Never ending quest for the best C4 ZR-1 exhaust system- Stainless Works

[mike100]

Been back and forth with a few different pipe combos- but the long story made short is that the 3" all the way back with the SW 3" X-Pipe makes great top end with plenty mid range torque using LS7 cats from a C6 Z06. It is faster than the stock mufflers on 2.7" pipe without cats. It's Freaking Loud, but then running stock muffs catless on longtube headers was a bit obnoxious too. There is drone, I will probably go to turbo mufflers again when I get some more money to spend. Additionally, I really like running catalysts again. Birds don't fall out of trees when you drive by, you don't get dirty looks from the beach hippy in a Prius, and it quiets things down and quells those decel backfires quite a bit. Lastly, I priced various aftermarket bullet cats with a 3" slip connect, but how can you beat factory Cats from a 505 hp car? You can tell it is running clean, the pipes aren't even blacked up yet and there is no odor at all. OEM parts FTW.

http://i29.photobucket.com/albums/c265/mschrameck/Cars/DSC02736_zps4fe8968e.jpg

http://i29.photobucket.com/albums/c265/mschrameck/Cars/DSC02728_zps20b00906.jpg


http://i29.photobucket.com/albums/c265/mschrameck/Cars/DSC02722_zpsd0302290.jpg

http://i29.photobucket.com/albums/c265/mschrameck/Cars/DSC02734_zpse71968aa.jpg


I had recently installed some LT5 headers and I found these 2" longtubes that were already setup for air injection. These aren't SW headers, but a mystery brand- maybe made by Morrison Motorsports in GA is the best guess I have so far. Anyhow, they fit perfectly and really woke up the car.
http://i29.photobucket.com/albums/c265/mschrameck/Cars/lt5-headers_sm_zps3c4a2ec2.jpg

I was running cat-less for a couple of months after the header install (using stock mufflers), but I got tired of my eyes watering every time I pulled up to a stop light with my windows down. Since I had some oem LS7 exhaust that was a stillborn modification on my C6 that I decided to not go through with, I put those nice 3" piped cats to use. They are pretty compact and just fit under the heat shields in the tunnel.
http://i29.photobucket.com/albums/c265/mschrameck/Cars/DSC02714_zpsb358eb2e.jpg

[mike100]

Notice that we were able to retain the use of the clamping system so the pipes can be separated for service.
http://i29.photobucket.com/albums/c265/mschrameck/Cars/DSC02715_zpsc2dd80a1.jpg
http://i29.photobucket.com/albums/c265/mschrameck/Cars/DSC02720_zps53dcd6cb.jpg




..
Factory air injection still in place. Does this car even have headers?? Stealth- Because California.
http://i29.photobucket.com/albums/c265/mschrameck/Cars/DSC02733_zps29a617cd.jpg
..

Also I got a good lesson in installation technique at my local muffler place. Check out the diff clearance. Perfect 1/4" spacing at rest. My old B&B sure wasn't able to achieve this, but it does have a lot to do with jacking up the center piping in place with a jack of some kind, then tightening the clamps before letting it hang.
http://i29.photobucket.com/albums/c265/mschrameck/Cars/DSC02726_zps643aa02b.jpg


more pics:

http://i29.photobucket.com/albums/c265/mschrameck/Cars/DSC02723_zpsdcccae37.jpg

http://i29.photobucket.com/albums/c265/mschrameck/Cars/DSC02719_zps5bbbd15b.jpg

[mike100]

and the pics from the group buy thread:
http://i29.photobucket.com/albums/c265/mschrameck/DSC02704_zps70066fa2.jpg (http://s29.photobucket.com/user/mschrameck/media/DSC02704_zps70066fa2.jpg.html)

http://i29.photobucket.com/albums/c265/mschrameck/DSC02708_zps2383f92c.jpg (http://s29.photobucket.com/user/mschrameck/media/DSC02708_zps2383f92c.jpg.html)

[FU]

Real nice job Mike !

