[M3 Adjuster]

Originally Posted by PrematureApex

All N55 turbos are integrated into the manifold.

Edit, covered above.

That's perhaps more telling. The standard N55 turbo is seriously running out of steam early in the rev range.

?

But you wouldn't have both. If the turbo is larger, it would have more lag, and slightly worse throttle response.

Well the throttle response comments are in comparing M4 and M2 correct ?

M4 has two turbos and makes bigger numbers and more power to compete with the Mustangs and camaro and other muscle cars and GT cars.

The m235/40 is a great blend of power, performance and reliability.

Slot the M2 in with a slightly larger turbo than the M235 that's not a big honking turbo and its goldilocks.

I'm actually surprised at how much energy people are wasting trying to shoot down what's obvious ...

Oh ye with so little faith In BMW M...

[shivaswrath]

So a Pure 2 turbo on an M2=everyone on the forum would be happy?

[PrematureApex]

Originally Posted by shivaswrath

So a Pure 2 turbo on an M2=everyone on the forum would be happy?

Oh yeah.

I'd even be good with just the stage 1.

And don't get me wrong, I OK with a standard N55 turbo, given the low price of the car.

I guess I take slight issue with the fact that the 340 is putting down 330 whp stock. At least for bragging rights on the internet, I'd have liked to see the M2 similarly underrated.

[PrematureApex]

Originally Posted by M3 Adjuster

Well the throttle response comments are in comparing M4 and M2 correct ?

I thought you were using it as alleged support that the turbo is different vs. the N55, which is what the rest of your post was trying to accomplish.

[SYT_Shadow]

Originally Posted by nishmaster2k

I'm also not of the opinion that a non-S series engine makes it a lesser M, any more than the North America E36 M3 was a lesser M because of the S52. These arguments get ridiculous. I don't see anyone saying the 1M isn't an M because it uses the N54. Then again, I don't hang around forums much, so maybe people were saying that at the time.

A couple things here


Anyone who has driven a Euro E36 M and a US E36 M will indeed tell you the US E36 M is a joke of a car. It's been built into a very reliable track platform but that is besides the point.
This is as obvious as the Earth not being flat.
The US got completely screwed with the E36. When you drive the Euro version it's like a different car. 50% more power does that.

Secondly, plenty of people said the 1M wasn't a 'real' M car due to the N54. It did not use a 'real' M engine, it used the 740i/Z4 35i engine which was never destined for a M car.
The fact that it's rare and looks really cool doesn't change the fact it is not an M engine.

M designates 'their' engines with an S. They've been doing that for a long time. If it does not have an 'S', it is not designed by M.

Apparently, someone at M division thought the changes wrought to the N55 for the M4 were enough to warrant a 'S'. The N55 they used for the M2 was not.


The BMWNA marketing could not be more deceptive. They allowed everyone to test euro spec cars with manual seats which won't even be sold in the US.

[nishmaster2k]

Originally Posted by SYT_Shadow

A couple things here


Anyone who has driven a Euro E36 M and a US E36 M will indeed tell you the US E36 M is a joke of a car. It's been built into a very reliable track platform but that is besides the point.
This is as obvious as the Earth not being flat.
The US got completely screwed with the E36. When you drive the Euro version it's like a different car. 50% more power does that.

I don't really want to rehash 20 year old arguments (jeez, it has been that long, hasn't it), and I'm not disagreeing with you that the US model was inferior. It was, however, still an M.

Secondly, plenty of people said the 1M wasn't a 'real' M car due to the N54. It did not use a 'real' M engine, it used the 740i/Z4 35i engine which was never destined for a M car.

I missed the boat on the 1M forum thrashing, so I can't speak to what was said at the time. I think history, though, has confirmed the 1M's place amongst the M heritage, certainly above other rarities like the Z3/Z4 M Coupes (which are both great cars, but little recognized), S engine or no. I'm no 1M fanboy, just my view as an outsider.

M designates 'their' engines with an S. They've been doing that for a long time. If it does not have an 'S', it is not designed by M.

Apparently, someone at M division thought the changes wrought to the N55 for the M4 were enough to warrant a 'S'. The N55 they used for the M2 was not.

