Afr or egt??
- Thread starter bradburck
- Start date
Both!
S
Sno Junkie
Active member
What are your egt's reading versus your A/f guage? I have both also. On a long pull I hit 1300-1350 but my AFR sits at 11.8-11.9. If I add fuel to bring down the EGT's, the sled is boggy.
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mynewuseddoo
Well-known member
You have placed your EGT sensors too close to the exhaust ports if this is the case.
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Sno Junkie
Active member
They were put in before I got the sled. I assumed this might be the case. they are mounted 2" from face of cylinder. I know they are just a tool, but it is hard to stay in it when you see 1350.
I like to run both that way I have an idea if I have a problem in one cylinder. The AFR will not show that.
Afr for turbo's and egts for NA sleds.
Mounting location on both is important. What kit is it, year version etc...
the 800 is a lot different than the 1000 also, the 800 can withstand a lot higher temps, the 1000 can't and will go down.
Mounting location on both is important. What kit is it, year version etc...
the 800 is a lot different than the 1000 also, the 800 can withstand a lot higher temps, the 1000 can't and will go down.
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Sno Junkie
Active member
2009 M-8 with 20120 head BD PG 2860 kit running 8.5psi at 8000 ft. I mix in a couple of gallons of 110.
I checked plugs on a long pull where I saw 1325 and they look great. I did not check wash.
You should be able to run the Afr in the 12-12.5 range pretty safe if the afr is installed right. But I'm not real familier with the bd kits either, my twisted kit ran great anywhere from 12.2-13.1 without problems, (under 12.8 on long pulls)
But the smaller turbo will build more intake heat so you might want to be a little lower, 12.5 ish
Sometimes egts will run hot if there is to much fuel going into the exhaust, it burn there instead of in the cylinder. Talk to someone that really knows bd kits though and don't just go off what I say.
But the smaller turbo will build more intake heat so you might want to be a little lower, 12.5 ish
Sometimes egts will run hot if there is to much fuel going into the exhaust, it burn there instead of in the cylinder. Talk to someone that really knows bd kits though and don't just go off what I say.
Hey Sno Junkie,
Did some more tuning this past weekend. We are now seeing 12.4-12.5 AFR and right around 1200F on the EGT's, this is on 91 pump at 7 psi.
Last time out saw 13.0 and 1300-1330. I like it when I get the results I expect when firing the fuel at it on the top end. Also had a lean spot on the trail - adding 5-6 points to the psiL LO number solved that right away.
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Sno Junkie
Active member
Thanks. I have checked plugs and they look great after a long pull at 1350 on the EGT's and 11.9 on AFR. My #'s are 20-32-52...so I am pretty rich on the top. I am thinking my probes are too close to the piston. HOWEVER, next ride (if we ever get snow) I am going to check wash on a long pull before I trust anything.
Right on man.
This one's a 901 big bore, so my numbers don't help you much. psiH HI is now 65 or 68 at 8 psi- this thing likes it's fawkin' fuel!
This one's a 901 big bore, so my numbers don't help you much. psiH HI is now 65 or 68 at 8 psi- this thing likes it's fawkin' fuel!
It depends on what kit you have Im on a twisted with AFR works great. A buddy on a Cutler has a AFR it dosent work he has tried different probes and probe locations nothing works Cutler says EGTs. Talk to the kit builder dont spend $400 for nothing.
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mynewuseddoo
Well-known member
It does not depend which turbo kit you run. I would suspect his AFR gauge its self wasn't working. There isn't a compatibility issue between what engine monitoring device you can use with which turbo kit. You can use an AFR or EGT with whatever turbo kit you want to. The main difference between AFR and EGT is that the EGT will allow you to see how timing affects exhaust temps through out the RPM range and throttle positions.
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jim
Well-known member
So I have a 09 boondocker pump gas with boondocker pipe. I run about 2 gallons of race gas a tank. Running at 7.5 PSI at 8000 feet. Running EGTs 2.5 inches from the outside cylinder edge. I am seeing 1190 on the left cylinder and 1290 on the right. What is going on with those numbers? Can i be off by 100 and be ok or is there something else going on. Are they too high? I'm 15, 24, 51. Can i trim the cylinder settings? I did find that I'm too rich at about 52-53 on top...it will puke out and both cylinders seem to fall off at the same time. It seems consistent during most of the pull but I have a max spike in the right cylinder. Is this just a spike when letting off because one might run a bit hotter? They seem to be pretty close during the climb but the right will climb higher.
