ZL1 exhaust pipe diameter?

[actireman]

Starting to do some homework on headers and system. Does anyone know the diameter of the pipes going to the back? The other is, I really don't care about sound as much as performance. I would like to keep the OE mufflers if possible, but I don't know how restrictive they are, I'm hoping they are not, seeing how they open up. Thanks for any advice.

[radz28]

I imagine they're going to be probably about 3-inches. Z06 and ZR1 are about that and have dual-mode exhaust, too.

As far as restriction, I think the muffler mod' for those cars will apply for ZL1, too. I plan on doing it because I like the OEM set-up and it will be less expensive than a catback. Because of the modest bolt-on power improvements above CTS-V (through the active exhaust, dual-inlet intake system, EPS, and more efficient upper plenum and intercooler) I really think improvements will be in headers and cats'. Removing any resonators and a good X-pipe will probably be a good idea, too, just like they are for SS and V6 models.

[paul2010]

Originally Posted by radz28

I imagine they're going to be probably about 3-inches. Z06 and ZR1 are about that and have dual-mode exhaust, too.

As far as restriction, I think the muffler mod' for those cars will apply for ZL1, too. I plan on doing it because I like the OEM set-up and it will be less expensive than a catback. Because of the modest bolt-on power improvements above CTS-V (through the active exhaust, dual-inlet intake system, EPS, and more efficient upper plenum and intercooler) I really think improvements will be in headers and cats'. Removing any resonators and a good X-pipe will probably be a good idea, too, just like they are for SS and V6 models.

I was advised by Lingenfelter that headers were a bad idea for the ZL1. They said they can make 700+ with just a cam, heads... No headers.

[cyrusthevirus]

but u def need to get some high flow cats those factory ones r way to restricted

[Z_Rocks]

Originally Posted by radz28

I imagine they're going to be probably about 3-inches. Z06 and ZR1 are about that and have dual-mode exhaust, too.

As far as restriction, I think the muffler mod' for those cars will apply for ZL1, too. I plan on doing it because I like the OEM set-up and it will be less expensive than a catback. Because of the modest bolt-on power improvements above CTS-V (through the active exhaust, dual-inlet intake system, EPS, and more efficient upper plenum and intercooler) I really think improvements will be in headers and cats'. Removing any resonators and a good X-pipe will probably be a good idea, too, just like they are for SS and V6 models.

Chuck, are you getting a ZL1 for sure?

[The Stig]

Originally Posted by paul2010

I was advised by Lingenfelter that headers were a bad idea for the ZL1. They said they can make 700+ with just a cam, heads... No headers.

Hmm I wonder why they recommend not getting LT headers.

[IOMZL1]

Probably because there are more cost effective HP gains to be had on a FI engine or the engine doesn't respond well to LT headers?

[radz28]

Originally Posted by Z_Rocks

Chuck, are you getting a ZL1 for sure?

One way or another

You?

Originally Posted by IOMZL1

Probably because there are more cost effective HP gains to be had on a FI engine or the engine doesn't respond well to LT headers?

It seems counter-intuitive, but I'm certainly no expert. I understand LS7/LA
S9 manifolds flow extremely well and it remains to be seen what improvements to ZL1 manifolds have been. I know they're stainless, but haven't seen photos up close. They look pretty srandard to me...

[actireman]

RADZ28, what is muffler mod? Also my buddy at GM who works along side with Pratt and Miller said to me a couple of months ago that a CAI, pulley and exhaust would easily make another 75 hp. I assumed he meant LT's and cat. I was hoping to keep the mufflers because I think they are pretty neat how they open up. And besides I want to keep it sneeky fast.

[Z_Rocks]

Originally Posted by radz28

One way or another

You?

I'm going to wait for 2013 for dust to settle. I'm also considering another car that is lighter (no, it's not GT500 )

I've had light & heavy cars, and for my taste, I want to stay around 3000lb or less. That's why I'm going to wait a bit longer for some new stuff showing up. Plus, I want to see how the Insurance companies are going to rate this monster (2 door, V8, Supercharged and over 500HP They're going to rape us ).

[radz28]

Originally Posted by actireman

RADZ28, what is muffler mod? Also my buddy at GM who works along side with Pratt and Miller said to me a couple of months ago that a CAI, pulley and exhaust would easily make another 75 hp. I assumed he meant LT's and cat. I was hoping to keep the mufflers because I think they are pretty neat how they open up. And besides I want to keep it sneeky fast.

I don't have pics' at this PC, however, the NNP (or NPP - I forget which code it is...) is the same active exhaust ZL1 is getting. Unless it's different internally, there is obviously one inlet, and two outlets, one of which has the valve in it. Inside the mufflers, there is a perforated pipe that comes off the inlet pipe and there are baffles, chambers, and packing. That perforated pipe will allow sound and gas to either travel through it, or dissapate inside the chambers, baffles, and packing. When the valve is closed, the sound and gas is forced through those chambers and such, and when open, the gas is allowed through one end of the perforated pipe and then out the other and then through the exhaust valve in the tip. Some of that exhaust and sound is still disipated through the perforations, however, a fair amount goes straight through (I imagine).

What the 'Vette guys have been doing is, is either cut the perforated pipe out and replace it with a solid pipe, or, throwing a couple band clamps around the perforated pipe. Then they have the mufflers welded up, and have pretty much straight-through mufflers with the valves open. Some guys also do either a fuse pull to keep the valves open all the time or buy controllers that allow them to control them from inside the car.

I'll try to remember to post a few pics' of the mods' I've found. They aren't difficult to find on the 'net, but I also had some pics' in another thread in this Section. I don't recall the topic, though, but I imagine searching for NPP or NNP will probably get you into that thread.

As far as mods', there is a company that I'm not going to post that works on Cadillacs for Cadillac and they have many mods' for LSA in CTS-V, and they should work directly on ZL1. They're getting something near 800 horse, I believe, on LSA through the 1900; that's pushing 19 psi, a complete ported SC, heads, cam, and supporting I/C, fuel, and exhaust mods', too. It'd be nice if they would come over as a Sponsor so I could share, but, you can search, too I know I'll be looking at pullies and some other stealth mods' so I don't get The Man mad at me I think I have a target on my back, lol. You gotta' pay to play!!!

Originally Posted by Z_Rocks

I'm going to wait for 2013 for dust to settle. I'm also considering another car that is lighter (no, it's not GT500 )

I've had light & heavy cars, and for my taste, I want to stay around 3000lb or less. That's why I'm going to wait a bit longer for some new stuff showing up. Plus, I want to see how the Insurance companies are going to rate this monster (2 door, V8, Supercharged and over 500HP They're going to rape us ).

AH!!! Yeah - for me - it's not because of choice, however, I am hoping they'll send the 5th Generation chassis out with a bang That's a good point about insurance though. I'm going to be leaving mine for weekends and fun only - no DD'ing

[radz28]

Here are a few, and "THANKS!!!" Dragoneye for some of these, too!!!

[actireman]

Thanks guys, that was perfect, now I understand.

[RocketCutlass]

I personally wouldn't do the band clamp thing. If for some odd reason they loosened up you would get all kinds of rattling from the muffler. Weld the pipe in there, close it up, and forget about it.