Hi everyone I am debating on if I should get the performance exhaust or the MBRP when I order my C8 I don’t want to spend thousands on just sound I know the NPP it’s about 1200 dollars option and the mbrp it’s about 1500 plus like 500 for install and From what I read in here the npp is not loud I would appreciate you guys opinion taking in mind that as I said I really don’t want to spend all kinds of money on borla or other expensive set ups so what would you guys recommend Npp or mbrp, thank you for your advice

 

YMMV, but the NPP exhaust on my C7 is plenty loud enough for me and based on the C8s that I have heard with the NPP, that would also be loud enough. Just depends on how loud you want to go.

 

Is there cabin drone with the MBRP? I had the performance exhaust and just replaced it with the Borla Atak. It is crazy loud with the cold start, but there is no cabin drone or loud exhaust while driving. I kept the AFM and NPP valves.

 

yeah and I’ll love to do that but I don’t want to pay 1100 for the NPP just to replace it with another exhaust although I’m sure it sounds great and you have the working valves to adjust the sound, I was sure to get the NPP but seeing so many people are changing them for something louder is what makes me think that I should just get the stock non performance and just getting the MBRP for only 1500 maybe someone heard or have them that can let me know if they are any good or not worth it

 

Yep, been following C8 exhaust design since the early Tenneco tech article and Boral 1st video (URL in pic) discussing the many temperature sensors used on the stock C8 to be sure they were within the OEM temp values.

The Tenneco tech info article discusses what and why they had many challenges with the ME C8 versus the C6 and C7 FE Vettes where they also designed, built and deliver a fully welded system to GM for install. They are an American company (and one of my good customers for welding accessories) but had their European Group engineers devise a way to deal with the V4 valves. The valves are close to the CATS (unlike the C7) and required a different approach to keep them from getting excessively hot. No doubt why Borla is the only exhaust system endorsed by GM and GM dealers can sell and install.

Know it's more money but IF I wanted more that NPP would be my choice. I do have Brola short Stainless Hot Rod mufflers and 3-inch Stainless pipes attached to the long tube headers on my ProStreet 8.2 Liter BB. Sounds great! About the size of those shown for their Atak system.


Have no experience with other systems BUT many show no heat insulation when it was a major challenge for Tenneco and Borla! This system has no mufflers and is relying on the CATs for what noise reduction they have. In my Street Rod the small Borla straight through Hot Rod mufflers keep it relatively quiet when cruising but are loud when accelerating.

 

Having spent a ton of money on performance mods for my c7, to include ecs supercharger, meth injection, and a full exhaust with cat deletes, the sound i got out of it was impressive, not to mention the car was a rocket-ship. With budget in mind this time around, I paid for the npp on my c8, and i plan to replace the cats with high flows for around $600. Hopefully some decent noise and i didnt break the bank doing it… food for thought.

 

that sounds pretty good so the high flows are around 600? How about the installation do you know approximately how much will be the cost

 

This is just my opinion, but when you crank the exhaust sound up in My Mode or have the car in any of the other modes that has the exhaust sound wide open, it is plenty loud outside the car. Inside the car with the top on/up and windows up.... it can be fairly quiet. I think thats partly a trait of having all of the exhaust system behind you, rather than pipes running the full length of the car, and how well the car seems to be insulated/sound deadened. Usually if I want to hear the exhaust, I'll just put the top down or put the rear convertible window down and can hear it pretty well. For a factory exhaust, I think its actually pretty good. You get a good amount of "burbles" and pops. Another thing you don't have to worry about with NPP is the potential for denied warranty claims due "changes in emissions", excessive heat from poor shielding, etc.

 

The quiet passenger compartment would be my concern. My 6 Vettes have been coupes and I very seldom have the roof off or windows down.

Tadge said they worked hard to keep the loud part the engine, the front, quiet in the cabin. The AC Compressor, Alternator, Water Pump, Bicycle Chain driving the cam are all close to our ear. He noted they found Ferrari used 9 mm thick glass from cabin to engine in their ME and they do nothing that adds weight unless needed. They copied. Note a windshield is only 5 mm thick and side glass 3 mm.

