[joeyp85]

So I've decided to get my secondary cats deleted and I found a video on YouTube of what I think and hope it will sound like. So if I delete the secondary cats on my car, will I experience drone or anything else unusual? I'd like to hear some input that would be greatly appreciated!

https://m.youtube.com/watch?v=fNhhWql9Nv4

[joeyp85]

Originally Posted by CreativeDawn

Drone? No! I have my secondary's deleted and I noticed a louder Wide Open Throttle by about 15/20%! It sounds bolder without the secondary's to be honest! Driving in Stealth is about the same for me however the rattle was a little worst lol.

Joey...Check this video out too! I've seen the one you posted months ago and the beautiful Dog to go with it. This is Matt's video and it's an outstanding mic to go along with the video for the full effect....If you want a bigger positive effect, wear earphones and listen so you pick up all the surrounding noise/frequencies!

1 MINUTE AND 7 SECONDS INTO THE VIDEO ....Drive by
On my part however, I'm dealing with a NEW issue that you might of come across but that's a whole other story. :(

What's the issue you're dealing with? Does it have to do with deleting the secondary cat?

[gdgraph]

Drone will depend on the mufflers you go with, if you are keeping the stock NPP and just doing secondary cat delete it won't change drone, you will just get a little bit more volume out of it and what people describe as a little more of a raspy exhaust note.

I have all of my cats but went aftermarket with the Borla S Type with Mid Pipes (that go up to a few inches behind the secondary cats) and when I hear the same set up with the secondary cat delete and it's only about 15% louder on WOT and a little bit raspier in sound.

[Teem0s42]

No Drone. Nothing unusual. Same sound as stock just maybe 10-20% louder

Heres a clip of my car after I took out my rear cats. everything else is stock!

https://www.instagram.com/p/BLrn01TgEuw/

[joeyp85]

Originally Posted by gdgraph

Drone will depend on the mufflers you go with, if you are keeping the stock NPP and just doing secondary cat delete it won't change drone, you will just get a little bit more volume out of it and what people describe as a little more of a raspy exhaust note.

I have all of my cats but went aftermarket with the Borla S Type with Mid Pipes (that go up to a few inches behind the secondary cats) and when I hear the same set up with the secondary cat delete and it's only about 15% louder on WOT and a little bit raspier in sound.

Now I'm debating if I should get rid of the muffler as well but I'm probably going to stick with the secondary cat delete for now but I know I'll be happy with it! I'll post a video of it after it's finished.

[gdgraph]

It just depends on what type of sound you are trying to get, if you delete the secondarys and the muffler latter, you'll have a very loud, raw, and raspy sounding exhaust. I went with after market because I needed to be able to turn the loud on and off.

Originally Posted by joeyp85

Now I'm debating if I should get rid of the muffler as well but I'm probably going to stick with the secondary cat delete for now but I know I'll be happy with it! I'll post a video of it after it's finished.

[White LT1]

I wonder if there is a loss in power if secondary cats get deleted...

[SuperSound]

Originally Posted by White LT1

I wonder if there is a loss in power if secondary cats get deleted...

Why would there be a loss? They are only there to pass CA emissions.

[gdgraph]

If you increase exhaust diameter without a tune, you can get a loss of low end torque because there's not enough back pressure, but I highly doubt any significant/noticeable loss with a secondary cat delete. Most people do the delete purely for the added sound.

You'd probably see low end power losses if you went to something like 2" headers with a full 3" exhaust and no tune, but not for something like a secondary cat delete.

Originally Posted by SuperSound

Why would there be a loss? They are only there to pass CA emissions.

[SuperSound]

Originally Posted by gdgraph

If you increase exhaust diameter without a tune, you can get a loss of low end torque because there's not enough back pressure, but I highly doubt any significant/noticeable loss with a secondary cat delete. Most people do the delete purely for the added sound.

You'd probably see low end power losses if you went to something like 2" headers with a full 3" exhaust and no tune, but not for something like a secondary cat delete.

Right, but we are talking about a section of pipe less than a foot long. Now if it was like your example that's another story.

[EFI Tuning]

Why does the myth of back pressure keep on living? You do not want back pressure... not even a little.

[DD goat]

back pressure is good....in a 2 stroke dirt bike!!

[tireslayer0331]

Can anyone attest to how much louder it is from inside the car? I plan to cut mine out in the next week or two. My blowoff valve is louder than my exhaust from inside the car (sounds like driving through a puddle) when driving below 20mph and I want to hear more exhaust and less air whooshing around. I plan to do primary deletes too next month so hopefully both will take it to the volume I want inside the car!

[tireslayer0331]

Originally Posted by CreativeDawn

I'd say it's not louder INSIDE the cabin but the general exhaust note is louder outside! That's a good thing...right?

The ONLY negative I noticed was a slightly (and I mean very slight) increase in the Stealth NPP Valve Rattle after the cats were removed but other then that everything was well worth the money to do so.

I can't say if the WOT was louder because when I had them removed I still didn't properly break-in my Engine! However it sounds great at WOT now. :-)

Awesome, thanks. I'm excited to try it out. I think the only time I will use stealth mode is if I run into a police officer to make me a bit less conspicuous so a slight rattle wont bother me.