NPP power gains w fuse pulled - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

markgws6 · 01-07-2014, 11:23 AM

I have a question that I hadn't seen answered after reading through countless NPP threads:

Is any power gained by pulling the fuse for the NPP on an otherwise stock LS3? I wonder what the differences are aside from more noise.
Seems you should see a couple HP through the lower RPM range. Please no speculation. I want to see a dyno chart or something similar. thanks.

AGM 1LE · 01-07-2014, 12:15 PM

its just for noise

litle88 · 01-07-2014, 03:14 PM

No gains

axis · 01-07-2014, 03:22 PM

Quote:

Originally Posted by markgws6

I have a question that I hadn't seen answered after reading through countless NPP threads:

Is any power gained by pulling the fuse for the NPP on an otherwise stock LS3? I wonder what the differences are aside from more noise.
Seems you should see a couple HP through the lower RPM range. Please no speculation. I want to see a dyno chart or something similar. thanks.

I can't believe that none of those threads said there's no HP gains. If you look at ANY catback or axleback thread, you'll see that they are ONLY for sound and possibly a weight savings. If you're looking for HP, you need to look at LT's, high flow cats, or straight pipes.

Anthony @ LG Motorsports · 01-07-2014, 05:22 PM

Due to how it works on the Camaro's I don't think you would see any change at all on the dyno.

The only car we have seen make a change is on the C6's with the dual mode exhaust. Even with the car WOT they do not open until 3000 rpm, unlike the Camaro that I believes stays open under WOT (correct me if I'm wrong here)...when the Corvette is on the dyno and you open or close the exhaust HP doesn't change to much but torque can change almost 15-20 ft-lbs under 3k when the flaps open.

Either way you wouldn't see a change in peak...and if you are racing someone your going to be over that RPM anyway. If you want a real gain...like everyone else said, headers, cold air....

Smartguy · 01-07-2014, 05:22 PM

I know your not asking for speculation but a dyno isn't going to tell you much. Dynos just don't give specific enough details to determine power gains from 1-3k rpm

Theoretically though with the fuse pulled you would have a more freely flowing exhaust throughout the entire powerband. With the engine pushing air through a bit easier you may be able to adjust the tune to gain a few hp down low where the flaps used to stay shut.

But it would be the tune taking advantage of the open exhaust. Just pulling the fuse isn't going to do that.

I don't think it's question you'll get a factual answer too. It also really isn't useful.

I say that because if you need the hp it means you're wanting to get the car moving. And if your doing that you're not going to be between 1-3k rpm

Smartguy · 01-07-2014, 05:25 PM

Quote:

Originally Posted by Anthony @ LG Motorsports

Due to how it works on the Camaro's I don't think you would see any change at all on the dyno.

The only car we have seen make a change is on the C6's with the dual mode exhaust. Even with the car WOT they do not open until 3000 rpm, unlike the Camaro that I believes stays open under WOT (correct me if I'm wrong here)...when the Corvette is on the dyno and you open or close the exhaust HP doesn't change to much but torque can change almost 15-20 ft-lbs under 3k when the flaps open.

Either way you wouldn't see a change in peak...and if you are racing someone your going to be over that RPM anyway. If you want a real gain...like everyone else said, headers, cold air....

You say "no change" then "not to much change"

Good example

I guess people could get on a dyno wi a switch and make a pull with it shut, then open and make a pull. But even the car getting up from the previous pull could cause more of a ch age than the exhaust.

Dynos aren't exact which makes it touh to determine answers for questions like this

markgws6 · 01-08-2014, 12:05 AM

Good enough answers for me (even though it would be nice to see a dyno graph showing both as confirmation). I'll just run it as intended for now. Yes a tune and possibly headers are in my future too. Just not now...

Anthony @ LG Motorsports · 01-08-2014, 11:43 AM

It's not a Camaro....but again the Corvette's stay closed til almost 3k RPM so in this baseline you can see what changes on those cars when it opens.

