUT EGT couplers in each exhaust port?

How did you decide which way to go?


As to the fixed throttle comment.
What I meant was the throttle position is set by the throttle and an aircraft/boat/stationary power supply is run with only minor adjustments to it.
The power requirements are static as the aircraft/boat requires the power at all times.
Just imagine trying to run a 914 at a constant 75% of throttle.
One of my mentors, Corky Bell, built a big block Chevrolet that could produce 1450 hp in the early 90s. That's not shit in an 8 second drag car, pretty much anyone can do that now and many could back then. Corky's engine was for an offshore endurance racing boat and that engine could hold 1450 indefinitely for hours...
1450 for 8 seconds is easy; 8 hours is HARD!

I'm from an aircraft background as well.
Dad was flying Voodoos when I was born.
He went on to flying with United.
9/11 destroyed his life. Luckily, he turned 60 almost 1 year before and was doomed to the FE position on 3 person cockpits. The last aircraft he was "Captain in Command" of was the United flight 175 that hit the tower.
That was HIS airplane 1 year before...
He was born 9/15/40 and was retired out of that airplane on his 60th birthday 360 days before the attack.

Had I not been born with a genetically weak right eye I would have taken the same route.
I was flying gliders (real ones) by the time I was 15.

I am a turbo guy; Corky is thought by some as the "father of modern turbocharging", and I got an early education from a grand master of his field. I helped him edit "Maximum Boost" which is a killer basic overall book regarding turbos.
The manuscript was far cooler than the book. So many of Corky's idiosyncrasies were edited out. I liked them!

Someone mentioned Turbine outlet temps.
With a turbo I want TIP/TIT and TOP/TOT (turbine inlet and outlet pressure and temperature). I also want both pressure and temperature from multiple sources on the intake side. Turbo inlet/outlet, intercooler inlet/outlet.

The absolutely most important ratio is the TIP to boost ratio. If you get boost higher than TIP, then the power production goes through the roof as you no longer have back flow/pressure during overlap.

This is EXACTLY why Porsche employs variable aspect ratio turbos on all the S variants today!

Corky was screwing around with VATN (Variable Aspect Turbine Nozzles) turbos in the 80s.
Aerodyne was the first...
We had to put snubbers on them to slow the boost rise down. These could hit boost as low as 1500 rpm and hold big boost all the way to redline.

Boost is NOT an indicator of how much power you can make!
Boost is an indicator of the resistance to flow that an engine has.
Put that same turbo on an engine that has been massaged and you will see more power at the same boost level as before and you can achieve the original power figure at lower boost which helps thermodynamically.

TIP/Boost is what shows the efficiency of the system and almost no-one mentions it...

All these measurements are for the tuning phase. Once I'm done provisioning a system the "science project" gets removed and a much simpler monitoring configuration is installed.
One boost and IAT at throttle inlet.
TIP/TIT at turbine inlet.
WBO2 24" down the down tube.
CHT on an air-cooled. I don't plan on trying to boost a T4.
Looks like too much heartache for my tastes.

I was just trying to adjust my EGT expectations in regard to air cooled engines.
This is a tuning thing, not a log forever and actively monitor from the cockpit thing.
The CHT is critical thing, both in logging and active monitoring.

Thanks for all of the replies guys!

Rick