To N55 Mid Pipe or to not...

[MLSavage]

That is the question for my N54 exhaust upgrade. I will be purchasing the Performance Exhaust regardless. Keeping my stock mid pipes would save me $333. So with the PE already being added, is the extra $300+ worth it?

[135IS]

Originally Posted by MLSavage

That is the question for my N54 exhaust upgrade. I will be purchasing the Performance Exhaust regardless. Keeping my stock mid pipes would save me $333. So with the PE already being added, is the extra $300+ worth it?

Depends on how loud you want it to be.

[Edogg218]

Originally Posted by MLSavage

That is the question for my N54 exhaust upgrade. I will be purchasing the Performance Exhaust regardless. Keeping my stock mid pipes would save me $333. So with the PE already being added, is the extra $300+ worth it?

Are you keeping the stock DPs?

[Cozy]

Yes it's worth it, it sounds fantastic! I'll admit it's pretty loud though and with DPs you may go deaf but otherwise a sweet mod and a nice little power bump going half catless.

[MLSavage]

Good questions which bring up things I didn't think about.

I plan on keeping stock DPs, it sounds as if it will be too loud with both mods together. I assume the PE will be louder than simply adding N55 mids?

The 4 options with this set up I have seen are as follows:
N55 mids alone
N55 mids + PE without adding the PE y-pipe
N55 mids + PE with Y = super (too?) loud
PE including Y with stock N54 mids

It's looking as if I should just save the $300 and go for the PE by itself.

[Colt]

If you keep the stock DPs I think you'll enjoy the sound. I put my stock midpipes back on the car after having catless DPs installed - hate having my N54 midpipes back on the car

[Cozy]

To give you an idea...

BMW PE, axle-back only with no Res-Delete, stock N54 mids and stock DP's.



N55 mids, BMW PE & Res-Delete - Launch



N55 mids, BMW PE & Res-Delete - Rev & Launch

[MLSavage]

Originally Posted by Cozy

Yes it's worth it, it sounds fantastic! I'll admit it's pretty loud though and with DPs you may go deaf but otherwise a sweet mod and a nice little power bump going half catless.

How is it cruising at 60-80 mph? That is 90% of my daily commute so if it's super loud then I would just keep my stock mids. Is there any drone at any constant speed?

The part I don't fully understand is why the N55 midpipes would make the sound that much louder than N54 mids. Would it simply be because you remove the secondary cats?

[Cozy]

It's not bad at all but you definitely know you've got a system on the car as you can hear that 6cyl burbling all the way along in front and out back. There are spots where it does hum a little in the cabin, around 2250rpm which personally don't bother me but I am accustomed to much louder cars. It's a refined tone and I'd say while cruising is very tame but that's my opinion and one that a video can't help you decide. Any chance you can ride in a local member's car?

The N55 mids as I have them are much louder as I deleted two cats and also the resonator so, with the PE, it is straight pipe after the DP's and a straight through muffler.

[Schmoops135i]

Are you going for just sound? Or do you also want a bit more power? The BMW PE won't give you anything but a better sound. Why don't you change your downpipes (catless AR for example) and keep the rest stock. The result will be a much better sounding car, 30hp + and your car will remain road legal as you have cats in your mids.

[MLSavage]

Originally Posted by Schmoops135i

Are you going for just sound? Or do you also want a bit more power? The BMW PE won't give you anything but a better sound. Why don't you change your downpipes (catless AR for example) and keep the rest stock. The result will be a much better sounding car, 30hp + and your car will remain road legal as you have cats in your mids.

I haven't looked into that but a quick search says that I have to have an O2 sensor fix if catless. How does that affect factory warranty? I still have a year left on that so I'm extremely hesitant to put anything non OE performance wise on the car until then and would rather use OE as much as possible anyways. Case in point is that I'm sure there are better performance gains to be had on other exhaust systems but I'd rather stay OE.

I wanted this mostly for sound, yes. I was assuming there would be minor performance gains, maybe more so with the N55 mids, along with the aesthetics of the sounds.

[Colt]

Originally Posted by MLSavage

I haven't looked into that but a quick search says that I have to have an O2 sensor fix if catless. How does that affect factory warranty? I still have a year left on that so I'm extremely hesitant to put anything non OE performance wise on the car until then and would rather use OE as much as possible anyways. Case in point is that I'm sure there are better performance gains to be had on other exhaust systems but I'd rather stay OE.

Yes, or a tune with auto clear on. Anything that happens to the car they could void with downpipes installed, just because they enjoy being assholes sometimes. I was voided for any warranty engine work because I had a charge pipe installed. Depends on your relationship with the dealer. Some people are FBO and know their dealer well, others haven't had luck (like myself). I would ask your SA about how they feel about aftermarket parts and get to know them before adding anything if you don't want to jeopardize your warranty

[Schmoops135i]

Originally Posted by MLSavage

I haven't looked into that but a quick search says that I have to have an O2 sensor fix if catless. How does that affect factory warranty? I still have a year left on that so I'm extremely hesitant to put anything non OE performance wise on the car until then and would rather use OE as much as possible anyways. Case in point is that I'm sure there are better performance gains to be had on other exhaust systems but I'd rather stay OE.

