Catatlytic Converter
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Catatlytic Converter
I have the stock catalytic converter on my truck and I am thinking about replacing it for performance reasons. So I can understand what's best for me, I have a few questions:
Are the advertised 'hi-flow' converters worth it? Do they perform better? Would this change the exhaust sound at all?
What if I had a hollow catalytic converter, I'm sure that would be louder but is this a lot louder or just a little?
Would either of these result in too little exhaust back pressure as long as I kept the same diameter exhaust pipe?
Thanks.
Are the advertised 'hi-flow' converters worth it? Do they perform better? Would this change the exhaust sound at all?
What if I had a hollow catalytic converter, I'm sure that would be louder but is this a lot louder or just a little?
Would either of these result in too little exhaust back pressure as long as I kept the same diameter exhaust pipe?
Thanks.
Postmaster
Joined: Oct 2009
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Ok, first off the cats from the factory will support more power than a stock engine can produce. So you will gain little to nothing for replacing them.
Most aftermarket cats that claim to be high flow are ordinary cats with the same catalyst density as stock, with the same or a smaller cross section. This means the flow is either the same as stock, or slightly more restrictive.
If you hollow it, not only did you not gain any performance because it was not restricting flow in the first place, you actually cost performance because now you have a turbulence adding device in your exhaust. Turbulence robs power. And yes, it is a lot louder.
Real high flow converters are expensive (think around $200 a piece expensive, if it costs much less than that, its either not a high flow, or it won't meet emissions). The only reason you would need one is either if you made wild changes to the engine (think cams, porting, valves, increased compression, etc.) or were running forced induction (turbo or supercharger).
Since your signature says you have a Vortech supercharger, then yes, a high flow cat will help you.
Most aftermarket cats that claim to be high flow are ordinary cats with the same catalyst density as stock, with the same or a smaller cross section. This means the flow is either the same as stock, or slightly more restrictive.
If you hollow it, not only did you not gain any performance because it was not restricting flow in the first place, you actually cost performance because now you have a turbulence adding device in your exhaust. Turbulence robs power. And yes, it is a lot louder.
Real high flow converters are expensive (think around $200 a piece expensive, if it costs much less than that, its either not a high flow, or it won't meet emissions). The only reason you would need one is either if you made wild changes to the engine (think cams, porting, valves, increased compression, etc.) or were running forced induction (turbo or supercharger).
Since your signature says you have a Vortech supercharger, then yes, a high flow cat will help you.
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So I just looked on Summitracing.com for comparison and I found 4 that would fit my truck. Two of them are over $200 and the others (obviously) aren't and there are only two different brands: Catco and Flowmaster. None of them say high-flow or even mention anything that might be considered less restrictive flow. Would the price be an indication it is high-flow? After comparing each side by side, I wasn't able to find any difference that would cause one of these to cost so much more than the others. It almost looks like the higher priced ones are the stock replacement with a higher price tag.
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Nope, neither are high flow, price does not indicate high flow.
Here are some real high flow cats.
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Here are some real high flow cats.
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From: In my house..
Khan is right on the money and please don't waste your money on "high-flow" cat's. Check out the Walker Super Converters at SummitRacing, they use a monolithic design catalyst and you can't go wrong with them.
The key to making power with the exhaust system is velocity velocity velocity, keep the gases hot and keep them flowing fast through the pipe, hot gases flow faster than cold and using the correct pipe size through out the system makes it all come together, a properly designed system will act as the 5th cycle in a 4-stroke engine and help to scavenge spent exhaust gases from the chamber leaving a less contaminated ballpark for the fresh air/fuel mixture to play in, cheers..
The key to making power with the exhaust system is velocity velocity velocity, keep the gases hot and keep them flowing fast through the pipe, hot gases flow faster than cold and using the correct pipe size through out the system makes it all come together, a properly designed system will act as the 5th cycle in a 4-stroke engine and help to scavenge spent exhaust gases from the chamber leaving a less contaminated ballpark for the fresh air/fuel mixture to play in, cheers..
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