skidude

iTrader: (3)

I have a 3" Enthuza catback, with an 18" magnaflow. I love the sound, and I like the volume at WOT, but around town and on the highway it drones loudly. I'd like to kill this drone.

I talked to Jason, and he doesn't have an NB to use, so he said it would probably just be better for me to find somebody locally who can weld in a resonator for me, that way I can make sure it will fit.

I haven't driven the car in a couple months, but if I remember right it drones at ~2500 rpm and ~4000 rpm. What are my options for resonators?

I will measure the length tonight, but I don't have a whole lot of space above the pipe. Maybe a little over an inch before I would hit.

I searched a little this morning, and there is a bunch of talk about 2.5" systems, and longer mufflers, but I couldn't find much about fitting a resonator on a 3" exhaust.

Braineack

iTrader: (62)

Any 3" bullet style will work. I have a louvered resonator I bought on ebay for like $20.

y8s

iTrader: (8)

EFF louvered. Get a dynomax bullet race muffler from summit or jegs or whatever for $35.

amazon doesn't have the stainless one but they do have the mild steel 12" long 4" diameter one in 3" in/out.

skidude

iTrader: (3)

So why a race muffler over a louvered resonator? I can't find a stainless dynomax bullet on Jegs either, do they not make those in stainless? I don't want any aluminized stuff in my nice stainless exhaust.

Jason mentioned a couple that he has used in the past, but now I can't remember what they were. One was a magnaflow, and the other might have started with an H.

Braineack

iTrader: (62)

they impede flow and dont work as well...

9671111

iTrader: (10)

*

EO2K

iTrader: (37)

^^ +1 I was going to say, Vibrant seems to have a pretty good rep.

http://vibrantperformance.com/catalo...Path=1022_1033

skidude

iTrader: (3)

Don't work as well for killing drone, or for reducing volume overall? It seems like something with a completely different design from the primary muffler would do the best job of cancelling drone.

JasonC SBB

Flapper valve cheaper to install than resonator.

The resonator that will fit on a 3" exhaust will have so little meat in them that they won't be very effective.

Enter, THE FLAPPER VALVE. Installed before the exhaust tip.

https://www.miataturbo.net/showthrea...xhaust+flapper

skidude

iTrader: (3)

Those vibrant units seem to be recommended quite a bit, and the description says "true straight-through perforated core", which shouldn't impede flow, but would be just like my magnaflow muffler.

JasonC SBB

Only 4" round resonators fit under the car.
If you have 3" piping, then the resonator will only have 0.5" of meat.

This is very little and will not reduce drone very much.

EDIT: IF you don't have a cat, then you can fit a large resonator where the cat normally is.

JasonC SBB

CTTOI I would just replace the final muffler with a DYNOMAX VT muffler which has the flapper built in. They are straight through very quiet in cruise. $80 for a 3-incher.

TurboTim

iTrader: (9)

you so crazy. I have to get a stiffer spring and/or stretch the spring more and/or lower the surface area of the flapflap. If I hold it up to the tip at idle it goes flapflapflap. Certainly quiets it on the outside though, I haven't tried it on the inside. Ducttape won't hold it on. I'm going to a trade show at the beginning of March, hopefully I can fingerfuk a VT flapflap to get a feel for the preload.

Odd though, I don't have any drone with a basically same manifold/exhaust/muffler as the OP. I run a 3" metalcore cat.

skidude

iTrader: (3)

I also have a 3" cat that I assume is metalcore. I thought of replacing it with a big resonator or something, but since it's my summer DD, I should probably keep the cat.

That is curious that I have such noticable drone and you do not with very similar setups.

So if I can fit a 4" *something* in there, it sounds like I should go with a 4" muffler, as long as I can fit rather than a resonator of the same dimensions.

Braineack

iTrader: (62)

Mine made the most minor amounts of difference in reducing resonance. Once it went to the 5x11x22 I'll never go back.

y8s

iTrader: (8)

http://www.dynomax.com/mufflers.php?muffler=racebullet
Part number 24248

Just have to find it.
edit: both jegs and summit have it. It's twice as much as the aluminized.



My car does not drone at all with the "only have 0.5" meat, a cat, and big magnaflow. Same with Braineack's.

JasonC SBB

Here's the Dynomax VT

http://www.dynomax.com/mufflers.php?muffler=vt

TurboTim,
The spring is pretty stiff, requires effort for a pinky.

JasonC SBB

That's mostly due to the Big Magnaflow (tm)

Anyone add an "only 0.5" meat" rez to a Big Magnaflow and have it fix a drone?