Exhaust too loud
 

Hello guys,

Currently my car is too loud, especially the drone in the inside. Recently changed my exhaust because my flow was too restrictive and I want to minimize loss of whp.

I have a supercharger, emptied cats for flow and a full Greddy evolution dual exhaust. The sound is deep and very little rasp which is good. But from the inside, the drone is too much.

What do you guys suggest:

1. Back to cats
2. Try to add an extra resonator/muffler
3. Change whole exhaust
4. ?

Update: The tuner has mentioned 30 or more whp loss if I go back to cats which is not my preference... so looking for other options. Thinking about adding some resonators in the y pipe which I hope will fit. Will contact a custom exhaust company for that.

You can try inserting these under the car:
https://www.moroso.com/moroso-shop-browse/29000/2901/
These will drop 5-7DB of noise

OR you can try these:
https://spintechmufflers.com/mufflers-1/ but they will be a challenge to fit under the car because they take up a lot of real-estate.

I put a pair of 14" hot-dog resonators into the centre-section on my car and it knocked the edge off the reverb in the cabin at 2800-~3000rpm (110kph freeway speed).

In for answers as well. My car is almost undriveable because the sound just eats away at me

As far as drone, Motordyne Art pipes make a big difference.

I thought they helped more with rasp? But if they take care of drone then I am interested... if I could find one that's not at rip-off prices

They act the same as Helmholtz resonators which are used to reduce drone. They greatly reduced the drone on my Fast Intentions exhaust. They definitely help with rasp too, especially if you're coming from unresonated test pipes

From Motordyne website

You can't have your cake and eat it.

1. You are supercharged. Should have went turbo if you wanted less sound.

2. You want max power so gutted your cats. There isn't really any good combination of exhausts that is going to reduce your noise levels enough to satisfy you. You're going to have to understand you'll have to eat some power in order to quieten things down through resonators and especially good mufflers.

As mentioned, definitely start with a resonated test pipe and go from there. There are other companies that make a knockoff motordyne test pipe that is similar and you don't have to wait 8+ months.

The 2.5" FI exhaust has drone? Oh no :icon14: I thought I could find some haven by purchasing an already made system but I guess drone will drone

Do you have links?

If max power if your top priority, then anything you do at this point to lower the drone will decrease power.

As others have suggested, ART pipes should help. If they aren't enough, maybe consider a different CBE, such as a Fast Intentions with resonators. The combination of the resonators and ART pipes should definitely solve your issue.

The FI 2.5" system seems like the best bet from what I've seen.

The design is very similar to OEM

The flow also seems to be reasonably good

Does this system drone even with the resonators?

The Motordyne y-pipe is restrictive since the dual 2.5" pipes are forced to converge into 3" space twice

The design adds quite a bit of power over stock, but as far as drone is concerned with the resonators, I can't answer that. My FI set up doesn't have resonators. I wanted max power, regardless of drone. My Z isn't my daily driver.

and as far as FI vs stock CBE is concerned, I don't think their design is very similar at all. The stock system is a Y-pipe, has a lot more bends and weighs considerably more.

I have the FI lth's with the 12" resonators. There is some drone around 2500 rpm. The 18" resonators take most of it alway. The FI CBE is a true dual exhaust.

That's where my FI got drone was at 2500 rpm

KC at Tig Welding Creations

1. True

2. You can't run cats in the factory location on a boosted car and expect them to last so he needed to get rid of the cats anyway. Even superchargers will destroy them in the factory location. I ran 100 cell mil spec cats in my lead pipes. My HKS Hi Power exhaust with Art pipes was super quiet and didn't rob the car of power. When it was on the dyno, we ran it uncorked because I thought I was getting an exhaust restriction. It only gained 10whp uncorked

It's a single merge and is more than enough for any N/A or mild boost application. Keep in mind oem header design have an output of 2.25"

But I do agree, F.I. is probably the best flowing exhaust on the market.

Its not that I expect/want to become a Tesla, but looking for options to reduce noise without MAJOR loss of performance. I understand that adding resonators etc will decrease HP. Just looking for the best way to do it…

I had a similar issue when I got my car. It had a resonated catless downpipe. Man, it was loud and I could not take it. Put the stock cats back on, much more manageable. Can you try putting the stock cats back on and giving it a try?

Will try to add resonators first, if not, plan b and will look for cats

I have the Greddy Evolution GT dual exhaust with motordyne Art pipes. Sounds great but is fairly loud and does drone at 3K rpm in my car.

Looks like their next batch isn't until March :excited:

thank you for that. That one becomes 3 in duals at the end which is why they're louder im guessing.

It drones even with the supercharger?

Yes.