NC916

I will probably drop by the muffler tech store tomorrow if I am not too busy, there is too much graduation to attend to right now ahah so kept me pretty busy.

Howitzer

So what's the deal? Quads DO lose power?

tex_phil

Yes, at least on mine, I want to swap my quads out soon for something back to the quietness to stock. I don't like the drone.

socale39

West was able to GAIN 10hp and that was dyno'd so the moral of the story is quads will only lose power if you use the wrong setup. Straight pipe it and you will definitely lose horsepower.

socale39

NC916, did you ever find out what Muffler Tech used on that 545i?

miguex

Very interesting. I didn't read your thread until now.... Amazing results and it probes no losing power like many members said. I love DIYs (many old senior members may know me well... yeah I got flamed and cheered. lol!) and I had many DIYs from my old 545i and I posted few on this forum.

Anyway, I am thinking to setup a similar custom exhaust for my M5. I rather to make a custom exhaust than buying. I like the parts you mentioned in the list but with 3" pipes because the OEM exhaust (M5) has that size. So do you think it is worthy?

r9ndy

You should give it a try. I'm sure you can make gains with your m5.

socale39

I think member "crmb" is making a custom M5 exhaust. I'm sure he could give you some pointers.

socale39

Can we get an update West? Any droning?

djdc78

following west's know how and instruction, i ended up going with the same set up. i really really do like it. initially it had a pretty annoying drone around 1.5K-2K when slowly accelerating and slightly pulling the engine. one of those cabin filling drones, i posted about it but didn't get any responses in making it quieter. it's been a good month or so i think it's broken in as it's lessened and very much less noticeable. what i like about it is that i can almost control how loud i want it, if i'm slowly accelerating, i can almost not hear it, unless it's under a lot of load, but if i open it up, definitely can hear it. no drone, if not very slight, on the highway at cruising speeds which is also cool. i do remember my stock having the slightest bit of drone on the highway which this is similiar to. no feeling of power loss, actually feels a bit more responsive and opens up faster, but that could all be psychological....

all in all, i do like this set up....

thanks for the info west, made it a lot easier for me to decide......