Muffler Bypass for a 1983
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Joined: Dec 2011
Posts: 70
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From: Richmond, Virginia
Muffler Bypass for a 1983
After doing some research, I have discovered that a muffler bypass system will not work on a 1983. I am hoping for that same kind of sound, even though my 1983 sounds fairly decent now. After all, what's the point of having a v-8 without it sounding great?
Anyway, does anyone know why a bypass system is incompatible with the earlier cars?
Second, any suggestions on a great sounding exhaust, even if it is not a bypass?
Thanks!
Bradster928
Anyway, does anyone know why a bypass system is incompatible with the earlier cars?
Second, any suggestions on a great sounding exhaust, even if it is not a bypass?
Thanks!
Bradster928
Race Car
Joined: Jul 2005
Posts: 4,794
Likes: 92
From: Mechanochondriacism
You could leave the final muffler for the time being and install an x pipe and high flow cats to start- it will add more volume and better performance.
Or, you can have a custom exhaust shop fabricate a pipe to fit in lieu of the final muffler. No great shakes, the bypasses are a couple of bent/formed pipes/tubes.
Or, you can have a custom exhaust shop fabricate a pipe to fit in lieu of the final muffler. No great shakes, the bypasses are a couple of bent/formed pipes/tubes.
Burning Brakes
Joined: Jan 2007
Posts: 1,117
Likes: 2
Bradster the early cars the final muffler does about 75% or so of all the noise reduction so installing a straight pipe is usually too loud and obnoxious for most. That is especially true if you are running catless. Remember it is all too easy to miss the "european sound" and end up sounding like a rusted out old Mustang. Besides more noise is NOT more power just more noise 
and often gets you "attention" from the boys in blue ! Any exhaust shop could cut off the muffler and fab up a bypass just be sure they cut it so you can get it welded back on if you change your mind or wish to sell the car someday.
and often gets you "attention" from the boys in blue ! Any exhaust shop could cut off the muffler and fab up a bypass just be sure they cut it so you can get it welded back on if you change your mind or wish to sell the car someday.
Race Car
Joined: Jul 2005
Posts: 4,794
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From: Mechanochondriacism
I agree with Brutus' comments.
You could always just do this:
http://www.ebay.com/itm/928-Borla-Ex...item2317e503d8
928 Intl was a retailer, not sure whether they still have/stock them.
You could always just do this:
http://www.ebay.com/itm/928-Borla-Ex...item2317e503d8
928 Intl was a retailer, not sure whether they still have/stock them.
Drifting
Joined: Sep 2010
Posts: 2,355
Likes: 188
From: Oakland CA
Interesting comments by all and I am perplexed as well
I just bought a Magnaflow which I am thinking of replacing the pumpkin with and eliminating the middle muffler, keeping a Magnaflow cat coming out of the MSDS headers thru a Y pipe. Not sure if all of this will work or what it will sound like.
Also has anyone had the system form the headers back welded up at the muffler shop off of the car?
I just bought a Magnaflow which I am thinking of replacing the pumpkin with and eliminating the middle muffler, keeping a Magnaflow cat coming out of the MSDS headers thru a Y pipe. Not sure if all of this will work or what it will sound like.
Also has anyone had the system form the headers back welded up at the muffler shop off of the car?
Advanced
Joined: Nov 2011
Posts: 64
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From: Northern NSW, Australia
On my 1981 non-S, I removed my rear pumpkin and had it replaced with just a tailpipe. So I still have front and mid mufflers, and that's it.
It sounds nice. Not loud on mine at all, in fact it's still muted until you rev it quite hard and then it sounds like it...
Mind you, I did have a rather bizarre tip welded on that I didn't notice at the time, and am now too embarassed to photograph!
It sounds nice. Not loud on mine at all, in fact it's still muted until you rev it quite hard and then it sounds like it...
Mind you, I did have a rather bizarre tip welded on that I didn't notice at the time, and am now too embarassed to photograph!
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Rennlist Member
Joined: May 2003
Posts: 8,706
Likes: 153
From: Frankenmuth, Michigan
Steve,
Since you just bought the car, my humble suggestion is to stay focussed on the mechanical end.
Base on the budget you mentioned, and having a shop do the work... you will use up all of that (highly likely, more) just to make the car operate reliably.
There are alot of fun things to do to these cars, but they eat up money (and your time) as well.
I would focus your efforts (outside of the shop) on the electrics. Big gains can be made there with low impact on your wallet.
Sorry to be such a buzzkill, just trying to help.
Since you just bought the car, my humble suggestion is to stay focussed on the mechanical end.
Base on the budget you mentioned, and having a shop do the work... you will use up all of that (highly likely, more) just to make the car operate reliably.
There are alot of fun things to do to these cars, but they eat up money (and your time) as well.
I would focus your efforts (outside of the shop) on the electrics. Big gains can be made there with low impact on your wallet.
Sorry to be such a buzzkill, just trying to help.
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Racer
Joined: Nov 2010
Posts: 253
Likes: 34
From: Central Va
I also have an 83 auto and my next step is to get the y-pipe from 928 motorsports and add either their high flow cat or a Magnaflow high flow cat. Leaving the pumpkin. My understanding is that this will tune the exhaust note a little closer the 32v models exhaust note plus increase the flow and a few hp's.
