I'd like to mod my exhaust, but it must be legal

[MuRCieLaGo]

Hi,

I'm pretty much an expert regarding the road laws where I live, especially regarding exhaust systems.

1. We do not have emission tests, never.
2. Our primary concern is the noise, it is measured by the police officer's ear only (sonometer has no value in court).
3. Police officer usually goes under the car to take some pictures of the modified exhaust system, if he suspects it is too loud. I don't think he'll be able to do that with my ZR-1 (too low and he is not allowed to use a jack).
4. I live in a 50,000 people city, nearest ZR-1 except mine is 200 miles away. So the police officers have no idea how loud a ZR-1 should sound.

Rule #1: I don't want to be harassed by police officers.
Rule #2: I want to mod my exhaust performance-wise.
Rule #3: A bit louder than OEM should be OK, they don't know the OEM sound of a ZR-1.

Project:

I want to install headers and I want to empty the catalytic converters.

Do you think it will much more noisy doing that?

I would like to simply install a full exhaust system, but I can't because it is much louder for sure (and it would have that aftermarket look). If you know an exhaust system that is as loud as the OEM (or less), everything would be fine buying it. But I don't think it exists.

Sorry about all the threads I've been posting lately, I just have too much free time now and I'd like to work as much as I can on the car.

[We Gone]

If you install headers you will do away with the cats as the stock cats are part of the stock exhaust manifold, headers you would have to add them aftermarket. The late model stock set-up flows better.
Everyone has their preference as to exhaust choice, Personally I like the sound of the old flowmaster best and have them on my 93, I have Corsa on my 91 for better flow. Both will pass sound laws but the Corsa is loud at WOT.

http://www.zr1specialist.com/HAT%20Web/presentations/A%20Review%20of%20ZR-1%20Exhaust%20Systems.pdf

[Gunny]

a few thoughts ...

Since you don't have to deal with the emissions aspect then headers sans cats would be a good start. The SW long tubes (they might refer to them as off road) have adapters for a direct fit to the OEM exhaust. The late OEM exhaust (94 & 95, possibly earlier) will become a little louder with headers/no cats but should be within the sound limits that you're looking for.

For performance the big restriction of the OEM exhaust is the mufflers ... if you wanted the best of both worlds, consider adding electric cutouts just prior to the mufflers. The cutouts can be opened just enough to get a little more sound, closed fully for almost stock OEM sound, or opened completely to completely irritate the sound police ... i.e. I'm sure you would be cited for noise pollution at that point. You can read more about the cutouts and see some pics by searching for WarpTen's thread.

I recently had cutouts installed and Marc did some porting, removed the secondaries, burned a new chip, and did back to back dyno runs with the cutouts open and closed. The difference was 15 HP at the wheels from closed to open and yes, I'm very pleased. As far as I'm concerned cutouts should have been a factory option.

There are several 3rd party solutions for the cat-back exhaust (or in your case attached to the headers). There are plenty of threads on this topic and no one correct answer. Beauty is in the ears of the beholder. Just remember that the greater the performance, the louder the sound so you will have to find the balance that works for you and your local regulations.

If you're not in a hurry I would recommend that you attend a gathering where several ZR-1's can be heard so that you can listen for yourself. The next big gathering that I'm aware of will be in Bowling Green in May, 2016. Hope to see you there.

[MuRCieLaGo]

We_Gone thanks for the article, very interesting stuff there.

I don't care if it is loud at WOT or partially opened throttle. Needs to be quiet only at idle.

Not super interested by the electric cutouts Gunny, as I like to have a car as simple as possible. Good to know that the mufflers are the big restriction of the exhaust system. I'd love to go to Bowling Green but I live in Canada which makes it quite complicated...

On my RX-7 I bought a resonated midpipe and I welded a plate under it so it looks like OEM.

I'll try to find some sound clips of different ZR-1 exhaust systems...

Thanks guys!

[MuRCieLaGo]

I just found some sound clips on YouTube.

OBX
https://www.youtube.com/watch?v=9Btec_YDAfs

vs.

5ABIVT's SW headers/Corsa Exhaust
https://www.youtube.com/watch?v=yfLcyPJZpS0

5ABIVT's is WAY too loud, however the OBX seems to have a very quiet sound, which would be perfect. Can't find any deep review on the OBX headers/exhaust system on here though...

Important question: does it say "OBX" on top of the tip?

Thanks!

[RussMcB]

I don't think that headers or lack of cats will add much noise. The biggest factor will be the mufflers you choose (and/or the resonator, too, if used).

