mschuyler

I have coded my exhaust to always be in Sport Mode. Some people report pulling a fuse to always be in Track Mode for exhaust. Is there a difference in sound between Track and Sport? Thank you.

smitty55

I have wrestled with this alot. I have mine in sport for driving and track for exhaust and pulled #42 fuse . This keeps exhaust open all the time. The exhaust only comes out the two outer tips. My two inner exhaust tips are as clean as day one. Still too quiet for me.

kenownr

Not that I can tell except the Track mode steps in to open the flaps a little sooner. I have pulled the fuse a couple times but always put it back in as the AFM (A8) sound switching back and forth at highway speed bugs me after awhile. Now I just code it to track mode all the time. I did put on the X-Pipe for a little extra volume especially at WOT.
(By the way schuyler, your Avatar is a bit un-nerving LOL )

dvilin

No difference in sound, pulling fuse #42 leaves the valves open 100% of the time. One of the first things I did, the sound is great.

Red Mist Rulz

For a little more detail:

As you probably know, with the NPP exhaust there are valves behind the mufflers that can open and close (and be partly open) depending on driving conditions like speed, throttle opening, gear and how you set the exhaust or driving mode.

In track mode, the valves are fully open MOST of the time, giving you the loudest exhaust possible with the stock exhaust. Even in track mode, though, the valves close at steady speeds below about 36 - 37 miles per hour, in certain gears, in order to pass federal sound tests.

In Sport mode, the valves are much more variable. Under strong acceleration, and large throttle openings, they open all the way, just like in track mode. But at smaller throttle openings, and during steady state cruising, they close PART way, so the exhaust won't be as loud. This is actually a plus, for me, when cruising on the highway as you get none of the drone that can occur in track mode. When you mash down on the gas pedal, though, the valves open up fully.

In Tour mode, the valves stay partly closed most of the time, opening up only under hard acceleration. In Stealth mode, they're closed all the time.

So what does pulling the fuse do? It keeps the valves from closing, ever. If you're running in track mode, pulling the fuse keeps the valves open even at 35mph and below.

One caveat, though: Whenever the engine goes into 4 cylinder mode, a second pair of valves, located ahead of the mufflers, comes into play. Generally known as AFM valves, these open and close (partially) based on engine rpm, throttle position, and maybe speed. They're designed to keep the engine from sounding like a 4 cylinder Honda with a fart can exhaust, but when they operate they make the exhaust quieter no matter what position the NPP valves are in. Even if you pull the fuse. If you have a manual trans, the engine won't go into 4 cylinder operation unless you choose. But automatics go into V4 mode frequently, unless you are in manual, paddle shift mode. So even pulling the fuse on an automatic won't make the exhaust louder a lot of the time.

madrob2020

I believe you'll find by holding your hand near inboard tips they do emit exhaust. I also believe (always hedge your bet) the reason the inboard tips stay clean(er) is that exhaust gas goes thru the mufflers which have a ton of wadding for muffling sound, ergo: filters black gases (no muffler on outside tips). Actually the outside pipes go thru mufflers but the mufflers are divided into 2 chambers w/inside chamber only having wadding, but you knew that!

themonk

Yes, even in sport/track mode the valves stay open only 80% of the time.

JerryU

Hmm, I have mine set to be in Track Mode wherever my driving mode is set. It IS NOT open all the time, just opens at a lower rpm BUT is shut when cruising on the Interstate for example. Even around town only opens when I accelerate.

Pulling the fuse keeps it open all the time. You will get a drone when cruising at highway speeds. Some tolerate the noise but even when playing Janis Joplin singing "Cry Baby" it was objectionable! In my C6 I installed a simple switch to bypass the fuse only when I wanted.

DETAILS: It was easy in the C6 to install a simple bypass toggle switch. The fuse panel was under the carpet on the passenger inside firewall. Pull the carpet down, install and Add-A-Circuit, wire properly and a simple toggle switch was all that was needed. $10 and installed the switch in the front cup holder.

