hey guys
whats the difference between sport and race cat's???
whats the difference between sport and race cat's???
jtviggen
The names...
But really you can get a cat with as low as 100 cells. 200 and below are generally considered race, 300-200 sport and more that 300 regular... from what I have seen.
But really you can get a cat with as low as 100 cells. 200 and below are generally considered race, 300-200 sport and more that 300 regular... from what I have seen.
If you look at a Catalytic converter, it is just a honeycomb of "cells". Think of it like a screen on a screen door, with all the little holes in it. Only the screen is about 8-10" thick. So each "hole" or "cell" acts like a tube.
The exuast gets passed through this thick honeycomb screen, and the chemicals inside the honeycomb react with the exhaust to "clean" it.
The number of "cells" and the size of them help determine if it is a sport/race cat.
The exuast gets passed through this thick honeycomb screen, and the chemicals inside the honeycomb react with the exhaust to "clean" it.
The number of "cells" and the size of them help determine if it is a sport/race cat.
I don't think there is generally a rule for how one cat called one thing is going to sound over a different cat called by a different term.
In terms of outright flow, there is probably little difference...I've heard that race cats handle more abuse...although this is just anecdotal.
A race or sport cat is usually a larger diameter, and thus flows more. Because it flows more, it probably muffles the sound less than a regular restrictive cat.
The catalytic converters that most parts stores carry are 2.25" max on the inlet/outlet, and expand up to 2.75" in the middle for the honeycomb.
A sport or race cat will have a 3" inlet/outlet or larger, and expand to me much wider in the center section.
The honeycomb of the cat does take up volume, and as such, restricts airflow. By making the honeycomb section larger, the increased volume of space counters the restriction that the volume of the honeycomb makes. So actual volumetric space for air to exist in a sport/race cat is more than in a regular cat... thus allowing it to flow more.
Any way you go with a cat, the cat will do some minor restriction on the flow, and quiet down the exhaust. If you want a louder ehaust, just remove the center muffler/resonator.
The catalytic converters that most parts stores carry are 2.25" max on the inlet/outlet, and expand up to 2.75" in the middle for the honeycomb.
A sport or race cat will have a 3" inlet/outlet or larger, and expand to me much wider in the center section.
The honeycomb of the cat does take up volume, and as such, restricts airflow. By making the honeycomb section larger, the increased volume of space counters the restriction that the volume of the honeycomb makes. So actual volumetric space for air to exist in a sport/race cat is more than in a regular cat... thus allowing it to flow more.
Any way you go with a cat, the cat will do some minor restriction on the flow, and quiet down the exhaust. If you want a louder ehaust, just remove the center muffler/resonator.
would i need the ver 2 dp from gs and would i need the space for the wide band o2 sensor??? for a viggen
Depends....what are your goals? Lots of people run various DP's with sport cats, race cats or no cats....the GS v2 DP is certainly the sweetest one. I have a homegrown 3" DP with a 3" sport cat...it works great. It's not pretty, though.
Wideband is necessary if you are going to be doing some serious/custom work to the car. Otherwise it's icing.
Wideband is necessary if you are going to be doing some serious/custom work to the car. Otherwise it's icing.
my vert w/o cat has a lot better spool up time, sounds a lot better, and gives you that nice gas/oil smell after a hard run instead of rotten eggs.
the main thing comes down to what year your car is. 94-95 knock it out and you will have no problems, anything OBD II will throw CEL's left and right because the rear O2 is seeing too much activity. unless you have some weird ECM burn that doesn't need a rear O2.
the main thing comes down to what year your car is. 94-95 knock it out and you will have no problems, anything OBD II will throw CEL's left and right because the rear O2 is seeing too much activity. unless you have some weird ECM burn that doesn't need a rear O2.
Where is Nick on this one? He did some testing i thought with different cats? Anyone know what brand race cat they use on their DP's?
I believe Genuine Saab uses a Vibrant metal core cat in their downpipes.
http://www.genuinesaab.com/catalog/product_info.php?products_id=425
I had one in the JT exhaust on my 9k for around a year. It held up just fine, no melting, didn't appear clogged. I decided to ditch it since I found someone who would pass me on inspection w/o a cat installed (nice to have a non-odb2 car) and I also replaced the entire center section of the exhaust.
The only real differences I noticed were a bit more noise, less joints to break on the exhaust system, maybe a slightly faster spool up and of course the smell.
http://www.genuinesaab.com/catalog/product_info.php?products_id=425
I had one in the JT exhaust on my 9k for around a year. It held up just fine, no melting, didn't appear clogged. I decided to ditch it since I found someone who would pass me on inspection w/o a cat installed (nice to have a non-odb2 car) and I also replaced the entire center section of the exhaust.
The only real differences I noticed were a bit more noise, less joints to break on the exhaust system, maybe a slightly faster spool up and of course the smell.
It can't be any worse then the other motor vehicles I have with no emissions stuff on them whatsoever (2 smoke pwcs, bikes, etc)
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