I wonder why nobody never talk about cat-converter. Normally i alway see people talk about i/h/e. I heard people say that cat-con can help more air flow from h-> e and can give hp from 5-10 and 8-20 on turbo appication. So i wonder is this for real or just scam, why people never talk about it. Thank

 

i have done this before, i punched my factory cats(98 Eclipse and 94 Accord Turbo) and did not notice a difference, and most people do not talk about it cause in most states you will not pass emissions.I my hand i do not have to take Emissions cause i live in the wonderful state of WA.

 

i was think to put new cat-con on my car after i put turbo on, damn. But why put new cat-con on can fail inspection.

 

Replacing the catalytic converter is a pointless venture for these scenarios

1) The exhaust system will flow only as much as it's most restrictive component allows. IE: Why an over-sized Converter if the Pipes or Muffler are too small?
2) The stock Converter has sufficient excess Flow Capacity to allow modest upgrades without requiring a larger unit.

And remember; If you're looking at a Replacement Converter for less than 150.00/ 200.00, It isn't a true DOT approved Converter; it's more than likely a 'Test-Pipe"

P

 

It is not a scam. Think about it. The easier air can get in and out of the head the more power it will make. I have my jdm h22 manifold welded directly to my exhaust with no cat at all. I can drop a marble down one of my primaries and it will roll out the muffler tip

 

No-one here has said that Free-Flow Converters are a scam (unless you're selling 'test pipes' as Converters). Every post here has mentioned that for stock, and mildly reworked rides, you won't see any improvements.
As a matter of review, you may have made my point for me. In your application you:
[quote]"I have my jdm h22 manifold welded directly to my exhaust with no cat at all. I can drop a marble down one of my primaries and it will roll out the muffler tip" [unquote]
Unless you plan and make provisions for the entire exhaust, you will see no gain.
The short of it, Putting a 2 1/4" Converter on a 1 7/8" system is pointless. It's like having a 2" water pipe feeding into your house, having it necked down to a 5/8" pipe and then complain b'cuz it takes 20 minutes to fill your bathtub. Much the same principle.

 

So converters will have best result for larger
exhaust. But anybody have dyno run before/after?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Newbiemoney &raquo;</TD></TR><TR><TD CLASS="quote">So converters will have best result for larger
exhaust. But anybody have dyno run before/after?</TD></TR></TABLE>

please don't over simplfy the principle.

bigger is not always better, there only so big you can go before you loose low end torque. try to put a 5 inch headerback system like the one they use on drag turbo supra, you lost torque because you have no back pressure.

what's work for turbo doesn't always apply to NA.

people always talks about ihe becuause the gain from high flow cat is almost not noticeable. It's illegal in most of the smog controlled state.
the 60 buck so called cat is a piece of muffled test pipe which do nothing to control emission, you'll get a fat ticket for it and the cop can tell by the smell of the fume. not to mention the CEL will put your car to limp mode

"I wonder why nobody never talk about cat-converter. Normally i alway see people talk about i/h/e. I heard people say that cat-con can help more air flow from h-&gt; e and can give hp from 5-10 and 8-20 on turbo appication. So i wonder is this for real or just scam, why people never talk about it. Thank "

changing sparkplug on turbo supra can gain a 5-10 horsepower but try that on your honda. again, what works for turboed car doesnt always transfer to NA. you'll be lucky to see a 10whp gain for IHE with vafc

 

You cant pass emissions with a turbo anyways, unless its a greddy.