Mod To Stock Mufflers

[We Gone]

First off congrats on getting the ZR-1 on the road again. and hope the wife is doing well as the C word can be devastating.

I would hesitate to open the second side as you will get a lot of un-wanted drone. You would be better off getting aftermarket muffs or a complete system. I'm sure you will get lots of great suggestions here.

[Paddy_SP]

Originally Posted by We Gone

First off congrats on getting the ZR-1 on the road again. and hope the wife is doing well as the C word can be devastating.

I would hesitate to open the second side as you will get a lot of un-wanted drone. You would be better off getting aftermarket muffs or a complete system. I'm sure you will get lots of great suggestions here.

Many thanks for your kind sentiments! As for the exhausts - if I can't modify the stocker mufflers, I'll leave it 'as is'. Right now, other things have call over my cash resources. Here in the UK we can hunt more or less as much as we want. I can, for instance, stalk deer 365 days of the year if I want to. Mostly, however, I specialise in high-tech fox hunting. I live in deepest farming country where left unchecked foxes do enormous amounts of damage to livestock. Right now, it's lambing season, and I'm out more or less every night (although NOT in the ZR1!) using high-end thermal imaging and night vision equipment. As this all costs serious money I don't have any spare to throw at a replacement exhaust!

[Racinfan83]

I know this is not related to the topic - but you talk about hunting in the UK - I thought you weren't allowed to own guns there??

[We Gone]

You can try various sizes of opening up the other side as long as you can close it back up if you don't like it. We can only Hunt wild boars and coyotes year round or deer if you farm but all other game has seasons.

[scottfab]

Originally Posted by Paddy_SP

Many thanks for your kind sentiments! As for the exhausts - if I can't modify the stocker mufflers, I'll leave it 'as is'.
...snip...

You can in fact drill out the non-functioning side of each muffler and as mention you'll pick up a nasty resonance (drone). Of more concern is the restriction in diameter going into the front of the resonator at the front of the stock exhaust system. The welding there ends up choking the diameter to 2 1/8 in. This is a performance hit. Many of us have removed this one way or another.

Originally Posted by Paddy_SP

I live in deepest farming country where left unchecked foxes do enormous amounts of damage to livestock. Right now, it's lambing season, and I'm out more or less every night (although NOT in the ZR1!) using high-end thermal imaging and night vision equipment. As this all costs serious money I don't have any spare to throw at a replacement exhaust!

I use to hunt pest varmints here in the US in the open country of Montana. Know what you mean. There was a bounty on some species. Take some night vision pics and post if you have the mind to.

As for the head light buckets design issue and hardware placement you mentioned before, I totally agree. I'd love to write a personal letter to the designer. I have to think he was pressured into leaving it that way for redesign cost constraints. (management)

[Paddy_SP]

Originally Posted by Racinfan83

I know this is not related to the topic - but you talk about hunting in the UK - I thought you weren't allowed to own guns there??

Ha, ha - I can understand why you might think that as we're not allowed handguns. But as for rifles and shotguns, so long as we have the right paperwork, we can have almost anything except semi and full-autos. I myself have .17HMR, .204R, .22-250 and .308. Other things make up for it - screw-on moderators, for example, are easy to get permits for, so I have them on everything.

Originally Posted by We Gone

You can try various sizes of opening up the other side as long as you can close it back up if you don't like it. We can only Hunt wild boars and coyotes year round or deer if you farm but all other game has seasons.

Thank you! As for the hunting - most of our deer have seasons too (not Muntjac), but the effect of the overlaps is that we can hunt them all year. We also don't need any kind of permit beyond the landowner's permission to hunt on his ground, and we can take as many deer as we like.

Originally Posted by scottfab

You can in fact drill out the non-functioning side of each muffler and as mention you'll pick up a nasty resonance (drone). Of more concern is the restriction in diameter going into the front of the resonator at the front of the stock exhaust system. The welding there ends up choking the diameter to 2 1/8 in. This is a performance hit. Many of us have removed this one way or another.

I use to hunt pest varmints here in the US in the open country of Montana. Know what you mean. There was a bounty on some species. Take some night vision pics and post if you have the mind to.

As for the head light buckets design issue and hardware placement you mentioned before, I totally agree. I'd love to write a personal letter to the designer. I have to think he was pressured into leaving it that way for redesign cost constraints. (management)

Thanks - I think I'll pull the exhaust and have a good like at the restriction you mention.

With regard to the varmints - as we don't have coyotes or anything similar here in the UK, our red foxes grow really big. I think the record is 36 lbs. but generally the mid-20's would be considered large. If you're interested, here's a link to a book I recently wrote on hunting foxes: http://www.countrybooksdirect.com/pr.../a-foxers-year I'd love to hunt in Montana!

[WARP TEN]

Those who mention a "Drone" if you open up the closed section of the mufflers are correct. Our engines produce frequency spikes that produce noticeable and annoying resonance at two primary RPM points--1,800 and 3,400, with a less noticeable one around 2,400. The closed pipes of the earlier mufflers are closed for a reason: They are behind the Helmholtz resonators which mitigate the resonance at (I think) the 1,800 RPM point, while the center resonator handles the 3,400 point. (Or vice versa; can't quite recall). Each resonator is a closed chamber with one opening and is sized for a specific frequency. The Corsa system uses a similar feature they call quarter wave tuners, as do some others. So opening up the Helmholtz resonator would result in an unpleasant exhaust sound. Later stock mufflers have only one outlet but still retain the resonator section to combat resonance.--Bob

[Paddy_SP]

Originally Posted by WARP TEN

Those who mention a "Drone" if you open up the closed section of the mufflers are correct. Our engines produce frequency spikes that produce noticeable and annoying resonance at two primary RPM points--1,800 and 3,400, with a less noticeable one around 2,400. The closed pipes of the earlier mufflers are closed for a reason: They are behind the Helmholtz resonators which mitigate the resonance at (I think) the 1,800 RPM point, while the center resonator handles the 3,400 point. (Or vice versa; can't quite recall). Each resonator is a closed chamber with one opening and is sized for a specific frequency. The Corsa system uses a similar feature they call quarter wave tuners, as do some others. So opening up the Helmholtz resonator would result in an unpleasant exhaust sound. Later stock mufflers have only one outlet but still retain the resonator section to combat resonance.--Bob

Thanks for your helpful post, Bob - it is most appreciated!

[Gunny]

Another suggestion, assuming that it will work with any government emissions requirements that you have ...

install long tube headers, no cats, and late model stock exhaust. there is no drone, almost stock quiet in the cabin, and a decent sound (subject, I know) behind the car. My current setup is SW headers, no cats, and stock exhaust from a 96 LT4 (h-pipe behind the resonator) and it works well for me.