If you want somethin' done right... (3" DIY exhaust)
08-30-2003, 04:41 PM
#1
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If you want somethin' done right... (3" DIY exhaust)
My 3" exhaust system was looking pretty sorry after the initial muffler shop's crappy squashed bends, additions of resonators by me for additional sound control, and finally the swap of the primary muffler.
So I finally chopped the whole damn thing apart and rewelded it properly.
I moved the primary muffler forward as far as possible, used 45 degree mandrel bends, and hacked and rewelded the Monza tip for better flow/shorter length. After welding together the forward assembly and installing it, I realized I could have multiple ends so I made an 'everyday' and a 'race' rear section.
The everyday section is fairly stock in appearance and is reasonably quite at idle/low speeds, and the sound pressure only rises to a certain level overall.
With the straight race section you can almost see the exhaust valves from behind!
It's much lighter in weight and the sound above 3 grand is just amazingly sweet. (It is not really that much louder inside as it exits straight out the back versus the side.)
Top: Everyday section - The Velvet Hammer
Bottom: Race section - Thor's Hammer
Details of the brackets
I definately recommend a Flowmaster Delta 50 versus a 40 series; they flow the same and the sound has a lot less of the 'motor boat' sound with the big bore pipe. I installed the resonators with the cuts facing rearward, so they would last longer and not be too quiet.
All 3" ID, prices approximate
Flowmaster Delta 50............. $100
Pacesetter Monza tip............ $50
7" 45 degree mandrel bends... $30 each!
12" resonators..................... $20 each
~thread~start~
So I finally chopped the whole damn thing apart and rewelded it properly.
I moved the primary muffler forward as far as possible, used 45 degree mandrel bends, and hacked and rewelded the Monza tip for better flow/shorter length. After welding together the forward assembly and installing it, I realized I could have multiple ends so I made an 'everyday' and a 'race' rear section.
The everyday section is fairly stock in appearance and is reasonably quite at idle/low speeds, and the sound pressure only rises to a certain level overall.
With the straight race section you can almost see the exhaust valves from behind!
It's much lighter in weight and the sound above 3 grand is just amazingly sweet. (It is not really that much louder inside as it exits straight out the back versus the side.)Top: Everyday section - The Velvet Hammer
Bottom: Race section - Thor's Hammer
Details of the brackets
I definately recommend a Flowmaster Delta 50 versus a 40 series; they flow the same and the sound has a lot less of the 'motor boat' sound with the big bore pipe. I installed the resonators with the cuts facing rearward, so they would last longer and not be too quiet.
All 3" ID, prices approximate
Flowmaster Delta 50............. $100
Pacesetter Monza tip............ $50
7" 45 degree mandrel bends... $30 each!
12" resonators..................... $20 each
~thread~start~
Last edited by PorKen; 09-19-2003 at 02:39 PM.
08-30-2003, 05:15 PM
#2
So, where's the cat's and 02?
I looked at the 3" route but even with the resonance (THUD, THUD, THUD)
not being considered I was worried about :
1. The heat issue as we don't have heat shields running the length of the pipe.
2. As the increase in diameter of 1/2" over the 2 1/2 " system was significant I was concerned theat the hangers, or, Pipes, or muffler/cats
would hang down in harms way and at the least would look ugly.
Your system seems ok, and doesnt look bad at all.
I wish I had the Monza tips but would have had to wait for a week to get them.
Did you put the resonator on to cut the DB's?
I know before I added mine backing off at speed -while it was a hoot- would attract cops across the county. Not a good thing.
If you start getting resonance/ rattle problems you might have to add a couple of those Euro - bungee- hangers at odd places on the system.
Rumble on Bro.
PS
I run an auto, too.
I didn't dyno or anything but I believe I lost just a little on the bottom end and picked up a little mid-range.
I looked at the 3" route but even with the resonance (THUD, THUD, THUD)
not being considered I was worried about :
1. The heat issue as we don't have heat shields running the length of the pipe.
2. As the increase in diameter of 1/2" over the 2 1/2 " system was significant I was concerned theat the hangers, or, Pipes, or muffler/cats
would hang down in harms way and at the least would look ugly.
Your system seems ok, and doesnt look bad at all.
