Monitoring EGTs on a turbo car
01-04-2011, 11:05 AM
#22
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You weld in the bungs and then you screw in compression fittings. Then the probes slide into the compression fittings and lock in. it all logs thru the Holley EFI System.
The Holley bunches them all up for some reason, including the one that is way off if you look at the values on the left. They are going to address that ASAP but it's a new system with little user feedback but they are working with us VERY closely.
FYI, it says nitrous tunning on top but that's just because we grabbed one of the tables that we weren't using in order to throw in the 8 EGT's without haveing to move stuff around.
The Holley bunches them all up for some reason, including the one that is way off if you look at the values on the left. They are going to address that ASAP but it's a new system with little user feedback but they are working with us VERY closely.
FYI, it says nitrous tunning on top but that's just because we grabbed one of the tables that we weren't using in order to throw in the 8 EGT's without haveing to move stuff around.
I'm assuming all the values on the left are measured at the line (7.41s). I don't see any trace way off graphically (that would match to the high reading for EGT1) Almost seems like a software glitch
01-04-2011, 11:09 AM
#23
IMHO the best EGT probes cost about 2 bucks each. Unless you are north of 1500 hp and have some $ what are you going to do with the data? If the AF is good, the plugs read out and the probes show 1,5,8 seventy five degrees higher than the rest???? Play with individual cylinder fueling....but the 2 buck probes will show that...
Makes sense for serious racers.....but hobby racing seems moot to me. Fun to gather the data, but not much to effect change.
Makes sense for serious racers.....but hobby racing seems moot to me. Fun to gather the data, but not much to effect change.
01-04-2011, 11:31 AM
#26
EGT's 1 and 3 have the biggest spread.
01-04-2011, 11:52 AM
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are they that far off at ambient (motor off)?
thermocouples are very simplistic devices...there is no calibration on them...there is a published volt vs temperature relationship that is fixed based on the two dissimilar wires that are connected at the measurement location...
thermocouples are very simplistic devices...there is no calibration on them...there is a published volt vs temperature relationship that is fixed based on the two dissimilar wires that are connected at the measurement location...
01-04-2011, 02:06 PM
#28
are they that far off at ambient (motor off)?
thermocouples are very simplistic devices...there is no calibration on them...there is a published volt vs temperature relationship that is fixed based on the two dissimilar wires that are connected at the measurement location...
thermocouples are very simplistic devices...there is no calibration on them...there is a published volt vs temperature relationship that is fixed based on the two dissimilar wires that are connected at the measurement location...
I'm pretty sure that cold, they read about the same. You can even see in the screenshot that I posted how they spread out as they get colder. In reality they are tightning up but because they are all scaled slightly different in the logging software, they separate when they should be coming together down low.
We did swap the probes from #1 cyl to #3 cyl and that probe still read 200-300 hotter so we know it's not an air or fuel distribution problem.
01-04-2011, 02:15 PM
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There is no calibration on these either. You just define the 0-5v range in the software and that's it. That's why they are replacing that one.
I'm pretty sure that cold, they read about the same. You can even see in the screenshot that I posted how they spread out as they get colder. In reality they are tightning up but because they are all scaled slightly different in the logging software, they separate when they should be coming together down low.
We did swap the probes from #1 cyl to #3 cyl and that probe still read 200-300 hotter so we know it's not an air or fuel distribution problem.
I'm pretty sure that cold, they read about the same. You can even see in the screenshot that I posted how they spread out as they get colder. In reality they are tightning up but because they are all scaled slightly different in the logging software, they separate when they should be coming together down low.
We did swap the probes from #1 cyl to #3 cyl and that probe still read 200-300 hotter so we know it's not an air or fuel distribution problem.
I'd be interested in seeing what it reads at ambient...seems like a faulty junction on the probe...
01-05-2011, 10:39 PM
#36
Yes. The thing is that they are definitely fucked up like Fireball said. I think that they are reading way high across the board. We turned the boost up to 23 psi tonight and were seeing 1700-1800* at the end of the track. There is no way that it's getting that hot with a solid 11.2-11.5 AFR on E85 (gas scale).
01-06-2011, 05:52 AM
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Yes. The thing is that they are definitely fucked up like Fireball said. I think that they are reading way high across the board. We turned the boost up to 23 psi tonight and were seeing 1700-1800* at the end of the track. There is no way that it's getting that hot with a solid 11.2-11.5 AFR on E85 (gas scale).
I'm going to try to get my system wired up enough to get an ambient reading on my EGTs for you this weekend (as a basis of comparison)
01-08-2011, 04:56 PM
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I played around with 4 egts...
my egt system apparently reads a minimum of 64F. Its 68 in my garage but putting them in an icebath still read 64.
I put them in 160F water and they allred mid 150s, with a ~3-4 degree variance.
my egt system apparently reads a minimum of 64F. Its 68 in my garage but putting them in an icebath still read 64.
I put them in 160F water and they allred mid 150s, with a ~3-4 degree variance.
01-08-2011, 07:02 PM
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Yes. The thing is that they are definitely fucked up like Fireball said. I think that they are reading way high across the board. We turned the boost up to 23 psi tonight and were seeing 1700-1800* at the end of the track. There is no way that it's getting that hot with a solid 11.2-11.5 AFR on E85 (gas scale).
if running a normal stainless valve they will melt at 1700.. a extreme duty will hold a little more...
with my methenol setup i usually only see 1250 or so, when it was on c16 we would see 1500 if a little on the lean side..