I just got an egt on my car. I have been tuning with a scanmaster and a Conley knock detector. My chip is an old max-effort set-up for my 50lbers. The timing is set at 18 degrees. My o2 sensor has'nt been changed in a while because the chip is open loop all the time. I am running 45lbs of fuel pressure(line off) AT IDLE. My question is what should my egt's be at idle. I know that at boost they should be at 1550 to 1600 roughly. I am seeing 1800 degrees at 19lbs with 94 octane and xylene. That seems WAY too high, but I am not getting any knock sensor reaction at all. I am not sure the egt is calibrated correctly. I am thinking that there should be a fairly consistant idle temp for all cars if the air/fuel ratio is correct. Any help would be appreciated.
exhaust temps
- Thread starter N2HIPSI
- Start date
ChrisCairns
Senior Member
- Joined
- May 24, 2001
I know what you mean. I had EGT's regularly of over 1800 with 26° of timing. I tried more fuel, less fuel, more and less timing...nothing deliberate seemed to change it much. It seemed to change more without me making any changes in the FAST. After that I simply used it as eye candy...lol.
Recently the engine was refreshed. Nothing was out of the ordinary.
In answer to your question...mine idled from 800 to 900°, probe was just under the turbo flange. Take it for what it's worth and I don't guarantee the accuracy of my gauge for the above reasons.
egt is useless for anything but relative readings at WOT.......you cannot use it for setting BLM's etc.......it is a race tuning tool only (well, you can look at your cruise egt and lean it out)
one thing to consider is, if you have very high egt, you could be very rich...fuel actually burns in the manifold and raises your egt...you need to find a place where increasing fuel lowers your egt and pulling fuel makes it go up......then optimize for your car
one thing to consider is, if you have very high egt, you could be very rich...fuel actually burns in the manifold and raises your egt...you need to find a place where increasing fuel lowers your egt and pulling fuel makes it go up......then optimize for your car
Steve Hill
New Member
- Joined
- Jul 13, 2002
quote: "egt is useless for anything but relative readings at WOT"
and for that it is extremely useful.
and for that it is extremely useful.
Steve Hill
New Member
- Joined
- Jul 13, 2002
I have mine very close to the O2 sensor, which, I believe, is where most are located.
On my TR, as well as a friends GN, 1400's egt is quite low. Need more boost <g>!
On my TR, as well as a friends GN, 1400's egt is quite low. Need more boost <g>!
Yup, I know I'm WAY rich. I was just waiting on my HD actuator so I could start tuning. Will probably start tonight. I was curious to know where exactly N2HIPSI's EGT probe was located. If it was on a #5 or #6 header tube that could explain for SLIGHTLY (maybe 50deg or so) higher readings. However I agree with the above post that his problem is related to too much fuel/not enough timing, thus burning some of the mixture closer to the exhaust.
!
tim87tr
Obsession or Digression?
- Joined
- Sep 19, 2001
Follow up question on EGT
I just started using the SMC EGT and had some general questions. I have read and the kit instructions also say that 1550 to 1600 *F is optimal. I have made a few "quarter mile type" blasts to check out the EGTs. I have a Trans + and seem to have the car dialed in for no knock on 93 octane and 16 psi.
The numbers so far seem to correspond well with the low O2 readings on my SM, and I did leave it in drive, so I think the low O2 was shifting into OD around 91 mph.
I am curious to find out if EGTs over 1600 without knock are something to watch out for, or if 1600s are ok at WOT as long as there isn't any knock. I know its lean as shown by the corresponding O2 and that's higher cylinder temp, but any "real use" data would be helpful to me. Here is my data:
EGT and 02
1460 828
1560 780
1580 769
1653 753
I just started using the SMC EGT and had some general questions. I have read and the kit instructions also say that 1550 to 1600 *F is optimal. I have made a few "quarter mile type" blasts to check out the EGTs. I have a Trans + and seem to have the car dialed in for no knock on 93 octane and 16 psi.
