Egt at 1360 with 12.2 AFR

Brucelee · Jan 21, 2016

I'm new to the 2stroke turbo world used to have a 4 stroke 9000 I have a 2016 M8000 with a used Silber turbo kit that i have just install, i am runnuing at 700 feet of elevation, 6 pound of boost, 100% av gas, i have a single fast probe koso temp gauge right in the of the y pipe this reading 1360 at wot, and afr is at 12.2. My red mode and my green mode are both at 8 so i cannot add fuel no more.
It was worse than that when i was running the recommended fuel from silber on my dobeck 3.5 controller i was running in the 12.6-12.8 afr and 1380-1400 egt.

Before i install my turbo the gauge were install and i was running at 1225 egt wot in the stock engine.
Should i just change the probe location just to one side of the y pipe.
Im scare to hold it and melt a piston, what do you guys think about this.

I have aslo calibrate my afr gauge about 6 time to make sure i even try a new O2 sensor still the same AFR.

Snopro_69 · Jan 21, 2016

Can you up the fuel pressure on the silber kit? Stock head?

Brucelee · Jan 21, 2016

Stock head, no fuel psi adjustement on this kit

wwillf01 · Jan 21, 2016

What rpms?

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Brucelee · Jan 21, 2016

8150 rpm

Snopro_69 · Jan 21, 2016

Have you tired turning boost down a bit. Might be bit much at that low of elevation and stock head.

wwillf01 · Jan 21, 2016

Brucelee said:
8150 rpm

There goes my theory

.... If I leave mine stock it runs 11s but that is at 9000ish feet... That is with the green blue at 5.... Are you sure your extra injector is running right ..

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Wheel House Motorsports · Jan 21, 2016

^^ guys are on the right path, boost fuel has more extra fuel then the standards green/yellow/red modes so that should be able to add a little more.

Your just pushing that motor pretty darn hard at that elevation and im betting the turbo is almost a little on the small side for the air you would be pushing hence the higher egts.

Brucelee · Jan 21, 2016

How i could check if my third injector is running properly, i have done a test i lower my green yellow light to 2 and my afr went to over the 13 so i think it is working.
So you think i should lower boost what do you guys are running at sea level. Will try that this weekend

w2bridin · Jan 21, 2016

Brucelee said:
How i could check if my third injector is running properly, i have done a test i lower my green yellow light to 2 and my afr went to over the 13 so i think it is working.
So you think i should lower boost what do you guys are running at sea level. Will try that this weekend

I dont have silber kits but my 2010 would handle about 6 psi on the stock injectors on pg kit. Now my 14' pc runs 8 psi (w/2872) no problem here at 800ft with 1 extra injector. I would say make sure your extra injector is working before you do to much. You said your boost fuel mode was wfo right?

Brucelee · Jan 22, 2016

Yes my boost fuel mode is at 8 recommend is 5, i would like to know how you guys would check if the extra injector is working properly.

Polarisrocks · Jan 22, 2016

I am guessing you are too far away from the piston face and getting a higher reading because of it. What is the koso recommended distance from piston face?

JSCC · Jan 22, 2016

12.2 on your afr is a good number. Before trying much anything with fueling, add a few gallons of your favorite race fuel on top of the av gas and run it. Note what your egt's are with that added. My guess is it will get them in check.
Also do as Polarisrocks said before me and check your piston to probe distance. The wrong distance will do exactly what you are seeing as well.
Lastly, run it and pull a plug. If you want it safe it should be the color of carhart. Egt sensors are just a number. You need to find the actual safe number for your setup, as there is no one set number. Probe placement, fuel, pipe etc can all contribute to egt numbers varying from one sled to the next. My 800 turbo ran high 1200's to 1300 on long pulls all day long. Afr in the mid 12's. Yours may be different.

wwillf01 · Jan 22, 2016

Brucelee said:
Yes my boost fuel mode is at 8 recommend is 5, i would like to know how you guys would check if the extra injector is working properly.

I would ask Silber as far as testing the injector but it looks like you have plenty of race fuel... How does it run with that much added... Does it run clean ?

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Brucelee · Jan 22, 2016

I have change the egt probe to 4.5 inch from skirt it was at 6.5 inch will test tomorow

snownman · Jan 24, 2016

testing your...

secondary Injectors if you have a dobec box just unplug your boost reference line. from the air box and using a hand pump pressurize it to 5 psi at idle and it should immediately flood and die. also your egt probes should be mounted 7" from the piston skirt otherwise they will read high.

Brucelee · Jan 24, 2016

Was unable to do some testing this weekend due to work

will try to go out this week. If i remember right the Koso instruction said the probe need to be in between 4-6 inch from piston try to find the instruction back to make sure but do not find it. Where do you guys put your probe at.

WyoBoy1000 · Jan 26, 2016

It's almost always been that if the afr is 12.2-12.8 your good to go. When your pushing that much fuel and air it can cause a higher reading in the exhaust because the fuel is still burning in the exhaust. Pull your plugs and look at them for a reading. Then pull your power valve and look at the piston wash. That is the only true reading you can go off of, then you will know where to read your gauges. The tm8 I had would barely run at 12.2, from to much fuel, but I had a bigger turbo to.

akMcat · Jan 26, 2016

X2 on what Wyo said. You need to take a look at plug color and wash and then you can use Egt as reference. A stock 2010 M 800 would hit 1650 on the Egt with the probes installed at Koso's generic recommended spot, I think 4.5 in from the skirt.

Brucelee · Jan 29, 2016

How long of a pull do you usualy do before shuting down the engine to check the piston wash to get the proper reading.

Egt at 1360 with 12.2 AFR

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