NPP Exhaust again

[Cjm1261]

I know there are a few threads regarding the NPP exhuast system.... But I dont beleive this has been thoroughly discussed.

My main item I want to discuss is again the aftermarket vs NPP.

I am about to place an order on Stingray and am curious if there is any benefit to ordering a NPP if I have intent to go aftermarket soon after. Are there aftermarket companies pursuing the possibility of integrating stock drive mode selector? And if so do you have to have a NPP equipped Stingray to take advantage of that?

Thanks for any insightful replies!

[purpleRac3r]

In my research into exhaust for my non-NPP Stingray, I've come across only one that is a direct replacement for the NPP. It's the B & B Performance Fusion syste. It uses the stock valves on new mufflers and pipes, so the operation and ability to change settings stays stock. I've neither seen the system on an actual car, nor heard it in person, so cannot vouch for it, tho B & B systems are known for a pretty aggressive sound. There may be others out there, but I didn't see any.

As for advantages, about the only ones I can determine are louder than stock sound in both modes and slightly better power than the stock system. This would be true of both NPP & non-NPP cars. One big disadvantage would be dollars spent. You'll pay around $1200 for the NPP only to take half of it right back off, then pay anywhere from $1500 to over $3000 (depending on brand and options you ultimately go with) for the aftermarket set-up. Seems to me like you'd be paying twice for exhaust before you're done.

A non-NPP car saves you that $1200 right off the top, which you could then put directly toward the aftermarket kit. The power will be equal to that offered by the kits for NPP. The better companies tune their kits to minimize intrusive sound while cruising, yet really crank it up when you mash the gas pedal. To me, the NPP is best for those who plan to keep things stock, the base exhaust makes better sense if you plan to upgrade for looks, performance and sound. That's the route I followed, and intend to go with Corsa as soon as I collect enough $$.

Just an FYI, every kit I've looked maintains the V4 valves located before the mufflers. Some use just the valves in new pipes & flanges, others use the stock over-axle pipe sections. This helps for those rare occasions in V4 mode and prevent a need for programming changes.

[zimm888]

Hey purp, you getting the corsa sport or extreme? Xpipe or not, and finally has anyone confirmed drone being absent? Myself considering the sport but I'm a little worried of losing a nice quiet cabin when cruising. Even though I love a loud start up, descent sounding idle and WOT sound you have to admit there's times when you just want a normal sound when you're not looking for a fuss. Thanks, appreciate your opinion. P.S. Is it silly not to get their x pipe?

[Cjm1261]

Thank you Purple! that clears up a lot of the questions I had. I am also looking going Corsa Xtreme.... As you were saying the they maintain the V4 valves on most aftermarket. I assume those are there on both NPP and non NPP.

Thanks again!

[H2OStingray]

I like my NPP exhaust I am getting headers and a x pipe so that should make it louder.

[Cjm1261]

my concern with the NPP is that Corsa is claiming something like 20hp gains... and NPP is 5, wondering if you can get something similar with headers & X-pipe with NPP exhaust

[zimm888]

Believe that claim is with their x-pipe as well.

[Cjm1261]

i thought it was with the whole system, x-pipe and back. wonder if you can get comparable with NPP + their x-pipe

[H2OStingray]

Hey gurl

Npp, ARH headers and x pipe that's what I am getting on Liotta.

Also a quality tune with those additions will give you a lot of power

[Cjm1261]

Aye Gurlfriend, thx I think thats the best bet now, maybe some powdercoated, or after market black tips will work with my scheme though

[purpleRac3r]

I'm planning on the sport, eventually with the x-pipe, but may have to get that later. Yes, from what the rep told me at the Bash, the power numbers are with both the mufflers and x-pipe and stock cast iron manifold & cats. Even with NPP, the exhaust is more restrictive than any aftermarket setup of quality.

FYI, Corsa has optional black chrome tips for an extra $200. They are the same color as the black chrome factory trim around the exhaust tips. Available on both NPP & non-NPP kits.

Something to keep in mind when adding power upgrades. Think about where in the power band you want it. For mostly street driving, you'll probably want more down low, as you won't hit the redline as often. If you see a lot of track time, higher in the rpms will benefit you more often than not. Different parts by nature tend to add power on either the lower area of the band, or the higher, but rarely both.. Granted, tuning can help some there, but not everyone wants to go to that extent. I will probably end up with the full Corsa exhaust, a cold air intake like AFE has, and leave it at that for a while, as my Stingray is my daily driver. Probably consider a tune once the warranty is up.

[zimm888]

Thanks for the info purp. Sry to ask again, but has anyone confirmed no drone yet?

[purpleRac3r]

I can verify no drone with the extreme variant in a 2012 Grand Sport (friend in my local club has it), but don't know in a C7. From what the rep said at the Bash, his display unit was the first available for sale (and it was sitting on a table!). Every website I've been to lists them as not in stock, available after June 1. So I'm pretty sure there aren't any in the hands of the public just yet. Give it a couple more weeks.

[purpleRac3r]

Based on some information that's floating around the web that may be inaccurate, I contacted Corsa to clear up a couple of questions. I talked to Micheal Geul, one of their technical assistants via email. Here is what I learned:

1. None of Corsa's C7 axle-back and double X pipe setups, individually or together, require a retune of the ECM to achieve the posted numbers. Those wishing to retune can see some minor additional gains, BUT IT IS NOT REQUIRED.

2. All of the Corsa C7 axle-back exhausts will eliminate the factory NPP valves if equiped. This means you will lose your dual-mode function (but honestly, if you're going aftermarket, you probably have it set to full open all the time anyway). He did tell me that it also does not require any retuning or dealing with diagnostic trouble codes, as you just turn it to full on all the time. I believe this in essence turns NPP "off" allowing removal of the valves, though he did not clarify the point, and I didn't pursue it as I don't don't have NPP. I suspect the way to deal with it is in the installation instructions.

3. All of their exhausts, regardless of it being Sport or Xtreme, maintain the factory valves for the V4-V8 switching (these cut out odd sounds caused by V4 mode). The factory valves and the short sections of factory pipe that hold them are reused.

4. Optional Black Chrome tips are available on all axle-back kits that match theBlack Chrome factory trim around the edge of the exhaust opening in the fascia.

I hope this helps dispell some misconceptions any of you may have encountered out around the internet. I was pretty sure of this information, but it's always good to see confirmation. I for one have the Corsa exhaust on my short list of Things To Buy for my Stingray!