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Tuning with EGT.

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Old 08-04-2003, 05:09 PM
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Default Tuning with EGT.

How do you do it? What temp do you get at the best A/F ratio? Is this more accurate than a wideband O2 sensor? Drawbacks? I have EGT in my jet but not sure how it would translate to a car. Thanks

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Old 08-05-2003, 09:28 AM
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Default Re: Tuning with EGT.

Hmm, I think it depends on the system it's on, you'll need to get a comparison of A/F on a wideband compared to the temps.

Drawback that I see is that it's supossed to be in the primary tubes meaning you are only monitoring one cylinder.

another drawback is that the outside temp also interfears with the readings.
Old 08-05-2003, 10:16 AM
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Default Re: Tuning with EGT.

Seems like that would work, they use them on piston driven aircraft as well to hand tune the mixture. Also used in diesel trucks to monitor load. In the case of the diesels, you want the EGT to never exceed 1100*F since aluminum pistons melt at 1400*F and become plastic before that. 950*F-1000*F is a safer choice. Talk to some piston aircraft pilots and see what EGT they like to cruise at.
Old 08-05-2003, 10:18 AM
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Default Re: Tuning with EGT.

How do you do it? What temp do you get at the best A/F ratio? Is this more accurate than a wideband O2 sensor? Drawbacks? I have EGT in my jet but not sure how it would translate to a car. Thanks

Kobwo
BTW, Go Vipers! I work on your F-16 OFP's here at Hill AFB!
Old 08-05-2003, 11:06 AM
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Default Re: Tuning with EGT.

Hey my bro-in-law that flys prop planes a lot says the kind of EGT readings to look for in a typical piston aircraft would be:

Idle: 400 - 600F
Cruise: 800 - 1000F

I'm guessing this would be conservative since it is continuous duty, not like drag racing.

Old 08-05-2003, 11:21 AM
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Default Re: Tuning with EGT.

I'm running an Autometer EGT probe in place of the AIR pump fitting on my Grot headers.

My dad's a pilot, we talked about this, and he used to fly based on EGT. They'd run the temp up to peak, and then back it off 50 degrees and cruise. Does that apply to drag racing? Not really, IMHO. Road racing, yes, I could see it. But drag racing doesn't really give constant RPMs.

Watching my EGT gauge at partial throttle, at 3k RPMs in 5th gear under load (4.56's) I see 1325-1350 degrees. That's the hottest I've seen it get. At idle it can drop down to 800, but it has to sit a while to get there. Since driving at 3k rpms in 5th gear down the freeway really isn't stressing the motor, I don't think 1350 is 'too high'. Show me 1450-1500 and I'll start to sweat.

I primarily bought it to see what happens when I hit the juice. But, I got the gauge installed just a couple weeks before the car went to LG (it's there right now for a cage install), and I haven't had time to work with the juice all that much.

-Andrew
Old 08-05-2003, 12:36 PM
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Default Re: Tuning with EGT.

Ask this over in the FI section. Turbo guys rely on EGT more than anyone else automotive wise. I think the Buick T's are using around 950-980, of course they like to run about 11.2:1 on the A/F also.
Old 08-13-2003, 09:10 PM
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Default Re: Tuning with EGT.

Thanks for the replies. Would wideband yield better results to tune with?

VIPERS RULE!

Andrew, let me know how the tunning session goes.
Old 08-14-2003, 03:23 AM
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Default Re: Tuning with EGT.

if WB wasnt reliable i dont think that tuners nation wide would use them. And things like the Accel DFI Gen7 wouldnt have an option to run full on closed loop with a WB. I plan on installing a WB in car.




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