When does an officer listen to the car to determine if it is too loud? Is it after they've heard you on the street and they thought it was too loud? If yes then I think you should also be concerned about WOT sound.

Personally, I really like the cut-out option. It's the best of both worlds. I'm not surprised Gunny is happy with his. But I do agree it adds complexity.

[MuRCieLaGo]

RussMcB yes it's after they heard me on the street, but "official" ear measurement is done at idle.

But now wait...

I just found out that my ZR-1 doesn't have the stock exhaust. I think it is Borla.

http://i841.photobucket.com/albums/zz332/TiGarsRotatif/20151111_1829101.jpg

It has a very stock look (very dirty, not shining at all) and most of the police officers have seen the car now. So I guess I can simply buy some headers. Do you have headers to suggest or cheap OBX headers are OK?

[We Gone]

Yes they look to be Borla

Cat back flowmaster Stock manifolds and cats.

https://www.youtube.com/watch?v=7gsYgGZN1fY

Same car headers cats and Corsa.

https://www.youtube.com/watch?v=delqgeptb2A

[efnfast]

The OBX has a little tag on the side of the tips that say OBX. I have OBX headers and exhaust. I love the sound, but it is pretty loud.

[MuRCieLaGo]

Thanks We_Gone,

efnfast, I'm surprised you say OBX is loud.

However, now I'm only looking for headers, since I just discovered I got a Borla catback.

[efnfast]

The OBX are pretty much a Stainless Works knock off, but made in China.

[MuRCieLaGo]

The OBX are pretty much a Stainless Works knock off, but made in China.

And I think that on such a dumb part, I can go cheap.

Thanks efnfast!

[Gunny]

.... However, now I'm only looking for headers, since I just discovered I got a Borla catback.

Remember ... exhaust choices are highly subjective and very personal. Choose what is best for you, not what you hear everyone else says is good or bad.

Having gone through at least 5 different systems while chasing exhaust nirvana I finally settled on headers, no cats, a stock '96 LT4 catback, and cutouts just before the mufflers.

But very possibly the best exhaust (for me) that I had before I arrived at my final destination was SW Headers, bullet cats, and Borla Challenger catback. I liked the sound a lot & was able to drive around town the way I wanted without fear of attracting a lot of unwanted attention because of noise. At one point I entertained the idea of changing the center resonator for either straight pipes or an x-pipe and then adding a flapper to one outlet of each muffler. I didn't know how to do the flapper mod but since then several of the FBI guys in the Chicago area have solved that (search the forums). Russ, who posted earlier in this thread, now owns my old Borla system, has modded it somewhat, and has indicated that he is really liking the system. Perhaps he will respond with further specifics.

[ZR1North]

I noticed you have a white car. I have heard that removing cats can lead to blackened stains on the rear bumper of light-colored cars. Something to verify and consider if this is indeed an issue. I retained cats because of emission tests in Ontario and I am very pleased with the Corsa system hooked to SW headers through the cats. It is loud at wide-open-throttle, but quite pleasant at idle and moderate acceleration. As Gunny wrote, sound is in the ear of the beholder. As for Bowling Green, it's definitely worth the trip - worth getting a passport to travel to the US if that was your concern.

[RussMcB]

Russ, who posted earlier in this thread, now owns my old Borla system, has modded it somewhat, and has indicated that he is really liking the system. Perhaps he will respond with further specifics.Yes, I'm very happy with my system. It is OBX headers, 3" pipes, no cats, StainlessWorks X-pipe and Borla mufflers. It sounds great (to me). Not too loud, not too quiet, no noticeable drone.

The SW x-pipe is very nice, but was pretty expensive (even with ZR1.net discount). I think an H-pipe would be as good, maybe better.

2.75" pipes would probably be better than 3" but the SW X-pipe was 3" so I went with that.

The Borla center resonator was ridiculously restrictive. I think the inlets and outlets snaked down to like 2" or 2.25". Hard to believe they would have used that on a bigger pipe system. It went into the trash.

[MuRCieLaGo]

Remember ... exhaust choices are highly subjective and very personal. Choose what is best for you, not what you hear everyone else says is good or bad.

Having gone through at least 5 different systems while chasing exhaust nirvana I finally settled on headers, no cats, a stock '96 LT4 catback, and cutouts just before the mufflers.

