0DashLogic

Using the DashControl display controller to control the NPP exhaust, we made dyno pulls in all conditions just to see the power effect. The car is a stock 2006 Z06

Blue = OEM function
Green = Full open
Red = Full closed (yes DashControl can hold it closed full time)

http://www.dashlogic.com/index.php?r...&product_id=68

RagTop69

So this tells me that the "full open" NPP setting is virtually identical to the OEM exhaust in both horsepower and torque and the "full closed" position is a real handicap, or am I misreading the chart?

Mike's LS3

Interesting to see when the NPP was open full time, HP and torque significantly improved below 3800 rpm. You can also see the HP and torque jump up when the oem NPP setting opened.
These were back to back runs, I wonder if heat soak contributed to some of the power loss on the third dyno run?

Interesting results, thanks for posting the dyno graph!

Corvette_Ed

I'm color blind. Would someone please explain what I am seeing on the graph as I can't tell which arc is which color?

TIA

Mike's LS3

Top line = NPP fully opened.
Middle line = NPP oem function which opens around 3600-3800 rpm.
Bottom line = NPP fully closed.

EvanZR1

Dang, that's a pretty big difference on the upper end when closed. I'd hate to see how big of difference it would be on my blown car (672RW).

Corvette_Ed

Thanks Mike.

Looks like I need to stop being lazy and pull the #10 fuse so mine will stay open all of the time. That's a pretty drastic difference.

Not So Fast

I knew it, my car is faster with the NPP fully open, I could feel it in the seat of my pants
No seriously thank you, so their claim to 6 more HP on an LS3 holds pretty true I would assume. That's it my wife can just live with the "drone" LOL
NSF

Zero_6

Wow.

EvanZR1

I'm still having a hard time believing flaps closed is a 40HP difference.
My guess is this must be a C6 Z06 (or maybe cam & LTs LS3). Even with that, it's a huge difference NPP closed full time. That's way more than 6HP, so if it's true, the NPP with flaps closed must be WAY more restrictive than the non-NPP mufflers.

Mike's LS3

He stated a stock 2006 Z06 which has NPP 3" pipes. Unlike the LS3 with NPP 2 1/2" pipes. I'm thinking a bit of heat soak on three consecutive runs and the third with NPP closed.

0DashLogic

There is no situation the Z06 will stay closed past 4000rpms at WOT on a factory car, and cars are rated at peak power levels. Clearly a NPP system in "Closed" is more restrictive than the non-NPP mufflers is what I would draw from this.

Quick Silver Z

C6 Z06 uses "Bi-Mode" not NPP.

https://www.corvetteforum.com/forums...e-exhaust.html

Just sayin'

RC4G

Not entire true.

While the mid-pipes and muffler connectors are 3" the muffler inlets neck down to 2.5" as they enter the mufflers themselves.

Other thing to consider is that 2006 Z06 bi-modal cans have perfed internal pipes.

Mike's LS3

Unlike the NPP which has perforated tailpipes and I believe remain 2.5" thru muffler inlet. Both systems bypass through straight pipe, correct?

96GS#007

Any ratings difference regarding the LS3 are NPP vs the non-NPP OEM exhaust. That is where the 6 hp comes from. It has nothing to do with open or closed.

EvanZR1

Z06 had perforated straight pipes on the bypass side, LS3/NPP has solid straight pipes on the bypass side. LS3/NPP is 2.5" all the way, Z06 is 3" to mufflers and then necks down to 2.5".

madmatt9471

Thanks for the test data - solid info - very nice!

Thanks,Matt

0DashLogic

Heat soak is always possible, but I don't think that is the case here. First reason I don't think heat soak played a part is we are in Utah and this was in January, if it was above 30* outside that day I would be surprised, the front of the car is barely inside the building and we all had coats on. Second reason is the beginning of the run followed the 'closed' numbers from the previous run exactly (that run being the first one that was within 3hp of best), if it was heat soaked I would expect the numbers to start out lower and remain lower, but that was not the case here.

artinist

according to this article, its worth 6hp. 436hp with npp option, 430hp non-npp.

http://www.caranddriver.com/reviews/...ression-page-2