Straight Piped my M135i!

All other aftermarket mods

Moderators: Rich196, marco_polo, Producethis, Lambster, babybmwadmin

Post Reply
User avatar
GeoffCollins
Enthusiastic Member
Enthusiastic Member
Posts: 646
Joined: Mon Feb 01, 2016 11:02 am
Location: Around London

Straight Piped my M135i!

Post by GeoffCollins » Tue Jan 02, 2018 10:12 am

Happy New Year All, hope you had a good Christmas break!

So over the holidays I thought it would be a good idea to straight pipe my car (for those who don't know it means there are no cats & no resonators, essentially a straight pipe from the turbo - out the back)

I know this will not pass emissions test's etc, and this will be changed to a sports cat due to the reasons below.

Before the De-cat, it had no resonators, just the CAT and the car sounded awesome, I wanted it a tad louder but I think I underestimated quite how loud it would be with the straight pipe,

Starting the car in the morning is deafening, I mean shakes the houses and wakes up the entire town I live in when I leave for work! As this is my daily driver it's rather inconvenient, especially when leaving from a meeting or something and having to wait for everyone else to go before I start the car so I don't look unprofessional!

I also should mention the drone, now I'm not stupid and knew it would drone a bit, which I accepted was going to happen, but sitting at 70 on the M25 I have to have my music at almost full volume to drown out the sound of the car!

Now for the good bit!

The sound of the N55 engine when you are fully on it is incredible, stupidly loud but not that raspy tone you get from the little 2.0l 4cyl engines in our competitors cars. This sound is deep and the pops and bangs from the car now are mental! They are more like gunshots than pops and bangs! Also after being on track or driving hard you get flames, FLAMES out of my little hatchback!!! The overrun pops are addictive and I can't get enough of them, this combined with the turbo noise I now get out of the exhaust, and the wastegate noise from the BCS intake is phenomenal!

In review then, I absolutely love the sound when driving hard, but due to the rare occasion that I do this, I think I'm going to go for a sports cat, more convenient, and roadworthy, and hopefully that little bit quieter when driving normally!

The other option was I was thinking of having a look into making a custom exhaust with a Cat bypass valve, so I would make a new pipe that has a valve to bypass the cat when I feel the need to, although not sure if this is possible or where it will fit, but this is for another day!

Also the DeCat will not be for sale as I will be going back to straight pipe for the BMW Show with the forum :)
M135i (2014 Manual) - Straight Piped (Custom), JB4, BMS Intake, Eibach Springs, Cades Bern Wheels, Maxton Splitter, Double Slat Grills

User avatar
GeoffCollins
Enthusiastic Member
Enthusiastic Member
Posts: 646
Joined: Mon Feb 01, 2016 11:02 am
Location: Around London

Re: Straight Piped my M135i!

Post by GeoffCollins » Tue Jan 02, 2018 10:13 am

Sorry for the badly written article! Writing is not my strong point!

Also video's will be up soon, with a review from a friend of mine with a Youtube channel :)
M135i (2014 Manual) - Straight Piped (Custom), JB4, BMS Intake, Eibach Springs, Cades Bern Wheels, Maxton Splitter, Double Slat Grills

Post Reply

Return to “Aftermarket modifications”