Cats.....do They Make A Difference?

[simpletool]

I'm after some performance points.....and I like the ones that come without a downside (besides money).

So anyway I have ~230rwkw, a nice dump pipe and exhaust (Fujitsubo twin 2.5") but I remember I bought a ceramic cat cause I only had a stock turbo back then. So, should I now fit a high flow 100 cell metal cat?

If I replaced the cat with a metal cat would I even notice where my $400 went? Anybody got some dyno numbers to back up claims?

Seem that the 3" outlet/inlet with 4" 100 cell biscuit is the go.

Edited May 23, 2011 by simpletool

[The Bogan]

Look around for a larger stock cat at a exhaust shop waste bin, lots of people replace the cats on 5.7 ltr GM cars, it may flow well enough for your power levels and cost not much to nothing.

[simpletool]

ahh ha. Found a dyno comparison after some searching. Makes about a 4% improvement from a ceramic cat and about a 3% drop from a straight pipe. Gain of 14whp on an Evo that started with 300whp (gains over entire curve).

http://forums.evolutionm.net/evo-engine-turbo-drivetrain/330000-ceramic-cat-vs-100-cell-metal-substrate-cat.html

[sinistaGTR]

100 cel venom cats are 250 del with flanges welded on...I run one...great cat

[beemae30]

If its fried it will make a difference replacing it just like every other item.

[DVS JEZ]

I have seen 30rwkw from a highflow cat to a decat without touching the tune

[Hanaldo]

I have seen 30rwkw from a highflow cat to a decat without touching the tune

Whereas it didn't make the slightest difference on my car.

[DVS JEZ]

U probably had a good/decent highflow cat

[itshimdazza]

Just a dumb ass question guys....

How do you tell if your cat is a highflow?

I have a 3"exhaust and have no idea about the cat..was already on there sorta looks like a standard one but in a 3" variety. can you get them checked? apart from looking at the cells...

Dazza

[tridentt150v]

If it has tinware covers over it then its probably standard. All the name brand hiflows are usually bare, and stainless.

Do a search on hiflow cats and you will find pics of metalcat, catco etc

[FineLine]

I went from a 100 cell cat to a single cell cat and it made a big diffeence.

[SiR_RB]

Single cell?

[HEKT1K]

Haha i have one of those 'single cell' cats myself

[Dave.TAS]

Single cell cat is for me also

[SiR_RB]

Ah I get it lol yeh I got one of those single cell very very high flow cats too lol

[Run-It-Hard]

Single cell FTW!

[simpletool]

I'd be wary of "single cell" cats......I heard they can be VERY expensive.

OK so let's assume it's $300 for a 4% power bump. That's pretty decent.

[RS4-S]

id say that apart from making little difference at the wheels, the only reason i would be changing to to a metal CAT is they are less likely to "meltdown". if a heap of raw fuel is punched down the exhaust and ignites and melts the monolith, then ofcourse going from a pile of melted (blocked) mess to a highflow you will notice a difference.

also metal CATs are arent known for cracking up and coming apart like ceramic CATs, including impact damage for those who like their cars low and their CATs eating speedhumps and driveways

[Brezza]

I dont think that you'll be noticing much difference.

pull your cat out and see how it looks, if you can see light through it then its going to flow well. the only time a cat is going to cause and issue is if it is collapsed.

as far as people saying you gain 30kw going to straight pipe, its probably on cars with well over 300kw. and maybe their cat wasnt flowing well enough and causing a restriction.

but at 230kw a 3in highflow cat should be fine even up to over 300kw.

[sucram]

Is the law still stating that the cat must be in the same position as the stock cat?