The BMWNA marketing could not be more deceptive. They allowed everyone to test euro spec cars with manual seats which won't even be sold in the US.

While I'm not strictly disagreeing here, I think it has more to do with difference from the base platform. The N55 has a particular design, and the S55 is a significant departure from it, because you have to remember that the engine is more than the block/head, it comprises the intake, exhaust, cooling setup, etc. The S55 intake and exhaust with 2 turbos is definitely enough to warrant a nomenclature change on its own. This is coming from a guy who's had to design a couple turbo systems over the years. That engineering requires the same precision and maths as the block does. Then you add a completely different cooling setup, block, pistons, and the like. M didn't need to modify as much to hit their power/price target in either the 1M or in the M2, so why call it an S55? That would be even more confusing.

It is clear that the engine is much closer to the N55 than the S55, and what is also clear is that I don't think it makes a lick of difference. It sits in a nice power niche below the M3/4, right where they wanted it, and punches above its weight. True M, not true M? Not sure it matters. Nobody's getting ripped off here when you can get one for less than an M235i. You can't slap the F80 chassis on one of those for $0.

[Mr. Nice]

My guess is same turbo housing milled out with a bigger impeller, similar to RB / Pure turbos. Would be fairly cheap and easy for BMW to do and allow the turbo to remain in it's efficiency range with the higher power numbers. Also would explain how it's making more power up top. I'd be happy with this. We'll all know for sure soon enough.

[Boss330]

Originally Posted by PrematureApex

Yes, but again, those sources SAY NOTHING. That is NOT the same as those sources saying it's an open block.

You can't make that logic leap.

We have no conflicting information. The only sources that specify the configuration of the block all say the same thing.

You have nothing to rely on.

The way I see it:

-The M2 engine is a N55
-N55 engines have open deck blocks
-BMW's tech training docs explicitly states that they only describe parts that are different from the std N55 (ie, any part not mentioned is similar to the normal N55)
-BMW M tech training docs does not say that the M2 N55 engine has gotten a new block but lists all other parts that are different from the regular N55

Nothing would be better than the M2 engine having a closed deck block, but BMW does NOT list the block as one of the parts that have been modified on the N55 for the M2 (and as stated above, BMW writes that the tech training doc describes parts that are changed for the M2 engine).

The N55 engine is by default an open deck block and as long as BMW does not claim the block is new or changed it is an open deck block. They don't need to repeat that info in the M2 docs. Just like they don't repeat a lot of other basic info not specific for the M2.

[CaryTheLabelGuy]

Originally Posted by Boss330

The way I see it:

-The M2 engine is a N55
-N55 engines have open deck blocks
-BMW's tech training docs explicitly states that they only describe parts that are different from the std N55 (ie, any part not mentioned is similar to the normal N55)
-BMW M tech training docs does not say that the M2 N55 engine has gotten a new block but lists all other parts that are different from the regular N55

Nothing would be better than the M2 engine having a closed deck block, but BMW does NOT list the block as one of the parts that have been modified on the N55 for the M2 (and as stated above, BMW writes that the tech training doc describes parts that are changed for the M2 engine).

The N55 engine is by default an open deck block and as long as BMW does not claim the block is new or changed it is an open deck block. They don't need to repeat that info in the M2 docs. Just like they don't repeat a lot of other basic info not specific for the M2.

I agree. I think the M2 motor is indeed open-deck if they're calling it a N55. It just doesn't make sense to redesign a closed-deck block based on the N55 and not use the S55 when that is already designed and well proven.

It also doesn't make much financial sense to do this. The R&D it took to develop the S55 has already been paid for, why not get a higher return on R&D investment by putting the S55 into the M2, which is going to sell like hot cakes?

[PrematureApex]

Originally Posted by Boss330

and as long as BMW does not claim the block is new or changed it is an open deck block.

BMW DOES CLAIM IT HAS CHANGED!

Jesus man.

You just choose to ignore the BMW sources stating as such.

Once again, you have how many sources saying it's an open deck block?

Zero.

All of BMW's sources that comment on it, call it closed.

[PrematureApex]

Originally Posted by CaryTheLabelGuy

It also doesn't make much financial sense to do this. The R&D it took to develop the S55 has already been paid for, why not get a higher return on R&D investment by putting the S55 into the M2, which is going to sell like hot cakes?

