128i mods- are they worth it?

**AsifLicious** · 05-21-2016, 04:46 PM

Hey everyone, I have a 2011 N51 automatic 128i and it's a great little car with only a few things I feel could be better. I got my car for a great price but unfortunately it does not have the sport package. Or any package apart from the heated seats. So to me, the suspension has just way too much roll. I'm thinking about getting coilovers to help reduce that problem. Will coilovers make a huge difference? Or are lowering springs and struts a better option if I don't care about adjustability? Another thing I've been considering is an engine tune from AA. I understand that the tune won't make the car significantly faster, but is the sharper throttle response worth the $500 or so? Are there any other benefits to having the tune? I've searched plenty on the forums but it seems like people either think it makes a world of difference while others think it's a waste of money and others had their ECUs freak out. So I just want some clear information. Thank you

**BimmerBreaker** · 05-22-2016, 06:21 PM

I wouldn't mess with a tune on a 128i but coilovers can make a big impact on performance and handling feel

**AsifLicious** · 05-22-2016, 07:26 PM

So the tunes aren't worth the money? I figured as much. So will coilovers make the car handle as good or even better than an M-Sport package equipped 128i?

**markslc1** · 06-09-2016, 03:18 PM

Originally Posted by AsifLicious

So the tunes aren't worth the money? I figured as much. So will coilovers make the car handle as good or even better than an M-Sport package equipped 128i?

If you have an N51 motor, a tune will net you some serious gains from the stage 3 disa manifold. Look it up. I had an N52 and added the n51 manifold + aa tune and the car was transformed power-wise.

I recommend koni+HR spring setup I have. Huge improvement in looks and performance, and much cheaper than coils.

**HarryN** · 07-06-2016, 08:55 AM

I am actually saving up for a Quaife LSD. Since I like taking corners pretty hard, the one-tire-fire gets old fast. Couple that with Bilsteins and H&R Springs (I like Koni as well, but more of a Bilstein guy because preference).

Powerwise, markslc1, do you have a link? I looked in Google and didn't get much results. My search criteria was "Stage 3 DISA Manifold N51".

**markslc1** · 07-06-2016, 10:00 AM

Originally Posted by HarryN

I am actually saving up for a Quaife LSD. Since I like taking corners pretty hard, the one-tire-fire gets old fast. Couple that with Bilsteins and H&R Springs (I like Koni as well, but more of a Bilstein guy because preference).

Powerwise, markslc1, do you have a link? I looked in Google and didn't get much results. My search criteria was "Stage 3 DISA Manifold N51".

you can get the tune here. You might also call active directly and discuss before you buy.

**HarryN** · 07-06-2016, 10:33 AM

Huh... I didn't know AA did anything for the 128i, especially the N51 engine.

**markslc1** · 07-06-2016, 11:40 AM

Originally Posted by HarryN

Huh... I didn't know AA did anything for the 128i, especially the N51 engine.

In my case (N52), I had to install the n51 manifold on my engine first. The tune does the rest. both combined, I had a huge improvement in power. Since you already have the manifold (n51), you wont see as much gain, but 15HP seems reasonable. Do this and get a BMW performance exhaust (for sound), and this car really rips!

**HarryN** · 07-06-2016, 11:44 AM

Wait back up, so N52 and N51 are different displacements? What's the big difference in power?

**markslc1** · 07-06-2016, 11:57 AM

Nope. same displacement. Just different emission controls and intake manifold. More answers can be found here

**HarryN** · 07-06-2016, 04:15 PM

Thank you very much, Mark. I really appreciate it. I am not keen on the newer BMWs, but the older ones are my favorites. I guess it's time to actually start learning more about my 128i. But what I am reading so far, I got screwed with my N51. I should have bought one from a Southern US state where emissions is not such a huge issue.

**markslc1** · 07-06-2016, 05:20 PM

Originally Posted by HarryN

Thank you very much, Mark. I really appreciate it. I am not keen on the newer BMWs, but the older ones are my favorites. I guess it's time to actually start learning more about my 128i. But what I am reading so far, I got screwed with my N51. I should have bought one from a Southern US state where emissions is not such a huge issue.

The power differences are disputable. But with higher compression and lack of disa manifold, the n52 rates the same as the n51. When adding the disa manifold to the n52 you get a nice power boost. In the end aa says the net difference on a tuned engine with disa manifold is 8-10 hp in favor of the n52.

**bimmerlust** · 07-15-2016, 04:48 AM

The answer to the thread topic is a resounding NO, because they made a 135i which costs negligibly more to buy / own AND it makes a ton more power / torque stock AND is much more mod friendly. Don't miss the forest for the trees.

**markslc1** · 07-15-2016, 10:08 AM

As a 128i owner I agree that the 135 can be had for only 2k more. But the question is about the value of modding it. After doing a couple power mods, the 128 is
Somewhere between the e36 and e46 m3. (I've owned both). If that's not fast enough get the 135. Otherwise bask in the glory of the masterpiece that is the n52. The last na motor from BMW

**bimmerlust** · 07-15-2016, 01:58 PM

Originally Posted by markslc1

Otherwise bask in the glory of the masterpiece that is the n52. The last na motor from BMW

Long story short, the motor in terms of output (absolute & specific) is pretty lukewarm by today's standards and there's no reason to get one over a N54 / N55 if you have ANY interest in performance whatsoever. The last desirable NA motors by BMW were the S62, S54, S65 and S85 (ordered from least desirable to most) and the N52 doesn't compare in the slightest. As far as technology goes, great it has a mostly useless valvetronic but not much else...I mean, it's not even direct injected!

