having no catalytic convertors increase horsepower?
04-20-2012, 09:47 PM
#3
TECH SAVANT
Join Date: Dec 2006
Location: Saint Augustine, FL
Posts: 10,938
No, it just makes more noise and stinks¹.
Though I have never done it with a GT, we ran back-to-back dyno runs on my supercharged '92 Miata some years back. With a Jackson Racing 4-2-1 header, and a "test pipe" and the cheapest catalytic converter we could get at what was then Discount Auto Parts, there was no, repeat NO, discernible difference in engine output--all the way to 8000 rpm. I ended up running the cheap converter because it kept the rear bumper cleaner.
If there exists such a back-to-back comparison for a New-Edge GT (even anecdotal like above) of an aftermarket catted H- or X-pipe, and a so-called "off-road" pipe, I have never seen or heard of it.
If your setup is otherwise stock a good tune will gain you much more than removing the cats could possibly provide...
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¹ - The "gotcha" here is that the OEM exhaust system is restrictive at higher engine speeds, so compared to the stock system and o/r pipe will show gains.
Though I have never done it with a GT, we ran back-to-back dyno runs on my supercharged '92 Miata some years back. With a Jackson Racing 4-2-1 header, and a "test pipe" and the cheapest catalytic converter we could get at what was then Discount Auto Parts, there was no, repeat NO, discernible difference in engine output--all the way to 8000 rpm. I ended up running the cheap converter because it kept the rear bumper cleaner.
If there exists such a back-to-back comparison for a New-Edge GT (even anecdotal like above) of an aftermarket catted H- or X-pipe, and a so-called "off-road" pipe, I have never seen or heard of it.
If your setup is otherwise stock a good tune will gain you much more than removing the cats could possibly provide...
-----------------------------------------------
¹ - The "gotcha" here is that the OEM exhaust system is restrictive at higher engine speeds, so compared to the stock system and o/r pipe will show gains.
04-21-2012, 12:08 PM
#6
2nd Gear Member
Join Date: May 2007
Location: miami fl
Posts: 467
I have actually had both on my car and to be perfectly honest it only becomes beneficial when you go over 400whp. I was able to feel the restriction with the cats and as soon as I took them off I could literally feel the exhaust come out much smoother. In Florida there are no emissions so it's legal where I live. You do indeed have more of a fuel smell when you're at a light with your Windows down but other than that and the louder growl it's a great piece to add on.
04-21-2012, 01:04 PM
#8
6th Gear Member
Join Date: Feb 2007
Location: South FL
Posts: 8,540
I have actually had both on my car and to be perfectly honest it only becomes beneficial when you go over 400whp. I was able to feel the restriction with the cats and as soon as I took them off I could literally feel the exhaust come out much smoother. In Florida there are no emissions so it's legal where I live. You do indeed have more of a fuel smell when you're at a light with your Windows down but other than that and the louder growl it's a great piece to add on.
Actually it's a federal law, and illegal to remove them in all 50 states. FL just doesn't check annually. If you get caught without them, you'll get a ticket.
04-21-2012, 02:20 PM
#9
1st Gear Member
Join Date: Jul 2011
Location: All around the World
Posts: 104
04-21-2012, 03:00 PM
#10
4th Gear Member
Join Date: Jun 2010
Location: TEXAS
Posts: 1,452
