Catalytic temp logging

[razorlab]

Anybody else with an Cobb AP want to monitor their Catalytic temps to compare?

Data points from my car:

70-75mph cruise on hwy: 1280-1350f
Idle: 1100-1200f

 

[dyn085]

If I remember I'll set up my AP3 and log on the way home. I don't hit 70-75 generally, but I'll see what traffic is doing.

 

[iso100]

Curious, what would high or low cat temps indicate?

 

[rodmoe]

High temps Lean, low temps fuel rich ??

 

[re-rx7]

I believe thats vice vera.

 

[rodmoe]

Could be as I was thinking of the old 2 stroke tuning days/nights when you jet'm down till they meet mr squeaky then richen them up a smidge per the EGT gauges

 

[re-rx7]

LOL i hear yuh. Rotaries melt cats because they put so much fuel into them they literally melt.

 

[dyn085]

It looks like I'm seeing 1350-1450 for 70-75 mph cruising. I didn't get to run at those speeds long enough to have everything stabilize though, so take it with a grain of salt.

 

[razorlab]

It looks like I'm seeing 1350-1450 for 70-75 mph cruising. I didn't get to run at those speeds long enough to have everything stabilize though, so take it with a grain of salt.

Awesome! Thanks for the data point. Are you still running cruise at the standard 14.7 AFR?

 

[dyn085]

Awesome! Thanks for the data point. Are you still running cruise at the standard 14.7 AFR?

Yup. I assumed yours were lower because I seem to remember you posting a log with lean cruise. My temps may have settled a touch lower with a bit longer of a drive, but nowhere near your numbers.

 

[iso100]

Wouldn't the wideband sensor readings from the O2 sensor be a better gauge for mixture than CAT temp?

 

[razorlab]

Yup. I assumed yours were lower because I seem to remember you posting a log with lean cruise. My temps may have settled a touch lower with a bit longer of a drive, but nowhere near your numbers.

Yea, currently running 15.1 lean cruise. I am going to run a little leaner, I just needed a general data point for normal running before I did that.

Wouldn't the wideband sensor readings from the O2 sensor be a better gauge for mixture than CAT temp?

Of course, I am more concerned with the AFR's effect on CAT temp.

 

[iso100]

Got it.

 

[dyn085]

Yea, currently running 15.1 lean cruise. I am going to run a little leaner, I just needed a general data point for normal running before I did that.



Of course, I am more concerned with the AFR's effect on CAT temp.

Next time I get a chance I'll try and get some CAT temps with some more sustained driving at speed.

 

[RAAMaudio]

I need to monitor mine to ensure the 5" 100 cell cat is getting hot enough to work properly, I know it takes a bit longer to heat up as can smell it then once warmed up I never smell fumes so it must be doing a decent job. I knew it might be a bit to big and 100 cell might now work out but I wanted to try the highest flowing one I could find.

I do have the DP double and triple wrapped which will help quite a bit and all SS parts of course which helps as well.

If it is not doing the job I want it to do I have already been looking at modding the stock DP to flow really well but cutting out the restrictive areas and welding in sections cut from 3" tubing and then adding a 3" flex and outlet.

 

[razorlab]

Cool story, bro?