But very possibly the best exhaust (for me) that I had before I arrived at my final destination was SW Headers, bullet cats, and Borla Challenger catback. I liked the sound a lot & was able to drive around town the way I wanted without fear of attracting a lot of unwanted attention because of noise. At one point I entertained the idea of changing the center resonator for either straight pipes or an x-pipe and then adding a flapper to one outlet of each muffler. I didn't know how to do the flapper mod but since then several of the FBI guys in the Chicago area have solved that (search the forums). Russ, who posted earlier in this thread, now owns my old Borla system, has modded it somewhat, and has indicated that he is really liking the system. Perhaps he will respond with further specifics.

I know exhaust systems are some kind of an "art", but my choice is pretty simple: I want something quiet.

Talking of that center resonator, mine rattles like crazy. And yes, I'm sure it's the issue because I just kicked it tonight and the "rattling frequency" changed. I need to fix that quickly because it ruins all the sound. Any idea?

http://i841.photobucket.com/albums/zz332/TiGarsRotatif/20151111_215421.jpg

I noticed you have a white car. I have heard that removing cats can lead to blackened stains on the rear bumper of light-colored cars. Something to verify and consider if this is indeed an issue. I retained cats because of emission tests in Ontario and I am very pleased with the Corsa system hooked to SW headers through the cats. It is loud at wide-open-throttle, but quite pleasant at idle and moderate acceleration. As Gunny wrote, sound is in the ear of the beholder. As for Bowling Green, it's definitely worth the trip - worth getting a passport to travel to the US if that was your concern.

Hey Canadian friend! I mainly work in Ontario and the Shell Sarnia Fuel Dock is a well-known place for me! I got my Passport of course, problem might be that I got to work in May... :cheers:

I don't see exhaust stain on my bumper actually. Fortunately for us in Quebec we don't have to deal with that emission s...tuff.

Yes, I'm very happy with my system. It is OBX headers, 3" pipes, no cats, StainlessWorks X-pipe and Borla mufflers. It sounds great (to me). Not too loud, not too quiet, no noticeable drone.

The SW x-pipe is very nice, but was pretty expensive (even with ZR1.net discount). I think an H-pipe would be as good, maybe better.

2.75" pipes would probably be better than 3" but the SW X-pipe was 3" so I went with that.

The Borla center resonator was ridiculously restrictive. I think the inlets and outlets snaked down to like 2" or 2.25". Hard to believe they would have used that on a bigger pipe system. It went into the trash.

My main exhaust problem now is that center resonator. Got a heavy rattling problem with it. I see that OBX exhaust system on eBay simply has two straight pipes, no resonator. Would it change the sound a lot?

http://i.ebayimg.com/00/s/NDgwWDY0MA==/$(KGrHqMOKogE6ekolrj5BOsy(BtNwQ~~60_12.JPG

Thanks for everything guys, you really help me...

[MuRCieLaGo]

Hello,

I can highly recommend the Magnaflow Tru-X muffler to replace your stock resonator; simply awesome (you get a middle muffler with bigger diameter than stock for better flow with an X pipe design integrated):

http://www.magnaflow.com/products?partnumber=12468

Here is the thread for my modification:

http://www.zr1.net/forum/showthread.php?t=25422&highlight=exhaust+system

Aloha,

:cheers:

I got a Magnaflow on my other sports car and I'm happy with it so that's a good idea there, thanks! It is not possible to fix my actual resonator at the moment?

[efnfast]

Couple of things on header install.
Steering shaft interferance. The shaft may rub the headers. I shimmed the engine at the motor mounts, but wish I had dimpled the headers.
Dip stick relocation bracket. The headers interferes with the dipstick. Paul Workman makes a relocation bracket.
O2 sensor gets moved back a little. You'll need an extension for the wire.
I bought the Stage 8 bolting system, but the locks didn't fit properly. $75 wasted.

[ZR1North]

Hey Canadian friend! I mainly work in Ontario and the Shell Sarnia Fuel Dock is a well-known place for me! I got my Passport of course, problem might be that I got to work in May... :cheers:

Sounds good. Let me know if you are planning to be in Sarnia so that we can connect. Good luck with the exhaust choices. As you can see, lots of help here on the forum.

[MuRCieLaGo]

Couple of things on header install.
Steering shaft interferance. The shaft may rub the headers. I shimmed the engine at the motor mounts, but wish I had dimpled the headers.
Dip stick relocation bracket. The headers interferes with the dipstick. Paul Workman makes a relocation bracket.
O2 sensor gets moved back a little. You'll need an extension for the wire.
I bought the Stage 8 bolting system, but the locks didn't fit properly. $75 wasted.

Very good info there... And I hope I don't have to lift the engine to install the headers?