Use that same logic. That's why the M2's block is likely shared with the S55.

Why didn't they put the S55, twins and all into the M2?

Really?

So...same motor/drivetrain/suspension/trans...and you want a ~15k discount vs. an M4? Let alone that the M2 would then be faster than the M4...

[PrematureApex]

Originally Posted by Mr. Nice

My guess is same turbo housing milled out with a bigger impeller, similar to RB / Pure turbos. Would be fairly cheap and easy for BMW to do and allow the turbo to remain in it's efficiency range with the higher power numbers. Also would explain how it's making more power up top. I'd be happy with this. We'll all know for sure soon enough.

Would not be surprised if that was the case.

[CaryTheLabelGuy]

Originally Posted by PrematureApex

Use that same logic. That's why the M2's block is likely shared with the S55.

Why didn't they put the S55, twins and all into the M2?

Really?

So...same motor/drivetrain/suspension/trans...and you want a ~15k discount vs. an M4? Let alone that the M2 would then be faster than the M4...

We're talking about the block, not the ancillary bits. Don't be silly.

[PrematureApex]

Originally Posted by CaryTheLabelGuy

We're talking about the block, not the ancillary bits. Don't be silly.

?

Yes, we're talking about the block.

BMW has stated the M2 uses a closed deck version of the N55 block. Guess what else does? The S55. It's likely that the M2 is using a version of the S55 block for exactly the reasons you posted. No sense in making a completely new closed deck block.

Unless BMW literature is wrong about the block. A little mistake that one would have thought would have been corrected after being posted for MONTHS already.

[CaryTheLabelGuy]

Originally Posted by PrematureApex

?

Yes, we're talking about the block.

BMW has stated the M2 uses a closed deck version of the N55 block. Guess what else does? The S55. It's likely that the M2 is using a version of the S55 block for exactly the reasons you posted. No sense in making a completely new closed deck block.

Unless BMW literature is wrong about the block. A little mistake that one would have thought would have been corrected after being posted for MONTHS already.

Maybe I misunderstood your post and for that I apologize.

So you're agreeing with me that the M2 likely has an S55 closed-deck block, if it is indeed closed-deck. Obviously BMW could easily de-tune the S55 by using a smaller single turbo (like the N55) and do away with the air/water intercooler in exchange for the N55-like air/air intercooler....etc. BMW might be calling it a N55 for the sake of marketing and not stepping on the M4's toes when in fact it's more S55 than N55.

[PrematureApex]

Originally Posted by CaryTheLabelGuy

Maybe I misunderstood your post and for that I apologize.

So you're agreeing with me that the M2 likely has an S55 closed-deck block, if it is indeed closed-deck. Obviously BMW could easily de-tune the S55 by using a smaller single turbo (like the N55) and do away with the air/water intercooler in exchange for the N55-like air/air intercooler....etc. BMW might be calling it a N55 for the sake of marketing and not stepping on the M4's toes when in fact it's more S55 than N55.

Yup, agreed.

If it is indeed closed deck, I think what you described is a likely accurate description of what the M2's "N55" really is.

I mean, of course some different machining operations may be made to the M2's block after initial casting. But if it's closed deck, one would think it has its basis in the S55.

Maybe an S55 short block for strength, who knows about the heads, and N55 turbo/accessories.

Then again, maybe it's a generally stock M235 N55, with drop-in pistons from the S55, and a slightly larger compressor wheel to hold boost past 6k.

Time will tell, awesome little car regardless.

[CaryTheLabelGuy]

One other thing that jumped out at me in the M2's docs were the reference to the M2's engine as having gray-cast sleeves.

The S55 doesn't have traditional sleeves. BMW utilizes a technique called twin-arc spraying which is much thinner/lighter but just as strong as traditional sleeves. Supposedly the B58 is using the same technique (the B58 is also closed-deck).

Just food for thought.

[PrematureApex]

Originally Posted by CaryTheLabelGuy

One other thing that jumped out at me in the M2's docs were the reference to the M2's engine as having gray-cast sleeves.

