Elleby13

Thanks for the update Motohead. At least they seem to have made progress!

EasyMoney11

Any status on the non-npp exhaust???????

slief

Just for kicks and giggles, I called them a couple minutes ago. A couple months out is the latest word on any Borla systems for the C7. That was also the case a couple months ago. It seems they keep pushing it back.

Motohead279

I called them last week and they told me a week to 2 weeks they should have the non NPP version available....

And under my breath I mumbled "yeah right..." I would rather they just come out truthfully from the start and say sometime first quarter instead of "2 more weeks" going on 5 months now. Because all it does is gets customers excited then **** them off.

Corsa said theirs will be mid May. I'm not holding my breath on that either.

I find it so hard to believe that its taken 8 plus months to come out with a system. The only option right now is a B&B but I hear it has so much drone.

Cuthroat

What I find interesting with all these butterfly systems is when the butterfies are closed isn't it rather restrictive? Where does the exhaust have to travel to get out the other exiting pipe? If you look at the factory npp systems for the C6, when the butterfly is closed the exhaust has to hit the closed butterfly, reverse it's travel, go back through either perforated pipe or holes in a wall by the exiting end and go clear around the muffler to exit out the other side.

Theta

I've posted the diagram of the stock NPP system in another thread if you're interested in the exhaust travel and flow specifics...

Cuthroat

That's what I was referring to. Look how much the exhaust has to travel and probable turbulence let alone restriction those mufflers have in the closed position. I guess that is the best that is available for the variable noise enthusiast.

Theta

That's the reality of fiberglass or poly-filled mufflers these days. They're all going to restrict flow, but in some cases, the backpressure is needed.

Not to mention, straight pipes (even the glass-pack types) on some modem engines sound terrible.

Cuthroat

I'm curious as to which motors may sound bad with a straight pipe? Is it because of direct injection or certain cam timing?

Theta

I could give you pages of engines that sound absolutely atrocious with straight pipes...

Not going to go too deeply off-track here, but GM also had to design a system to control the awful sound of V4 mode with the pulses. So, the exhaust wasn't optimized for full-time V8 performance as many of the aftermarket systems are.

Also, the less rear pack you have, the great propensity for drone you have.