drew47000000

From what I can tell GM used certain mufflers/over axel pipes in 08 then changed them for 09+ and also z06 and gs. With that said what's involved to use those different mufflers for an 08. Anyone done this? How difficult is this and would you recommend it?

Thanks in advance!

Top_Fuel

If you have an '08, you have 2 options that are true "bolt-on" solutions...meaning no welding is required:

1) Find NPP mufflers from a 2008 and they will bolt right on. The problem is this may be a difficult task, as there aren't many out there.

2) Buy NPP mufflers from a 2009-2013. If you do this, you must also replace your mid-pipe with one from a 2009-2013. If you buy 2009+ NPPs and try to bolt them onto your 2008 mid-pipe, it won't work. Replacing the mid-pipe is no extra work...it has to come off any time you replace the factory mufflers.

Lots of people have gone with option #2.

peter pan

I did but then I did an entire ZR1 setup

dealer06

I did option number 2 from Top Fuel, above. It was super simple. I think I paid $100 or so for a 2009+ x-pipe.

you mention Z06 mufflers too, but that's a different deal, b/c they have 3" pipes and LS3 exaust pipes are 2.5"

drew47000000

Thanks! How about GrandSport systems? Are they the same as the 2009+ or are they like Z06 or different all together?

HOXXOH

Option #3 is to cut off the pipes from your '08 and the '09 right near the mufflers and weld the '08 pipes onto the '09 mufflers.
Then it becomes a bolt on without other changes.

I'm not 100% sure, but I think it's only the passenger side that is different. So try fitting on the driver's side before you cut and weld.

Top_Fuel

Yes. NPP mufflers on a GS are the same as NPP mufflers on a "base" model. Z06 and ZR1 dual mode mufflers have larger pipe diameters and would need to be welded on with reducers.

Now...you know you'll have to tap a vacuum source at the engine and install a controller like NPP-in-a-Box, right?

Top_Fuel

That's the way I remember it. I think one side does work, but you're screwed on the other side because the bends in the pipes are off.

Did you just tell him to cut and weld pipes to make it a bolt-on solution? Actually, if he had an exhaust shop he could trust, that's not a bad approach.

drew47000000

Great information! Yes I am on the lookout for a good deal on NPP in a box. Maybe someone's looking to go aftermarket and willing to unload theirs? or is their alternatives to NPP in a box?

HOXXOH

Sure enough, once you cut and weld, then bolt-on is all that's left.

If he's not doing the work himself, then he has to trust someone else regardless of the method.

RonNSoCal

Read all of the threads on the conversion because there are options for routing the vacuum line and where you place the controller box. I had my vacuum line run through the rocker panel on the passenger side to avoid exhaust heat and put the controller below the tail lights on the same side. I feel this worked out better than using the back compartment in the hatch area because it does not take up the space and does not require holes to be drilled. I am very happy with how this all worked out on my car. I used a '12 GS NPP exhaust on my base '11 coupe and not only is the open exhaust great, but the closed exhaust is a tad racier sounding than my stock pipes. The tips are a half in larger, which may be a factor.