Cats

[hognutz]

Originally Posted by toilets

So radz, from strictly a sound perspective, what would you feel will boast the loudest sound while maintaining the stock mufflers (I like the valve idea) but more importantly, not ruin the efficiency of the exhaust flow?

what people do is cut the muffler open and take calmps and put them over the perforated section of pipe you see in the picture above. this turns it into as close to stait pipe as you can with the factory system in tact. this is basically like instally cutouts in a way. then you can close the switch to co back to mild exhaust.

[radz28]

Originally Posted by toilets

So radz, from strictly a sound perspective, what would you feel will boast the loudest sound while maintaining the stock mufflers (I like the valve idea) but more importantly, not ruin the efficiency of the exhaust flow?

Like hognutz mentions, below, once you're in the muffler, you could use stainless band clamps, and wrap them around the perforated by-pass pipe. This essentially would seal the perforations, and make the muffler nearly 100% "closed" when the valves were open. Others were doing essentially the same, except they'd cut-out the perforated pipe and replace it with the same-size regular exhaust pipe and weld that in. That would really do the same thing but probably cost a little more.

That's what I'm planning on doing. That will probably add a little more rasp (but not by much) and it might get a little more boomy in the car. Neither of those should do anything to impair exhaust flow, however. It should improve it, if it's done correctly. I don't know that I'd say it's cost-effective, however, I like what I see in the factory exhaust and unless there is a more cost-effective aftermarket alternative, I'm sure I'll spend the money to do this.

JMO

Originally Posted by hognutz

what people do is cut the muffler open and take calmps and put them over the perforated section of pipe you see in the picture above. this turns it into as close to stait pipe as you can with the factory system in tact. this is basically like instally cutouts in a way. then you can close the switch to co back to mild exhaust.

I wish I had a picture ready, but a search can show everything I was going to try to show

[toilets]

Originally Posted by radz28

Like hognutz mentions, below, once you're in the muffler, you could use stainless band clamps, and wrap them around the perforated by-pass pipe. This essentially would seal the perforations, and make the muffler nearly 100% "closed" when the valves were open. Others were doing essentially the same, except they'd cut-out the perforated pipe and replace it with the same-size regular exhaust pipe and weld that in. That would really do the same thing but probably cost a little more.

That's what I'm planning on doing. That will probably add a little more rasp (but not by much) and it might get a little more boomy in the car. Neither of those should do anything to impair exhaust flow, however. It should improve it, if it's done correctly. I don't know that I'd say it's cost-effective, however, I like what I see in the factory exhaust and unless there is a more cost-effective aftermarket alternative, I'm sure I'll spend the money to do this.

JMO



I wish I had a picture ready, but a search can show everything I was going to try to show

Thanks all. Are you planning on anything else to go with this? Like hf cats or x pipe?

[One-Bad-ZL1]

So if the car has dual cats per pipe and the second burn chamber further conditions the exhaust gases why place the oxygen sensor in the middle, wouldn't it be better to be after the last converter?

[hognutz]

Originally Posted by toilets

Thanks all. Are you planning on anything else to go with this? Like hf cats or x pipe?

in my case I will go high flow cats with X-pipe. x-pipe just produces better power. Cats cost money but they do reduce fuel smell. I have not figured out why factory uses h-pip still. itis cheaper maybe that is why.

[toilets]

Originally Posted by hognutz

in my case I will go high flow cats with X-pipe. x-pipe just produces better power. Cats cost money but they do reduce fuel smell. I have not figured out why factory uses h-pip still. itis cheaper maybe that is why.

I like this set up. Any worries about boost loss?

[SlingShot]

I know this thread is a year old, but what cats are you guys using. I can't seem to get a good answer from Solo if the SS cat will work for sure. All I can get from them is they should, and they don't seem to have anything specific just for the ZL1.

[hognutz]

Originally Posted by SlingShot

I know this thread is a year old, but what cats are you guys using. I can't seem to get a good answer from Solo if the SS cat will work for sure. All I can get from them is they should, and they don't seem to have anything specific just for the ZL1.

Well the JBA catted mid pipes will fit I know 100%. they place I bought my mods from though is trying to talk me out of doing that though say's the cats are not high enough quality.

right now I am contemplating just going catless. I can't make up my mind basically.

I just want some more volume out of the exhaust really. The JBA off road pipes are only $200 so I might just try those for the giggles.

He is trying to talk me into stainles power o/r longtubes for $699.

[AMCBimmer]

I just purchased Kooks LT 1&7/8 and Kooks green Cats. The headers are at the coaters now. I am going to dyno stock first then dyno after I put the headers and cats on. I will be keeping the factory exhaust. I will post my result. I also am NOT going to tune