How hot are your cats?

[Justin@VMP]

I know how hot mine are.

Today I was testing some high-flow 2.5" cat pipes that I had made a while back.

I installed thermocouples at the inlet of the cat and inside the cat itself.

Cats usually melt around 1650F, being that the factory ones are so close to the engine and so restrictive, they tend to melt very easily on higher HP cars. Reducing backpressure and moving the cats farther back will help extend their life.

I would like to keep cats on my car (while still producing alot of power) to keep the odor and noise down, not to mention its enviromentally friendly if you like to hug trees.

Here is a shot of some of the data I acquired:



I basically beat the piss out of the car on the dyno to see what kind of EGTs I could produce. The peak under load was about 1700F before the cat and 1750F inside the cat, I experienced some type of misfire when the car got very hot and saw even higher temps on decel (off the chart 1800F+). For reference peak ECT was 196F and DSACT was 150F. Cat protection was disabled during testing, but the car was running pretty rich, high 10s, so at 11.7:1 the cat temps would be even higher. I will test these cats out at sebring in April and measure temps and see how they hold up.