With the combo from 928 MS you should not have to make any modifications to the existing pipes either.
I think that will be plenty loud. I already have sound deadening in the rear floor and a 10 in sub in order to hear bass ! I mostly listen to the exhaust but on longer trips the music is a nice break.
Good luck!
With the combo from 928 MS you should not have to make any modifications to the existing pipes either.
I think that will be plenty loud. I already have sound deadening in the rear floor and a 10 in sub in order to hear bass ! I mostly listen to the exhaust but on longer trips the music is a nice break.
Good luck!
Drifting
Joined: Sep 2010
Posts: 2,355
Likes: 188
From: Oakland CA
If you notice the tips on the pumpkin come out more towards the side of the car
and many shops run the tips more straight back. I would think that to the drivers ear
you should pay attention to where you route the tips. My guess is Porsche ran the tips more to the side to appease the driver as well as keep the sound legal. Remember Porsche was wrestling with the Feds on sound in the mid 70's with the 911's.
One of the reasons for a water cooled motor
and many shops run the tips more straight back. I would think that to the drivers ear
you should pay attention to where you route the tips. My guess is Porsche ran the tips more to the side to appease the driver as well as keep the sound legal. Remember Porsche was wrestling with the Feds on sound in the mid 70's with the 911's.
One of the reasons for a water cooled motor
Rennlist Member
Joined: Feb 2009
Posts: 1,202
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From: Gainesville, FL
The exhaust on my car is on my to-do list probably for 2013 (have other projects in higher priority).
I've done a lot of forum searching on this and it seems like the best overall exhaust set-up recipe for normally aspirated 16V cars is are the 32v manifodls (or MSDS headers), y-pipe, and single 3-inch exhaust with a flow-through muffler (like Magnaflow). This is the route I will probably go since the PO already had the 928 Motorsports y-pipe on the car when I bought it.
But there has been very little posted in terms of before and after dyno testing with specific setups.
Also, when I've fabricated exhausts for some of my other cars I've usually bought aluminized exhaust mandrel bends from JCWhitney and been able to piece together a decent mandrel bent system. You can also buy them from Jegs, but JCW was a little less expensive. Good quality pieces too - no issues with that method. It really seems to be the only option on 16V cars since there don't seem to be any good aftermarket systems for the early cars anymore.
I've done a lot of forum searching on this and it seems like the best overall exhaust set-up recipe for normally aspirated 16V cars is are the 32v manifodls (or MSDS headers), y-pipe, and single 3-inch exhaust with a flow-through muffler (like Magnaflow). This is the route I will probably go since the PO already had the 928 Motorsports y-pipe on the car when I bought it.
But there has been very little posted in terms of before and after dyno testing with specific setups.
Also, when I've fabricated exhausts for some of my other cars I've usually bought aluminized exhaust mandrel bends from JCWhitney and been able to piece together a decent mandrel bent system. You can also buy them from Jegs, but JCW was a little less expensive. Good quality pieces too - no issues with that method. It really seems to be the only option on 16V cars since there don't seem to be any good aftermarket systems for the early cars anymore.
Rennlist Member
Joined: Nov 2008
Posts: 826
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From: Park Hills, KY
I recently posted a thread asking for advise about 16V and headers. read lots of threads but all the real advice was for 32V cars. basically headers/exhaust mods on a stock 16V may only get you 15hp. now if you put on a SC, need to open up the exhaust to get all that extra volume out the back to avoid too much back pressure. also some comments about the more you open up the exhaust on a 16V you may loose some low end torque but gain HP in the upper RPM range. from talking to one supplier, due to the limited benefits the 16V crowd are not inclined to spend much on exhausts so a lack of incentive to invest in offering the range of options as for the 32V.
I cobbled together a CAT back for my 84 last year. I got a Y from Roger to replace my CAT due to exhaust leaks. results were a bit loud but the big issue I encountered was the sound. seems the pumpkin baffles had rusted out, even though no leaks. all I can say is my exhaust note sounded like it exited through an empty garbage can. replace pumpkin with small aftermarket and the resonator with a round magnaflow. now great sound.
PS. tacked on my pumking heat shield to prevent damage to the bumper cover.
recently got a set of MSDS headers to install this winter. I agree with Chris, seems the best suggestion for 16V cars is 85/86 or header into a Y then 3" all the way back.
going to get the headers installed and collectors to figure out how to fab the rest.
good luck to ALL of us in our quest for more HP and great sound.
I cobbled together a CAT back for my 84 last year. I got a Y from Roger to replace my CAT due to exhaust leaks. results were a bit loud but the big issue I encountered was the sound. seems the pumpkin baffles had rusted out, even though no leaks. all I can say is my exhaust note sounded like it exited through an empty garbage can. replace pumpkin with small aftermarket and the resonator with a round magnaflow. now great sound.
PS. tacked on my pumking heat shield to prevent damage to the bumper cover.
recently got a set of MSDS headers to install this winter. I agree with Chris, seems the best suggestion for 16V cars is 85/86 or header into a Y then 3" all the way back.
going to get the headers installed and collectors to figure out how to fab the rest.
good luck to ALL of us in our quest for more HP and great sound.