Hey Canadian friend! I mainly work in Ontario and the Shell Sarnia Fuel Dock is a well-known place for me! I got my Passport of course, problem might be that I got to work in May... :cheers:

Sounds good. Let me know if you are planning to be in Sarnia so that we can connect. Good luck with the exhaust choices. As you can see, lots of help here on the forum.

Oh yes this forum is very helpful! I'll hit you up if I get to Sarnia with the ZR-1!

[WARP TEN]

As Gunny mentioned, I have posted a lot on my exhaust cut outs. There are a couple of pictures in my albums section, and here is a link to a thread about my switch hidden under the carpet.
http://www.zr1.net/forum/showthread.php?t=25554&highlight=exhaust+cutouts

There is also one picture of the cutouts themselves. I enjoy mine. Quiet and legal when anyone is listening and straight pipes when I want it. I usually drive around with them about one third open for a little rumble and close them when I come home so my wife doesn't complain about the sound. --Bob

[RussMcB]

You don't have to lift the engine to install headers, BUT, it is very easy to do, and if you slip in a shim on the driver's side it gives you a little more clearance between the header tube and steering shaft. I had to dimple my OBX header tube to get desired clearance.

The Stage 8 bolts are kind of nice even if you don't use their locking feature. Their combo external/internal hex heads give you the option of using an allen wrench (especially nice with a ball head wrench).

Some O2 sensors have a longer harness, so no need for an extension. I think you can find the brand/model by searching here.

[MuRCieLaGo]

As Gunny mentioned, I have posted a lot on my exhaust cut outs. There are a couple of pictures in my albums section, and here is a link to a thread about my switch hidden under the carpet.
http://www.zr1.net/forum/showthread.php?t=25554&highlight=exhaust+cutouts

There is also one picture of the cutouts themselves. I enjoy mine. Quiet and legal when anyone is listening and straight pipes when I want it. I usually drive around with them about one third open for a little rumble and close them when I come home so my wife doesn't complain about the sound. --Bob

Seems to be a great system, but I don't like the idea, unfortunately.

You don't have to lift the engine to install headers, BUT, it is very easy to do, and if you slip in a shim on the driver's side it gives you a little more clearance between the header tube and steering shaft. I had to dimple my OBX header tube to get desired clearance.

The Stage 8 bolts are kind of nice even if you don't use their locking feature. Their combo external/internal hex heads give you the option of using an allen wrench (especially nice with a ball head wrench).

Some O2 sensors have a longer harness, so no need for an extension. I think you can find the brand/model by searching here.

That's definitely something that can be done as a winter project, not a late season project. At the moment I really need to find out which resonator/x-pipe is the best. Someone here said Magnaflow is the way to go for a resonated X-Pipe...

[Dynomite]

Couple of things on header install.
Steering shaft interferance. The shaft may rub the headers. I shimmed the engine at the motor mounts, but wish I had dimpled the headers.
Dip stick relocation bracket. The headers interferes with the dipstick. Paul Workman makes a relocation bracket.
O2 sensor gets moved back a little. You'll need an extension for the wire.
I bought the Stage 8 bolting system, but the locks didn't fit properly. $75 wasted.

It all depends on which Headers you are installing.
With Stainless Works Headers none of the issues you mention exist.
The O2 sensor pigtail extension comes with the Stainless Works Headers and the Stage 8 Locking Bolts fit perfectly using either a socket or allen head wrench :p

[5ABI VT]

Hi,

I'm pretty much an expert regarding the road laws where I live, especially regarding exhaust systems.

1. We do not have emission tests, never.
2. Our primary concern is the noise, it is measured by the police officer's ear only (sonometer has no value in court).
3. Police officer usually goes under the car to take some pictures of the modified exhaust system, if he suspects it is too loud. I don't think he'll be able to do that with my ZR-1 (too low and he is not allowed to use a jack).
4. I live in a 50,000 people city, nearest ZR-1 except mine is 200 miles away. So the police officers have no idea how loud a ZR-1 should sound.

Rule #1: I don't want to be harassed by police officers.
Rule #2: I want to mod my exhaust performance-wise.
Rule #3: A bit louder than OEM should be OK, they don't know the OEM sound of a ZR-1.

Project:

I want to install headers and I want to empty the catalytic converters.

Do you think it will much more noisy doing that?

I would like to simply install a full exhaust system, but I can't because it is much louder for sure (and it would have that aftermarket look). If you know an exhaust system that is as loud as the OEM (or less), everything would be fine buying it. But I don't think it exists.

