The Gamma Enrichment Gauge

[geewiz]

I am running MS2/V3 board/ver. 2.886. I do not understand why my gamma enrichment gauge never approaches "0". With the engine fully warmed and the intake air temp above the point chosen for enrichment needed, my gamma enrichment gauge never goes below about 65%. The engine runs well, & VE tables etc. are "normal". What is causing this? I have read the explanation of (and believe I understand) the variables involved in gamma e & but I can't come up with an explanation for the 65% reading. I posted in another area on this issue Sept. 11, but got "0" replies. please advise

[geewiz]

To reflect my fully warmed operating conditions, (using TOOLS-REVIEW) I have set CLT=200 & IAT=170 . With the engine running at a constant speed of 1200 rpm: CLT of 202 & IAT of 170, the gauge reads 84%. A low of 79% was displayed at: CLT=215 & MAT = 205.

[66fb]

This thread caused me to remember I often see gamme e that is above 100%. Using the info Lance provided I set the stimulator for 70* IAT, CLT above WUE range and gamme e was 110% instead of the expected 100%.

I discovered the reason is I've installed the "baro" sensor and it's reading 79 kPa (I'm at ~6000ft). I knew that's the purpose of the second pressure sensor...just never connected the dots.

[geewiz]

Lance did not mention an altitude "standard", but at 6000 feet , I would think that you should get a gauge reading below 100% (indicating a leaned mix). I am also running a second BARO,but at 1500 feet. This could not possibly require a 20% difference in the mix.

[geewiz]

I'm going to make an attempt to better define what I have read over & over in the megatune manual. GAMMA: Is the total enrichment factor. It includes accel./decel., barometric @ ???? Ft. altitude, & IAT at 70 degrees F. GAMMA"E": is GAMMA + (or -) the change in percent instantaneously required to GAMMA due to[EGO,BARO change,warm-up,MAP & VE (determined by the instantaneous table value). I hope that Lance or another senior member can fill in the altitude & correct or confirm my definition.

[geewiz]

It would seem to me that one should be able to configure the gammae gauge so that it would read 100% when the engine is fully warmed & all normal operating parameters (including the persons home altitude) have been met. One would then be able to see the effects of altitude changes, IAT change -etc. Is this possible or am I interpreting the purpose of the gauge incorrectly?

[66fb]

Doing that would make sharing information in this forum much harder. What would be the benefit?

[grippo]

In addition you should notify SAE - the standard for 100% comes from their standards for baro (sea level) and temp 70 deg F - these may not be exact but very close. It's probably done that way because they do their testing in dyno rooms - and they don't like to work in 120+ deg rooms which is more typical of under hood temps.

The point is you need a standard to be able to compare different engines and the same engine with different modifications. So you correct all data to a standard environment so you can take the environment out of the equation. Once you agree to a standard, it doesn't much matter what it is as long as everyone adheres to it and presents performance data after it is corrected to standard environment.

[geewiz]

After review of the above three posts, I have a new understanding of the gammae. I was ignorant of the automotive standards involved. I believed gammae to be a MS exclusive value & had no idea that this factor is common to the automotive industry. I now understand why the norm for this gauge is less than 100 with a warm engine. I also understand why the norm for this person will vary from another's norm- yet they are both correct. I thank you all for replying to an individual that you felt might be 1/2 a bubble off. I hope that others who review the "Gamma Enrichment Gauge" will benefit as I have.