L99 Exhaust Versus ZL1 NPP Exhaust with LT's
 

I swapped the factory L99 exhaust out for a factory ZL1 NPP exhaust on my car. :) Dynoed before and after a couple of hours apart. The factory L99 exhaust is not to bad, the ZL1 NPP exhaust made 4rwtq and 2rwhp at peak and 4-5rwhp through the middle over the L99 Exhaust! :nod: It has a deeper tone at idle than the L99 and is not as raspy at wide open throttle. :thumbsup: Also I have 1 7/8's Stainless Power headers and no cats with both combo's. :D

You got it from GMPP?

:pop2:

No, got it off a ZL1.

I was thinking of getting this exhaust. suggestion?

I like it and I can run it open or closed with the flip of a switch! :D

cut outs too?

NPP exhaust has a vacuum control cut out built into the muffler ( duel mode exhaust). ZL1's and 1LE cars have this.

This exhaust is an option one all manual SS's starting with 2013 models.

And standard on 2012 and up ZL1's.

yup love mine will never change it out.
sounds and performs flat NASTY with LTs and a cam. and M2W rocks.

Are they 2.5" or full 3" ?

They are all 2.5" (ZL1 and 1LE).

Well so much for the 6rwhp everyone claims that NPP exhaust is worth! :sorry: But it was worth it for the sound! :D :biggrin: