[AlpineSwift]

So no one has actually tested this theory to use the N55 coils? Seems like a lot of BS floating around in here about N54 vs N55 reliability...

[romanonj]

Originally Posted by Dark9T

Over all n54s are way better than n55s, that's why the 335is and 1m still use them instead of n55..

Even though I probably like N54 better than N55, its hard to state one is better than the other. Reason 335is came equipped with N54 vs. N55 is due to BMW having more expereince with tunning N54 at the time of the 335is launch in mid 2010. 135is is equipped with N55 tuned version.

As mentioned earlier, lower cost of production is key with N55. Cost savings translated into lesser tunning platform, with N54 being far superior and capable platform than N55.

Differences worth mentioning:
Certain forged internals (i.e. crank) vs. cast on N55
Two turbos vs. one hence running less boost to achieve same output
N55 uses valvetronic N54 does not (efficiency improvement)

[N54B30A]

Originally Posted by MDORPHN

Yes, they did. Two pieces of "ancient" technology and all of the related pieces are way more expensive than a single turbo set-up. Plus the N55 substituted cast pieces for several forged pieces in the N54. And, btw, the N55 turbo -- though a far more advanced design -- is also journal bearing.

Neil

I don't think the n55 is much cheaper of it even is cheaper. Yeah it has one less turbo but it's a Borgewarner twin scroll ball bearing which I can promise is a lot more than two td03's not to mention the n55 head is much more to produce considering it has valvetronic and the n54 does not. The n55 may be cheaper but if also gets torque much sooner and has lower emissions which is all BMW cares about

[MDORPHN]

Originally Posted by sahyoun

I don't think the n55 is much cheaper of it even is cheaper. Yeah it has one less turbo but it's a Borgewarner twin scroll ball bearing which I can promise is a lot more than two td03's not to mention the n55 head is much more to produce considering it has valvetronic and the n54 does not. The n55 may be cheaper but if also gets torque much sooner and has lower emissions which is all BMW cares about

AFAIK, the N55 turbo uses journal bearings, not ball bearings.

EDIT: Excerpt from posting by Rob Beck:

"Secondly, the N55 Turbo is pretty cool. It does use a custom version of the smallest Borg Warner EFR Billet Compressor wheel (62mm). However it has a custom inducer sizing, which is quite abit smaller than the exact wheel that is used in the BW EFR 62mm (45.8mm vs. the EFR's 49.6mm) with the extended tip technology. It also uses the twin seal arrangement as do the EFRs (not sure if this is common across other BW units). The turbine has the backing plate like the EFRs as well, but I do not think its a Ti wheel. The turbine is also quite small, approx. 53mm Inducer and 46.1mm Exducer. It is a Journal Bearing Turbo, unlike the EFR. Both housings seem to be built on the EFR foundation. Overall it seems like a very nice unit OEM unit, just does not have much flow potential."

Neil

[parksjm7]

I've been running them for a little over a month (all 6 Delphi coils on N54) runs perfectly fine - I noticed less stumbling rpms but that may be just because the older coils had 53k on them. Ive done multiple wot runs and some hard driving on tuned/ stock maps on procede. AFAIK the Delphi are used on n55 as well as n20 engines. I don't have the means to further test/measure performance but if they should fail or degrade performance over time, i'll post.

[AWDBooSTIn90]

I had a coil go bad on my 07 335i.

I have all original coils with 120k miles so it was only a matter of time. '07 335i with 2006 build date.

I bought a new cheap coil online to replace the bad one in the meantime.

On a side note. I was getting no misfires under boost. It jst died one day taking off normally from a red light. Never worked again.

Now after changing the coil my car starts up so much faster. Idles smoother. And doesnt do the cold morning first throttle press stumble it used to have. So the old coil was causing some problems. But these were very subtle problems and jst seemed normal

The reason i didnt just order a new bosch coil is because im going to order the N55 delphi coils instead and see how they hold up.

So when i order the new coils next week ill post pics comparing the two brands.

N54 vs N55

Bosch vs Delphi

I will also be doing new plugs since im tuned running an E30 blend.

Just by looking at pics of the N55 Delphi brand coils they look like better quality and will hopefully last another 100k miles.

On a side note:
What spark plugs should i get for my 2007 335i with jb4 and no mods yet. FBO in the future. I only buy oem parts. So im assuming oem is a bosch or ngk plug? But what brand and part #

[AWDBooSTIn90]

The price difference is so close i would suggest delphi over bosch anyway. Im sure they changed manfuctures due to coil failures on n54 equipped cars

[wobbles1]

I have been running the Delphi's in my 1m for about 1500 miles now. No difference except the heat shield on the coils.

[MK335i]

This morning I got cylinder 4 misfire and limp mode after trying to pass someone on the interstate

Anyone know the part numbers for these DELPHI or BOSCH OEM coil packs and where the best place to purchase??

I drive 2009 e90 N54 335i

I'm just going to replace all of them now since they seem to be going out one by one.

[prelude2perfect]

Just purchased mine from here:
http://www.amazon.com/Delphi-GN10328...ype=automotive

lowest price I could find

[The Convert]

Originally Posted by jeffblue

Lol less expensive to produce? The turbos on the n54 are shit ancient ass journal bearing technology. I dont think they saved much money in production from n54 to n55

The auto industry is all about saving every single penny they can. Just think, one penny over a million cars is still $100,000! They will shave any cost they can.

[e92_boost]

http://www.amazon.com/gp/product/B00...w_bottom_links

I just ordered these for 172 today and they went up in price

[BMSE92_Harry]

What spark plugs are you guys running? Bosch or NGK?

[knissel]

Originally Posted by 3000GT MR

I saw that ngk had coils for the n54 pretty cheap. Didn't really look into it but just came across it during my searching

link

[torn08]

Will be installing the delphi coils and ngk iridium in my n54 335i later today

[ferocity02]

Originally Posted by torn08

Will be installing the delphi coils and ngk iridium in my n54 335i later today

Which coils did you go with, seems like both GN10571 and GN10328 would work for our cars. 10571 is for N55 and 10328 is for N54, but I think they are interchangeable.

[CarAbuser]

Is it worth replacing coils until they start to miss?

I had one fail last week and replaced it. The car runs fine now. Is it worth replacing the rest of them? They have 46k on them so not huge miles.

[torn08]

10571. Car just got back from stage 2 fuel pump, vrsf cp, 7 fmic, dps, and vtt inlets, bms occ instal. As soon as I get home plugs and coils will be in

[smitty513]

My wife has a X1 3.5i (n55) and I swapped coils just to cure my curiosity and my N54 ran just fine. Currently running 3 of them on the noisey bank 2 but haven't logged to see if there's any difference. The N55 coils are definitely better insulated.

[dlbrooks18]

Originally Posted by e92_boost

http://www.amazon.com/gp/product/B00...w_bottom_links

I just ordered these for 172 today and they went up in price

So these work for the N54 right?

[dlbrooks18]

Originally Posted by smitty513

My wife has a X1 3.5i (n55) and I swapped coils just to cure my curiosity and my N54 ran just fine. Currently running 3 of them on the noisey bank 2 but haven't logged to see if there's any difference. The N55 coils are definitely better insulated.

Good to know, thanks.

[e92_boost]

Originally Posted by dlbrooks18

So these work for the N54 right?

Yes I've had them for 15k miles now still strong no misfires, well worth the 170 bucks for my n54