For the C7 the fuse is in the engine compartment fuse panel so adding an Add-A-Circuit requires routing two wires from the fuse box into the passenger compartment. It's a 20 map circuit so need the right size wires.

As there was for the C6, you can now buy a remote relay system prewired for you, called Mild to Wild (google, ~$70.) The issue with it is what mode it starts in and what I found with remote relays is the time it takes to operates, varies. Just like my remove garage door opener! In fact, if you have a 2LT or 3LT can use one of the 3 buttons to active the Mild to Wild fuse bypass versus using the supplied remote FOB, if you want.

I liked the direct toggle switch as it is instant on or off and you can look and see what mode it was in. However, for me, happy with "Always Track" setting.

SOUND: The NPP is a simple cut-out that essentially bypasses the muffler. Sound is fine when accelerating, in fact my low restriction air intake makes a nicer almost as loud a noise, IMO! Borla, Flowmaster and others spend time to design the system to have different sounds. You listen to a sound clip or video and pick the model you like, they are more than simple cut-outs!

IMO the Flowmasters I had installed in my S-10 sounded better at all speeds. The Borla mufflers I have on my street rod also sound better. They are fairly quite at idle and cruising even through the long tube headers and 3 inch pipes. However at WOT they are loud as is the air coming through a 14 inch diameter X 5 inch high K&N oiled cotton air filter. That sucking sound is almost as loud as the exhaust!

Foosh

I can't tell any difference in max loudness between Sport and Track. It seems to be a minor variation in how often valves are open vs. closed.

Dr Man

I could have written this. I feel exactly the same way.

vbdenny

Same deal. #42 in spares slot. I'm thinking it must be louder than I think. I about never drive with even the windows down and people have told me it's loud. I woyld prefer the sound be somewhere between annoying and obnoxious. With #42 out, barely even to annoying.

joemessman

There was a long post on this about a year ago. The short answer is that if you pull fuse 42 it doesn't matter what mode you are in. Removing the fuse overrides mode position. If you have the fuse installed there is a very very slight difference between Track and Sport. Even so none of the posters could tell the difference. But if you are in Track mode the car behaves more aggressively in performance shift than in Sport mode. So the exhaust pops at gear changes in the Automatic are slightly more exaggerated at the shift points. And that has been my experience.
Personally I have the fuse removed and use Range device. So the v4 to v8 is a non-issue for me.

JNess

I agree. My fuse is pulled.

It sounds.... european? It really doesn't sound like a big 6.2l V8.

I wish it sounded half as mean as an SVT Mustang...

I'm thinking a Borla Mid-pipe and ATAK system is in my near future.

JerryU

Thought this Borla Video was worth watching and listening to for anyone considering an aftermarket exhaust:

B Chas

I've only had my C-7 for 3 weeks, 1k miles. I have the stock exhaust on the base car, still I love the way it performs and sounds.

I can't tell any difference in the modes. All 4 modes sound the same and seem to work the same. I change modes while cruising, no change in sound or RPM. I haven't played with the settings much, Am I missing something?

Patman

With the base exhaust, it will sound the same all the time, there are no flaps in it, so the different modes cannot change the sound in any way.

LbulletM

The NPP RPO code!

JerryU

Yep, appears you have the standard exhaust. All exhaust always goes through the muffler so will not have any difference.

Those of us with NPP have that $1100 option (or it comes with certain models) that essentially bypasses the muffler internals starting at certain rpms. The outer two pipes have valves that open at like ~2400 rpm when set at Touring, ~2000 rpm when set at Sport and `~1700 rpm when set at Track.

Can't really be added as it's intergrated with the car's computer.

IF you have NPP, you may have inadvertently selected an option to have it in Sport or Track all the time like mine. I have my NPP set in Track Mode regardless of my Driving Mode. That is an option in Set-Up.

B Chas

NPP is the performance exhaust option? I didn't choose that.

B Chas

Is there a code that might be missing in the software?