The numbers so far seem to correspond well with the low O2 readings on my SM, and I did leave it in drive, so I think the low O2 was shifting into OD around 91 mph.
I am curious to find out if EGTs over 1600 without knock are something to watch out for, or if 1600s are ok at WOT as long as there isn't any knock. I know its lean as shown by the corresponding O2 and that's higher cylinder temp, but any "real use" data would be helpful to me. Here is my data:
EGT and 02
1460 828
1560 780
1580 769
1653 753
Steve Hill
New Member
- Joined
- Jul 13, 2002
tim87tr.... my experience is the O2's are low resolution and do not correlate very well with egt's. OTOH, once you get used to the numbers *for your specific car* they may be used as a coarse, 'quick and dirty'-type reference.
The egts are more precise and predictable at indicating your a/f ratio. A friend of mine, Dman, has an engine setup very close to mine, and his egt's mirror mine quite nicely when our fueling adjustments are similar (i.e., same fuel pressure, injector duty cycle, boost and timing).
We have found as little as 100 degs F makes a big difference in the way these engines respond.
For instance, 1550 would indicate a tad too rich, and the engine would be relatively sluggish.
1650 is a sweet point, with a nice margin of at least 50 degrees before we want to start thinking about being lean.
If we want to make power, we crank boost until 1700-1720. Beyond that, the power holds to 1800 but you're risking internal damage and maybe uncontrolable knock.
Another item to mention: It takes awhile for the egt's to reach and stabilize at peak. We find this is about at the top of third gear, increasing slowly a few more deg's if you hold in fourth.
Now, a disclaimer: this is just an insight into my experience with two, similar cars, and I won't speculate on how well this data relates to your car.
The egts are more precise and predictable at indicating your a/f ratio. A friend of mine, Dman, has an engine setup very close to mine, and his egt's mirror mine quite nicely when our fueling adjustments are similar (i.e., same fuel pressure, injector duty cycle, boost and timing).
We have found as little as 100 degs F makes a big difference in the way these engines respond.
For instance, 1550 would indicate a tad too rich, and the engine would be relatively sluggish.
1650 is a sweet point, with a nice margin of at least 50 degrees before we want to start thinking about being lean.
If we want to make power, we crank boost until 1700-1720. Beyond that, the power holds to 1800 but you're risking internal damage and maybe uncontrolable knock.
Another item to mention: It takes awhile for the egt's to reach and stabilize at peak. We find this is about at the top of third gear, increasing slowly a few more deg's if you hold in fourth.
Now, a disclaimer: this is just an insight into my experience with two, similar cars, and I won't speculate on how well this data relates to your car.
EightSecV6
MDBL
- Joined
- Jul 18, 2001
Marley,
I agree with Steve, 18deg at that boost will produce high EGT's.Put some race gas in it, turn the boost up and put it on the 24 deg setting, that will drop you right in the range.
Bill
I agree with Steve, 18deg at that boost will produce high EGT's.Put some race gas in it, turn the boost up and put it on the 24 deg setting, that will drop you right in the range.
Bill
tim87tr
Obsession or Digression?
- Joined
- Sep 19, 2001
Steve, and others, thanks for the great info. My car felt stronger at 1650s than in the 1500s, so I was hoping that was ok, even though there was no knock. I'll use the 1700 as a max limit. The trans + is great to tune the car, I just needed to know some "real use" limits to work towards. I want to eventually run the ME on my Turbo T with the EGT, but haven't talked myself into changing the injectors yet since it runs well now.
Steve Hill
New Member
- Joined
- Jul 13, 2002
tim87tr,
talk to the Yakman about the ME setup. He's a good guy.
Dman and I been using that for a couple years and have found it to be flexable, easy to work with and works as advertised.
talk to the Yakman about the ME setup. He's a good guy.
Dman and I been using that for a couple years and have found it to be flexable, easy to work with and works as advertised.
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