Author Topic: Running lean: Air/Fuel Meter or EGT  (Read 4445 times)

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Low Sodium

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Running lean: Air/Fuel Meter or EGT
« on: January 24, 2009, 09:50:16 PM »
Hi all,
Trying to get a handle on watching the mixture (carbureted roadster) while at speed - have run on the lean side a few times over the years, for various reasons (mostly stupidity on my part  :-D), with expensive consequences. What does work - a $65 A/F gauge, $350 wideband A/F meter, or perhaps a Pyrometer/EGT gauge? How reliable are any of those at sustained speeds at/beyond 200mph? Had an EGT back in the 80s that was almost impossible to read at speed. Ideal would be a series of colorful LEDs . . .

Offline Stainless1

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Re: Running lean: Air/Fuel Meter or EGT
« Reply #1 on: January 25, 2009, 10:50:35 AM »
Here is what we have been using since we went to the turbo...

http://www.zeitronix.com/Products/zt2/zt2.htm

makes it easy to figure when you have to choose.... get off the gas or buy more pistons....  :roll:

Sidenote. you need a computer onboard to record the run
Stainless
Red Hat 228.039, 2001, 65ci, Bockscar Lakester #1000 with a little N2O

Offline Sumner

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Re: Running lean: Air/Fuel Meter or EGT
« Reply #2 on: January 25, 2009, 12:06:16 PM »
We run and Innovate Wide Band with the Aux-box on Hooley's Stude for the air-fuel and it also data logs one EGT.  We run another EGT with an anolog gauge right in front of his face with the dial cocked to 1600F in our case.  If the dial is straight up and down (1600) he aborts the run or at least he is suppose to  :cry: .  Without clocking the dial it is impossible to read at speed (over 200) with all the vibration.

After the run we look at the data from the Innovate and make decisions as to whether changes need to be made, but this is data that could be after blowing up the motor, so I feel strongly about the gauge EGT being there also as a safety measure.

We probably have about $900 into all of that, but I'm convinced that it has saved a $15,000 motor.  I'll have pretty much the same capabilities on my lakester.

c ya,

Sum

Offline Dean Los Angeles

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Re: Running lean: Air/Fuel Meter or EGT
« Reply #3 on: January 25, 2009, 03:13:37 PM »
Both the EGT and AF are tools to help you determine where in the mixture curve you are. Or were.

Logging for after the run analysis is valuable information.

Trying to determine it during the run is almost impossible. You are too busy to try and read a seriously shaking readout. LCD's don't have enough contrast to see.

Quote
Ideal would be a series of colorful LEDs . . .

That's probably the best you can hope for and be able to see it during a run.

Does anybody make something like that?
Well, it used to be Los Angeles . . . 50 miles north of Fresno now.
Just remember . . . It isn't life or death.
It's bigger than life or death! It's RACING.

Offline Bob Drury

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Re: Running lean: Air/Fuel Meter or EGT
« Reply #4 on: January 25, 2009, 03:58:40 PM »
  I run both a FAST air/fuel with two real time readouts, and a Red Alert 8 EGT recorder.  Although both are downloadable, I like being able to track the individual cylinders after the run.  For in the car, the A/F is the one that tells me if I am in trouble instantly...................
Bob Drury

Offline sheribuchta

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Re: Running lean: Air/Fuel Meter or EGT
« Reply #5 on: January 25, 2009, 04:56:05 PM »
http://www.rbracing-rsr.com/rsrgauge.htm     I run one . It also has an extra red light that you can use for low oil pressure ar as a shift light.                    


                           Sheri Buchta
« Last Edit: January 25, 2009, 04:59:21 PM by sheribuchta »

Low Sodium

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Re: Running lean: Air/Fuel Meter or EGT
« Reply #6 on: January 26, 2009, 01:39:51 PM »
Thank you for your input, everybody!
I'm looking into getting a gauge like Sheri uses.