He did say the short-coupled C8s CATs to muffler was also a sound reducing factor versus a FE Vette with long exhaust pipes.

He said the tried to get some "good noise" close to the thin side glass. He described what I found when installing a low restriction intake air filter (see pic.)

My NPP set to Track is definitely quieter than my two C7 NPPs. As you note it louder from outside the car. So my concern spending ~$5000 for a Borla system, with my windows always up might not be much louder inside the car! Expect at WOT it would be BUT NPP's is already pretty good at WOT.


Found this intake air passage as Tadge described they used to get "good intake sucking sound noise" close to the thin side window glass.


I used my fiberoptic camera to find where the intake passages went after disappearing in the rear fenders


Intake air comes from a passage in both rear fenders to the central air filter. Tadge said they routed it high in the fender so it was closer to your ear via the thin side glass. BTW have to dismantle the Truck to get this far! Not easy to change engine air filter.

 

I think you guys are right I should go with the NPP that way I don’t have to deal with the warranty and if I feel like is too quiet I can always consider getting some high flow like someone else said, you guys are great thank you

 

Theres a few recent threads related to exhaust upgrades and installing only high flow cats along with the stock npp. Some folks quoted $600 with labor. I have not gotten any prices myself but i plan to call my local speed shops soon. My only fear in doing the cats is potential problems with warranty claims.

 

How was your mod? Did it make a difference? I have the performance but want another 25% in loudness. I had mbrp street on my GT and miss the roar.

 

I went with the mbrp exhaust on my c8 and loved it. 100x better than stock or stock performance. My opinion. I was looking at a manual mustang gt and have the mbrp picked as my exhaust for that ifi purchase one too.

 

They're a standup company and make a great product. They're my go-to. I love my C8 but miss my GT so much.

 

Buy an NPP exhaust used for $100, bolt it on. Biggest pain is getting the bumper off, did mine in about 5 hours. The exhaust will run loud all the time, the good news is it isn't loud inside the car, no drone. You'll hear it at cold start though. Pocket the $1100 left over for a different exhaust if you don't like it.

 

I hope you're saying the 5 hours was for doing the whole thing..... bumper removal is about 30 minutes.....

 

The NPP exhaust provides more options for sound quality. The raw sound is available with any straight pipe exhaust, I like the sound of the 917 gulf Porshe and Ferrari 330 P4 for the raw option. The 458 Ferrari Italia with the Novitec exhaust is a good reference for high pitched refined tone. More sounds are available with NPP exhaust options for the c8. The most difficult sound to replicate is the 459 Ferrari 358. The Zo6 is an attempt to replicate this sound. Go for the NPP.

 

yess I end up doing the same thing, after hearing the npp borlas Corsas and others I decided to get the mbrp and so glad I did, the sound and look are amazing plus easy to install with no cells

 

The decision on which exhaust to get really depends on how much drone you can deal with in cabin. C8 drone even with muffler deletes isn't as bad as a muffler delete on let's say a C6 or C7, but drone is still there. Having a valved setup allows you to cut that drone. Add headers and / or sport cats, and the drone becomes worse. That's where the option to close the valve is nice.

I am working on a dual mode exhaust that works on cars that don't have npp from the factory. I'm actually not too far from Manalapan, NJ. I had a prototype on my C8 this year at the Red Mill car show in Clinton, NJ this past August.

The muffler delete setups like the MBRP also has no valves. So when you go into 4 cylinder mode you get this odd frequency tone emitting from the engine. It sounds like a very long, constant hit of bass. Again, it all depends on what you need and want in your exhaust. Having no valves at least makes the exhaust note more consistent. With valves on the highway the car is constantly opening and closing depending on how hard you're on the gas and the engine note goes from loud to quiet more often.

 

I have MRBP on my C8 and its loud as hell and exactly how I wanted it. LOL Cold start I do with the garage closed for sake of the neighbors. LOL Once the valves close it is reasonable. Yes there is a little drone because they are so loud, but its not bad at all and doesnt bother me. You can see my other 2 boosted cars below which both have Corsa and the C8 is much louder lol. If you want loud you'll love MRBP lol.