Catalytic converter(s)/exhaust help
08-07-04, 04:52 PM
#1
Junior Member
Thread Starter
Join Date: May 2004
Location: Mogadore, OH
Posts: 15
Likes: 0
Received 0 Likes
on
0 Posts
Catalytic converter(s)/exhaust help
I have a 1987 NA with a Borla cat-back system. Other that that, my exhaust is pretty much stock. 2 of the 3 catalytic converters on my car are in good shape (no leaks, etc), but the first cat has leaks in it and I want to get it replaced. I have a couple of options here:
1) Replace the first cat (or all 3) with Catco high-flow converters. Any opinions on Catco? Worth the investment? Any idea how loud my FC would be with these high-flow cats? At the moment it isn't very loud at all, but it has a very nice, deep, bassy tone.
2) Keep the 2nd and 3rd cats (or only the 3rd), and bypass the first one(s) with straight pipes. Is this a good idea? Any potential problems to my car? How loud? Any back pressure issues with the 5th and 6th ports?
3) Get rid of all 3 cats and invest in a pre-silencer. Any idea of the cost? Again, how loud will it be? This would probably be my last option because of the limited amount of money I have at the time (that is, if good pre-silencers are as costly as I imagine).
Any expert advice would be much appreciated! Thanks.
1) Replace the first cat (or all 3) with Catco high-flow converters. Any opinions on Catco? Worth the investment? Any idea how loud my FC would be with these high-flow cats? At the moment it isn't very loud at all, but it has a very nice, deep, bassy tone.
2) Keep the 2nd and 3rd cats (or only the 3rd), and bypass the first one(s) with straight pipes. Is this a good idea? Any potential problems to my car? How loud? Any back pressure issues with the 5th and 6th ports?
3) Get rid of all 3 cats and invest in a pre-silencer. Any idea of the cost? Again, how loud will it be? This would probably be my last option because of the limited amount of money I have at the time (that is, if good pre-silencers are as costly as I imagine).
Any expert advice would be much appreciated! Thanks.
08-07-04, 05:27 PM
#2
Senior Member
iTrader: (6)
Join Date: Oct 2003
Location: Elkin, NC
Posts: 291
Likes: 0
Received 0 Likes
on
0 Posts
hmmm
Alright well...I went with option 3....I have a RB header/presliencer combo to corksport catback and it is loud...but I got some really good power out of it. I would recommend that, but if your state does emissions then it is also a good idea to get a main rear cat, I had one made for my car and I just swap it out every year when it comes down to emissions......As for your backpressure..I know that on my 91 I need my airpump to open the ports, but for your 87, I believe that you dont need your airpump...correct me someone if I am wrong...?...but I enjoy my setup...just my 2 cents.....enjoy
08-07-04, 09:25 PM
#3
Junior Member
Thread Starter
Join Date: May 2004
Location: Mogadore, OH
Posts: 15
Likes: 0
Received 0 Likes
on
0 Posts
Yeah, I live in OH and emissions tests are every 2 years here I do believe. How much of a difference would it be if I just kept the main factory rear cat and took the pre-cats off? Basically just putting a midpipe in there. Could I still pass emissions with this set-up? Would there be a notable difference in sound and loudness? How about if I only took off the first pre-cat?
Honestly, my main concern is to eliminate the exhaust leaks down there. The state that cat is in at the moment is making my car sound like crap. BUT, I don't want to risk creating any potential problems to the vehicle. That's why I'm seeking advice on this forum. Also, if it means shelling out $300 or more to fix this then I would rather just keep it how it is. It isn't a terrible leak or anything, but I want my exhaust to be sealed up and only coming out of the tail pipes!
By the way, can anyone point me to a place where I can learn more about the exhaust systems for these cars? I want to find out more about how the converters work and what each one's purpose is.
Honestly, my main concern is to eliminate the exhaust leaks down there. The state that cat is in at the moment is making my car sound like crap. BUT, I don't want to risk creating any potential problems to the vehicle. That's why I'm seeking advice on this forum. Also, if it means shelling out $300 or more to fix this then I would rather just keep it how it is. It isn't a terrible leak or anything, but I want my exhaust to be sealed up and only coming out of the tail pipes!
By the way, can anyone point me to a place where I can learn more about the exhaust systems for these cars? I want to find out more about how the converters work and what each one's purpose is.
08-07-04, 11:07 PM
#5
2 Rotors, 1 Turbo
Join Date: Feb 2004
Location: Atlanta, GA
Posts: 1,099
Likes: 0
Received 0 Likes
on
0 Posts
My cat went to hell (half of catalyst stuff broke into chunks, rattling around inside), so nothing is in it for a while 
Ive been looking at cats, since we have emissions testing here in GA. Does anyone run a magnaflow catalytic converter (one that retains the 5th and 6th port action)?
Ive been looking at cats, since we have emissions testing here in GA. Does anyone run a magnaflow catalytic converter (one that retains the 5th and 6th port action)?
08-08-04, 03:35 AM
#6
Rotary Enthusiast
Join Date: Mar 2004
Location: St Louis
Posts: 1,473
Likes: 0
Received 0 Likes
on
0 Posts
I ordered the Catco direct fit converters. There are only two on it though. Summit sells it for $160 or somthing like that. There is more info on it if you search under "Gateway Clean Air program on this board. There are part numbers and emission test results.
Thread
Thread Starter
Forum
Replies
Last Post