I wanted this mostly for sound, yes. I was assuming there would be minor performance gains, maybe more so with the N55 mids, along with the aesthetics of the sounds.

Gotcha, yeah I would say speak to your service rep first, some of them are completely ok with mods like DP's. I am told that AR DP's won't trigger any codes as they are direct plug and play. I have a friend with a 2010 N54 135i, all he did was install AR catless downpipes and the car has become noticeably quicker. Sound is fantastic (should of come this way kind of feeling), quiet when driving normally but really roars when your having fun.

Good luck but I would definitely speak to your service rep first.

[twin fed]

I just installed the N55 mids recently hoping to increase the sound of my exhaust. I have an AFE Stage II intake, stock DP's and Maddad axle back section and I actually wished it was a little bit louder. I was expecting more from the new mids. I have not really driven it all the much yet, so maybe it needs some more time to break in.

[Stan.mac]

Originally Posted by twin fed

I just installed the N55 mids recently hoping to increase the sound of my exhaust. I have an AFE Stage II intake, stock DP's and Maddad axle back section and I actually wished it was a little bit louder. I was expecting more from the new mids. I have not really driven it all the much yet, so maybe it needs some more time to break in.

Twin, I'm trying to quiet mine down; I have cat-less DP's, N55 Mids, and berk Race axle back. I'd be willing to work a deal if you want for a Axel back swap...

[twin fed]

Originally Posted by 011100001

Twin, I'm trying to quiet mine down; I have cat-less DP's, N55 Mids, and berk Race axle back. I'd be willing to work a deal if you want for a Axel back swap...

Well the thing is it is actually getting a little louder and I really love the look of the Maddad exhaust and don't really like the Berk. Sorry. Don't mean to

[Stan.mac]

NP Bro... I actually just replaced the Mid pipe back to stock and I'm in love with the exhaust note... So with that being said OP if you want a N55 MP I'll cut you a good deal on one.

[2totalled2months]

Originally Posted by MLSavage

Good questions which bring up things I didn't think about.

I plan on keeping stock DPs, it sounds as if it will be too loud with both mods together. I assume the PE will be louder than simply adding N55 mids?

The 4 options with this set up I have seen are as follows:
N55 mids alone
N55 mids + PE without adding the PE y-pipe
N55 mids + PE with Y = super (too?) loud
PE including Y with stock N54 mids

It's looking as if I should just save the $300 and go for the PE by itself.

I completely understand where you are at right now in the decision process. I went to my local dealer to discuss the options and the warranty issue as well. Each dealer is different, I was lucky enough to get a SA with upgrades and her refers repairs to the mechanic with 2 135is with over 450 dyno hp. So my point is each dealer is diff, work your dealer and talk to a few people, chances are someone there is on your side you just have to find them. OK, that being said, as you will find on other threads, this is the deal,,,,,,,some repairs the SA or mechanic has no control, ie turbo blown, tranny etc, in the big money warranty repair BMW themselves pull your log history and can see any upgrade you have made, yes COBB too, they throw codes when installed and reverted back to stock as well as log pressures of turbos etc...in short, if you blow something big,,,they will fight it,,,not dealer but BMW,,,on a better note, you would have to pump serious tq thru your tranny to blow it,,,so my question to the mechanic with hot cars was this,,,whats safe,,,what can I do and not be screwed,,,his answer was this,,,,Go Cobb,,,catless mid pipes and cold air intake, run Cobb stage 1 and stage 2 when you want. As far as PE, his response was that he runs stock, the flap stays open 99% of the time on stock and is wide open when you are wide open and that even the intake was super, that BMW made this car with speed in mind, even though there is plenty of room for improvement. He advised to keep away from catless DP, they throw codes because the are monitored and that the cats in the mid pipes are not. Basically his round about numbers were as follows,,,stock 135i dyno,,,260 hp,,,coold air intake,,,mid pipes and CObb,,,around 325 dyno,,,he did say its an educated guess,,,maybe a little more or less...Last info was this,,,I have the PPK2...its not a true 20hp gain,,,its maps a peak at certain points,,,4500rpm it peaks turbo pressure, also at low rpm,,,,buy not all the way thru the power band. I hope this info helps,,,,and to the poster with N55 mids for a good deal,,,PM me,,,Ill take them.

[SalemChiro]

Originally Posted by twin fed

Well the thing is it is actually getting a little louder and I really love the look of the Maddad exhaust and don't really like the Berk. Sorry. Don't mean to

^^^ PM sent

[MLSavage]

The other option I just thought about would be N55 mids with only the Y-resonator delete from the PE. Getting only the Y-pipe might be tough though, I'll look into that. Deleting the resonator could also introduce the drone, but again not sure on that.

Based on this thread it might break itself in and a review that I was looking for and could have prevented this thread from being created.

[moveswiftly]

If you have cat-less downpipes, it'll smell. My friend had it and you could smell the fuel while at stops or in a garage. It was pretty strong.