Anyone here does it? If so what tuning instruments you use?



I was considering this: http://www.ifamilysoftware.com/8525.html
has anyone use these what or the pro's/con's of this

Cool little gadgets.. I have found it's best to jet for mph

EGT have been used for years for fuel tuning, especially on gasoline powered airplanes
My airplane had a single probe EGT, some have two and some have one for each cylinder that displayed all of them on the same screen
Mine had a single gauge that did not read low exhaust temps. below 900 F I was taught in flight training to lean it down in flight once I was above 3000 ft. slowly until it reached peak EGT and then richen it up to 25 F to 75 F rich of peak, depending on the brand of motor and if it was normal induction or turbo charged, you would run the turbo charged engines lean of peak by 25 to 50 F
On the rental airplanes that did not have the EGT you could do the same thing on leaning them down in flight by leaning it down slowly until it started to miss or run rough and them turn the mixture control in 1/4 to 1/2 turn
I got taught the hard way to do that on my second flight in my airplane, I fouled both spark plug out on one cylinder in the second flight shortly after take off about ten miles west climbing from the airport in Bull Head City, AZ and I had left the mixture in at full rich above 3000 FT

I want to log EGT as well. DIYAutotune has a device that can do 8 EGT sensors and talk directly to a laptop or to an EFI system. From what I have understood using EGT to set up cylinder balance is better than to set it up for power. In my case I am fuel injected and can adjust timing and fuel per cylinder so it would be nice to have.

Exhaust gas temperatures on E85 had me completely baffled. The only time I checked them with our 500" stroker on the dyno, shooting for 8:1 AFR, it went like this...........

12:1 AFR......680 HP......900 degrees EGT
11:1 AFR......760 HP.....1000 degrees EGT
10:1 AFR......845 HP.....1100 degrees EGT....out of dyno time.....seems like it would be pretty hard to blow up an engine on E85

LaRoy.......did you happen to record your egt#'s at idle?......Thax for your response .

Sorry, I don't remember and I didn't record them at idle.

I'll take a chance and if anyone spray(n20) there car using some sort of egt unit and monitored the gas temps....

When I first starting spraying with E85 I tried to use EGT. There wasn't much info that I could find to even get a baseline so I thought I'd keep it safe by EGT. I chased my tail for a few months before giving up on it. Seemed like no matter what I did with fuel and timing, the EGT would read 1400-1600! That gauge plugs the hole in my dash now and I couldn't even tell you if it works. I found that plugs, time slips and pan vac give a much better picture of what's going on. I also use O2 as another data point, but don't live and die by it. You can chase your tail there too IMHO.

Thax you for that info.

challenger 451 you spray a pretty good dose of the nos right?
Do you remember you idle gas temps?

One of the things I had to learn as a instrument rated commercial pilot is that the existing weather has a lot to do with the performance of the airplane and power plants, especially N/A piston engines.
Altitude, both actual and density altitude, as well as outside air temps., barometric pressures and humidity determine how much air the N/A motor can suck in to make heat in the combustion chambers and exhaust pipes Better conditions, lower altitudes and better tuning make more power and heat in the exhaust
E85 and both pure alcohols have considerably less latent heat per gallon than gasoline does

Just a baby shot. Only a 0.030 jet in a fogger. Idle temps were pretty low, maybe around 700-800? For driveability(idle, part throttle), O2 seems to be a good tool. Certainly more useful than EGT from what I've seen.

Thaxs....

IMO leave EGT's to the Methanol and blower guys, or just to make sure that cylinder is working I suppose. Prefer O2's but still read plugs and watch the slip.

what's a good meter that use's a o2 censor that reads e-85 and records the highest temp.?.....Thax for your response fellas

I'm not sure which O2 system is best to use on any alcohol based fuel I do know that you need to buy NTK sensors, the expensive ones for alcohol, for alcohol based O2 systems to get accurate readings

I just got a egt gauge and am running e85. Curious as to what cylinder I should put the probe in. Thanks.

That's not correct for a NA engine. A regular LSU 4.2 sensor will read down to 4.5 a/f ratio, which is well below the normal 5.5 - 5.2 A/f ratio that is normally seen. Now On a supercharged engine "normal" a/f is 4.2-4.4 a/f.

In addiction, the Daytona sensor wego 5 unit goes down to 3.2 a/f using the lsu 4.2 (Bosch) sensor. ( I have not use this controller)

Also any O2 sensor can be used for just about any hydrocarbon fuels. I have used mine for gas, e85, methanol and diesel. They all output 0-5 volts, it's the Scale factors that are different.

Joe

this is a copy and paste from a rant on went on about 2 years ago

When I have a engine on my dyno, I DO NOT use EGT’s to tune a engine. I use BSFC and O2 sensors (with ALL fuels) but even with that, I pull the plugs ever time I make a timing change. I use EGT probes to tell fuel distribution and other things, I never use or heavily rely on EGT as A/F Ratio determination
Using the EGT probes for fuel distribution studies is their greatest value.
You can't ask some other racer what EGT is best for you .
example= no matter how well you tune a 9:1 normally
aspirated engine, its EGT's will be higher than a similar
properly tuned engine with 15:1 Compression Ratio .
....no matter what you do , the 9:1 CR engine is going to have
higher EGTs because it will waste heat out exhaust more than
a 15:1 engine, or any CR higher than the 9:1 CR reference point .

If you asked a group of racers that all had their engines
perfectly tuned and maxed out with the best possible ignition
timing curve and A/F Ratio ....
one racer might say 1350 deg F ,
another might say 1250 deg F ,
another might say 1150 deg F,
another might say 1050 deg F
.....they could all be correct and have the very same A/F Ratios
.....the varying EGTs depending primarily upon Compression Ratio,
Volumetric Efficiency percent % , Combustion Chamber/Piston
top design and camshaft design.

Another thing you have to watch out for is
where are you placing the EGT probe??
1-at 12 o'clock or so ...
2-How far away from heads exh port flange ???
3-How deep is the EGT probe protruding into header pipe diameter ????
4-EGT probe type and response time

all these factors greatly influence EGT temps making
it very much impossible to directly compare EGTs between racers
if no standards are set to probe placement

So basically , if you walk around the pits at a National Event
and ask the SS racers that have CR from 9 to 11:1 mostly ,
they'll tell you 1250 to 1350 EGT and maybe a few at 1450

you ask the ProStock and Comp guys with 16+:1 CR
they'll tell you 1000 to 1150 deg F
maybe some of the very large Mountain type engines
with HiCr tell you 850 to 1000 deg F EGTs

Hi Compression Ratio = Lower EGT temps

Lo Compression Ratio = Higher EGT temps

Correct ignition advance(32+ to 40+ ign deg range)= Lower EGT temps

Wrong ignition advance ( below >25 or so deg range)= High EGT temps
..... burn slower and later in stroke , continuing to burn
while exhausting and if severe...cycling/snowballing into rising
coolant temperatures, preignition, then detonation.




bottom line is you need to tune your car by reading plugs and adjusting from there.





https://board.moparts.org/ubbthreads/ubbt...tml#Post2020087


Joe

After seeing Pettis tune this way I found that I ALWAYS had to jet em back up after a dyno session but this was on gas and prefer afr's...........