[-=Jeff=-]

Those might be Watson headers

[GOLDCYLON]

Those might be Watson headers

Concur. I would have had em coated as well but that might have not have been stealth enough for CA

Interesting rear tips really fill out that cutout

[Dynomite]

Concur. I would have had em coated as well but that might have been stealth enough for CA
Interesting rear tips really fill out that cutout

SW started shipping the Exhaust with the SW rectangular single Outlet as I installed recently on my 90' vice SW twin round pipes as I have on my 91'.
I like the looks as the New Style Outlets match the cutout perfectly :thumbsup:

Nice Photos Mike and not too many notice the gap between Exhaust and Differential but here is another idea ;)

SW Headers ZR1CORVOR and SW Exhaust ZR1CHAMSW were installed on both the 90' and 91'.

For both the 90' and 91' a Copper spacer was added (1 x 6 inch copper pipe with pipe end caps and pipe coupler) to keep SW exhaust 1/4 inch away from Differential Housing.

Copper spacer added (two each 1 x 6 inch copper pipe
with coupler and end caps) to keep SW exhaust 1/4 inch
away from riding against Differential Housing. The end caps
and coupler actually keep the spacer in place without any ties.

http://i287.photobucket.com/albums/ll142/dynomite007/A%20Corvette%20LT5%2090/74c3b050-4f4e-4410-8ec5-62a8a78ecc2a.jpghttp://i287.photobucket.com/albums/ll142/dynomite007/ZR1%20NET/31013826-ffad-45c4-a7d9-07b0159940d5.jpg

I set the two rear hangers so they pull the exaust up tight against
the copper spacer. Also set the rear "L" hanger so there is freedom
of the exhaust system to move to the rear at least 1/2 inch when hot.

[batchman]

Thanks for the tip on the Z06 cats, sounds and looks like a great answer.

Thanks for posting!
- Jeff

[emmvette]

That looks like a great set up. Thanks for sharing!

What is the reason for the drone? I've got the drone in 6th at 65-75, which is unfortunately normal cruising speeds. Is it just a resonant frequency?

Is there anything that can change this on an existing set-up? I've got a nice exhaust with headers, so no reason to spend more $ on mine.

[GOLDCYLON]

That looks like a great set up. Thanks for sharing!

What is the reason for the drone? I've got the drone in 6th at 65-75, which is unfortunately normal cruising speeds. Is it just a resonant frequency?

Is there anything that can change this on an existing set-up? I've got a nice exhaust with headers, so no reason to spend more $ on mine.


I would hazard to guess lack of a resonator

[XfireZ51]

That looks like a great set up. Thanks for sharing!

What is the reason for the drone? I've got the drone in 6th at 65-75, which is unfortunately normal cruising speeds. Is it just a resonant frequency?

Is there anything that can change this on an existing set-up? I've got a nice exhaust with headers, so no reason to spend more $ on mine.

Here in FBIland, we 've been using the Z06 exhaust control valve. It seems GM decided it was cheaper and weighed less than a resonator to control drone at cruising speeds (on mine that's anywhere from 1400-1800 rpm). I think there are several factors that can help mitigate drone:

1. A too flabby (rich) tune will give the exhaust more of a blub blub blub sound particularly on an incline when the MAP goes higher and RPMs drop.
I like a bit of a leaner AFR for cruise. Found it tightens up the exhaust sound bringing it into a higher frequency.

2. I think the double walled construction of tips like the Z06, Corsa, MagnaFlow also help. The exhaust opening of these tips is shaped more like a trumpet while the outer portion of the tip is cylindrical. IMO, this cuts down any resonating the tip would generate. The B+B for example are single wall. AL has driven my car and BobGs car, different CIDs but both using the Z06 tips. Meanwhile Pete and Al use the B+B tip w the control valve.
AL has noticed that even tho each car uses the control valve, Bob's and mine seem quieter and less resonance.