Sorry about all the threads I've been posting lately, I just have too much free time now and I'd like to work as much as I can on the car.

My .02 on the subject :)

One setup I loved on my 93 LT1 car was longtube headers, no cats to factory cat back. It was loud at wot, and almost stock like in all other conditions and had 0 drone or resonance at any speed. That would be my suggestion (although with high flow cats) based on what you are looking to achieve.

regarding my car yes I do feel its loud at wot but to say its loud all the time would be an overstatement. Don't forget many of my videos on my channel are using a microphone on the back of the car to help capture the LT5s awesome engine sound. If you listen at 1:40 and beyond in the video you linked of my car.. listen to how quiet it actually is. it does NOT rumble and make noise all the time. far from it. I like to think of it as a Jekyl/hyde system where it can be quite tamed.. especially at cruise and relaxed driving and super angry on command :-D.

here is a video of me warming the tires for fun.. from my iPhone from 15 feet away. Hardly obnoxious in my opinion... You can actually hear the engine over the exhaust through most of it.

https://www.youtube.com/watch?v=keqajaZSp7g

Going with no cats may gain 1 hp but gain lots of stink and smell and will make the exhaust sound more 'raw'. Me I prefer a refined and toned sound even if it cost me some hp (admittedly a straight through system like corsa wasn't all that appealing to me but it was the silence at cruise that made me go this route along with the construction material)

I have lots of videos of just idleing and walking around the car Ill post one up for you so you can hear how it sounds from all sides. Still , my recommendation is Longtubes, high flow cats, factory cat back. It will sound much better than stock, well muffled, no drone or resonance, loud at WOT, and appear factory stock from the outside. :cheers:

[edram454]

i actually love you exhaust note so much i went and bought a corsa and had it installed with long tube headers and no cats. i have not heard it yet since my car is still at south georgia corvette but i will be picking it up in a week. corsa is the best exhaust i have heard. i removed my flowmaster force system. i found the resonator was very restrictive along with the three chamber flowmaster mufflers.

it was the sound of your car that made me go out and buy the corsa. i cant wait to hear it and with additional engine porting and a fidanza flywheel i should see more power along with more sound.

ed ramos #3028

[MuRCieLaGo]

It all depends on which Headers you are installing.
With Stainless Works Headers none of the issues you mention exist.
The O2 sensor pigtail extension comes with the Stainless Works Headers and the Stage 8 Locking Bolts fit perfectly using either a socket or allen head wrench :p

Very good to know, but the SW headers are way, way more expensive. I think the OBX are worth the PITA...


My .02 on the subject :)

One setup I loved on my 93 LT1 car was longtube headers, no cats to factory cat back. It was loud at wot, and almost stock like in all other conditions and had 0 drone or resonance at any speed. That would be my suggestion (although with high flow cats) based on what you are looking to achieve.

regarding my car yes I do feel its loud at wot but to say its loud all the time would be an overstatement. Don't forget many of my videos on my channel are using a microphone on the back of the car to help capture the LT5s awesome engine sound. If you listen at 1:40 and beyond in the video you linked of my car.. listen to how quiet it actually is. it does NOT rumble and make noise all the time. far from it. I like to think of it as a Jekyl/hyde system where it can be quite tamed.. especially at cruise and relaxed driving and super angry on command :-D.

here is a video of me warming the tires for fun.. from my iPhone from 15 feet away. Hardly obnoxious in my opinion... You can actually hear the engine over the exhaust through most of it.

https://www.youtube.com/watch?v=keqajaZSp7g

Going with no cats may gain 1 hp but gain lots of stink and smell and will make the exhaust sound more 'raw'. Me I prefer a refined and toned sound even if it cost me some hp (admittedly a straight through system like corsa wasn't all that appealing to me but it was the silence at cruise that made me go this route along with the construction material)

I have lots of videos of just idleing and walking around the car Ill post one up for you so you can hear how it sounds from all sides. Still , my recommendation is Longtubes, high flow cats, factory cat back. It will sound much better than stock, well muffled, no drone or resonance, loud at WOT, and appear factory stock from the outside. :cheers:

I listened to your car even before I bought my car. It sounds great on my 60'' TV! :handshak:

But it is too loud for where I live. I even linked one of your videos on the 1st page of this thread. They are pretty strict here regarding exhaust noise.

Thanks for all your reviews guys!

