Questions about loudness

[Starfall]

Originally Posted by Gunmetal Speedster

I believe there are 4 cats total, 2 per side, when the car is stock. Longtubes are the same length as a factory manifold plus the first cat. So you're left with the length of the second cat before you reach where the catback begins. The tiny pipes you received with your longtubes are most likely hollow, indicating they are catless midpipes. If they were high flow, they would have cells. Either way, the length of the cats after longtubes is drastically shorter/smaller due to how much longer the longtubes are compared to a stock manifold/shorty, so there is less room to work with before the start of the catback. Hopefully that makes sense, it's kind of hard to explain lol I'm going to include a picture for reference, comparing a stock manifold and its cats to a longtube with its cat(less) pipes.

Thanks, that cleared up everything

[BandRcAMARO]

Its a v6, save yourself the money and headache and leave the exhaust how it is, maybe do a catback. Anything with removing the cats or resonater it will drone and sound like crap.

[Gunmetal Speedster]

Originally Posted by yzinger

Thats a great find Gun.

Originally Posted by Starfall

Thanks, that cleared up everything

[Indydriver]

I was an exhaust novice when I joined this forum so I researched like mad before taking the plunge on my “14 LS3 convertible. I didn’t want to get it wrong. My goals were power oriented, not necessarily “noise”. In addition to virtually any combination possible by various members, I got a couple of very authoritative recommendations from BITOG vendors.

Bottom line: the best conventional wisdom from all the experience here is, modify from the engine back. I ended up going with headers, HFCs into the stock NPP catback. I got most of the power available (+42rwhp) without being obnoxiously loud and preserving the excellent NPP functionality that I had just paid $1000 for. I was thrilled with the mods in 2014 and remain so today.

Also, on the V8, stock throttle response is “mushy”. A $150 polished throttle body makes a big improvement in everyday driving. Can’t speak for the 6 guys but I wouldn’t be surprised that they’ve had the same experience.

[The camaro show]

I got the mrt v1 and i love it its perfect the v2 is bad

[Cenafan85]

Originally Posted by The camaro show

I got the mrt v1 and i love it its perfect the v2 is bad

The V2 is one of the most popular exhaust for the V6

[Starfall]

Originally Posted by Indydriver

I was an exhaust novice when I joined this forum so I researched like mad before taking the plunge on my “14 LS3 convertible. I didn’t want to get it wrong. My goals were power oriented, not necessarily “noise”. In addition to virtually any combination possible by various members, I got a couple of very authoritative recommendations from BITOG vendors.

Bottom line: the best conventional wisdom from all the experience here is, modify from the engine back. I ended up going with headers, HFCs into the stock NPP catback. I got most of the power available (+42rwhp) without being obnoxiously loud and preserving the excellent NPP functionality that I had just paid $1000 for. I was thrilled with the mods in 2014 and remain so today.

Also, on the V8, stock throttle response is “mushy”. A $150 polished throttle body makes a big improvement in everyday driving. Can’t speak for the 6 guys but I wouldn’t be surprised that they’ve had the same experience.

That's alot of details and i like how in deph you went with it, people that are here to help and share experiences are amazing. thank you even though this is for the v8 i would like to get more info on the whole throttle body thing one thing i noticed is the delay in higher gears 3rd and 4th have somewhat of a delay, obviously they're higher gears but it seems like if i mash the throttle i don't get the acceleration that i should be getting, i was thinking it's either the delay that things like the vitesse/ throttle body's fix or it's just that it's a high gear, i was by no means lugging the engine.

[go_go_gadget88]

Originally Posted by Cenafan85

The V2 is one of the most popular exhaust for the V6

Maybe he meant bad as in good?

[Theloots]

Originally Posted by Gunmetal Speedster

I believe there are 4 cats total, 2 per side, when the car is stock. Longtubes are the same length as a factory manifold plus the first cat. So you're left with the length of the second cat before you reach where the catback begins. The tiny pipes you received with your longtubes are most likely hollow, indicating they are catless midpipes. If they were high flow, they would have cells. Either way, the length of the cats after longtubes is drastically shorter/smaller due to how much longer the longtubes are compared to a stock manifold/shorty, so there is less room to work with before the start of the catback. Hopefully that makes sense, it's kind of hard to explain lol I'm going to include a picture for reference, comparing a stock manifold and its cats to a longtube with its cat(less) pipes.

Gunmetal ... thanks for the pic. I'm scoping headers for my 2012 2SS in NJ. In your pic is that an actual cat that comes with the headers? meaning, would you still pass emissions? or is is a fake for the dreaded state inspection mirror?

[Gunmetal Speedster]

Originally Posted by Theloots

Gunmetal ... thanks for the pic. I'm scoping headers for my 2012 2SS in NJ. In your pic is that an actual cat that comes with the headers? meaning, would you still pass emissions? or is is a fake for the dreaded state inspection mirror?

Not a problem buddy. As far as your question, I'm not sure. As far as I know, I think the only way to tell between a high flow or catless midpipe is just to look inside. One will be hollowed out piece of pipe and the other will have the cat material in it. If there is a way of differentiating the two from the outside, I'm unaware of it.

[rtcat600man]

Let me throw my 2 cents into the mix.

I have had the MRT 2.0 for over 6 years. These are the most populuar axle back mufflers around.

I have since added the OBX headers, which eliminated the cats.

The RASP is so bad you will want to add the Magnaflow resonated X pipe.

Here are some photos and sound clips.

ENJOY.

Hope this helps.