I wish I had the Monza tips but would have had to wait for a week to get them.
Did you put the resonator on to cut the DB's?
I know before I added mine backing off at speed -while it was a hoot- would attract cops across the county. Not a good thing.
If you start getting resonance/ rattle problems you might have to add a couple of those Euro - bungee- hangers at odd places on the system.
Rumble on Bro.
PS
I run an auto, too.
I didn't dyno or anything but I believe I lost just a little on the bottom end and picked up a little mid-range.
08-30-2003, 05:38 PM
#3
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John Struthers,
Cat, sensor, and the entire factory exhaust are stored safely in the garage for the bi-yearly e-mishun test!
I removed all the heat shields but made sure to leave a minimum of 1" air space between the exhaust and the car. The larger exhaust pipes actually run cooler as the exhaust doesn't hang around long in there (especially without the cat).
There are actually two resonators to knock the Db level down. If I had installed them with the cuts facing towards the engine (normal way) they would be a lot quieter (but would burn out/fill up carbon sooner/flow slightly less)
There are no rattles with only the one joint and the factory hangers balance the weight quite well.
With the 'race' pipe, loose items in the rear interior are what rattles (annoying)!
You might check if the idle switch (lower) on the throttle body works/adjusted properly as this cuts fuel when you lift off the throttle and helps with the popping.
I disconnected mine cuz I like the burble, and with the automatic it drives smoother without the cutout.
Cat, sensor, and the entire factory exhaust are stored safely in the garage for the bi-yearly e-mishun test!
I removed all the heat shields but made sure to leave a minimum of 1" air space between the exhaust and the car. The larger exhaust pipes actually run cooler as the exhaust doesn't hang around long in there (especially without the cat).
There are actually two resonators to knock the Db level down. If I had installed them with the cuts facing towards the engine (normal way) they would be a lot quieter (but would burn out/fill up carbon sooner/flow slightly less)
There are no rattles with only the one joint and the factory hangers balance the weight quite well.
With the 'race' pipe, loose items in the rear interior are what rattles (annoying)!
You might check if the idle switch (lower) on the throttle body works/adjusted properly as this cuts fuel when you lift off the throttle and helps with the popping.
I disconnected mine cuz I like the burble, and with the automatic it drives smoother without the cutout.
08-31-2003, 04:10 PM
#4
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Slideshow showing installed clearances...
09-01-2003, 08:45 PM
#6
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Thanks drnick!
I just came back from a drive with the 'race' pipe. I gotta tell you, it's addicting! It is fairly rumbly up to about 1800RPM where the Flowmaster starts to do it's job. From there it actually mellows out.
There is a flat spot between 25 and 35 MPH in second but first goes all the way to 60, so I have to force myself to downshift 'down there'. There is no restriction above 4000 and it just goes and goes, wow!
I went up this steep road called 'GermanTown' which is all 10 to 15MPH corners, in first all the way. All power, from 2500 to 4500RPM with the most beautiful roar you can imagine.
I definately have to get my eBay LSD installed, these tight corners really show the inside spin problem.
The 'neighbor friendly' pipe's resonators calm the noise in the low rpm's, especially on takeoff (where it makes the most noise) but is 20lbs heavier. The idle note is about the same as the neighbor's '84 'vette, with single cat into dual 2 1/4" pipe and dual flowmasters.
I just came back from a drive with the 'race' pipe. I gotta tell you, it's addicting! It is fairly rumbly up to about 1800RPM where the Flowmaster starts to do it's job. From there it actually mellows out.
There is a flat spot between 25 and 35 MPH in second but first goes all the way to 60, so I have to force myself to downshift 'down there'. There is no restriction above 4000 and it just goes and goes, wow!
I went up this steep road called 'GermanTown' which is all 10 to 15MPH corners, in first all the way. All power, from 2500 to 4500RPM with the most beautiful roar you can imagine.
I definately have to get my eBay LSD installed, these tight corners really show the inside spin problem.
The 'neighbor friendly' pipe's resonators calm the noise in the low rpm's, especially on takeoff (where it makes the most noise) but is 20lbs heavier. The idle note is about the same as the neighbor's '84 'vette, with single cat into dual 2 1/4" pipe and dual flowmasters.