[C4Ray]

I have lots of videos of just idleing and walking around the car Ill post one up for you so you can hear how it sounds from all sides. Still , my recommendation is Longtubes, high flow cats, factory cat back. It will sound much better than stock, well muffled, no drone or resonance, loud at WOT, and appear factory stock from the outside. :cheers:

No offense to you buddy, but I think you over did your ZR-1. The amount of money and time you invested you will never re-coup, and most people would never buy a crazy modified C4 ZR1, and IMO your Z looks almost like something made in Europe. And as I understand it, you are a Canadian Mr. Mom and stay home with time on your hands. But if you're happy, this is all that matters.

To the OP, I think Warp Ten has the best Set-up of all and his Z does not look so crazily pimped out like others here.

My $0.01 :)

[mike100]

Hi,

...

I want to install headers and I want to empty the catalytic converters.



You don't have a prayer on having a quiet car.

Even if you run stock mufflers with no cats and headers (the quietest combination) you will still find it very loud. Headers just open these engines up and the decibels increase a lot.

I did run the LS7 catalysts on the end of Watson headers with the StainlessWorks mufflers using a flap on one of the outlets. This helps IF you keep the flap closed. It is loud as hell if you open it up.

[C4Ray]

Warp Ten has the best C4 Exhaust Set-Up I have ever seen.

[MuRCieLaGo]

Well guys,

Since I've already got a Magnaflow resonator on my RX-7 and I like it, I followed HAWAIIZR-1's advice to order one for my ZR-1. Only got to find some good headers now! :)

[secondchance]

No offense to you buddy, but I think you over did your ZR-1. The amount of money and time you invested you will never re-coup, and most people would never buy a crazy modified C4 ZR1, and IMO your Z looks almost like something made in Europe. And as I understand it, you are a Canadian Mr. Mom and stay home with time on your hands. But if you're happy, this is all that matters.

To the OP, I think Warp Ten has the best Set-up of all and his Z does not look so crazily pimped out like others here.

My $0.01 :)

I beg to differ.
I believe in having fun with my car. If that involves time and money, so be it. If I wanted to invest, I would have bought stocks.
What 5AVI VT has done so far, I wouldn't call crazy modified. Not yet anyway.
Lastly, I disagree that it looks like something from Europe. Not that any European exotics look bad, Corvettes always look very american.

Life is short, do what you want and enjoy doing it. Don't care to be a caretaker for the next guy.

No offense.

[5ABI VT]

No offense to you buddy, but I think you over did your ZR-1. The amount of money and time you invested you will never re-coup, and most people would never buy a crazy modified C4 ZR1, and IMO your Z looks almost like something made in Europe. And as I understand it, you are a Canadian Mr. Mom and stay home with time on your hands. But if you're happy, this is all that matters.

To the OP, I think Warp Ten has the best Set-up of all and his Z does not look so crazily pimped out like others here.

My $0.01 :)

Lmfao no offense taken. I'm just not sure where that outburst came from. You mad bro? And for the record I work 12 hrs 7 days a week i'm no stay at home mom. Thanks for your input on resale. Never asked for it and don't care what you think nor will I ever!

Anyways was just providing input on the exhaust setup. Never claimed it to be anything special or custom or godly. Just a corsa exhaust on catted sw headers. And I was simply saying it may sound louder than it actually is because I have a microphone on the back of my car.

[C4Ray]

The Corsa brand is very viable and I like Corsa exhaust a lot but be aware that only one tip in each muffler is functional. I suppose this means one tip in each muffler is fake? Strange.

[XfireZ51]

The Corsa brand is very viable and I like Corsa exhaust a lot but be aware that only one tip in each muffler is functional. I suppose this means one tip in each muffler is fake? Strange.

The C6Z06 flapper valve does the same thing. Wi one tip closed off, it significantly reduces drone and noise. Unlike the Corsa however, I can open up the second tip by flipping a switch in my console and gain some additional HP relieving the back pressure. It also makes for a louder and deeper rumble.

[XfireZ51]

The Corsa brand is very viable and I like Corsa exhaust a lot but be aware that only one tip in each muffler is functional. I suppose this means one tip in each muffler is fake? Strange.

The C6Z06 flapper valve does the same thing. With on tip closed off, it significantly reduces drone and noise. Unlike the Corsa however, I can open up the second tip by flipping a switch in my console and gain some additional HP relieving the back pressure. It also makes for a louder and deeper rumble.

