What little I've read, we should disabled the catalytic converter overtemp.

I had the car dyno-tuned last month, and noticed that the tuner left COT enabled.

So, what does that all do?
What will change if I disable it?

 

DISABLE COT! If you leave it enabled the PE table does nothing... I found this out first hand on my car. In fact you will pick up some power by disabling COT and dialing in your PE to 12.8-13.2.... My car commanded a rich A/F with COT, like 11.7. I could change the PE until the cows came home and it did nothing to the commanded AFR. As soon as I disabled COT, commanded and PE agreed.

 

Yep same here. Tuning for WOT tomorrow morning and then dyno'ing my ride. What's funny is why even bother having the PE table there if under WOT the COT is enabled and thereby screws up any values the PE would set??

Either it's a feature there for cars that don't have COT, or it's used in other calculations we don't know about that aren't affected by COT.

Anyone know?

 

Just disable it and be done with it.....

 

OK, thanks for the info.

But since my car was already dyno-tuned, if I go and disable it now, without any other changes, is that alright?

I dont know what I would need to change in any of the VE tables.

 

No. You are going to need a wideband to dial in your A/F after disabling COT. Some tuners, just scale the MAF or injector flow rates to achieve the A/F they want. If you just disable COT no telling where your actually WOT mixture would be.... At least thats my take on it.

 

COT is a complex calcuation to determine when it turns on, in EFI Live they display the temps at which the 4 levels of COT come into effect, hpt does the same with the 4 levels, with the 3 baro modifiers, as well as the enrichment rate vs temp.

You can normally do a quick dyno run in a low gear on a lsx car without having COT kick in, but anytime I have done a 3-4 gear pull, it kicks in at the top of the run, killing power.

Ryan

 

Thanks for the information.

Now I'm left wondering why my tuner left COT enabled then!

So, what are the drawback of disabling COT?

 

The disadvantage is, you trash the cats. If yours
already wandered off the reservation then there
is no reason to blow excess fuel out the exhaust.

You could have the COT max enrichment set to
your lowest PE table value and have some, non-
interfering quench but whether that would actually
protect anything, dunno. Better than nothing but
maybe not by much.

It's not true to say that having COT enabled,
makes the PE table nonfunctional. That only comes
about after you've been on it enough to wake up
the COT protection action. But once it's awake,
it'll ride your *** for a long time.

These cars (F-bodies) are set up like sprinters and
this is one thing that fights sustained high power
output.

 

Your tuner may have disabled COT for the dyno tune then re-enabled wnen finnished, if you still have cats in place .

Car would perform ok untill you got up it for a period of time and COT kicked in.

 

OK, thanks for the insite jimmyblue. and yeah, that may be true - he disabled COT, tuned it, then re-enabled, and yes, I do have cats.

 

Hmm.. interesting. I might do a different tune then. I've got mine commanding about 12.6:1 AFR on the dyno (which should be 12.8-12.9:1 on the street in 2nd/3rd gear). Now... I need my CATS as we've got e-test police up here. I've got it disabled right now so hopefully I haven't fried them already.

When I was runing for WOT on the street originally, we set the PE to command 13.0:1 and immediately did a WOT pull (first WOT pull). COT kicked in right away and showed us 11.8:1. We scaled the MAF back and still saw 11.8:1 on the next run. We knew something was up, disabled COT and immediately saw 12.9:1 on average at WOT.

I should check the enable ranges and see whats up. I know it's stock, but it seems to kick in right away on my ride. The temps were cool that day too. Perhaps it was because we'd just come off the highway... not sure.

At any rate, going to have to play with this. I might just enable it again in a new tune matching the one I've got now. When I head to the track, load up the other tune or just disable it.

Any knowledge on how others get around this?

Thanks for the response!

 

Son of a bitch... I just thought of something.

Would the rear 02's be responsible for activation of COT???

If so, the fact that I don't have them on might be why it's ALWAYS on... sort of a Just to be safe kind of thing the PCM is doing to me.

A buddy of mine has his rear 02's in and enabled. He didn't have the issue with COT always coming on.... I think I know why now..

Anyone verify this???

 

I know for sure, when disabling the rear O2's on a 1998 WS6 M6, COT is not always on

just log your "commanded air fuel ratio" with your scanning software to see when it kicks in. Mine kicks in around 5000 rpms on a loaded mustang dyno run in 4th gear.

Ryan

 

Gotcha. Good to hear. I'll have to try that myself with it enabled again. I don't wanna kill my CATS but I also don't wanna be robbed of power I should have.