The red line is stock with headers but the exhaust in std mode opening only after 3200 RPM

01-07-2014, 11:23 AM	#1
markgws6 Drives: 2019 Chevy Equinox Premier AWD Join Date: Mar 2011 Location: Silicon Valley, CA Posts: 1,344 View My Garage	NPP power gains w fuse pulled I have a question that I hadn't seen answered after reading through countless NPP threads: Is any power gained by pulling the fuse for the NPP on an otherwise stock LS3? I wonder what the differences are aside from more noise. Seems you should see a couple HP through the lower RPM range. Please no speculation. I want to see a dyno chart or something similar. thanks. __________________ 2013 AGM 1SS/1LE, NPP, Camera (1 of 43)

01-07-2014, 03:14 PM	#3
litle88 V8 Lounge member #2 Drives: 2001 Ws6 Join Date: Sep 2009 Location: Burbank,IL Posts: 6,373	No gains __________________ 2001 ws6, 40k miles, Ls3 416 stroker, short block built by PER the rest by me. LPE Ls3 heads milled to 12-1 comp, FAST 102, NW 102, kooks 2", dual DMH cutouts, Magnaflow C/B, BTR cam + springs. Full UMI suspension.

01-08-2014, 12:05 AM	#8
markgws6 Drives: 2019 Chevy Equinox Premier AWD Join Date: Mar 2011 Location: Silicon Valley, CA Posts: 1,344 View My Garage	Good enough answers for me (even though it would be nice to see a dyno graph showing both as confirmation). I'll just run it as intended for now. Yes a tune and possibly headers are in my future too. Just not now... __________________ 2013 AGM 1SS/1LE, NPP, Camera (1 of 43)

01-07-2014, 12:15 PM	#2
AGM 1LE Drives: 14 SS/ 1LE Join Date: Jun 2013 Location: parts unknown Posts: 928	its just for noise

01-07-2014, 05:22 PM	#5
Anthony @ LG Motorsports Drives: 1994 1LE / 2006 Z51 Corvette Join Date: Jul 2009 Location: Plano, TX Posts: 2,829	Due to how it works on the Camaro's I don't think you would see any change at all on the dyno. The only car we have seen make a change is on the C6's with the dual mode exhaust. Even with the car WOT they do not open until 3000 rpm, unlike the Camaro that I believes stays open under WOT (correct me if I'm wrong here)...when the Corvette is on the dyno and you open or close the exhaust HP doesn't change to much but torque can change almost 15-20 ft-lbs under 3k when the flaps open. Either way you wouldn't see a change in peak...and if you are racing someone your going to be over that RPM anyway. If you want a real gain...like everyone else said, headers, cold air....

01-07-2014, 05:22 PM	#6
Smartguy Drives: Chevy Join Date: Jan 2014 Location: Moon Posts: 14	I know your not asking for speculation but a dyno isn't going to tell you much. Dynos just don't give specific enough details to determine power gains from 1-3k rpm Theoretically though with the fuse pulled you would have a more freely flowing exhaust throughout the entire powerband. With the engine pushing air through a bit easier you may be able to adjust the tune to gain a few hp down low where the flaps used to stay shut. But it would be the tune taking advantage of the open exhaust. Just pulling the fuse isn't going to do that. I don't think it's question you'll get a factual answer too. It also really isn't useful. I say that because if you need the hp it means you're wanting to get the car moving. And if your doing that you're not going to be between 1-3k rpm

01-08-2014, 11:43 AM	#9
Anthony @ LG Motorsports Drives: 1994 1LE / 2006 Z51 Corvette Join Date: Jul 2009 Location: Plano, TX Posts: 2,829	It's not a Camaro....but again the Corvette's stay closed til almost 3k RPM so in this baseline you can see what changes on those cars when it opens. The red line is stock with headers but the exhaust in std mode opening only after 3200 RPM