Buying a 135i, need some insight!

[APhuze]

Howdy folks! Hope everyone is doing well, i'm new to the forum but I figured this would be the best place to put my question as this a community dedicated to BMW 1 series cars!

I currently have a 987.1 Cayman, it's everything i want out of a car, minus the power. It really costs far to much to squeeze out marginal gains from the engine. That being said i've aligned my vision to getting a 135i, with the hopes of upgrading suspension, throwing in a LSD and ofcourse a stage 2 single turbo setup.

I've ran into the age old problem between n54 and n55 engines. I have recently been leaning more to the n55 engine (less carbon build up and a few other things have been fixed in this generation to my understanding) Although... I am concerned if i want to push 500-550hp that i may blow the engine, or just cause some real internal damage. I've came to this conclusion after doing some research on forums mentioning how the internals of n54's are better suited to these higher HP figures.

That being said, can the N55 reliably handle these figures? I understand tuning any car to high HP comes with its reliability draw backs. But when applying what i want to do on a n54 or n55 engine, should i be looking for n54's or n55's. Also if there is any sort of financial draw backs to choosing a n55 over the n54 when it comes to tuning please give me your two cents. I'd greatly appreciate it, and I can't wait to be a part of the BMW community!

[asbrr]

I can't comment on the N54 vs N55 debate because I have neither (N52 lol) - but I did just pick up a 987.2 CS last summer. One thing I'll say is if you're selling your cayman and planning to track the 135, you're going to need to do a lot more work to the chassis/brakes etc to make up for the extra weight, higher CoG, and understeer to match the 987 which is just a better "starting point" for that kind of thing.

If you're into getting more ower/drag strip, for sure the 135 is going to be a better platform vs the Cayman.

[StevieJ2]

This is what I've learned over the past 2 months with my 135i:

People like the n54 because it makes decent power with cheap bolt ons. When you start looking at doing a proper build, there's really no difference in price between the two.

At this point, pretty much anything you buy is going to be a roll of the dice. I personally went with an n55/DCT even though it's costing a bit more for the build, because of personal preference. If you're just looking for a cheap slop box, get an n54. If you plan on doing a proper engine and suspension build, consider the n55 too.

[Eyeman]

I'm a Porsche guy but when i was ready for a new fun daily driver around 2008 I bought my 135 with plans to full bolt on mod it. I guess I still prefer driving Porsches and have been looking at Cayman's with bigger motor options. But yep, a modded 135 or a M235 are great options too.

I've been at 400wHP for over a decade now and plan to upgrade the turbos somewhere down the line. I'm fine with my step transmission so I think any of the options will work fine for you. Mainly as others have said, the car is too short and top heavy and it's hard to get the thing to handle well. But that is part of the fun and probably why the 1M is so popular.

[darkrom]

Originally Posted by StevieJ2

This is what I've learned over the past 2 months with my 135i:

People like the n54 because it makes decent power with cheap bolt ons. When you start looking at doing a proper build, there's really no difference in price between the two.

At this point, pretty much anything you buy is going to be a roll of the dice. I personally went with an n55/DCT even though it's costing a bit more for the build, because of personal preference. If you're just looking for a cheap slop box, get an n54. If you plan on doing a proper engine and suspension build, consider the n55 too.

Originally Posted by StevieJ2

This is what I've learned over the past 2 months with my 135i:

People like the n54 because it makes decent power with cheap bolt ons. When you start looking at doing a proper build, there's really no difference in price between the two.

At this point, pretty much anything you buy is going to be a roll of the dice. I personally went with an n55/DCT even though it's costing a bit more for the build, because of personal preference. If you're just looking for a cheap slop box, get an n54. If you plan on doing a proper engine and suspension build, consider the n55 too.

As someone who owns both I don't really agree. I think once you are talking big turbo swaps the n55 is weaker. There's not many big power builds. The n54 is the opposite. Lots of little issues at any power level but you see guys running stock motor 700 hp with a doc race kit etc. I'm sure it can be done on the n55 but I would be stressing badly about my rod bearings on that motor if I even did a moderate 400-450 hp turbo swap, which can be achieved easily on the N54 with stock turbos.

N54 = more headaches, but way more head room

[Billy C]

New owner of an N54 135i here. I don't have any modern Porsches to compare the day to day experience with but I like the 135i overall. It does feel like it has a short wheel base and high cg but that can be fun in it's own way. My N54 required almost all of the 60k mi maintenance when I got the car. I do the work myself on all of my cars so direct cost wasn't that high but time is money and it was a ton of time. I have over 50+ hours of just PM in it already. If you are used to dealing with a 987, the 135 will be a familiar game. It is a rewarding car when everything is working just right.

Regarding N54 vs N55..
The N55 is the newer, more refined version in every way. Reliability is going to be better and the long term cost on a stock car will probably be less.
The N54 is known for it's big power potential but I think most that is because it runs a speed speed density tuning strategy. That's more versatile than the N55's MAF setup for easy high power goals.
As far as internals and overall motor strength, there seems to be a ton of conflicting info out there. I certainly have no idea. There are N54s and N55s in the wild holding big power numbers so most of the critical components that are different between the two probably have similar strength with the biggest internal differences being things people just like to brag about but really have no data to back up.

[APhuze]

I want to thank everyone for their input, it really has helped in my decision making process! I ended up going with a n55, as much as i like to think i am mechanically inclined, im not sure i have the place or time to be wrenching on the car more often than not, which lead me to choosing a n55. That being said i have many plans for it! LSD swap, swaybar, m3 control arms, bushings, lowering springs, i will be getting this thing handling the best i can before i go with the turbo upgrade! I figured i want it to handle in more than just a straight line, especially since im coming from the cayman

[APhuze]

Haha, too short and top heavy sounds like a riot to me. I'll have a lot to learn in this case! Yeah, only thing i can think of that makes my 987.1 more desirable at this point would be to LS3 swap that bad boy, now that would be something!!

[mistacarder]

I went with n55 for the reliability reasons. I am FBO with upgraded turbos and it's plenty for me