My HFC on my VIII stinks lol, i can't imagine what a TP would be like.
Smell wise it won't be much different.
It it is really bothering you though. it would be maybe a few hp loss.

 

Mil.Spec is the only true 3" 100 cell cat on the market at the moment....

for install buy a test pipe, cut to the approx. length and have the 100 cell welded in between the two halfs...

https://www.evolutionm.net/forums/ev...available.html






evo 8/9




3" INLET/OUTLET CAT

 

opps i didnt realize, haha

 

What's the differences between 300 cell cats and 100 cell cats?

One's going to flow more than the other? The other's going to have cleaner exhaust gas than the one?

 

100 cell will flow better compared to 300

 

I noticed Mil.Spec compared their results vs aftermarket ceramic cats. I wasn't aware there were any aftermarket ceramic cats made for the Evo X, so why the comparison? How well does the Mil.Spec flow versus a similar product such as the Invidia which also uses a 100 cell metallic cat, or Harman Motive who uses 200 cell, or AMS which is 300 cell, etc?

Regardless I'm still getting the AMS hfc, but just would like to know what slight differences there may be.

Edit: not sure, but I don't think there's any ceramic cats available for the 8/9 either...

 

What are the numbers? I can't see this at work.....

 

I run the MIL-SPEC 100 cell cat. I can confirm that there is no stink, which was a concern for me.

I had RRE weld my 100 cell into a removeable piece with flanges. This way I can drop in a test-pipe or stock cat if desired.

 

You guys are concerned with pressure drop across the monolith. Stainless steel supports typically have less pressure drop than ceramic monoliths of the same diameter and will flow better. This is why performance cars usually utilize stainless steel catalyst supports.

Catalyst performance (destruction efficiency) is affected by residence time (the amount of time the hydrocarbons stay in contact with the precious metals). Longer residence times (often referred to as space velocity) result in higher destruction efficiencies. Performance is also affected by catalyst operating temperature, and precious metal loading. It is likely that the OEM catalyst has higher precious metal loading, and is carefully positioned to provide fast warm up and reduce the likelihood of overheating. Since the EVO often runs rich, this presents design challenges, ones that are unlikely to have been considered by the aftermarket. You can make more power with a less restrictive aftermarket converter, but don't expect it to do its job like the OEM one.