Cat protection

[raycer]

My car goes into cat protection in 3rd and fourth at the drag strip . Afr goes to .66-.69 lambda all through those gears. Is this hurting my performance? If so what can I do?

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[smann]

IMO that seems like a tune issue, car is running rich?

Do a datalog and post here if possible

 

[Jay-rod427]

tune probs. yes that's hurting you big time.

 

[ProChargerTECH]

My car goes into cat protection in 3rd and fourth at the drag strip . Afr goes to .66-.69 lambda all through those gears. Is this hurting my performance? If so what can I do?

Well, technically its doing what it is supposed to be doing.
If you no longer have that emissions device in place, there is no reason to protect it.

(And depending on your tune, it could be WAY off from reality)

We have spent a LOT of time on what the actual temp of the cats using thermocouples, and EGT's probes. (before, inside, and behind the cats)
I have loads and loads of logged data from startup, drive, idle, and WOT. And frankly, the cars "assumption" of temp can be drastically incorrect from reality.

 

[raycer]

I still have the factory cats and would like to keep them. I will have to send my tuner more logs. I thought my trap speed should have been higher than 124.

 

[F1scamp]

Mine has kicked in a couple times, usually knocks off 3mph on my setup.

 

[raycer]

Mine has kicked in a couple times, usually knocks off 3mph on my setup.

If that’s the case I need to get this fixed. Wow

 

[Performance nut]

Well, technically its doing what it is supposed to be doing.
If you no longer have that emissions device in place, there is no reason to protect it.

(And depending on your tune, it could be WAY off from reality)

We have spent a LOT of time on what the actual temp of the cats using thermocouples, and EGT's probes. (before, inside, and behind the cats)
I have loads and loads of logged data from startup, drive, idle, and WOT. And frankly, the cars "assumption" of temp can be drastically incorrect from reality.

Anything you care to share? That is some really great data to have. What did you use for the thermocouple?

 

[ProChargerTECH]

Anything you care to share? That is some really great data to have. What did you use for the thermocouple?

There are many out there that you can use. However I don't see any reason for a consumer to need that kinda level of details. It was more for me to learn whats really going on with some values that the computer "estimates" such as cat temp.

The most common that I see for people that don't want to blow the budget on OEM grade equipment, is something like the Racepak stuff.

 

[raycer]

Would it be risky to flat out turn cat protection off? The longest pulls I do are quarter mile runs.

 

[oesman]

I would either cut the cats out or just live with the performance. I suppose you could get a tune with cat protection off and run it when doing a pass like this. I'd say figure out what you're trying to do with the car. If its a street car maybe cat protection is part of the performance drawbacks, your cats on their own don't help performance either.

 

[raycer]

Definitely not going to live with it. I’ll put headers on if I have to. It’s a street car but I can’t have it running that fat all the way through 3rd and 4th when I go to the track. Still waiting for an answer from my tuner.

 

[Boduke0220]

you do not want to melt a cat either. good way to blow a motor

 

[oesman]

Another option is the Mak delete pipes. You can weld a flange and get bolt on bolt off cats.

 

[ahl395]

+1 get MAK delete pipes. 4 Bolts and you can remove/reinstall the cats as needed.

You can turn cat protection off, many tuners do. But obviously your risking killing your cats in the process. Cats on a boosted motor is risky and there's an off chance you could lose the motor that way too. That was enough for me to go catless.

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