Most liked posts in thread: Straight exhausts on R53

--->minispeedrcr: Did you buy Randy's MINI? I was wondering where that ended up! Regarding your concern, it looks like the metal simply disintegrated from too much heat. I would recommend going with at least some 304-grade stainless tubing [usually 18 awg is all that's needed] from the header rearward and then use whatever muffler tickles your fancy [3" in/out perf-core like a Magnaflow muffler would change the peak torque slightly]. Is the battery box cut out, or does the pipe run underneath it? This would significantly impact the nature of a recommendation.

 

yes I bought randy webbs mule in December off eBay. Gotta love eBay! Battery is relocated, straight 3" pipe that goes through the rear diffuser and under carriage panel. Anbody tried the Supertrapp sound tunable muffler?

 

To deviate for a second and comment on drPhilGandini's statement; my Flowmaster scavenger box [pic at top of page] made 5wHP @ over a standard Milltek cat-back [and lost power nowhere], so they do work over a simple perf-core muffler provided they're well designed. That said, it was louder than having a straight pipe, so it's definitely not recommended to minispeedrcr for a loudness fix!

Most likely a good solution for minispeedrcr will be to cut out the battery box, make a flat boot floor, and install a big volume perf-core muffler like a Magnaflow.

 

Here is what I ended up with, Dynomax Bullett 3" in/out 21" long.

Still loud but not as annoying at higher revs. Will find out this weekend how loud it is at the races.

 

No, I used a Delta Force Race 40 series 8.5" body. Essentially no acoustic amplitude reduction over an open pipe.

I'm guessing you had a big resonance at 3200 rpm because you had no center muffler to change the tuning frequency? Running a huge volume center muffler helps tons to quiet down the car [incidentally on both R53 and R56].

--->minispeedrcr: Good to see you were able to fit something in there, although it'll only take the edge off it might be enough to be tolerable.

 

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It's possible to do a straight-back without batt box removal...
Showing a G4, and the 2.25" G4 prototype. Adds between 12-15WHP, no foolin', and the "burble" causes folks to "duck and cover". Definitely want to look into the Heimholz though...

 

Don't see how it could be done without removal? And highly skeptical about them hp numbers?

 

Wow... I've got scrapes on my battery box skid/protector plate... I'd hate to see what I would have done to that exhaust pipe over the past 6+ years on my car!

It would be nice to get a little more clearance around the back pipe, though... On a drive across at MOTD in 2011, I got a stick jammed up there between the back pipe and the shifter housing... that sucker was smouldering after a 15 minute hard drive and it smelled like I had a campfire under my car.

 

If you look at the Yellow Mini in the exhaust sound off thing from MOTD this year you will see and hear the exhaust I made. I lent it to my friend when his exhaust broke and he was low on funds. It makes power and is 2.25 under an un modified battery box on a lowered car.

The yellow car with my exhaust:YouTube - Broadcast Yourself.

See it, believe it, it can be done and sounds great on an R53.

All cars in the sound off:MOTD 2012 Exhaust Sound Off - YouTube

 

Mine's actually the Checkmate in the Exhaust Sound Off thread... 2.25" under the batt box, including 2 inline louvered SS glasspacks and a corvette tip... and available commercially in stainless from G4 (see Mark's post, below...), it's also available in several versions, from mildly aggressive to "holy crap".
[ame]http://www.youtube.com/watch?v=lSrcbA6B_eM[/ame]

 

You do not have to relocate the battery and delete the box. Our system is a simple install and adds between 13 to 17 hp depending on other mods. Look on our web site and contact me for further info and specs.

Mark

 

Very nice!

 

Hi folks. I'm the new owner of Dr. Phil's Mini. I have to say the car is awesome. Except for the exhaust. It was left with the straight pipe exaust system pictured at the start of this thread.

Removing this has become my top priority for the car. The reason: The 5 hour drive from Tacoma (where I bought it) to home in Spokane WA was probably the worst and best time I've ever had in a 'new to me' car. Best in that the car handled and drove very well. The worst because of the horrible drone at highway speeds. And 5 hours of it was damn near torture.

Luckily I had the earplugs I carry with me for flights on Q400's. Otherwise I might have stopped and had the car towed! It was that bad.

Now that I've had it home for a couple weeks, I've had a chance to do some research on different exhausts and found this thread.

So, I'll be un-doing the straight through exhaust and replacing it with a dual muffler design (not decided on which one yet) and will be relocating the battery back to where it was.

This means I'm going to fabricate a new battery box and in my mind, correcting a pretty bad mistake by the previous owner.
The rest of the car though is, like I said earlier, AWSOME. I've got very little to do to make it what I need for autocrossing/HPDE & FATT.

 

Wow! Always wondered where his Mini went. Very cool that you now have it I remember his adventures with that exhaust :crazy: Don't see any need to try and put a battery box back in? Didn't he use a couple small batteries and lay them in the back? Also, a few people have had some success in using R56 straight exhausts on their R53, just a thought?

 

Hi Jim! Yeah, not sure what happened to the smaller batteries but when I bought the car it had a full size Optima yellow top and a carpeted box covering it. :confused5:
It really doesn't go with the car so it's got to go.

I'll check into the R56 exhaust. Thanks for the suggestion!