[WARP TEN]

As has been noted many times over the years, dual tip Corvette mufflers either stock, Corsa or possibly some other brands have one clearly open tip and one completely or partially closed. The closed tip is there because some portion of the muffler is a closed chamber called a Helmholz Resonator which effectively eliminates our infamous drone at one of the two most annoying frequencies or rpm points (Corsa calls them "Quarter Wave Tuners"). On older Corvette dual tip mufflers there was a small approximately 3/8" tube in the non operational tip that did flow a small amount of exhaust through the Helmholz Resonator directly from the main pipe without adversely affecting its resonance cancelling ability. Many Corvette owners over the years thought they could improve the sound by opening up the non-functional side and ended up very disappointed to discover the sound was worse and there was now resonance. There is no effort on the part of manufacturer to deceive the public with "fake" tips. The dual tip look is cosmetic and the Helmholz Resonator is there for a purpose. --Bob

[rkreigh]

The C6Z06 flapper valve does the same thing. Wi one tip closed off, it significantly reduces drone and noise. Unlike the Corsa however, I can open up the second tip by flipping a switch in my console and gain some additional HP relieving the back pressure. It also makes for a louder and deeper rumble.

this. take a look at the c6 design. the flappers allow quiet crooze

so I can offer you this buy my B&B exh, and I have a pair of c6 tips that can be grafted on.

the b&b will go for 650 plus shipping, and I need another 200 for the tips

PM me if interested.

[C4Ray]

As has been noted many times over the years, dual tip Corvette mufflers either stock, Corsa or possibly some other brands have one clearly open tip and one completely or partially closed. The closed tip is there because some portion of the muffler is a closed chamber called a Helmholz Resonator which effectively eliminates our infamous drone at one of the two most annoying frequencies or rpm points (Corsa calls them "Quarter Wave Tuners"). On older Corvette dual tip mufflers there was a small approximately 3/8" tube in the non operational tip that did flow a small amount of exhaust through the Helmholz Resonator directly from the main pipe without adversely affecting its resonance cancelling ability. Many Corvette owners over the years thought they could improve the sound by opening up the non-functional side and ended up very disappointed to discover the sound was worse and there was now resonance. There is no effort on the part of manufacturer to deceive the public with "fake" tips. The dual tip look is cosmetic and the Helmholz Resonator is there for a purpose. --Bob

Interesting response from you Bob but with all that said why is the B and B Exhaust so highly touted for the ZR-1 when in fact this system has drone that some say is very bad. Clearly Corsa has no drone but some people can't get past the non functional or fake tips. I like the Corsa but I also think stock is very good also. I'm not crazy about how the Corsa tips sticking out past the bumper where as stock does not. I love the B and B for the ZR-1 because the tips look perfect and the sound is the best but the system still has drone points and B and B has never admitted to eliminating the drone. Comments Bob?

[rkreigh]

well I'm not bob but I have a comment. there are a few variations on the B&B the old systems were more free flowing but would rattle your teeth out with drone

the newer systems went to a more restrictive muffler design which helped and they are very "streetable"

with the x pipe and headers I find them not bad at all unless you drive in 6th gear at 1500 where the engine is lugging

I've got 4.10s in the rear and anything above 1800 rpms is just fine with the x pipe and new design B&B

[RussMcB]

well I'm not bob but ...This classic joke immediately popped into my mind. I first heard it (read it) in Road & Track magazine a long time ago:

I was driving the other day and came up on a Triumph Spitfire with a license plate reading 'BOBS MG'. I yelled over to him, "Hey, that's not an MG." The driver looked back at me and said, "I'm not Bob."

I'm not sure exactly why, but I've always thought that was hilarious.

[WARP TEN]

This classic joke immediately popped into my mind. I first heard it (read it) in Road & Track magazine a long time ago:

I was driving the other day and came up on a Triumph Spitfire with a license plate reading 'BOBS MG'. I yelled over to him, "Hey, that's not an MG." The driver looked back at me and said, "I'm not Bob."

I'm not sure exactly why, but I've always thought that was hilarious.

Well I am Bob and I did once own an MG. But that's not my plate. :proud:

[Gunny]

Here's Bob's plate

http://zrwon.com/albums/plates/slides/WARP_TEN.JPG

[KFoster]

5ABI, maybe I like cars too much, but I think yours looks great. Love the wheels. As for Euro look, I guess maybe. I wasn't aware you could spend too much money on a car. Here is a pic of my Euro car. Unfortunately I sold it about this time last year to a buddy of mine that deals in Porsches and wanted it to keep for himself. Caught me at a moment of weakness. Now they have gone through the roof. On my ZR1 I have flowmaster cat back. Sounds pretty good. Not too loud. No drone. Not sure on the HP add, it was on there when I bought the car. Now the 930S was a different story. Many mods. When you got into the boost it would make a Harley pilot squirt three to four drops of pee in his chaps as you shot by.

