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Hi All - I have an R57 ( N14 ) - rebuilt engine, airwerks turbo and currently running a milltek catted downpipe ( 2.5 inch ) with the resonated borla exhaust. It seems the borla is a great option for oem cats, but does not agree with a high flow cat - ie DRONE ! So am looking to replace the Borla ( I considered trying to add a resonator - but this is an R57 with some adding bracing in the way. Plus in the past, I have found this usually requires a few iterations and turns out being more expensive then buying an exhaust where that has all ready been done ). Plus the Borla is 2.25 - so this might be adding a little more non compatibility ...
Looking for any hands on experience.
I am leaning towards the 2.5 resonated Milltek catback - even though it will take a little heating/bending to fit the R57. Does anyone have any experience with the Milltek with a high flow cat on a N14 car ?
I know the Akrapovic has a good reputation and could almost be in the consideration set - but I can't stomach the price ( over $2K ). Actually, I almost could for the base unit, but over $700 for tips - OUCH ! Has anyone put inexpensive tips on ?
I have some second hand feedback that the Milltek is as quiet ( with no drone ) as the Akrapovic ... or even quieter. Can anyone confirm ?
My goal is no drone and as quiet as possilbe. I realize it will be louder than stock - but my preference is to listen to music or talk radio LOL
All - I thought I would give an update to this post:
I "installed" the Miltek exhaust with the Miltek catted downpipe on my Blue R57 ( 2009 ). Installed is in quotes, as it was not a very good install. Find attached a few photos:
1) The angles of the exhaust do not line up with the routing of the exhaust. Not sure why these angles are there.
2) No way could this be crush bent or even heated and formed to fit without dropping the exhaust 1 - 1.5 inches. Not a good solution
3) I still exhibited some drone in the 2K - 3K range. More on this later ..
The Miltek exhaust could fit with proper angles, but as is - cannot recommend. Even on the R56, without the extra convertible bracing, you still have unacceptable angles that do not look good and am sure has some negative impact on flow ( perhaps not material though ... )
I plan to keep this exhaust and bring in a welder fabricator to 'straighten it up" so it can be a drop in. I also think I can add an extra resonator by pushing the existing resonator forward and free up space between that and the muffler.
I gave all this feedback to Miltek - with photos with the recommendation that this can easily be fixed, but not sure if they are interested.
I bought the exhausts from ECS ( I bought two ) and was able to return 1 unused and they offered a little off the one I installed. They were great to work with. They do note on their website that:
"**R57 and R59 MINI Cooper models will need to drop the rear subframe and add spacers/washers or slightly dent/bend exhaust around the main union of the rear subframe bracing.**"
However, I believe this is an understatement. I see no way that you can slightly bend this to fit, and need 1.5 inch bushings to drop - which is huge !
Last edited by gauss66; 02-14-2024 at 07:09 AM.
Reason: adding more context
Miltek install: You can see the four 1.5 inch spacers top drop the conv spacing. Also, you can see the angle of the exhaust piping pushing the exhaust all the way to one end of the exhaust routing tunnel. It angles to the other side where you hook up to the downpipe - not straight at all
Last edited by gauss66; 02-14-2024 at 07:00 AM.
Reason: adding more context
On the other side, I bit the bullet and bought an Akrapovic exhaust. This install was seamless - everything lined up perfectly. They even added extra rubbings to mount to the cross brace on the tunnel. While the tips are very pricy - they look superb and we did not have to fiddle with alignment to make it look square in the back. In short - this was 30 mins, while we played with the Miltek for 3 hours. The Akrapovic even came with instructions !
Sound wise - not a big difference from the Miltek, perhaps a hair quieter, but still have the same drone in the 2000 - 3000 range. However, this could get softer over some time. My current hypotheses is that this is do to both being an automatic car and when lugging in 6th, when you accelerate - you get the drone before it downshifts. But more importantly, I think it has to do with the 200 cell race cat ( vs stock 400 cell on an S or the 2 stage cat on the JCW - N14 editions ).
Something is wrong - but it is not the install. I talked to Way at length about this and they stopped selling the Miltek for this application. He also offered to 'fix' the fit by cutting and welding so the piping would align to the to the exhaust flow and they could then use as a template to update their process. They did not see to have interest
I was on the phone with Miltek several times when trying to install this, sent them photos - of which I only heard that their R&D team is investigating. Then crickets ..
All - thought I would give some updates.
I have two R57 convs - a 2009 S and a 2010 Laurel. Both have had rebuilt engines, airwerks turbo. Miltek catted downpipe in 2009, JCW cat in the 2010. One has the miltek exhaust, while the other has the Akrapovic.
As noted earlier - the Miltek did not fit all - bad angles and needed to lower the bracing. I was able to fix this with a good exhaust fab guy. He cut and rewelded to make as true as possible. It fits pretty well now.
The Akrapovic fits perfectly - welds and fittings are world class !
I have run both exhausts on the 2009. Both had ( to me ) unacceptable resonance/booming/drone at the 2K - 2.5K. Much of that could be that it is an auto vs manual and lugs in 6th gear on the highway ....
However, when running the refitted Miltek on the 2010 with the JCW cat - all drone is gone. Note the Miltek is a 200 cell cat, while the JCW is a little over 300 ( estimate ).
