Yeah, I searched....
I just installed my autometer EGT gauge which is mounted on the exhaust manifold near the #1 cyl. I was curious about how hot the EGT should be. At idle I was at about 850F. The gauge reads up to 1600F. I don't really know at what temp it's time to be scared. It will basically tell me if i'm running too lean, right?
EGT Temps
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msaskin
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You tapped it into the #1 runner just before the collector on the manifold, right?
If so, you want to tune so you're right at about 900 deg. celsius (~1650 fahrenheit), at the END of a 3rd or 4th gear pull.
The reason I don't like guess-o-meter gauges is the fact that the EGT only goes up to 1600. Basically, you want it to be hitting 1600 just before the top of 3rd or 4th gear (assuming you're doing a full throttle pull).
EGT's are really a relative tuning tool; pay attention and notice what the EGT's are on your car @ part throttle cruises, full throttle blasts, etc. If you ever notice it's reading hotter/colder than it should be, or it's climbing much faster than normal, you should pay attention and see if something is wrong.
~matt
If so, you want to tune so you're right at about 900 deg. celsius (~1650 fahrenheit), at the END of a 3rd or 4th gear pull.
The reason I don't like guess-o-meter gauges is the fact that the EGT only goes up to 1600. Basically, you want it to be hitting 1600 just before the top of 3rd or 4th gear (assuming you're doing a full throttle pull).
EGT's are really a relative tuning tool; pay attention and notice what the EGT's are on your car @ part throttle cruises, full throttle blasts, etc. If you ever notice it's reading hotter/colder than it should be, or it's climbing much faster than normal, you should pay attention and see if something is wrong.
~matt
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highmilehatch
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Egt is a great reference tool, not a tuning tool. I personally think 1650 is waaaay too hot, and you are on the verge of melting a piston. This depends on where you mount the probe too. On my turbo honda, the probe is mounted about an inch from the cylinder head in the number 3 runner. With a wideband we tuned for 12.0:1 a/f under boost, and total ignition advance was 17 degrees at 16 psi. This was on a T3/T04E 57 trim, .63 exh. This is too keep the cylinder pressures down and the engine together. During 3rd and 4th gear pulls on the highway, my egts get to 1300 f and stay there. You DO NOT want your egts to keep climbing to 1650. 850 sounds about right at idle. It would be especially bad if you hit those temps with the probe mounted farther away from the head. Are you running the stock ECU?
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highmilehatch
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msaskin
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What I listed are the temperatures that I'm used to seeing with the probe mounted 4-6" from the head (which on an SR puts you right before the collector).
The drop in temperature in the first 6" or so from the head is pretty negligible because the exhaust gas velocity is still relatively the same. It's only once you hit the collector/turbo/downpipe and have a larger volume that the exhaust gas velocity decreases, and as such, the temperature decreases.
To sum it up: the EGT's should be damn near the same right next to the head (say, 1") as it is 6" after the head (or at any point before the collector). I'm sure I can dig up the formulas to prove it if I have to
~matt
The drop in temperature in the first 6" or so from the head is pretty negligible because the exhaust gas velocity is still relatively the same. It's only once you hit the collector/turbo/downpipe and have a larger volume that the exhaust gas velocity decreases, and as such, the temperature decreases.
To sum it up: the EGT's should be damn near the same right next to the head (say, 1") as it is 6" after the head (or at any point before the collector). I'm sure I can dig up the formulas to prove it if I have to
~matt
At 10psi I did a pull to redline in 3rd year, the EGT got to about 1300f. I'm on stock ecu, stock injectors, etc. A few times at idle it would stay at 1000 or a little bit lower, but it didnt go back down to 850. but most of the time it does. It's mounted on the exhaust manifold in the hole for the heat shield, the one that's closest to the #1 cyl.
I put my EGT probe in the elbow after the turbo. Both the turbo elbow, exhaust manifold and down pipe are ceramic coated. At idle, I see 850. The highest I've ever seen after a WOT run is 1450. Usually while cruising at ~3500 RPM in 5th, it runs between 1200-1300.
The EGT is a good tuning tool when you are able to use it to get a good base line reading. For example, my car is at stock boost and stock fuel. I'm willing to believe that Nissan knew enough about what they were doing to have their stock engines keep running for a long time. In the future, when I make changes to the motor, I can compare the new EGTs with the stock ones. If they are hotter, then I know I need to adjust something to get them back to 'stock'.
The EGT is a good tuning tool when you are able to use it to get a good base line reading. For example, my car is at stock boost and stock fuel. I'm willing to believe that Nissan knew enough about what they were doing to have their stock engines keep running for a long time. In the future, when I make changes to the motor, I can compare the new EGTs with the stock ones. If they are hotter, then I know I need to adjust something to get them back to 'stock'.
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Cyberkreig
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#RealRiceGSR#
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