Must_Have_Z

Absolutely not. You just need to loosen those shields above where the mufflers sit. There is zero reason to drop the cradle. Zero.

buckmeister2

That was NEVER my intention. There are so many variables in this thread, that I understand how you saw it that way. I would never make those two connections permanent.

There are a lot of moving parts. The only Z06 parts that MUST be in place are the manifolds, downpipes, and mufflers, NOT including the over-axle pipes from the Z muffs. The mid-pipe and over-axle can be from either car. I was trying to satisfy my needs, and those of the (failed) shop by using the 2.5" mid and over axle.

Now that I am doing it by myself, I can use whatever I want, or what works best.

Thanks for your input.

buckmeister2

Good info for me. I will be applying everything you, and others, are saying. Others have done it, so I know I can. I was just really taken aback by what the "pro" at the shop said about the difficulty.

You know, the last thing they want to hear is, "You can't be right about that, because my friends on the internet say different."

Rather than argue, I just went home and whined to all of you...haha

HOXXOH

When I did mine and a couple of friends, I only loosened the clamps between the axle-back pipe and the mid-pipe (X or H). Removed the bolts and nuts to allow the sway bar to swing down. Disconnected the vacuum hoses if NPP. Then removed the four muffler hanger bolts. Nothing else got removed or loosened to get the mufflers out. That was with the OEM 2.5" pipe size.
I've removed my mufflers several times for different reasons and it takes longer to get the car on jackstands than to take the mufflers out. However, using the Z06 mufflers/axle-back 3" pipe and trying to snake that around your A6 trans and still having rattle free clearance is above my paygrade. AKA I never want to do it.

I assume your mufflers are NPP and still in place, but the OEM X-pipe is removed. I also assume you have the Z06 manifolds and downpipes installed too. I also assume the Z06 system you bought has an H-pipe for the mid-pipe. If I'm correct so far, you'll need a hacksaw, two 3 to 2.5 reducers, two 3" clamps, two 2.5" clamps, and two hours labor before beer time. You wont even need to take your mufflers out to do it. If you want to go that direction, I'll get you a pic of the most recent one I've done tomorrow morning.

mcm95403

FAUEE

Bingo. The 3" over axle pipes will not fit with the automatic transmission in place. You would need to weld the z06 mufflers onto the stock over axle pipes.

Boomer111

On me for misunderstanding.

Happens more and more the older I get.

wayback

I have a question about why your doing this. Will the Z06 manifold flow that much better to over come the choke of the base pipe?

Seems to me long tubes would be a better solution, unless you have a visual inspection like in Cali.
Not an expert, just wanting to learn.

Mike's LS3

Z06 manifolds are basically shorty headers, four individual stainless steel pipes that meet at the collector. The four pipes are covered with a stainless steel jacket.
Long tubes will provide more power, but the Z06 exhaust is at least 1/2 of the power gain when upgrading from the cast iron LS3/2 exhaust manifolds. Yes, ideal for CA inspections.

wayback

Thanks, that's what I thought.

But wouldn't the step down to 2 1/2 stock pipe reduce those gains....or would it increase the pressure to where it needs to be for the LS3/2?

In my mind the system is limited by the smallest part....correct?

Mike's LS3

When you run the Z06 exhaust manifolds you also run Z06 3" downpipes with cats. The LS3's 2 1/2" downpipes will not bolt on because the collector is smaller. You should also run the Z06 3" mid pipe. From the mid pipe, you have the option to run 3" Z06 mufflers or add reducers to fit the 2 1/2" NPP mufflers. The Z06 mufflers actually reduce size at the inlet of the muffler, but the rest of the piping is 3". The exhaust velocity at this HP level is not as critical as you go downstream over the axle, so reducing to 2 1/2" piping has negligible HP loss.

buckmeister2

Mine is all done now, and the 3" over-axle pipes did fit quite well with my A6. After a couple unsuccessful tries, I realized that I needed to take 3" off the driver side over-axle pipe, and drop the sway bar, so that the pipe would drop down before contacting the shift linkage area, which is too narrow for a 3" pipe to drop through. Once I did that, it practically fell into place. I also had to grind off the clamps from the 3" mid-pipe because they are mounted horizontal. I turned them down 90 degrees, then had a short sleeve put on the driver pipe that I cut, and it all bolted up like it was made that way. No rattles, tips in perfect alignment.

The whole swap is kind of a moving target for folks because there are several ways to make it work. Once I decided I wanted an entire 3" Z06 system all the way through, it was not that hard to see what needed to be done to make it work.

CamarosRus

I am a Newbie 2012 Grand Sport owner.

I'm interested in this Z06 Manifold, Etc upgrade vs the HUGE $ for
aftermarket headers.