[MuRCieLaGo]

Received Magnaflow 12468 resonator today. A bit too large, had to cut one bolt on each side. It is now installed.

The car sounds like a small V6, very quiet. Too quiet. Can't wait to get headers now.

[edram454]

:saluting:Lmfao no offense taken. I'm just not sure where that outburst came from. You mad bro? And for the record I work 12 hrs 7 days a week i'm no stay at home mom. Thanks for your input on resale. Never asked for it and don't care what you think nor will I ever!

Anyways was just providing input on the exhaust setup. Never claimed it to be anything special or custom or godly. Just a corsa exhaust on catted sw headers. And I was simply saying it may sound louder than it actually is because I have a microphone on the back of my car.

5abi I love your exhaust and sound so much I ran out and bought a corsa for my car. i think you car and your complete setup is fantastic. the sounds your car makes is the best i have ever heard from a zr1. there will be people who will be jealous or haters simply because there car doesnt sound like yours. what is there not to like in your car??? its all good and I am hoping my long tube header no cats car with a full corsa exhaust sounds the same as yours. I will be receiveing the car soon from south georgia corvette and i will let you know.

ed ramos #3028

[WARP TEN]

Catalytic converters do muffle the sound a bit. I think it makes it a smoother sound. When I was doing more in-depth research on exhaust systems way back when, I concluded that the cats reduced sound about 15%-20%. removing the cats does add a few horsepower but does change the sound a bit. I used to run mostly Corsa with cats, sometimes headers, sometime stock manifolds, but now run headers, no cats, stock exhaust. When cutouts are wide open, I don't care about the subtle difference in sound and tone!--Bob

[C4Ray]

There will be people who will be jealous or haters.

I'm not a "hater" nor am I "jealous" and for you to imply that I or others are because we disagree then you are in error Sir. I already own a C4 and other "toys" and I live part time in Brazil where beautiful approachable women are all over... The single life ... No complaints here! :)

If we can respectfully disagree. Thank you.

[RussMcB]

<snip> ... where beautiful approachable women are all over... We need to see pictures (to prove you're telling the truth).

I'm guessing no one would complain too much about that type of thread hijack.

[Hib Halverson]

Hi,

I'm pretty much an expert regarding the road laws where I live, especially regarding exhaust systems.

1. We do not have emission tests, never.
2. Our primary concern is the noise, it is measured by the police officer's ear only (sonometer has no value in court).
3. Police officer usually goes under the car to take some pictures of the modified exhaust system, if he suspects it is too loud. I don't think he'll be able to do that with my ZR-1 (too low and he is not allowed to use a jack).
4. I live in a 50,000 people city, nearest ZR-1 except mine is 200 miles away. So the police officers have no idea how loud a ZR-1 should sound.

Rule #1: I don't want to be harassed by police officers.
Rule #2: I want to mod my exhaust performance-wise.
Rule #3: A bit louder than OEM should be OK, they don't know the OEM sound of a ZR-1.

Project:

I want to install headers and I want to empty the catalytic converters.

Do you think it will much more noisy doing that?

I would like to simply install a full exhaust system, but I can't because it is much louder for sure (and it would have that aftermarket look). If you know an exhaust system that is as loud as the OEM (or less), everything would be fine buying it. But I don't think it exists.

Sorry about all the threads I've been posting lately, I just have too much free time now and I'd like to work as much as I can on the car.

If you are going to install headers and gut the catalytic converters, your engine, even with stock exhaust, will be louder under all circumstances. This is because, when you remove or gut the cats, you eliminate probably a third of the entire system's ability to attenuate sound. Also, headers, in place of the stock manifolds and shields, will radiate noise from their structure in addition to the noise coming out of the pipes.

If the standard is a law enforcement officer's "ear" with the engine at idle, you're going to need some really good aftermarket mufflers.

Lastly, you mentioned that the law enforcement agency in your area won't have a standard to judge by because they don't know how loud a ZR-1 is. I'd be careful with that assumption because that means the officer is just gong to go on his intuition. Since he won't have a "baseline", he or she is just going to decide if the system is loud or not based only on his/her idea of what "loud" is.

[Johnny5]

A lot of people told me headers do not effect the way the car sounds especially if you maintain cats. The sound part is in the resonator and mufflers. I bought OBX cat back, it was a little too quiet, heard every exhaust possible at Carlisle and than bought Corsa. I love it. I just hope when I put on my OBX with cats it won't take away from the sound I've grown to love now.