exhaust gas temps

[slow305]

What is a good exhaust gas temp? At idle? At cruise? At full throttle? This is all on a basically stock '87 with only a few fuel system mods, so shoot for stock boost levels. I've looked all over the forums, but I can't find anything relating to this subject. Would it be better to have a pyrometer or an air/fuel ratio gauge? I've heard that the a/f gauges can be inaccurate and fluctuate while driving, making the pyrometer better to measure the tune.

 

[SFITurbo]

Lots of variables. Mine at idle is 650's, full throttle blast 1530. Wifes is 675/1540. Probes are in downpipe just after turbo. Each car is going to be different depending on tune and placement of probe(most put them by O2 sensor). Look for consistency in your own setup and compare only to similar setups. Money is better spent with a scan tool with what you have.

 

[WSLN 6]

I have just over 700 at idle, and 1675 pre turbo when it's running just right.

 

[slow305]

Thanks for the quick responses guys. I'm just trying to get in the ballpark to know what to expect.

 

[grocerygetter]

I did a lot of research on this. Mine is 1.5" off the head. Accurate as crap man. Most Buick tuners will give you EGT goals for tuning referencing the probe at the location of the stock O2 sensor. This is too far away in my opinion...but it's what most use.

 

[John Wilde]

I did a lot of research on this. Mine is 1.5" off the head. Accurate as crap man. Most Buick tuners will give you EGT goals for tuning referencing the probe at the location of the stock O2 sensor. This is too far away in my opinion...but it's what most use.

I agree it is my understanding that you want it closer to head
for a true reading.

 

[Chuck Leeper]

Yep....

I agree it is my understanding that you want it closer to head
for a true reading.

as long as you have 6 of them. While the sensor at the turbo base is an "average", a sensor at the head is about the same accuracy. In neither case, does one know exactly what's going on in all cyls, w/1 location.
Steve at SMC, was building a system to monitor all cyls... Don't know if he went so far as to begin selling it.

 

[slow305]

I've noticed on a lot of used poston headers that most people drill the hole for the probe just down from the number 1 cylinder. How would you be able to tell what the 5 and 6 are doing seeing as they are the most prone to lean out?

By the way, are you guys using a tool like the one from seturbo or do you use a guage (eg. autometer's pyrometer) to measure to gases?

 

[Chuck Leeper]

They..

I've noticed on a lot of used poston headers that most people drill the hole for the probe just down from the number 1 cylinder. How would you be able to tell what the 5 and 6 are doing seeing as they are the most prone to lean out?

By the way, are you guys using a tool like the one from seturbo or do you use a guage (eg. autometer's pyrometer) to measure to gases?

won't. That's the logic behind my post.
A gauge.
Not sure what tool you are talking about?

 

[slow305]

Sorry, I mean the one from rjc racing.

EGT Gages

 

[slow305]

Bringing back an old thread I started last year. What should the EGT readings look like if the probe is close to the head? What do you have to do to get it to move up and down? Fuel pressure?

 

[grocerygetter]

I'm flashing 1700 at the head on the shift. cruise is around 1350. EGT's will go up if you are too rich and go up if you are too lean. A little rich and EGT's will be lower than if you were lean...timing also effects EGT #s. What I am getting at is that EGT's are helpful if also looking at a wdeband.

 

[slow305]

Which cylinder did you put the sensor down from?

 

[grocerygetter]

3...it was easiest to get to.

 

[slow305]

Did you just pull off the cross-over instead of pulling off the whole header? That's a good idea...

 

[grocerygetter]

I had to pull off the header to drill and weld the bung in. It's an inch off the head.

 

[slow305]

I see....