General Lee

Iv searched for the answer to this specific question, i see a lot of guys changing other or all of the exhaust, i just want to swap manifolds only and leave the rest of the exhaust alone.
Possible or is it necessary to change
down pipe too?
My car has 2 cats each side a pre and regular cat, 2013 6 speed car.
Thanks.

Boomer111

I believe the ZO6 manifolds matte to a 3 inch down pipe with the cats. Then to the 3 inch H pipe then to the axle over pipe were most get a reduced piece to matte down to 2 1/ inches.

You have to use at least the whole Z06 unit at least back to the axle over pipes to be of value in exhausting the hot exhaust.

Not sure why you would want only the manifolds?

EvanZR1

You have to use the cat pipes that come with the Z06 manifolds and H-pipe. From there you can fit the stock mufflers although it will take a little work. This is the setup I have on my GS.

General Lee

I was understanding from reading some other threads that the LS7 piece is better flowing than the cast one on the LS3 was hoping that it would be a simple swap (manifold for manifold) and the downpipe would mate up, but i guess not. thanks for the tips & info.


Ok so now i know i have to look for complete set except for axle back thanks .

LD85

Ok so now i know i have to look for complete set except for axle back thanks .[/QUOTE]

The Z06 mid pipe is 3" and your axle back is 2.5"

el es tu

What you would use would be the z06 manifolds cats and part of the h pipe - just cut the z06 hpipe after the crossover and use reducers to neck it down to 2.5." Use some good sealing clamps and youre good to go!

Misael

Other than flow, is the exhaust tone gradually changed? Considering changing out my Corsa and mid pipe setup.

el es tu

swapping out mufflers makes the biggest difference in sound over manifolds

Boomer111

Yes the bigger diameter pipe will make more noise, somewhere between stock and long tubes.

You need the bigger pipe to remove the exhaust heat away from the manifolds for the power to increase.

By the time the air gets to the over axle smaller diameter pipe the power has increased a
ready, the bigger mid pipe is needed.

0Stainless Works

Run headers make way more power and wicked sounds!!

EvanZR1

Z06 mani/cat/H-pipe will make about 12-15HP on a stock car (I picked up 14RWHP), and does not require any tuning (where long tubes will). There is a noticeable change in the sound, and I think it makes the sound close to perfect with LS3 NPP exhaust, and I've had many people comment that they love the sound.

Misael

My LS3 came with a corsa exhaust and aftermarket(not sure who made it) piping from headers back. Next thing will be longtubes, I was just curious if its worth redoing exhaust to 3" all the way back or keep it how it is and add the LT's.

0Stainless Works

Depends on what mods are done to the car? The addition of the long tubes will increase the exhaust volume and scavenging, giving the extra kick in the pants your looking for. Running a 3" center section will do the same, good thing is the LS motors like to breath and can handle a 3" center even if mildly modified.

What do you have done to the car?? Heads or cam?

Misael

It's pretty stock just the exhaust setup and intake. LT's, mild cam and a good tune is what I will be shooting for soon.

General Lee

Thanks for all the replys. I know headers are the better choice but at roughly $2 grand+ with labor it's not in the cards right now
(or maybe ever)


For what your describing wouldn't it be better to completly swap in the z06 exh front to back ? (of course cost being a factor)
How difficult was it for you to find the pieces you used?
Thanks

el es tu

The Z06 mufflers neck down to 2.5" at the end, are heavy, and way overpriced even for a used set (ranging 500 to 1000 bucks with around 600 -800 being the average going rate). Some folks even argue that 3" the whole way isnt as helpful on lower output setups... of course others claim the opposite.

I bought a set of Thrush "Welded" (rebranded Flowmaster 40s) 2.5" offset in/offset out mufflers for $38 bucks each, added $30 tips and had them welded in with hangers for $75 in labor.

The clamps, mufflers, reducers, and tips were sourced from oreilly and autozone without having to special order anything.

After all was said and done I spent roughly $600 for a new exhaust from the manifolds to the mufflers.

General Lee

ok so i would want to reuse my factory NPP, i would then only need the manifolds, downpipes w/cats & H-pipe.
Just curious does the H-pipe have cats inline? my '13 has precats & the regular ones further down i that started with '12 & also '13 model year for that setup on C6.
Thanks.

el es tu

All the c6 models eventually got secondary cats on the hpipe. They also changed the gasket configuration between the cats and hpipe, so make sure you get the parts from the same or similar year z06 (or zr1). If you plan to run gutted cats, having the secondary set of hollowed cats (as on the newer z06s and zr1s) should help lower the sound level since theyd act as resonators.

To match up the two h pipes before deciding where youre going to cut, use the spring hanger bracket:


Image from this thread (c5) http://forums.corvetteforum.com/c5-t...sion-pics.html

EvanZR1

BTW you can use a 2011 or earlier Z06 manifolds, cats and H-pipe and it will mate up to a 12/13 mufflers with reducers. I actually noticed not only better sound on mine with this setup, but the center tunnel is also cooler since I now don't have the secondary cats.

General Lee

Ok guys thanks for the info, so i could go with 1 the full z06 using those muffs or 2 manifolds back and reduce that down to fit my npp's.
In either case i would be eliminating those center cats which from what iv looked at have no o2'sensors to them.
got it now thanks.