Attached is a photo of the MIltek tips on my 2010, after the cuts and welds. Looks pretty good.
My plan is locate another JCW cat ( finding these are like panning for gold for the R series ), but I have time.
I might update with some pics later, but I was looking for the same thing and went with a Scorpion Resonated setup specifically because videos made it sound like the most quiet option (and people complain that it is TOO quiet), and a lot of other options are very close to stock diameter.
Fit and finish is great, but I have two huge gripes:
1: Pretty bad drone at 2500-3000ish. Basically this is 110-130kph highway cruise speed.
Not the loudest, but enough to get your ears ringing after an hour.
Idle/part throttle isn't super quiet, but very deep vs my old exhaust.
2. Exhaust is advertised as 2.75in, but only the piping is 2.75. The resonator necks down significantly (around 2.1in, maybe less), and the muffler necks down to around 1.9in.
After grinding at that big blob of weld a bit, It now measures:
Front clamp sold separately.
Going to add I emailed Scorpion about this crazy transition a month or so back, and they have not responded.
Probably going to live with it, or if I suddenly end up with a ton of free time - build an exhaust like I should've done in the first place.
I was updating my exhaust to accommodate a stage 2/stage 2 plus mods, of which going with a race cat or catless tend to be needed. If I was only going with a stage 1, I would have settled for a Borla 2.25 exhaust ( which is supposed to work well matted to the stock downpipe - no drone, a little deeper and not to loud ).
However, I have run the Borla, a Miltek and an Akrapovic with the race cat ( 200 cell Miltek ) with my set up and had drone in each set up. When I replaced the 200 Cell Miltek with the JCW downpipe, the drone on the Miltek exhaust was non existant or very minimal. So to me, the culpret is the 200 cell Miltek.
In your case - since you are running stock downpipe and no tune, it seems you got drone from the Scorpion - I take it you had no drone before. What was the reason/goal in upgrading your exhaust? I had not heard that Scorpions are quiet though - and in my research, Milteks were known to be quieter ( same price range as the Scorpion I believe ). The Akrapovic is too - but more than double in price ...
However, if you are stock or stage 1 at best, I wonder of the need for a '2.75' exhaust. I am running 2.5 inches. Yes - turbos like as little back pressure as possible ( for spool up ) but not sure if there is a material gain from 2.25 - 2.75 for your performance set up. Unless you plan to go to big hp down the road... But when pushing high hp, people seem to live with the drone ( or put the $$$ for a custom set up ). To me - the 2.75 inch diameter might be the culprit. Muffler looks bigger than OEM, but am sure it is a straight thru and not sure what OEM is. You might be able to fit another resonator in the straight run before the muffler ( as long as you don't have the bracing I have with the conv ). My past experience in futzing/adding resonators to existing exhausts has not been good though ( non Mini )
1: To future-proof/support other mods. Tune, turbo, downpipe, etc, without being too loud.
2. The PO cut the second cat, resonator, and muffler out, installed some ebay muffler and it was loud as hell. I quieted it down with a vibrant resonator in the middle, but it didn't do enough. Still loud, droned louder than the scorpion by a fair amount, but not as much as the difference in muffler/resonator size would suggest.
3. The car failed inspection for the flex section. Didn't want to spend any more money on the old abomination so this is what twisted my rubber arm to pull the trigger.
Would love to mod this car, but it prefers to be a perpetual pain in my ***, and the tune/DP/turbo all basically need to be done at the same time and it's a fair chunk of change.
At the end of the day, it's not really a highway car, so if I can do an hour and not get a splitting headache, its OK on the sound front. The 1.9in reducer is the real sour point.
I don't think there's any reason to ever go smaller diameter on an exhaust post-turbo (well, noise aside), yeah there will be diminishing returns, probably after 2.5in but I don't think that's a reason to avoid it.
Do you think the PO futzed with the cat in the downpipe at all ? Was the ebay muffler 2.5 inch ?
So my guess is the 2.75 ID is the main reason here - you could try to add another resonator in that straight run before the muffler ?
Of if you don't plan on upgrading for a while - find a used OEM exhaust on the cheap ( I doubt you are realizing any gains without a tune could even be losing a little at low end ... ).
I borescoped the cat when I was in there to check the WG flapper and it looks 100% normal.
Ebay muffler and the vibrant res were 2.25in to fit the stock stuff (or the gross aluminized pipe they replaced it with).
I'd love to upgrade - like today, but priorities. I was going to install the DP and turbo while I had the front end apart but I chose not to because I didn't want to add mods while the car refuses to run right in stock config.
Hopefully the car begins to cooperate before this winter and I can do it then, but there's a laundry list of items to work through.
I'm going to leave this exhaust alone for now. If/when it becomes a problem, I'll probably favour offloading it in entirety and making something from scratch in 2.5 or 3 depending on the rest of the car at that time, throw some big mufflers in, then figure out the drone frequency and add a helmholtz resonator/J-tube to cancel out whatever the drone peaks at.
Given that you moved from a 2.25 system ( even if it was Frankenstein ' d ) and had a reduction in drone going to a 2.75 system - I would consider a win
I looked at the J tube science - seems really cool - but not to sure how to fit that under an r57 with the bracing ! Would love to see what you fab with that.
11-21-2023, 04:07 AM