3. I think the tips should extend at least just a bit past the rear valence panel. This avoids dumping the exhaust towards the rear panel and setting up a resonance.

The above are strictly based on observations involving my car and some of the other FBI ZRs. Your results may vary. Also, I have used:
1. stock exhaust
2. B+B 3rd Gen
3. Magnaflow C4 catback both w and w/o resonator
4. SW Xpipe w Magnaflow mufflers and tips/no resonator
5. Current system is Watson headers, 3" SS pipe, SW Xpipe, DynoMax
Ultraflow muffs w Z06 tips and exhaust control valves. I have posted vids of the exhaust previously.

[tomtom72]

Sahweeeeet! Nice job Mike! The tips are killer and thanks for the install tips.

Man those OE ZO6 cats look like our cats. Are they brick or spun s/s?

To many miles of smiles! Here's to ya! :cheers:

Tom

[mike100]

Sahweeeeet! Nice job Mike! The tips are killer and thanks for the install tips.

Man those OE ZO6 cats look like our cats. Are they brick or spun s/s?

Tom

They look to be typical oem substrate (brick) internally with a tight pattern that looks restrictive, but they work pretty well on a 7 liter Z06 and they are compact. My other theory is that oem Cats usually have more of the rare earth metals and work better than the typical universal. I forgot to take a camera when we cut the cats out of the factory mid-pipe, but they look like the honeycomb on the LT5 cat and pretty much the same as an LS2/LS3 cat if you have ever seen one. As a matter of fact, I have a pair of those also (much easier to buy as take-offs). They are sort of a flat package with a 2.5" pipe inlet. I suppose you could maybe use those adapted to a Corsa catback, but the shape might not lend itself well to fitting underneath the slave cylinder.

[mike100]

Concur. I would have had em coated as well but that might have been stealth enough for CA


Bingo

I'm also considering dually out with a pair of conventional tips because the best way to make these c4's stop resonation from the back hatch area seems to be stopping up dual outlets to a single one...like Corsa's do and GM as well with the factory fake 2nd outlet. I think it's about time to figure out how to get the NPP valve hooked up on my car. Also very likely will go to some quieter muffler type as mentioned in my first post.

The main question I have on GM's NPP system is what controls the valves to open up at roughly 3500 rpm besides low manifold vacuum? If there is electronic control, how do you adapt it to older cars?

[vilant]

Wow, sweet job:thumbsup:. Have any video of how the new exhaust sounds?

[XfireZ51]

Bingo

I'm also considering dually out with a pair of conventional tips because the best way to make these c4's stop resonation from the back hatch area seems to be stopping up dual outlets to a single one...like Corsa's do and GM as well with the factory fake 2nd outlet. I think it's about time to figure out how to get the NPP valve hooked up on my car. Also very likely will go to some quieter muffler type as mentioned in my first post.

The main question I have on GM's NPP system is what controls the valves to open up at roughly 3500 rpm besides low manifold vacuum? If there is electronic control, how do you adapt it to older cars?


The exhaust valve is controlled by vacuum. They are closed at idle and open up approaching WOT. The valves are controlled using the Charcoal Canister vacuum line. You can go further and install an electronic control to allow vacuum to pass or not. Should be pretty simple to install although I don't see a need for it.

[mike100]

Wow, sweet job:thumbsup:. Have any video of how the new exhaust sounds?

I'll try to make something on Saturday when I return home. It does sound great when you are going for a 10 mile drive to open it up and play, but difficult to travel a highway in for any length of time in 6th gear.

[mike100]

The exhaust valve is controlled by vacuum. They are closed at idle and open up approaching WOT. The valves are controlled using the Charcoal Canister vacuum line. You can go further and install an electronic control to allow vacuum to pass or not. Should be pretty simple to install although I don't see a need for it.

