"EGT, O2 (A/F) Tuning, Etc."

[Morg]

I'm married with child, believe me my junk is dry. :hammerhea
But seriously, the water in my headers is dumped from a #4 hardline, 1" in from the end of the collector. I can put in an o2.

[Unchained]

Good tech info about this subject,
http://www.sdsefi.com/techegt.htm
Here's a few quotes for those that don't like to read tech articles,
"It is really the AFR that is important, not the EGT. "
"Some gauge manufacturers say you should tune to achieve maximum or peak EGT for maximum performance. This is incorrect. Peak EGT generally occurs at an AFR of around 14.7- 15.0 to 1 on gasoline. This is far too lean for maximum power and is dangerous under continuous WOT conditions. Many people think that the leaner you go, the higher the EGT gets. This is also incorrect. Peak EGT occurs at stoichiometry- about 15 to 1 for our purposes. If you go richer than 15 to 1, EGT will drop and if you go leaner than 15 to 1 EGT will ALSO drop."
"Extensive testing with laboratory quality instrumentation on aircraft engines universally indicates that best power is NEVER made at AFRs richer than 12 to 1."

[MandDPerformance]

I agree with using both EGT and O2 but the O2 method is basically useless on an engine with zoomies isn't it? Unless the engine with zooms was tuned on a dyno with headers before it was installed in a vehicle with zooms O2 can't be accurate.
I'm just assuming that all the engines being talked about in this thread are being run with headers.
Correct me if i'm wrong.

[Unchained]

I agree with using both EGT and O2 but the O2 method is basically useless on an engine with zoomies isn't it? Unless the engine with zooms was tuned on a dyno with headers before it was installed in a vehicle with zooms O2 can't be accurate.
.
Probably using the O2 sensor on each individual cylinder would be the ideal like Mesa Balancing said but at $ 60 ea. just for the sensors it would get pricey.
I think the norm would be to have one sensor doing all the cylinders or one bank.
You could put a bung in each pipe and switch the sensor back and forth or Innovative has a thing that clips on the end of the pipe too.
The sensor needs to be able to read exhaust gas and outside air at the same time.
You want to try it?
I'll be done boating soon so if you pay the shipping and take care of it good I'll send it out. You'll be hooked though.

[MESA BALANCING]

With the good efi set ups you can tune the fuel to every cyl with my set up and when you get the fuel curve were you want it we'll install it in the boat or vehicle and fine tune in percentages up or down with a single sensor on each side this accomidates for air quality in the engine compartment that makes for great drivability and performance. To answer the ex temp question that all depaends on the fuel and engines performance I've had 9:1 race engines with exhaust temps in the 1400s which would be higher then I would want it for a street car but you cant burn the fuel in the cyl and some gets burned in the pipe these engines will run 500mile races or 24 hour events with no problems. Good luck guys Laz

[UBFJ #454]

When I started this thread I said: "We use both to tune ... And/Or ... Monitor Our Motor ...".
What I should have said was we use both O2's (A/F's) & EGT's to Check Our Tune, Moniter it as atmospheric conditions change and record data the for review at a later date in terms of changing the tune and for potential problems that might be starting to stick their ugly head(s) up. We primarily pay attention to the A/F data as we don't want to go lean using nitrous ... The EGT's are checked secondarily just to make sure cylinder temps are in line with where they should be and the motor is, and remains in 'good health'.
We're running Stepped SS Headers with Burns Tunable Collectors. Each tube has bungs in it for both O2's & EGT's and both collectors have bungs for the A/F's. Currently, we are only using 2 A/F's & 2 EGT's, typically one of each on both sides of the motor, but, have been known to put everything on either one side or the other to check specifics of both the even & odd banks.
To date, in competition, we have only run a 250 shot as we haven't been able to effectively use the additional Hp due to our not having the 'Bottom' Sorted Out ... Now that it appears that we are very close to having (if we're not there already ... next Race will tell) the bottom configured 'properly' and will be stepping up the Hp with larger and larger nitrous shots, we'll be watching the A/F's & EGT's even more carefully and taking far greater care in setting up the tune of the motor ... fuel & nitrous pressures, timing phasing, etc., etc, ..... etc. .
While A/F's & EGT's are, in my opinion, useful aids in tuning a Competition Motor, they are just that, Aids and should be used accordingly ... There are many other factors that must be taken into consideration when setting a Competition Motor to perform at its Best.