**BimmerBreaker** · 07-17-2016, 02:49 PM

I love the N52 - sure it isn't an M engine, but it wasn't designed to be. As a daily driver I think it's a perfect blend between power and economy and ease of drivability. I have two other sports cars (Z3 M Coupe's, one S52 one S54) and those are a hoot to drive but sometimes I don't need or want all that power and those engines aren't always great to DD. It's fun to take the N52 to redline and just as fun to putt around in traffic. I love the 128i and though I may eventually land in a 135i I would never discount the benefits of the 128i. The N52 really is a phenomenal engine, especially with the DISA intake manifold upgrade it has torque and an all around wonderful powerband. Outright speed only matters when you are racing, which I really don't. The sensation of speed is just as important to a good sports car (the E30 M3 - one of the "best" BMW sports cars - its dreadfully slow by today's standards, yet still highly sought after).

Direct injection just means you have to do valve cleaning. Thats just one more thing the N52 has in it's favor IMHO, it's not a detriment that it doesn't have direct injection. Conversely, valvetronic is a wonderful way to increase power and efficiency through the entire rev range - the N54 doesn't have that... if you want pure speed, get the 135i and be prepared to spend more $$$ in gas, insurance, repairs and maintenance. Want a more affordable and more reliable daily driver without sacrificing anything but that "pinned to the seat" power? Get the 128i, throw the DISA intake manifold on it and be done with it.

Also funny you list the S65 and S85 as the "most desirable BMW engines" ...great when they are running, but a bloody fortune to maintain and ridiculously unreliable. Rod bearings are not a "sometimes failure" item on those like with the S54/S62. They will fail on those and even if you can DIY, its a fortune to repair and a major pain to service. The best BMW engines to me are the S52, S54, S62, N52 and N54. An engine to me is about more than "one time performance" its about ownership of the engine and the costs incurred. I can fix rod bearings on an S62/S54 fairly easily, whereas for an S85 it requires basically disassembling the entire front of the car (as opposed to just dropping a subframe for the S62). S54 will always be the best N/A BMW I6 to me, but for daily drivability, I love the N52. My next car may very well be a 3.0si Z4 coupe because I don't need another S54 M coupe. I want the N52 in that case, I am not merely "settling" for it...

**markslc1** · 07-17-2016, 04:00 PM

Well said. The n52 is better suited for track work as well. Less overheating overall.

**bimmerlust** · 07-28-2016, 06:59 AM

Originally Posted by BimmerBreaker

Direct injection just means you have to do valve cleaning. Thats just one more thing the N52 has in it's favor IMHO, it's not a detriment that it doesn't have direct injection. Conversely, valvetronic is a wonderful way to increase power and efficiency through the entire rev range - the N54 doesn't have that... if you want pure speed, get the 135i and be prepared to spend more $$$ in gas, insurance, repairs and maintenance. Want a more affordable and more reliable daily driver without sacrificing anything but that "pinned to the seat" power? Get the 128i, throw the DISA intake manifold on it and be done with it.

Direct injection doesn't only mean you need to clean the valves, and need for valve cleaning is overstated anyway with some spirited driving, especially on N55. DI has way more benefits than drawback especially with forced induction. It gives you more headroom from detonation under any given conditions and can also allow extremely fuel efficient lean burn, although this is not allowed due to emissions laws. N54 doesn't have valvetronic, and it doesn't matter, because it has really good power potential even on the stock turbos and a very mature tuning scene. N55 engine adds valvetronic, but valvetronic is not nearly as big of a deal as the DI is. It also only makes a difference under part throttle, and it's not a big difference. There is no difference on wide open throttle. As for the 128 with a manifold...won't come close to either N54 or N55 even stock.

Originally Posted by markslc1

Well said. The n52 is better suited for track work as well. Less overheating overall.

Yes, N54 and N55 do need cooling mods for track time. Full water in the radiator and blower on heat will get you there for a car without huge mods, water meth really helps if you run a stock intercooler. Really though these cars all need a lot of mods if you want them to do serious track time. To start with they have pretty soft suspension and incredibly soft bushings from the factory as well as no choice of a locking diff.

**boro92** · 07-29-2016, 11:34 AM

FWIW the N51 already has the 3 stage IM. Difference between N51 and N52 is in the head - N51 is lower compression and the head does not flow as well.
The manifold is active with the factory tune--so whatever gains an N52 guy got from using an N51 intake manifold will not be the same for the N51 (read: N51 will not net huge gains - it already has the good parts. Unfortunately, the CR and head are the limiting factor in holding back the power).
Going AA will not net huge gains - BUT it will improve throttle response and make the car much more entertaining.
The AA tune will adjust ignition map, throttle map, fuel map. Though it isn't cheap, and the gains are marginal.

The alternative is to find the PBX (BMS power module/juice box). This is a piggy back tune which alters ignition map, afr and provides improvements to throttle response.
A car with any of the above tunes will feel much faster at part throttle simply due to the removal of the throttle lag. Makes it more enjoyable to drive. Out right power though? Not really.
Your biggest gains on an N51 will come from headers (+10 to +15WHP).

**Desertman123** · 08-10-2016, 12:02 AM

Is this just gonna turn into another turbo vs NA thread?

Check out the AA or Supersprint headers too. On a bone stock N52: headers + 3 IM + AA tune should net you like what, 40whp? Pretty decent if you ask me.