Are these Z06 takeoff parts hard to find.....???

My Below GS has NPP mufflers. Will the replacement
Z06 Mufflers Not have NPP and I eliminate/plug the vacumn ??

I will re-read this thread and try to put together a list of what I need

Will somebody please help me....I do have a lift and tools

Thank You

buckmeister2

No, the parts are not hard to find, and they are far cheaper than aftermarket.

I did the swap by myself, on the garage floor, car on stands. I am NO mechanic. I learned a lot, and was able to do something almost everyone said could not be done...swap in the entire 3" Z06 system, front to back, in an A6 car. No rattles or vibrations.

Other than the expected swap in of parts, I found a few things that had to be done,which make it much easier, and to accommodate my A6. They are:
1. Remove the sway bar...easy to do, 6 nuts/bolts
2. Cut off about 4" from the driver side over-axle pipe. With that done, and the sway bar out, the 3" pipe drops in behind/below the A6 lever, then slides forward for perfect fit.
3. Grind off the clamps on the rear of the mid-pipe. Remount them facing down for trans pan clearance. I did this after I had installed the pipes....duh.
4. When installing down-pipe onto manifold, use a stud/nut in the rear-most hole only. The other holes will need bolts (Thanks, HOXXOH!)
5. When all done, have a shop weld a sleeve in to replace the 4" you removed, and tighten everything up.
6. Buy two 02 sensor extensions in advance. Lots of people say you can slice the tape and unravel enough of the harness to reach the rear sensor, but if you slice into a tiny wire, you are screwed. Buy the extensions on ebay, about $30 for 2.

If I had known the over-axle pipe could be cut and dropped right into place, I would have saved at least 6 hours under the car. This complete swap is so much easier knowing these few things. With a lift and someone to help, I would be surprised if it takes more than 4 or 5 hours. I assume that you have Allen sockets for the sway bar end links, and an air ratchet wrench. You can reuse the Z06 manifold-to-downpipe gaskets if they came with the purchase, but you must use new Z06 manifold-to-head gaskets ($30).

Buy a can of PB, and spray every bolt that will be touched as soon as you get it on the lift. By the time you get to each bolt, it will make it much easier to undo them. You need to bust them loose with a regular ratchet wrench, but the air ratchet really saves time after that.

I have seen complete Z06 system take-offs as low as $400, and as high as $1200, so it pays to shop around. Also, any shop that tells you you have to drop the cradle is full of crap. Two local shops quoted me $900 to $1500 for the job...what a joke.

I have a set of Z06 manifolds for sale....$200. Perfect condition, with heat shield for starter.

CamarosRus

Buckmeister2, Thanks for your detailed instructions above.....I have questions of course !!!

1) "Grind off the clamps on rear of mid pipe" Are you refering to the OE 3" Z06 clamps ???
and to replace them with ???. Why cant these original Z06 clamps be reused ???

2) " have a shop weld a sleeve in to replace the 4" you removed" A sleeve goes over something.....Why cant
the same 4" piece you cut be welded back on ?? (Your pics would sure explain a lot)
May we assume without cutting this 4" off the that the drivers side over axle pipe just WONT FIT ?????

3) What about vacumn hose or whatever is currently going to my NPP mufflers .....Just plug it ??

Again pics would have been so helpful

I will be shopping for COMPLETE Z06 system

buckmeister2

Good luck...they are out there, fairly plentiful. Do check all the parts for damage, as some folks bust off the header bolts, or ding the tips, either of which may require a specialty machine shop to repair, depending on condition. Also, if you can snag the oval downpipe gaskets, which are reusable, you will save $60.

CamarosRus

Buckmeister and others, I have just ordered 1 7/8" American Racing Headers and their Catted X-pipe
for my LS3 2012 Grand Sport A6 (Inferno Orange above picture)

I dont know or comprehend what over the axle pipes or what OE Muffler Setup will be best for 2012
Grand Sport....

Im looking for another thread where a member stated that the 2011-2013 Z06 Muffler(s) were better than
my current stock set-up

Chuck Sharin Auburn,WA

449er

Buckmeister, nice work getting everything in place & bolted up, but that's a lot of work for what? Bite the bullet & buy a set of long tube headers & a X pipe designed for those headers for a way easier installation. I'm assuming that you are after the performance gains? If you are, the header/X pipe combo is the way to go. Most aftermarket X pipes will fit your existing axle back pipes & mufflers if you want to keep them also

buckmeister2

U R correct, and I would have done so if it were not for a 48-month GMEPP, with 40 months left. Headers invalidate the plan. I may have gained 15 HP total--not much--but I also gained the dual mode exhaust, which I did not have stock, and wanted.