The S55 doesn't have traditional sleeves. BMW utilizes a technique called twin-arc spraying which is much thinner/lighter but just as strong as traditional sleeves. Supposedly the B58 is using the same technique (the B58 is also closed-deck).

Yup. I think the sleeving operation is cheaper. But if that's the case, maybe it would be technically a different base block casting given the possible differences in bore.

BMW M used to be anti-sleeving. Hence the iron lump in the S54.

Times, they are a-changin'

[Boss330]

Originally Posted by PrematureApex

BMW DOES CLAIM IT HAS CHANGED!

Jesus man.

You just choose to ignore the BMW sources stating as such.

Once again, you have how many sources saying it's an open deck block?

Zero.

All of BMW's sources that comment on it, call it closed.

Originally Posted by PrematureApex

?

Yes, we're talking about the block.

BMW has stated the M2 uses a closed deck version of the N55 block. Guess what else does? The S55. It's likely that the M2 is using a version of the S55 block for exactly the reasons you posted. No sense in making a completely new closed deck block.

Unless BMW literature is wrong about the block. A little mistake that one would have thought would have been corrected after being posted for MONTHS already.

I'll repeat once again that I do aknowledge that BMW USA claims the M2 has a closed deck crankcase block.

But that's the only source we have that claims this. In my opinion the BMW USA website is a source of a lower degree than the official BMW AG/M press releases and technical training documents. The manufacturer of the car has published a press release and a technical training document that in the first case doesn't mention anything about a new block and in the second case makes a point of saying that it's only the parts that differ from the normal N55 that is described.

From the Tech training doc:

http://f87.bimmerpost.com/forums/att...2&d=1457027357

The N55B30T0 engine is the power plant for the F87 BMW M2. It is a further development of the N55B30O0 engine from the BMW M135i and BMW M235i, which is familiar from the current BMW 1 Series and 2 Series models.
This document describes only the differences compared with the N55B30O0

.....

Piston

The pistons were adopted from the S55 engine.
Adaptations were necessary on the first pistonring, the plain rectangular compression ring. This had to be adapted as regards the material pairing to a liner made of grey cast iron. This is in contrast to the S55 engine, where this is LDS-coated.

The info regarding piston rings also points to the M2 NOT using the S55 block since the liners have different coatings. Why change the coating and also have to change the piston ring if you allready are using the S55 block and pistons...???

In my opinion the fact that the official BMW litterature explicitly says that the Tech training doc ONLY describes the parts that are different from the N55B30O0 engine and that this document says NOTHING about a new block or a closed deck block is very strong evidence indicating that the N55B30T0 (M2) engine uses the exact same block as the other N55 engines...

I guess it all depends on whether we rely on the official BMW AG/M litterature or the BMW USA website here...

[PrematureApex]

Originally Posted by Boss330

I guess it all depends on whether we rely on the official BMW AG/M litterature or the BMW USA website here...

This is faulty logic 101. No, it does not depend on that. The BMW AG/M Literature DOES NOT TEACH the block configuration.

So naturally, you can't rely on it for teaching block configuration.

You're making an assumption. And you know what they say.

[Boss330]

Originally Posted by CaryTheLabelGuy

One other thing that jumped out at me in the M2's docs were the reference to the M2's engine as having gray-cast sleeves.

The S55 doesn't have traditional sleeves. BMW utilizes a technique called twin-arc spraying which is much thinner/lighter but just as strong as traditional sleeves. Supposedly the B58 is using the same technique (the B58 is also closed-deck).

Just food for thought.

Originally Posted by PrematureApex

Yup. I think the sleeving operation is cheaper. But if that's the case, maybe it would be technically a different base block casting given the possible differences in bore.

BMW M used to be anti-sleeving. Hence the iron lump in the S54.

Times, they are a-changin'

FWIW, these are the BMW ETK illustration of the M2 N55 and S55 engine blocks.

The S55 and N55 engine blocks are very different both externally and internally.

[CaryTheLabelGuy]

Originally Posted by Boss330

FWIW, this is the BMW ETK illustration of the M2 engine block:



The M235i engine block:



The S55 engine block:



The S55 and N55 engine blocks are very different both externally and internally.

Pictures aren't working for some reason.