Sound levels w/ turbo+no cat+enthuza?
 

Couldn't find a thread that pertained to this exactly. Kinda seeing if anyone has some readings

Basically one of the locations for my local autox has a sound level restriction. The limit is set at 94 dB and they have the reader set correctly with forgiving conditions for the most part. They'll run the meter at locations that don't have restrictions so people can try out different mufflers,silencers, etc. I was the loudest at the last event, lol. It read 97.9 dB at WOT probly around 6300 rpm.

Im running stock header to a 2.5" text pipe to Enthuza's 2.5" turbo exhaust. Was wondering if anyone with a test pipe + enthuza catback with a turbo has any idea on how loud they're car is.

I'll be running a gt2560r with FM's manifold and 2.5" downpipe.

I have the 3" enthuza with a bullet cat and people can hear it grumble from a mile away. I don't have any db numbers, but it can't be track legal at 93db.

For a short while, I ran a test pipe with my 2.5" Enthuza and a Greddy turbo. It was slightly louder than with the cat in place (a 2.5" ceramic-core unit) but by no means completely outrageous. On the downside, it was a tad stinky.

I bought this and it really quieted down my car: eBay Motors: 93-97 MAZDA MX3 323 626 Catalytic CONVERTER REPLACEMENT (item 170307813235 end time Apr-01-09 15:54:23 PDT)

I haven't tried it with a full exhaust but it appears that it would work. The local autocross is fairly strict and I haven't had a problem running the resonated testpipe and a turndown. For $6.90 it might be worth a shot. It's 2.5 inch and bolted right up to my Begi 2.5" downpipe.

Greddy turbo, test pipe, 3" Enthuza:

The cat isn't a huge sound attenuator anyways, when I first put my 2.5" together I rolled without a muffler for a day. It was LOUD.

I have a 2.5 Enthuza and test pipe that I just installed yesterday. I can say that it isn't much louder than my Racing Beat Power Pulse set up I had. Very liveable.

I would have gone 3", but I DD this car. Unlike some, I will sacrifice some power for comfort.

3" Enthuza with 3" CAT from them:

The 3" Enthuza, left exit, test pipe, and no muffler is louder. :)
Stephanie

It's loud enough I drive with the HT on and windows up like a pussy. I'm excited to add a cat next February.

is the testpipe resonated? if not, have Jason make you one. (FYI, just 3 glasspacks and no muffler is definately too loud)

All that my OTM has after the cat is 3 glasspacks (well, resonators), and that's all stock.

whoring this out:
and that is with a cat.

Sounds pretty good Hustler.. definitely has taken out the rasp and a little of the volume of my setup. Does it drone at all?

my cell phone sucks, but I have to put it on speaker and next to my ear in the car. After a few hours of road tripping headaches start. Its not bad for 30-minute commuting. It actually hurts the ears in tunnels and passing cars on the loud pedal, but the turbo is part of that.

edit: Its not my daily driver so I don't mind the noise. I would pull the cat but don't want it any louder.

Sr20 t25
FM mani and 2.5" downpipe
Custom 3" testpipe
3" alumanized steel enthuza

At least you can hear your cellphone in your car.. I barely can at anything over 40. I don't take roadtrips in it, which is one of the reasons it's coming out here on a truck as I type this. :) I'm not looking forward to driving to TX in it after I graduate here. My exhaust is just like yours, but with no cat, and I also don't have any boxing around the intake yet, however much sound deadening that might add.

I have tried both with and without a cat on my last Miata that had a Greddy setup, RM 2.5 downpipe, and the Enthuza 2.5. Definitely prefer running a cat. A high flow cat will not inhibit power enough to justify not having piece of mind from cops and keeping your hearing.

Would a decent sized resonator take enough off or would a cat be pretty much the only option to bring it down to a comfortable sound level?

Why not just run a proper high flow cat?

I'd love to see some real data on this...but none exists on this forum.

Jason/Enthuza claims they saw a negligible drop in output on a V8 with the cats he uses...but too many confounding variables exist.

from what I've read, and what I did with the turbo vw, resonators only stop the popping noises and "rasp." It basically made the car sound boring and OEM. I have no resonator and think my car sounds pretty coo / mature / respectable.

bigger mufflers seem to be the right answer for making it quiet.

That seems like under 94 dB, ill just have to test it at the next autox after i put my car back together haha.

When you put the turbo in, the system you already have it will quiet down a bunch. A turbo exhaust without a turbo is VERY loud. That's what you are currently running. No wonder you were loud car of the day. Add the turbo it will mellow things out considerably.

On Enthuza's site and at Goodwin I remember this being discussed. A turbo exhaust without a turbo is loud. Not a good loud, an annoying raspy loud.

while we're whoring out exhaust vids:





stainless header, Enthuza stainless N/A racer exhaust w/ resonated midpipe, resonated testpipe and Borla muffler. Resonators are ANSA/Silverline glasspacks.

I had a 3" enthuza and a 3" silverline reasonator and at idle it sounded not much louder than stock. My chevy truck is louder with a turbo muffler.

And when driving it was perfect. No worries of cops, you can hear the radio, spool was awsome!, and everyone around you could tell you where not average. It was not bumble bee, it was quality bass and perfect.