[ocurtis]

Do any of you with convertibles and non NPP have an exhaust cutout system you like? I had a 98 Z28 that had the cutouts and I loved them. I wanted to do the same on my new car, but every one I find says it wont fit a convertible?

thanks

[ember1205]

The convertibles have extra bracing under the car that interferes with pretty much any of the aftermarket pipes between the cats and the muffler(s) - that's why you're finding what you are...

[seethruya]

I didn’t go with cutouts but this would apply to you also. Your only option is to purchase a universal cutout and goto an exhaust shop that does custom work. I wanted to remove the secondary cats and replace all the piping from the main cats back with 3” piping for sound reasons but also so I would be ready for headers at a later date.

I bought the 3” x-pipe kit below for $200 even though they clearly state it won’t fit convertibles and the exhaust shop I went to was able to weld it all in place without removing or modification to the bracing. It was definitely not a plug in play job, modifications to the piping from the kit had to be made, but it wasn’t a job a more reputable exhaust shop couldn’t handle.



https://wildhammermotorsports.com/16...ed-engineering

[c4racer]

most cat-backs fit the way they come - even if they claim they will not. I don't think most companies bother checking on a Convertible. I have a MagnaFlow cat-back kit and there were no issues installed on a convertible at all.

[ocurtis]

So after reading these, I Looked under my car at the exhaust - the factory exhaust is squished almost in half where the added x members are for the convertible! Is that normal?!

[vtirocz]

Originally Posted by ocurtis

So after reading these, I Looked under my car at the exhaust - the factory exhaust is squished almost in half where the added x members are for the convertible! Is that normal?!

Yes. The coupe's have that crushed section as well (despite not having that x-brace), but the data shows this has no impact on the power curve: https://www.mishimoto.com/engineerin...he-crimp-myth/

[ocurtis]

Interesting!

[seethruya]

Originally Posted by ocurtis

So after reading these, I Looked under my car at the exhaust - the factory exhaust is squished almost in half where the added x members are for the convertible! Is that normal?!

That is correct. There’s very little room underneath the convertibles but as I learned, just barely enough where you can go the custom route/modifying an aftermarket kit without any major impediments.

[c4racer]

The cat back kits connect behind that squished section, so there really isn't any difference in fitment coupe vs. vert.

[dmcmahan60]

Try the AWE Touring non NPP axel back. That is what I went with and love it

[xqwisit23]

So after reading this thread, I had a Borla axle back exhaust installed when I purchased my car (was told cat back was not available), can I purchase the 3" X-Pipe and call it good?

[cellsafemode]

just note, swapping a resonated "x" pipe for a non-resonated true-x has been known to introduce rasp in certain muffler combinations.

Not a big deal if it does, you just go back and have them use a resonated one (they're more expensive) ...but yea.

[ocurtis]

What does adding the x pipe do?

[gtfoxy]

Originally Posted by ocurtis

What does adding the x pipe do?

Basically X/ H-pipes allow opposing exhaust pulses more volume to move in. Think of it as a car pool lane during rush hour. There can also be a scavenging effect.

Aside from the firing order differences, this pretty much explains it.

http://www.superchevy.com/how-to/exh...-for-your-ride