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and that really only mildly damaged the head gasket enough to push some combustion into the coolant passage. Not knowing if it caused any damage or not, I pulled the timing and boost back on the next run and made the quickest, and fastest pass the car has ever done. EGT's on that first run were just over 1650. Just over 1610 on the quicker pass, but saw the damage in the pits (air/foam in the coolant tank).I run my EGT's in FUR much higher than that. My car typically runs about 1750-1775 on the SMC digital meter, Max I have ever seen was 1785 once. I had over 100 runs on the motor when I tore it down this winter. Exhaust valves and seats were fine but were naturally replaced to be on the safe side. I run stainless valves so replacing them is cheap enough and cheap insurance.Originally posted by TurboDave
Whether they're right, wrong, or indeferent, I can tell you what I like to see (assuming you're talking about a blast down the quarter mile).
About the highest I've been comfortable letting mine go on pump gas (93 octane) was about 1450°, and I see that about the last 200-300 feet. This was running the afformentioned fuel, 20# of boost, and moderately conservative timing in the 18° range through 3rd gear.
In "my" race trim (114 unocal, 25# of boost, and 28° of timing) the EGT's will be pushing 1625 or so out the back door. The only time I've hurt anything on the track is when I wasn't paying close enough attention to the timing, and made a pass at 31° and 27# of boost.
Don't know if that's what you're looking for.
Mine is a few inches before the turbine inlet (before the turbo). It's directly after where the cross over from the left bank blends in with the right header.Originally posted by Phatman
I know it probably isn't going to make enough difference to notice, but is the probe placement pretty close between your different set ups?
Nah, never mind....
I'm not sure of the EGT's at the exhaust port. My headers are jet hot coated so they probably keep heat in them more and my headers don't have any sharp turns and are 1 7/8" tubes so should hold heat better than say the ATR headers.
My EGT is from Steve Chlupsa. I believe it's an Omega K Probe with a welded bung.
I think the 1600-degree rule is with a stock displacement motor. I assume people are thinking that with 8 bolt heads and a significantly weaker motor than a stage motor somewhere in the 1600's is the max. With a stage motor where you are burning way more fuel and generally pumping in more air you are going to get higher EGT's. Initially I was concerned when I was tuning in the stage car cause at low boost, 10-15 psi I was getting EGT's above 1600 and the tune was rich, plugs showed this. In talking to lots of other stage people they confirmed that they are running higher EGT's. I think there isn't really a rule that can be followed with a stage motor. It's only an indication to when something is going wrong with a known good tune. If you usually run at 1750 consistently and then you run in the 1800's something is probably going on that needs attention. Same in the opposite direction, you're either running rich or maybe have a leaking hear gasket. Last year when I popped a head gasket my EGT’s dropped into the 1500’s but like a dummy I didn’t follow my own advice because I wasn’t seeing water in the oil. I kept racing the car and eventually the little leak became bigger and eventually congealed and clogged in my oil filter and I lost oil pressure. Luckily it happened in the staging lanes where I noticed it immediately and not when racing otherwise I probably would have broken something.
Kind of just goes to show that it's the total combination. If you don't have a wide band sensor to tune with then the EGT is the next best thing. I typically ignore my EGT readings, they are what they are. If the FAST isn't sucking out fuel and the plugs which are pulled after each day of racing don't show problems then I know things are running well. If I notice an increase or decrease in the EGT's then I know something might be up. I'll pull plugs first as they are what's going to tell you what's really going on in the combustion chamber. An EGT gauge is just a tool, not the Holy Grail.