The reason I ask is because I wouldn't want it to work below 4000 rpm or so. I took a spin in a friends C6 and kind of disliked how much attention the extra noise brought me. My C6 doesn't have that option. I found it distracting (along with the HUD too).

[BigJohn]

What's New?

[KFoster]

Good info. I bought mine with a two into one big flowmaster, then two out and the pipes split into dual tips each side. Sounds surprisingly good. I usually don't care for mixing the exh like that. Many times it sounds like a UPS truck. I've been looking around to see what is out there in stainless. Might even change to long tube headers. Your pics look really good.


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[BigJohn]

I like the sound of the UPS truck!

[Hog]

I like the sound of the UPS truck!
Some of the car mags used to describe the sound of a Viper exhaust as the same as a UPS truck with a plug wire disconnected.

[gtcollins@maxnet.co.nz]

https://uploads.tapatalk-cdn.com/20170528/63bc3d454ef6c42cc6063433bc0d2eed.jpghttps://uploads.tapatalk-cdn.com/20170528/fc6788455631a2f8bed9eebabd294a3a.jpg
Hi this is my headers have just made them and will be getting them ceramic coated as well Glen Collins

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[Dynomite]

https://uploads.tapatalk-cdn.com/20170528/63bc3d454ef6c42cc6063433bc0d2eed.jpghttps://uploads.tapatalk-cdn.com/20170528/fc6788455631a2f8bed9eebabd294a3a.jpg
Hi this is my headers have just made them and will be getting them ceramic coated as well Glen Collins

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Glen.........Appears you have solved the issues of equal runners each side between exhaust ports and collector. Let us know how Drone is effected and the overall sound at various rpms.

With equal runners, rpm effects on sound is taken out of the picture it would seem.

These Headers will fit a ZR-1 clearing the steering and chassis?

Are the inside clean at the welds?

[gtcollins@maxnet.co.nz]

Glen.........Appears you have solved the issues of equal runners each side between exhaust ports and collector. Let us know how Drone is effected and the overall sound at various rpms.

With equal runners, rpm effects on sound is taken out of the picture it would seem.

These Headers will fit a ZR-1 clearing the steering and chassis?

Are the inside clean at the welds?
Hi Craig
Here's photos of what the inside of the pipes look like and also a photo of the stearing clearance I am waiting for a shipment of parts from the state's to arrive should be here end of June then I will start to assemble the ZR-1 I am using flow master 50 series muffler 3" in and twin 2.5" outlet I am a little worried it might be to loud
Regards Glen https://uploads.tapatalk-cdn.com/20170530/53920cf38a8837d03943df108cda4e62.jpghttps://uploads.tapatalk-cdn.com/20170530/b6151f648b4115b77e9739f13362d0f6.jpghttps://uploads.tapatalk-cdn.com/20170530/4fb588ef6fffd76eef418f2cccea19d4.jpg

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[gtcollins@maxnet.co.nz]

Hi Craig
Here's photos of what the inside of the pipes look like and also a photo of the stearing clearance I am waiting for a shipment of parts from the state's to arrive should be here end of June then I will start to assemble the ZR-1 I am using flow master 50 series muffler 3" in and twin 2.5" outlet I am a little worried it might be to loud
Regards Glen https://uploads.tapatalk-cdn.com/20170530/53920cf38a8837d03943df108cda4e62.jpghttps://uploads.tapatalk-cdn.com/20170530/b6151f648b4115b77e9739f13362d0f6.jpghttps://uploads.tapatalk-cdn.com/20170530/4fb588ef6fffd76eef418f2cccea19d4.jpg

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Hi Craig
A couple more things the pipes are unequal in length and here is photos of the tail pipes I have made
Glen https://uploads.tapatalk-cdn.com/20170530/fbc696f1464122e23074d9b20161d5b4.jpghttps://uploads.tapatalk-cdn.com/20170530/44c74f6c68ba54681b0be73500c6fe18.jpg

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[rush91]

Wow, it looks like someone can fabricate from scratch......that is impressive sir! I love those exhaust tips and that license plate. I hope you can post some videos when its all back together! Nice job

[GOLDCYLON]

Some of the car mags used to describe the sound of a Viper exhaust as the same as a UPS truck with a plug wire disconnected.





