Added NPP Exhaust to 1LE Dyno Comparison
 

2013 1LE Standard then changed to NPP

Test conditions:

• The same car and same dyno were used for both tests.
• No air quality info available, but the first day was mild for late August in GA. The second day was a little warmer and more humid.
• Stock Exhaust test 8/29 10:45 - 2 pulls
• NPP Exhaust test 8/30 10:15 - 2 pulls
• DynoJet 224X (Vengeance Racing, Cumming GA)

Notable items:

• Got the NPPs from Ofer at 2SSRS@Gen5diy.
• No vacuum lines connected to the NPP mufflers. They are spring loaded and stay wide open at all times.
• Oil and filter changed between tests. (first oil change)
• Approximately 30 minutes drive to the dyno.
• Tested within 15 mins of arrival.
• Less than 100 miles between dyno tests.
• No fuse pulls or ECU resets within several weeks of this testing.

Six videos attempting to capture the sound differences:

http://www.youtube.com/playlist?list...wwx0KROmJmXGIU




Blue is Standard Exh - Red is NPP Exh

Thank you for doing this. Not having air quality hurts the analysis, and I am sure the heat and humidity of the second day had an effect, and we have no idea on barometric pressure, but I think it supports the my theory that the NPP system is worth little to nothing in terms of power. For those that like the noise, it may still be the best bang for the buck. Again thanks for the effort. Very interesting.

What I see is 10 more HP at peak revs, and a tade more tq! Even though peak numbers are the same, you can see that up top the engine is breathing and pulling a tad stronger! I would not say it does nothing for power when it clearly does... Add some mods and that top end with the NPP exhaust will start to show even more! So if you want to keep a bone stock car it's fine, but add standard boltons I would want the NPP as I think it would clearly perform better.

Ron at Vengeance pointed out the same and marked the graph accordingly.

Making a bit more power past the shift point does not mean much to me. I am all for non-stock cars, but kind of like to see a bit more bang for the buck. I am not knocking anyone that went the NPP route, I just can not justify it. I do see your point if cam and head mods are made and shift points are going to be raised. It may make a difference at that point, but then I would think a complete exhaust system would be in order.

Only real benefit I see is looks and weight.

I realize it's a matter of taste, but the change in sound is a significant benefit IMO

Could it benefit from a CAI system? Maybe if the engine breathed in better the benefit would be more manifest.

No catback is a good bang for the buck on a stock car. It's nice for a factory upgrade and definetly sounds how it should! The stock SS exhaust Sucks, so if I were to buy a 1le I personally would have liked to have the NPP. I just built a 3" system for my car and it made a huge difference over the stock pipes I had, but my car has a cam.

Did you get a chance to weigh it? Not sure if anyone has made a concrete difference in weight between the stock exhaust vs NPP. Just curious.

No way I could justify almost a grand for that. It may not sound as refined but changing mufflers or muffler delete seems like a better move from a financial standpoint. The twin pipes look cool. Just not 1K dollar cool.

When you say sucks, are you referring to performance with stock HP, performance with modified HP, or sound?

Can you share your 1k dollar reference?
I have $600 in this not counting the oil change or dyno time.

I guess that's better than what you have said in the past. Glad we can finally put this to rest. Every little bit counts...

Quote:

Originally Posted by gajagfan (Post 6618168) Make no istake, NPP frees up no horsepower. NONE! You folks need to stop it. NPP is the modern day equivelent to glass packs!

:popcorn: Seems like it adds 9 to me....:popcorn: