[tbaig]

Originally Posted by morphomeman

OP has still not told us what increase he expects in HP or torque from going CATless.
With modern engines , there may be minimal gain.
Inquiring minds want to know.

I am following what is noted in this thread:
http://www.2addicts.com/forums/showthread.php?t=1150729

[beMtroubleYou]

Originally Posted by morphomeman

OP has still not told us what increase he expects in HP or torque from going CATless.
With modern engines , there may be minimal gain.
Inquiring minds want to know.

Well. Try blowin air into a straw, the blow it into, i dont know 10 straws in a circle.

What gives you a headache and a faint feeling and what offers least path of ressistence? Its the same here.

HP gain is different depending on situation, but its there. Is it worth? Only you can tell. There are tons of dynos cat/catless/sportcat/racingcat. Cons and pros are different depending on what you will use the car for.

[Maynard]

Originally Posted by beMtroubleYou

Well. Try blowin air into a straw, the blow it into, i dont know 10 straws in a circle.

What gives you a headache and a faint feeling and what offers least path of ressistence? Its the same here.

HP gain is different depending on situation, but its there. Is it worth? Only you can tell. There are tons of dynos cat/catless/sportcat/racingcat. Cons and pros are different depending on what you will use the car for.

I think the correct metaphor would be - blow through 10 straws in a bundle - now blow thorough a pipe the same diameter as that bundle. That very subtle difference is what you gain with a catless. I don't track the dyno sheets closely, but assume that, all else being equal, a good performance cat can deliver at least 90, probably 95+% of the power you get with a catless. Most of the huge power boost claimed for catless setups will come from running alt fuels that would kill the converter (meth, AV gas, etc).

And just found this lurking in my inbox - GRM tested a Miata with test pipe vs. aftermarket Cats, finding almost no difference (except for the emissions levels). true it is not a direct comparison, but I'd expect NA to be more sensitive to restriction than a turbo. https://grassrootsmotorsports.com/ar...paign=GRMDaily