LS7 Manifold on LS3
 

I have been reading quite a bit on here about installing LS7 exhaust manifold/cats/h-pipe on a LS3. My '08 is a daily driver and wanting to keep it tame but love the throatier/almost choppy idle. The car currently has a B&B Fusion exhaust and love the sound for the most part, but thinking the Z06 exhaust might roughen up the idle a bit.

I love the burble of the stock h-pipe and don't want to lose that, but was wondering what the LS7 exhaust manifold would do for my current setup? From my research, the h-pipe is what keeps the burble/popping on decel, do all C6 Z06s have h-pipes or do some years have x-pipes?

I'm trying to keep the cost down, which is why not looking into cams or longtubes.

I believe the changeover from H to X pipe for ZO6 occurred starting with the 09 model. I have an 08 system that I never installed which has an H pipe.

Does anyone have any links where I could hear a comparison of the factory LS3 exhaust system and LS7 exhaust into LS3 mufflers, preferable NPP?

Aftermarket works too. I'm basically trying to gauge if it is worth adding it to my BB Fusion. I'm not so much after the performance gains as I am the sound.

Sound will be about the same, perhaps a touch louder. People make the swap for two main reasons...

- GM parts so they pass visual inspection in states like CA that have strict rules
- Add 12-15 rwhp without a tune, more with a tune

If you want more power than above and you want the car to be noticeably louder, then you need to go to headers and bullet cats.

Going to the 3" Z system is not going to "roughen up" the idle.

The x-pipe will retain the burble and popping during decel (I must admit I like the sound on my '13 which has the x-pipe :lol:)

Yeah I'm not really wanting to have a tune done on it,which the more I read into longtubes was mandatory. A little more volume at idle is what I'm wanting, but I found a comparison video that had the fusion exhaust with and without headers and got me rethinking longtubes. They almost completely negated the difference between open/closed positions of the valves in the mufflers.

I'm thinking the Z06 manifold will just slightly alter what I have currently and be relatively inexpensive to boot. All while keeping factory appearance and functioning equipment.

Pm sent!

:lurk:

For you guys that have done this mod, does your muffler shop alter the Z06 mid pipe to allow the axle-back exhaust to still bolt together? I am not wanting to cut up the Fusion exhaust, in case I don't care for the LS7 parts, I want to be able to install my factory manifolds and mid pipes.

It can be done either way. Just tell them which one you want modified.

I'd still check the AFR on a dyno if not getting tuned to make sure everything is kosher if it was my car.

The Z06 pipes are 3" and your stock exhaust is 2 1/2". Some sort of reducer will have to be added to either the Z06 parts or your Fusion pipes. It doesn't have to be welded, but better if it is, and when you add an adapter, it lengthens the pipes which means one side or the other has to be shortened. I had the same dilema and just told the muffler shop to make it fit...they did.

My dad knows a good muffler shop and I'm gonna see if they can reduce the back end of the Z06 mid pipe to bolt to my current axle-back exhaust. If they can't, or it's going to be too difficult for them, I'm going to contact one of the speed shops in the area and see if they have a set of mid pipes off a base C6 that I can cut the end and flange off and take that to the muffler shop to reduce to. From several threads I have read, it seems that base mid pipes are basically trashed when putting anything aftermarket on, so I'm hoping to get them for next to nothing from a shop that puts on aftermarket exhausts.

Do any of you know a link or sound clip of ls7 exhaust manifold, cats and mid pipe on a ls3? I would really like to hear a before and after. Assuming I put the Z06 exhaust parts in front of my BB Fusion, I will try to make a quality before and after for future reference.

:lurk: