125i to 135i?

[jamiewalkaa]

Hello, I currently have a stage 2 125i, it’s fun, super good backroad car, and is quite quick for what it is. But I’m feining something quicker, I’m just looking to get some advice on what to get next? I want more power but I’m pretty scared of n54, seems like a massive headache, some advice would be awesome!

[Cannonfodda101]

hey fellow aussie honestly the n54 isnt that bad lol could always do a supercharger kit

[wheela]

Get a n55 with the newer style hpfp. Add a relatively cheap pure500, Dorch stage 2.5 hpfp and a custom tune and you've got around 450whp on 93, or around 500whp if you're willing to run around an e50 mix.

[jamiewalkaa]

Originally Posted by Cannonfodda101

hey fellow aussie honestly the n54 isnt that bad lol could always do a supercharger kit

Would be sick if I supercharged but its Gonna cost around 15,000 for the kit and supporting mods

[jamiewalkaa]

Originally Posted by wheela

Get a n55 with the newer style hpfp. Add a relatively cheap pure500, Dorch stage 2.5 hpfp and a custom tune and you've got around 450whp on 93, or around 500whp if you're willing to run around an e50 mix.

One thing I’m worried about is the oil starvation issues as I like to drive cars through the back roads and hard and slide them around

[wheela]

Originally Posted by jamiewalkaa

One thing I’m worried about is the oil starvation issues as I like to drive cars through the back roads and hard and slide them around

I'm probably biased, as I've had my n55 since 2017, but I think as long as you stay on top of oil leaks (keep your oil level full), and aren't tracking on r-compound tires (or doing a bunch of donuts), you'll probably be fine. That said, I believe some of the n55 folks here track their cars, maybe some of them can chime in?

If you're still uncomfortable, you can now do the s55 oil pump swap and have bullet-proof oiling, as long as it's a RWD car (s55 oil pump unfortunately doesn't work with the x-drive oil pan). There's even a guy on here now selling the custom brackets needed for the conversion.

For what its worth, I asked Google AI for its thoughts on the matter. Here's what it said:

[jamiewalkaa]

Originally Posted by wheela

I'm probably biased, as I've had my n55 since 2017, but I think as long as you stay on top of oil leaks (keep your oil level full), and aren't tracking on r-compound tires (or doing a bunch of donuts), you'll probably be fine. That said, I believe some of the n55 folks here track their cars, maybe some of them can chime in?

If you're still uncomfortable, you can now do the s55 oil pump swap and have bullet-proof oiling, as long as it's a RWD car (s55 oil pump unfortunately doesn't work with the x-drive oil pan). There's even a guy on here now selling the custom brackets needed for the conversion.

For what its worth, I asked Google AI for its thoughts on the matter. Here's what it said:

Wow thanks for the thorough answer brother. I appreciate it!

[wheela]

Originally Posted by jamiewalkaa

Wow thanks for the thorough answer brother. I appreciate it!

No problem, I hope it helps!

[wheela]

Nice looking one'r by the way!

[kashikoi]

Have you considered a 3.73 rear diff (aka poor man's supercharger)? Here's a vid of me doing a short 60-80mph 3rd gear pull (cluster gauge is a 1M replica).

I think I have all the FBO mods:
- 3SIM.
- Silicon intake boot.
- Euro intake box.
- AA catless headers.
- MILVs.
- StageFP tune to account for these mods.

[jamiewalkaa]

Originally Posted by wheela

Nice looking one'r by the way!

Thanks man!

[jamiewalkaa]

Originally Posted by kashikoi

Have you considered a 3.73 rear diff (aka poor man's supercharger)? Here's a vid of me doing a short 60-80mph 3rd gear pull (cluster gauge is a 1M replica).

I think I have all the FBO mods:
- 3SIM.
- Silicon intake boot.
- Euro intake box.
- AA catless headers.
- MILVs.
- StageFP tune to account for these mods.

https://www.youtube.com/watch?v=ve_c3SdYhsQ

How much of a diff did the diff make?
Also how much of a difference did MILVS make? Talking to my tuner apparently it’s a marketing scam, doesn’t actually do much at all.

[kashikoi]

Originally Posted by jamiewalkaa

How much of a diff did the diff make?
Also how much of a difference did MILVS make? Talking to my tuner apparently it’s a marketing scam, doesn’t actually do much at all.

When I did my valve cover gasket, "while I was in there" I threw in the MILVs upgrade. It does seem like a controversial upgrade in the N52 world. Tbh, I don't know if it actually made a difference as I have nothing to compare it to. At the same time I upgraded to a 3SIM and purchased an off the shelf tune from StageFP that was specifically for 3SIM+MILVs. I believe 22RPD also offers MILVs tuning. So my take is if you just install MILVs by itself, it's not going to do anything. You need a tune to compensate for the extra valve lift from MILVs. Since StageFP and 22RPD provide a MILVs tune and are pretty much the gold standard when it comes N52 tuning, I'll take their word for it that it's a valid upgrade.

Regarding the 3.73 rear diff, if you have an auto you already have the 3.73. The 3.73 is really for manuals and yes it is very noticeable. However, your RPMs are gonna be sitting a little higher cruising on the highway in 6th at higher speeds than with the standard 3.23 diff. But for around the town driving, it definitely gives the 1er some more pep in its step.

[wheela]

About MILVS, take a read through this thread, and the linked threads within. This one is pretty long, but hang in there, some good discussion starts up around page 8.

https://f87.bimmerpost.com/forums/sh....php?t=1724885

If you read through that thread, you'll see my personal take on MILVS, along with my reasoning. I won't duplicate all my reasoning here, but a brief summary is I don't see any conclusive evidence in that thread (or the linked threads within it) proving a meaningful improvement. To the contrary, the numerous reports (even from believers, and even on n52 engine) that it nets no gain unless you get a tune for it really suggests to me that it doesn't provide any meaningful benefit. The whole rationale for the MILVS improvement is more valve lift = improved volumetric efficiency. All those n52 guys were able to net gains (without a tune) from their other volumetric efficiency boosting mods (intakes, exhausts, etc.) proving the engine did not require a tune to nets benefits from improved volumetric efficiency. But all of a sudden it can't do the same thing from MILVS? Plus almost all the n52 pre/post MILVS gain results were on stock tune before, and custom tune after. Would they have gained just as much from a custom tune WITHOUT MILVS? No clear answer. When MILVS came out, almost none of those n52 guys were getting tunes. It almost seemed like MILVS was getting used as a tool to convince people to start buying custom tunes.

Given that MILVS is changing geometry of a very complex valve train developed by BMW engineers, and nobody (myself included) seems to have demonstrated a solid understanding (in my opinion) of how the MILVS actually impacts valve lift and the dynamics of the valve train, and the lack of solid evidence (in my opinion) that it actually nets meaningful gains, I won't be installing it on my car.

[kashikoi]

Fair enough, I can definitely see your point regarding the lack of isolated data. For me, it fell into the 'while I’m in there' category—since I already had the valve cover off for the gasket, the install itself was a fun little project. At the end of the day, even if the gains are marginal, I enjoyed the process and the peace of mind knowing the top end is as 'unlocked' as possible with my StageFP setup.