Exhaust Post your questions and suggestions about stock or aftermarket exhaust setups. Third Gen exhaust sound files and videos!

Dual exhaust system???

Thread Tools
 
Search this Thread
 
Old Oct 15, 2006 | 12:56 AM
  #1  
85TransAmDude's Avatar
Thread Starter
Member
 
Joined: Oct 2006
Posts: 141
Likes: 0
From: Newfoundland, Canada
Car: 1985 Firebird Trans Am.
Engine: 305 H.O. 4bbl
Transmission: 700R4.. I think
Axle/Gears: Not Sure, 3.73?
Dual exhaust system???

Hey...I got an 85 TA with the 305 H.O. 4bbl...and recently i ran over a deer and it bent crushed the exhaust to hell lol (lucky it diddnt damage anything else lol)...it was the stock exhaust so ive been checking around but cant seem to find any true duel exhaust systems for my car...would i have to get one custom made?...if so how much HP do you think i will gain from it? and how much do you think it will cost?...thx
Reply
Old Oct 15, 2006 | 01:06 AM
  #2  
DocHoliday's Avatar
Member
15 Year Member
 
Joined: Dec 2005
Posts: 179
Likes: 0
From: San Antonio, Texas
Car: Red 1984 Z-28
Engine: 4.8 LS
Transmission: 4L60E
Axle/Gears: 3.73
Before you get flamed by everyone on the exhaust board, Search. This topic pops up all the time. Yes, you will have to custom fab up your own exhaust if you want true duals, because no one makes a kit. As for HP, not sure, good question though.

DH
Reply
Old Oct 15, 2006 | 07:51 AM
  #3  
85TransAmDude's Avatar
Thread Starter
Member
 
Joined: Oct 2006
Posts: 141
Likes: 0
From: Newfoundland, Canada
Car: 1985 Firebird Trans Am.
Engine: 305 H.O. 4bbl
Transmission: 700R4.. I think
Axle/Gears: Not Sure, 3.73?
Ok...I was going to just simply get an 80 series muffler or somethin from flowmaster and put up in place of the stock muffler...but ive heard that just putting in a muffler can actually reduce performance...is this true?
Reply
Old Oct 15, 2006 | 05:51 PM
  #4  
DocHoliday's Avatar
Member
15 Year Member
 
Joined: Dec 2005
Posts: 179
Likes: 0
From: San Antonio, Texas
Car: Red 1984 Z-28
Engine: 4.8 LS
Transmission: 4L60E
Axle/Gears: 3.73
Depends, does the new muffler flow more than the stock? If it flows better than the stock muffler, then I highly doubt your performance is going to be affected in a negative way. On that same note, I doubt adding an aftermarket muffler alone is going to get you any increases in power, probably just sound. BUT, I could always be wrong . So, maybe someone with some first hand expierence will chime in. Good luck!

DH
Reply
Old Oct 15, 2006 | 07:16 PM
  #5  
25th327RS's Avatar
Senior Member
15 Year Member
iTrader: (2)
 
Joined: Jun 2006
Posts: 576
Likes: 4
From: Gobles, Michigan
Car: 92 Ttop Z28
Engine: Cammed 6.0
Transmission: T-56
Axle/Gears: Built 10 bolt-3.90s w/ PBR discs
i have 2 1/4 inch duals exiting infront of the rear tires under the rocker mouldings. if running a true dual exhaust setup, keep in mind, you are almost positively not going to run them over the rear axle, not room for 2 pipes on the passenger side and nowhere safe to run over the driver side due to fuel lines ect... there are no provisions on the drivers side floorpan for a muffler or exhaust and will have a low hanging exhaust, expect to hit the exhaust on sharp dips going 70 or better on country roads, carefullk parking lot entries and other things of the sort, bash that pipe on the pavement too hard and expect to replace a donut gasket, speaking from experience.

muffler cost obviousely depends on what you pick, mine were 40 a piece for a dynomax super-turbo, the pipe and labor were 250 bucks, which seemed to be close to the other quotes i got, but good luck finding a place to put the exhaust on your car without a cat, these guys put it on my car under the condition "if it dont have one when it comes in, we can let it leave without one"

Last edited by 25th327RS; Oct 15, 2006 at 07:21 PM. Reason: more info
Reply
Old Oct 15, 2006 | 07:21 PM
  #6  
85TransAmDude's Avatar
Thread Starter
Member
 
Joined: Oct 2006
Posts: 141
Likes: 0
From: Newfoundland, Canada
Car: 1985 Firebird Trans Am.
Engine: 305 H.O. 4bbl
Transmission: 700R4.. I think
Axle/Gears: Not Sure, 3.73?
Originally Posted by 25th327RS
i have 2 1/4 inch duals exiting infront of the rear tires under the rocker mouldings. if running a true dual exhaust setup, keep in mind, you are almost positively not going to run them over the rear axle, not room for 2 pipes on the passenger side and nowhere safe to run over the driver side due to fuel lines ect... there are no provisions on the drivers side floorpan for a muffler or exhaust and will have a low hanging exhaust, expect to hit the exhaust on sharp dips going 70 or better on country roads, carefullk parking lot entries and other things of the sort, bash that pipe on the pavement too hard and expect to replace a donut gasket, speaking from experience.

ah ok thx for the info...so I guess I'l just get the Borla catback or somethin...I was wondering about Hooker Headers...I was thinking about getting the Competition series headers but was also wondering if the borla cat-back would fit right on to them...or would i have to cut some pipe off the exhaust or weld some onto the exhaust so they will meat up with the headers...kinda hard to understand lol...does anyone know?...thx for the replies.
Reply
Old Oct 15, 2006 | 11:17 PM
  #7  
DocHoliday's Avatar
Member
15 Year Member
 
Joined: Dec 2005
Posts: 179
Likes: 0
From: San Antonio, Texas
Car: Red 1984 Z-28
Engine: 4.8 LS
Transmission: 4L60E
Axle/Gears: 3.73
I would recommend this setup to you:

Hooker 2055's and y-pipe
A high flow Catalytic Converter (if you are still running smog)
And the Borla Catback you are looking into.

Should be a straight forward install. If the I-pipe with the Borla kit is flanged, than I would recommend a Catco High Flow cat (9118). This catalytic converter slides on the 2055's y-pipe like they were made for each other. And then the Borla I-pipe and Cat should bolt up. If not there are ways around this. But I would need more info on the Borla Catback. Again, people with a little more expierience should chime in. Hope I could help just a little!

DH
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Street Lethal
Power Adders
634
Apr 30, 2019 12:14 PM
billybob6110
Tech / General Engine
16
Sep 24, 2016 09:50 AM
beastin91rs
Tech / General Engine
18
Oct 9, 2015 07:38 AM
formula_novice
Exhaust
32
Sep 5, 2015 03:58 AM
makaveli09
Exhaust
1
Aug 12, 2015 09:07 PM




All times are GMT -5. The time now is 01:31 PM.