Tuning by EGT
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Just finished up installing a pyrometer. Never had one before, but figured it would help tune ignition when I get to that stage. As a general rule for now, what temps should I expect to see at idle, cruise, and boost? What is too hot?
Or if you could just point me to some good readin', I'd 'preciate it.
Or if you could just point me to some good readin', I'd 'preciate it.
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http://sdsefi.com/techegt.htm
Was an interesting read.
I've got EGT in my car and I see 600-800F at idle, cruise is all over the place but I 'd say no higher than 1300-1400. And full boost right around 1600.
Lots of good threads over at m.net on the subject.
Was an interesting read.
I've got EGT in my car and I see 600-800F at idle, cruise is all over the place but I 'd say no higher than 1300-1400. And full boost right around 1600.
Lots of good threads over at m.net on the subject.
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One thing I have a lot of experience with is pyrometers and EGT gauges. Temperature is meaningless in and of itself because the damn sensors vary so widely. Get five senors from the same manufacturer and none of them will be calibrated the same. The results of this are the crap you'll read on the internet about EGTs. One guy will swear that 950C is right where you should be while others will say 850C, then you'll have a guy who will say, "I was using a wideband and at X.X:1 I was at 900C." All these people will argue with eachother nonstop never realizing the sensors have so much variance.
What you're looking for is behavior rather than the numerical value.
What you're looking for is behavior rather than the numerical value.
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How much of a difference are you seeing between different sensors? 100F? 500F?
Since I'm not datalogging EGT (my ancient link dosen't do that) if it is out by 100F or so I'm not too concerned. What I want to be able to catch is odd behaviour. I'd like to see if my EGT gauge is pinned over 1600 at cruise.
I think the EGT and Wideband used together will help you keep everything that's in the engine, in the engine.
Since I'm not datalogging EGT (my ancient link dosen't do that) if it is out by 100F or so I'm not too concerned. What I want to be able to catch is odd behaviour. I'd like to see if my EGT gauge is pinned over 1600 at cruise.
I think the EGT and Wideband used together will help you keep everything that's in the engine, in the engine.
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cruise and boost matter.. idle, not so much.
you want to use it to tell you your timing isn't retarded too much. lean/rich will come from a wideband, but the EGT can be used as a gut check if your WB looks right and you're running a lot of advance.
Rule of thumb, 1600F is a pretty reasonable "max" for cruise or boost. as mentioned above, there's debate over what it really should be but I use that generically. I wouldn't run 1600 sustained in cruise for hours and hours but for peaks it's ok. sustained should be a few hundred lower.
at cruise it will tell you more if you're too lean than too retarded.
in boost it'll tell you if you're too retarded rather than too lean.
you want to use it to tell you your timing isn't retarded too much. lean/rich will come from a wideband, but the EGT can be used as a gut check if your WB looks right and you're running a lot of advance.
Rule of thumb, 1600F is a pretty reasonable "max" for cruise or boost. as mentioned above, there's debate over what it really should be but I use that generically. I wouldn't run 1600 sustained in cruise for hours and hours but for peaks it's ok. sustained should be a few hundred lower.
at cruise it will tell you more if you're too lean than too retarded.
in boost it'll tell you if you're too retarded rather than too lean.
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Had a egt gauge on my greddy setup, but unless youll have someone in the car to read and fully understand the gauge, it has no use...
You just don't have enough time to look at the gauge and tune from there.
The reaction time is also not fast...
For the money, buy a wideband...
Don't buy it unles youll have free dyno time...(or a posibility to log the data)
At least thats my $0.02
You just don't have enough time to look at the gauge and tune from there.
The reaction time is also not fast...
For the money, buy a wideband...
Don't buy it unles youll have free dyno time...(or a posibility to log the data)
At least thats my $0.02
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Had a egt gauge on my greddy setup, but unless youll have someone in the car to read and fully understand the gauge, it has no use...
You just don't have enough time to look at the gauge and tune from there.
The reaction time is also not fast...
For the money, buy a wideband...
Don't buy it unles youll have free dyno time...(or a posibility to log the data)
At least thats my $0.02
You just don't have enough time to look at the gauge and tune from there.
The reaction time is also not fast...
For the money, buy a wideband...
Don't buy it unles youll have free dyno time...(or a posibility to log the data)
At least thats my $0.02
Any tool that gives me a hint of what's going on with the engine is worthwhile. Am I going to tune to the ragged edge using the EGT alone? No.
Like y8s said, it's a gut check.
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Try finding deserted roads here in europe...(let me know if you find some...without speedtraps/camera's)
At least we can go to germany and go top speed... legal...if you can find the room.
At least we can go to germany and go top speed... legal...if you can find the room.
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How much of a difference are you seeing between different sensors? 100F? 500F?
Since I'm not datalogging EGT (my ancient link dosen't do that) if it is out by 100F or so I'm not too concerned. What I want to be able to catch is odd behaviour. I'd like to see if my EGT gauge is pinned over 1600 at cruise.
Since I'm not datalogging EGT (my ancient link dosen't do that) if it is out by 100F or so I'm not too concerned. What I want to be able to catch is odd behaviour. I'd like to see if my EGT gauge is pinned over 1600 at cruise.
If I recal, some of the probes had 100C differences between eachother. Don't quote me on that. It was enough for us to say, "what the ****?" That's what I do remember.
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