LOL accurate !!!

[gtcollins@maxnet.co.nz]

Hi I will have a go at a video it's taken me quite while to figure out how to post the photos Glen

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[Roadster]

Glen, great job...they look fantastic....
IMO, you should be fine with the Flowmaster 50's. I had one on my '03 SSR, and it had a great sound, with no drone.
Again, nice work!!!


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[rush91]

Hi I will have a go at a video it's taken me quite while to figure out how to post the photos Glen

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No worries....I'd just love too hear that setup after you finish. And those exhaust tips look factory, very nice!! Thanks for posting :)

[Roadster]

Glen, great job...they look fantastic....
IMO, you should be fine with the Flowmaster 50's. I had one on my '03 SSR, and it had a great sound, with no drone. The 40 series is loud, the 50 series is more mellow.
Again, nice work!!!


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[gtcollins@maxnet.co.nz]

Hi Thanks for the kind comments the exhaust tips I made a mandrel and press them over Glen

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[rush91]

LOL accurate !!!



Very accurate!! I remember wanting a 1996 GTS Viper, and then hearing the exhaust note. Yikes!

[jss06c6]

Running full SW system on my '91, headers to tips.. Yes, there is drone at about 1700 rpm with light load. I'm going to add some sound insulation this winter below rear deck and rear quarter panels. Hope to settle it a bit. It's not bad, but would like the interior cruising sound level I had on my 2006 LS2, which was running LG headers and Corsa Sport exhaust from there back.

I do have high flo metal matrix cats on my LT-5... this exhaust sounds phenomenal under load and the idle note is very nice..

[gtcollins@maxnet.co.nz]

Hi Thanks for the kind comments the exhaust tips I made a mandrel and press them over Glen

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Hi here is a couple of photos of the exhaust have just finished welding it together https://uploads.tapatalk-cdn.com/20170605/111f8ea1f37869f308ad99175a110c45.jpghttps://uploads.tapatalk-cdn.com/20170605/fd39d7c39fb08dd1261177eb26174a4c.jpg
Regards Glen

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[Roadster]

Glen, that is one nice looking system....I'll be right over with the 94...:)

[gtcollins@maxnet.co.nz]

Glen, that is one nice looking system....I'll be right over with the 94...:)
Looking forward to seeing you (and the ZR-1)

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[gtcollins@maxnet.co.nz]

Looking forward to seeing you (and the ZR-1)

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Hi All have just got the headers back today after having them ceramic coated https://uploads.tapatalk-cdn.com/20170814/cb0063345e46ca6b30efe22764ca52d7.jpg

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[S.hafsmo]

That looks insane. It's a shame they're so hard to see when installed.

[USAF Retired]

Headers look very nice, wow.

[Bob Eyres]

The older these cars get, the better they look. Just look at that butt...even the new ones can't compare....especially the new ones.


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[Bob Eyres]

BTW, I'm pretty sure those headers are old Watson's like mine, exactly the same except for the oxy sensor bung placement. Check inside collector, mine had gaps in some welds and had to be redone.


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[gtcollins@maxnet.co.nz]

BTW, I'm pretty sure those headers are old Watson's like mine, exactly the same except for the oxy sensor bung placement. Check inside collector, mine had gaps in some welds and had to be redone.


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Hi Bob I have just finished making my own headers
Glen

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[gtcollins@maxnet.co.nz]

Hi here is a link to a video of my car running
Earlier in the day I got this engine running first time the engine has run since 1995
Regards Glen
https://youtu.be/gZmNqKtO4wc

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[XfireZ51]

A little blue oil smoke on accel?