DIY Stealth Mode for noisy cold start
 

Hi folks,

Before I get a ban from the Forum :bellyroll: I want to say that everything started just as a game with extra parts I had in garage but at the end it worked and pretty well though :bellyroll:


I just installed the axleback Borla S-Type. I love them but during the cold start, they are quite heavy and honestly I was feeling bad for all my neighbors and their kids when I was leaving at 5 am for work.

Anyways the stock exhaust too were pretty annoying at cold start.

My ride has the exhaust dual tip non NPP; however I read that also who has the NPP has the same problem since during a cold start, the valves stay open for the first seconds.

so, here is what I have made:

Cold Start with S-Type


Cold Start with the 'boxes of shame' :)

the Videos are taken from the same distance, I just zoomed a little more on the first one.
As you can hear, these crappy boxes do their job, and I have to say, they are quieter than the stock exhaust I had!

I've put at the end of the post the pictures on what it's inside the boxes.

I know :sorry:, foam, cardboard and plastic are not really a good idea when we talk about exhaust but I wanted to test first if the idea I had in mind was actually working (I don't trust myself :rolleyes: ).

In addition, I'm going to use them only for a cold start, the gases are not so hot to damage something there. I'm just worried about the condensation and the chemicals that may damage the foam in a long term process.

worst case scenario I will build a new couple, 96c the box, $9 pipes and $5 the foam sheets :thumb:

in case of quad tips, the box layout will change but I guess it will work anyways.

thoughts? Can I still stay in the forum after sharing how crazy I am? :der:

This is true if you use the mode selector and have the valves tied to the modes, but you can select "stealth" mode manually in the infotainment system and it will start with the valves closed

So this Home depot box filled with foam to a Camaro is like a silencer for a Gun

Yeah the last place that I lived I always would get some comments from my neighbor from when I had my 2010 with the Flowmasters on the cold starts, but since I moved to the country I don't worry about that anymore but good idea with the boxes.

Oh, Good to know, thanks for the info.

I didn't have the chance to see an NPP by person and looking at some video I thought even the stealth mode was doing that trick.
I thought they were doing in that way to prevent the cat poisoning

Thanks again, more inputs today ;)

Haha yep, actually the original idea was coming from there.

I know, they look horrible, for sure the car deserves a better reputation than me posting those creepy things around the world.

But I can tell you they work great. I have to say it, the videos are not giving the real comparison. For real, the difference is more consistent.

My neighborhood has the highest concentration of hybrids and electrics that I think they are trying to test me :biggrin:

Honestly, I had fun working on them and my neighbors really appreciated the move, it was not asked.

[QUOTE=Can I still stay in the forum after sharing how crazy I am? :der:[/QUOTE]

Sorry. You gotta go!! :lol::lol::lol: