SoCalM5Mang

QUY---What about Rody's question here? I guess I'll be putting her to the test when I go back to Triple AAA on Wed or Thursday to add some right and left side resonators.

VT(Joe)---How in the world did you get "no droning" with your RDS Exhaust when you deleted all 3 resonators? FedCaper---What about you with your RD Sport?


Thanks Guys!

So Cal

tbal

ivan545 got any sound clips.. anyone else of soundclips?

Bimmer32

There's plenty of sound clips on previous threads in the Parts Dept. (subforum). I guess somebody could create an Official Exhaust Mod Thread.

I have 2 round 4" resonators (cherry bombs, glasspacks, small mufflers, whatever you want to call them) at the rear, and it will NOT get rid of your droning unless your Remus 4.5" are some magical canisters or baffled (I am assuming they're straight throughs). I've got a sound clip on my camcorder that records the droning on my vehicle. Let me find some time to edit it and post it.

4.8L is a big engine. 4 resonators alone, will not eliminate your droning. As for the TQ loss, you may noticed your rpm going a little higher for you to feel the "oomph." The sound note can either be interpreted as performance or as engine strain. Either way, your engine breaths better than before in conjunction with your CAI.

Was the exhaust note too exciting to add the oval turbo mufflers at the rear?

Bimmer32

See post #33 and after about muffler and resonator location and x-pipe.

SoCalM5Mang

Hi Quy! If I add the Turbo Mufflers at the rear will it help with Torque Loss?

I've been driving it more and I'm concerned some of the pipe bracketing in the center of the car has come loose? There is an annoying rattling sound/vibration when rolling over bumps/potholes-uneven road surfaces. It also vibrates at start-up and putting in reverse? I'm going back to Triple AAA on Wednesday to have it checked out.

Any idea what this might be? This was not happening the first two days. I was riding around surface streets on Saturday and it started happening yesterday. Maybe hitting a pot hole or something knocked something loose?

Merry X-Mas to everybody!

So Cal

Bimmer32

If anything, the turbo mufflers will help quiet down the sound level; with the sound level down, your butt dyno may feel some reclaimed torque. Sure, turbo mufflers help with low end torque. I thought you were going to re-install the OE center resonator box and turbo mufflers at the rear? Hopefully, those AAA won't charge you additional for installing the mufflers in the rear.

As for the sound/vibration, those Remus canisters look a bit tightly confined in those spaces. I could only guess that it's the canisters or a hanger or 2 come loose or hang too close.

SoCalM5Mang

Merry X-Mas Quy!

I will see what Triple AAA recomends but it's gotta get fixed. There is definitely heat coming from the piping. When I stick my hand outside of the car(passenger side)at a light, I feel pretty intense heat coming from the back(I suppose).

If I have them re-install the Center OE Resonator Box---where would they do it? The two Remus Canisters are right where it used to be. Install right before them and then the Turbo Mufflers in the back? What exact mufflers are you using in the back left and right? I need to make sure they fit completely with no hang.

Thanks bro.

Jay C

vegastrashed

I've been doing a lot of research and I truly believe that bullet resonators are not glass packs (cherry bombs) and that they will minimize, if not eliminate, droning. I'm going forward with this when I get back to the Bay Area.

Bimmer32

Merry Christmas to you as well.

1. The heat - all cars have heat eminating from the bottom. The radiator fan usually blow heat under the car. As for the piping, exhaust gas are very hot, so of course, the pipes will be hot. There are OE heat shields until you get to the back right side. As long as the pipes and/or resonators/mufflers are not touching any walls or compartment, you should be OK.

2. The OE center boxed resonators go where your remus canisters are now. If you want to try your luck again, you can install the canisters at the rear. Warning: I would expect droning to continue. I serious think the stock OE resonators only lower the sound level by 2-4 db and at certain frequencies (usually 90 hz range). So goes the same for the Remus canisters.

As I said before, I'm using two 4" round magnaflows (one on each side). And the droning is unbearable for a 5er type car after a couple of weeks. My cheap fix (mod) is stuffing SS wool to muffle the sound down. It's working so far. This mod is like using Turbo mufflers. I will change to turbo muffs if and when I'm tired of my cheap but effective mod.

Bimmer32

VT, if you're going back to stock resonators, I agree with you. They are design to muffle that certain frequency that your engine produces at a certain load. But to go with a universal (aftermarket resonator) may not guarantee the objective(s) you want to achieve.

A quick review of terms:

1. Mufflers - a device that muffles or reduces sound level (usually use to eliminate or reduce low frequencies) from an exhaust system
2. Resonators - a device that muffles or reduces sound level (usually tuned to eliminate or reduce higer frequencies) but not as effective as a muffler. It is also used to "tune" an exhaust sytem to give it a certain sound and the size is smaller than a muffler.

Mufflers and resonators are used synomymously, but mufflers usually mean a bigger device than a resonator. Technically, a resonator is called a resonator because it is designed to "tune" a certain note from the exhaust noise.

Cherry bombs were so called in the 50s, 60s, and 70s. Then people began to call them glasspacks . . . later bullets. I think that's the order, but someone correct me if I'm wrong. In any case, they all have similar design and purpose.

1. A straight-through perforated pipe. Pipe size and perforation degrees may vary.
2. Cover with SS wool and/or fiberglass and encased. Amount of SS wool and/or fiberglass used may vary.

If it's a tube and fat in the middle, it's a cherry bomb/glasspack/bullet muffler/resonator. For example, I have a 4" O.D (outer diameter) with a 2.25" I.D. (inner diameter) pipe. That give me about 2+ inches circumference volume of SS wool/fiberglass for sound absorption. The size allow me to fit it in small places. It's a resonator by design, but can be called a muffler because it has some absorptive material inside. Cherry bombs/glasspacks/bullets have even smaller amount of absorptive materials.