Should I remove my cat???
08-09-2007, 11:46 PM
#1
Registered User
Thread Starter
Join Date: Jan 2006
Location: Hollywood, AL
Posts: 112
Should I remove my cat???
Here in Alabama, we don't have emission test'n. From the research I've done, I will get more HP w/o a cat than with a highflow cat (ceramic or metalic), isn't this illegal? To run w/o a cat? What should I do...mind u, I live in the STICKS of AL so I'm sure a pig isn't going to check to see if I've got a cat or not...but anyhow, I'm look'n for some in-put/advice...
THANX!!! Props to all those who respond!!!
THANX!!! Props to all those who respond!!!
08-10-2007, 03:31 AM
#2
Registered User
Join Date: Mar 2007
Location: Fairmont, West Virginia
Posts: 100
well ya you are some what right having no cat you will have a little more power especially if your cat is clogged. but i wouldn't do it i would just get a high flow cat so you can have better exhaust flow good back pressure and still be legal. the biggest down fall of having no cat is the fact you loose some backpressure in your exhaust which helps your engine out. but when it comes down to it you are gonna do what you want.
but i'll leave you with this. in my old ford ranger my cat was cloged and i decided to unclog it ( hollow out the cat ) and before i did it the truck ran kinda "poopy" and after i did it the truck ran awesome cause the engine could breath and afterwards i could finally power break the truck and do burnouts.
so really it all just depends on how your current cat is.
p.s. cheap ebay cats = junk that breaks in 10,000 miles so do not buy
if you want a good high flow cat get a name brand like catco or magnaflow
hope that helps you out
peace
Erik
but i'll leave you with this. in my old ford ranger my cat was cloged and i decided to unclog it ( hollow out the cat ) and before i did it the truck ran kinda "poopy" and after i did it the truck ran awesome cause the engine could breath and afterwards i could finally power break the truck and do burnouts.
so really it all just depends on how your current cat is.
p.s. cheap ebay cats = junk that breaks in 10,000 miles so do not buy
if you want a good high flow cat get a name brand like catco or magnaflow
hope that helps you out
peace
Erik
08-10-2007, 03:50 AM
#3
Registered User
Thread Starter
Join Date: Jan 2006
Location: Hollywood, AL
Posts: 112
From what I've read/researched, removing the cat for a high-flow pipe will not decrease my back pressure (too much for a NA car), however, it is illegal - even though AL does not have emission testing and my exhaust would be LOUDER than it is now (w/ a full catback exhaust system - i.e. header & exhaust pipe + muffler).
So, what should I do...highflow cat??? Ceramic or Metalic??? Need more input/advice!!!
BTW: Thanx Erik
So, what should I do...highflow cat??? Ceramic or Metalic??? Need more input/advice!!!
BTW: Thanx Erik
08-10-2007, 05:23 AM
#4
Registered User
Join Date: Aug 2007
Location: Oklahoma
Posts: 3
Removing or gutting the cat will indeed provide you with a significant increase in response, and perhaps even notably more power. The decision whether to take advantage of this or not pivots entirely on personal ethics. Most of my cars have straight through exhaust designs, so I obviously have no compunctions about running "illegal" equipment.
Also. It should be noted that "backpressure" is an erroneous term, and a widely misunderstood concept. Positive pressure in the exhaust system of a naturally aspirated engine is detrimental to waste gas evacuation, and reduces output drastically. When people who design racing application motors refer to backpressure (again, this is a misused term) they are actually talking about exhaust velocity. A properly designed exhaust system will maintain an almost constant flow of exhaust gas, this gas velocity creates negative pressure at the exhaust valve each time it closes. When the valve opens again this negative pressure helps draw the waste gases from the cylinder. Positive pressure impedes the evacuation of these gases, and as a result some waste gas is left in the cylinder when the exhaust valve closes. This is a simplified explanation that ignores pulse tuning, but the concept is pretty much the same.
Also. It should be noted that "backpressure" is an erroneous term, and a widely misunderstood concept. Positive pressure in the exhaust system of a naturally aspirated engine is detrimental to waste gas evacuation, and reduces output drastically. When people who design racing application motors refer to backpressure (again, this is a misused term) they are actually talking about exhaust velocity. A properly designed exhaust system will maintain an almost constant flow of exhaust gas, this gas velocity creates negative pressure at the exhaust valve each time it closes. When the valve opens again this negative pressure helps draw the waste gases from the cylinder. Positive pressure impedes the evacuation of these gases, and as a result some waste gas is left in the cylinder when the exhaust valve closes. This is a simplified explanation that ignores pulse tuning, but the concept is pretty much the same.
08-10-2007, 03:01 PM
#6
Registered User
Join Date: Mar 2007
Location: Fairmont, West Virginia
Posts: 100
Well guy
i would go with a high flow cat , so you will be legal, have more flow than stock, and won't be so loud that you can here urself think. wait? what size is your exhaust? i noticed you are stil n/a. i like the 2.5 inch exhaust personally for n/a. 3"inch is a litle much unless you plan to go turbo soon or down the road. but i have seen dyno charts and the size doesn't really effect the number to much it mostly just effects the "loudness" of the exhaust.
so if 2.5" isn't loud enough for you then gut that cat cause your not in cali you don't have to worry about emissions.
but if 3" is plenty loud for you which im sure it is then i would have a high flow on there to help quiet it down a little. just my 2 cents.
peace
Erik
i would go with a high flow cat , so you will be legal, have more flow than stock, and won't be so loud that you can here urself think. wait? what size is your exhaust? i noticed you are stil n/a. i like the 2.5 inch exhaust personally for n/a. 3"inch is a litle much unless you plan to go turbo soon or down the road. but i have seen dyno charts and the size doesn't really effect the number to much it mostly just effects the "loudness" of the exhaust.
so if 2.5" isn't loud enough for you then gut that cat cause your not in cali you don't have to worry about emissions.
but if 3" is plenty loud for you which im sure it is then i would have a high flow on there to help quiet it down a little. just my 2 cents.
peace
Erik
08-10-2007, 06:15 PM
#7
a high flow cat sounds good to me. i gutted my cat first and hated it. it was too loud so i got a high flow cat instead. get one off of ebay it doesn't have to be expensive to do the job.
Thread
Thread Starter
Forum
Replies
Last Post
j00ni3
NA Motor
4
11-23-2005 01:18 PM
jackyliem
General
2
03-13-2005 05:33 PM