anand_rahim

According to RealOEM.com the following parts are identified as follows:
Attachment 99501
Attachment 99502
Attachment 99503

Can the terms "muffler" and "resonator" be interchanged? I.e. can a muffler be used as a resonator and vice versa? From what I've researched it seems a resonator is just a smaller muffler and can sometimes be used as a muffler. If my logic is on track the V8 exhaust system is manufactured like this:

headers>catalytic converters>two "resonators">box "muffler">two can "muffler"

Your thoughts/input are appreciated.


Anand

anand_rahim

I suppose my point of posting is to determine the best configuration that will not compromise low end torque, but still using components from muffler manufacturers like Magnaflow, Borla etc. I like that RPI produces an exhaust that has proven gains throughout, but from what I've heard on this forum, the exhaust note is a little raspy for my taste.

I love the throatier sounding exhausts, but I don't like the fact that you lose HP in some way with most of them.

CampioniShop

What are your goals? (keep catalytic converters, catless system, full system, header back, cat back, rear muffler)
What is your budget?

Let me know and we can find a solution.

anand_rahim

I suppose the ultimate goal would be to get an exhaust that is as throaty as a Magnaflow quad with the performance of an RPI. This member worked on a custom exhaust system in the following thread:

https://5series.net/forums/topic/777...ustom-exhaust/

The pics don't come through anymore, but the workmanship appeared top notch. They used a magnaflow exhaust and I believe changed to high flow cats and were able to get performance gains from low to high rpms. The question is, what cats did they use? Did they change the headers also?

Members beg for an RPI quad system, but I think Eloy@RPI said quads lose a lot of HP and torque.

CampioniShop

Supersprint uses the following:

• Equal length headers - catless
• Catted front pipe (they replace the resonators with high flow catalytic converters)
• From that point on it's a regular cat back (with your choice of resonated mid pipe and single/quad muffler setup)

The most gains in most exhaust systems will be had from changing to equal length headers without primary cats and/or switching to high flow components. Arguing about performance gains from a muffler replacement is somewhat pointless if you have the means to go with a full system. To my knowledge, Supersprint is the only company with headers for the V8 E60.

anand_rahim

I agree a full replacement would be most beneficial, but not everyone has the money for that including me. Plus, I'm not sure its the best configuration for what I want. Sometimes changing all of those parts makes the note much louder than welcomed. For me, I'd be looking for a deep note that won't resonate me out of the car.

navin

I had the same problem when i was deciding on my exhaust, ended up getting a used m5 driver side muffler from jcool and removing the center muffler.
Zero drone and no power loss, my car was the test car for the rpi scoop for the 545s and was dynoed with this setup.
The dyno run before fitting in the scoops showed zero loss compared to a stock 545.
I'm sure you can find some m5 owner here that has changed out their exhaust to sell the driver side to you.

The exhaust note is deep when you push it and close to quiet with a deep hum otherwise.Just another option.

anand_rahim

Thats pretty interesting that you used the M5 exhaust. I spoke with a local shop who said I could even eliminate the center muffler and leave the rear muffler, and that might give me a better note. It's hard to justify $1000+ for an exhaust on a car that only has 320HP, its not like its an M5.

TAJARO

I really wonder about all the ideas without supporting data. I replaced my rear two cans with a transverse Magnaflow with dual exits, each routed to twin tips for a quad look. Similar to the Remus setup but with the Magnaflow and 2.5 inch pipses it will easily flow 6 liters. I can't tell any difference at all except for a wonderful sound. If I did lose 10 ft.lbs of torque (highly doubt it) it's still a fair trade for the sound and the look. The 550i with stock exhaust is just way too quiet and it mutes the fun of the manual tranny. Now I have great off throttle sound, zero drone and a sweet low end sound without ever being too loud.

I think the fact is most all of your back pressure and scavenging is going to be a result of your cats, and the further back you mod (in my case aft of the center muffler) I just can't believe it's all that menaingful to power.

Still as an engineer I'd need to see a lot of data to prove gains/losses.

jpar002

My sentiments exactly. I need an inexpensive setup with no adverse effects that sounds slightly more aggressive than an infinity FX or G35. I need to come up with a solution soon because my M5 rear bumper is being painted as we speak.