Due to a recent family addition, I'm looking at quieting down my exhaust to as-close-to-stock as possible by whatever means possible without adding too much back pressure for my setup. I need ideas before I start shelling out a bunch of cash, yet again. Please help! The background: This has been my dedicated autox car for years. My husband thought it would be fun to try and minimize the exhaust to save some weight. Coming from a drag-racing/V8 background, he took it in and had the exhaust shop put in a straight pipe (/facepalm). After about rupturing his eardrums, he took it back in and tried about 4-5 different configurations until we got to where we are now: 2.5" pipes, RMW race header, a cat, a 24" glasspack, and a relatively small magnaflow turbo muffler. This is attached to a ported (but stock valve size) head. It's still much too loud for my tiny new co-driver to ride with me. So I need to get it quieter. The only idea I came across that I liked so far was a post by Fracky on NAM about using 2 custom Coast Fabrication mufflers and a resonator. This is an expensive option. I have been told by autox friends who deal in these mufflers, and love them, that they are great, but only worth the money if you are really trying to cut weight. Since the MINI is retiring from autox status, reducing the weight on the bottom of the car is not really worth it to me for the money. SO: What would you do instead? I'm thinking 2 large mufflers, the biggest that will fit. I don't know much about which specific styles I should try, or what configuration I should put them in. I currently still have the stock battery box in place. I could move it if it would help tremendously with the noise issue, but I'd prefer not to. Suggestions?
The best way to quite that exhaust would be to remove the long tube RMW race header and exhaust and sell it for a RMW shorty header and a Milltek. If you are on the RMW board someone will buy your setup.
look at my build thread in the exhaust video portion. (i can dig it up on request) granted I also have a turbo in there that muffles some, but! 1x vibrant ultra quiet 2x magnaflow straight through mufflers. (1x same side in and out, the other is a center inlet, offset outlet) run in same configuration as a stock exhaust It is quiet as hell, and only straight through mufflers (perforated tube) serious sound reduction until you really get on it and not too much back pressure. (we are talking stock volumes below 3.5k rpm)
Split cans will do it, the Milltek option is the best, I have the JCW, but it goes from 2.5 to 2.25 at the split (I have a 2.5 mangaflow up front). I'd like to go to a straight exhaust, but at 250hp the group 4 straight exhaust was too much drone. I'll eventually go coastfab or something else straight through, if I hang on to my current MINI.
Thanks for the advice! I'd go back to a stock header, but just because I'm no longer regularly autocrossing this particular car anymore doesn't mean I want to give up having any fun on the street The goal is still fast--just fast and subtle too. The Milltek sounds like a good option, even if a bit pricier than I was hoping. I'll look more into it. Thanks again.
The Milltek is my nice and quiet (wife approved) exhaust and it connected to Jans RMW street / Shorty header. If I want loud I put on my custom cat back straight pipe exhaust.
Depends where you live but I got a possible trade for 10 month old invidia cat back. Resonator was removed but I still have it.
The invidia is pretty quiet. I have a gutted cat, no cat converter and it doesn't drone, and very quiet low bass
Thats the most Sissy thing i have seen you post in a long time dave. My car is not that loud and you know it. Maybe thats a consideration. What you really should do is call coast fab and ask if they have any "damaged" parts and get one for a discount, or do what i did and run a miltek back section a cat and a JCW resonator.. its not that loud. Problem also is one persons quiet is another's loud. In just like Geriatric Dave here.