[itbettergofast]

good thread!, awesome to know that i have forged internals

[anerbe]

Originally Posted by mikeith

that wasnt were i was going with it. what i meant was that there was a markup for the cost of that additional cost of the piston. and ultimately that attitional cost went to the buyer anyway. initially the 335i was a big deal because it was the first turbo platform bmw had offered in a long time so you would guess it would be mainly "enthusiasts" buying them. i'm sure when they found a much larger demographic buying them and having to dump so much money in their hpfp hiccup they had to cut cost somewhere. i just meant that in innitial design they knew the price dif between cast/forged and went forged. but i promise they didnt "throw it in".... we paid for it lol.

bmw fixes prices not only on cost of production, but market competitiveness, profit margin/shareholder reports, etc...

BMW fixed the price to the consumer, and it's up to cost optimization and engineering/manufacturing changes to increase their margin. Their pricing strategy is much more complex than what type of materials used. The pricing was fixed to be competitive in the market, and it's up to the team to analyze field data to determine which areas can cut down costs vs. areas that need more development.

The price of the 335 for the consumer did not go up for the forged internals. BMW's margins on the car grew changing to cast. We do not see those savings.

[cwn23]

Originally Posted by anerbe

bmw fixes prices not only on cost of production, but market competitiveness, profit margin/shareholder reports, etc...

BMW fixed the price to the consumer, and it's up to cost optimization and engineering/manufacturing changes to increase their margin. Their pricing strategy is much more complex than what type of materials used. The pricing was fixed to be competitive in the market, and it's up to the team to analyze field data to determine which areas can cut down costs vs. areas that need more development.

The price of the 335 for the consumer did not go up for the forged internals. BMW's margins on the car grew changing to cast. We do not see those savings.

+1 well stated

[RoundelM3]

Originally Posted by eamon

Kindda old thread, but (FBOs) downpipes and intakes and such help engine longevity?
I also saw yous said you drive your cars rather spiritedly,
By suffering consequences are you saying that your cars broke down quickly because of your diving habits?
I've just been trying to keep my car reliable, but at the same time I can't resist temptations

I think you're making some incorrect assumptions here. More boost induces more internal stress on the engine. The 2007 and early 2008 N54 engines had forged internals - pistons, rods, crankshaft - which are better able to take the stress induced by higher boost and the resultant higher engine output. An aftermarket oil cooler would likely help longevity by keeping the oil temperature under control. The turbos as well as all the internal engine moving parts are lubricated by the same oiling system, and as more power is produced (by increased boost or other means), more heat is produced within the engine and transferred to the oil. If it breaks down, that will seriously reduce engine life.

Higher boost pressures also put more stress on the pistons, rods, crank and the rod and crank bearings. As these parts press harder on their bearing surfaces, the lubricating oil film is squeezed harder and will at some point weaken the bearing and then fail altogether. Another weak point is the head gasket which has to contain the internal combustion pressures. And as the turbos are pushed harder to create more boost, the impeller/compressor bearings are also put under a lot of stress.

All that said, no - I personally have not had any engine failures or loss of longevity because the modifications I have made are relatively conservative and within the manufacturer's stated "safe envelope". Anyone who has built performance engines will tell you that you can squeeze amazing performance from a given engine, but eventually all that extra power will overwhelm one or more weak points and reduce engine life. Heat and friction will win out eventually!

[conquistador]

Bringing it back from the dead...this was/is a great thread, thanks to those that contributed.

So which other years had forged, if any?

[Evil///M]

So....N55 doesn't have forged parts??

[924er]

Damn so no forged internals for my 2010 n54 booo

[135Pats]

Originally Posted by Evil///M

So....N55 doesn't have forged parts??

Crank is still forged IIRC. Rods and Pistons are cast, albeit a very high quality cast.

The notion of the N55 being weaker than the 54 is to this point complete speculation. At BIG power is it more likely to throw a rod? Yea, probably. But I for one am done calling the N55 'weak' just because the tuning sucks. Motor hasn't had a chance to shine yet.

Originally Posted by 924er

Damn so no forged internals for my 2010 n54 booo

I think you are kidding?

[335NJ]

Not to bring up a shit storm here, but didn't VAC (and others for that matter) confirm the pistons are cast, however the rods (maybe, I forget) and crankshaft are forged?

Here it is: http://www.e90post.com/forums/showth...541474&page=10

[Fundguy1]

N54=forged
N55=cast
we still don't know what either can handle as it hasn't been reached yet. But N54 currently has parts pushing close to 30 psi. N55 doesn't. And if these engines are like anything built before or since, forged can ultimately take more than cast.

[135Pats]

Originally Posted by 335NJ

Not to bring up a shit storm here, but didn't VAC (and others for that matter) confirm the pistons are cast, however the rods (maybe, I forget) and crankshaft are forged?

Here it is: http://www.e90post.com/forums/showth...541474&page=10

That's not a shit storm, it's the facts. The rods and crank are forged, pistons are cast.

The pistons are without question the "weak point" of the rotating assembly. I'd start getting worried about burning one up north of 600ish WHP, ethanol becomes key to protect 'em. In my humble opinion.

[Fundguy1]

Sounds reasonable. Crank and rods need it the most though.

[335NJ]

Originally Posted by 135Pats

That's not a shit storm, it's the facts. The rods and crank are forged, pistons are cast.

The pistons are without question the "weak point" of the rotating assembly. I'd start getting worried about burning one up north of 600ish WHP, ethanol becomes key to protect 'em. In my humble opinion.

Agreed 100%, fortunately the common weak points on most performance based engines are forged, however it's obviously not uncommon for an actual piston to grenade under certain conditions.

I just don't really care for the whole "N54 is forged" statement a LOT of people make (Understandably), considering that the pistons themselves aren't even forged.

[135Pats]

Originally Posted by 335NJ

Agreed 100%, fortunately the common weak points on most performance based engines are forged, however it's obviously not uncommon for an actual piston to grenade under certain conditions.

I just don't really care for the whole "N54 is forged" statement a LOT of people make (Understandably), considering that the pistons themselves aren't even forged.

It's just the relative relationship between "forged" and "quality". I agree it's over stated. The motor will hold whatever it'll hold, who knows. A few dyno pulls at 850WHP show that it's an ox, but would it run like that for 40K miles? I doubt it, and at some point the open deck is going to be an issue.

I'm thinking keep it under 650WHP with the appropriate turbo and you should be ok. We'll see.

I'm not worried about the rods, the crank is

[torn08]

Great read. Thanks to those that came before me

[Milan]

Originally Posted by 135Pats

It's just the relative relationship between "forged" and "quality". I agree it's over stated. The motor will hold whatever it'll hold, who knows. A few dyno pulls at 850WHP show that it's an ox, but would it run like that for 40K miles? I doubt it, and at some point the open deck is going to be an issue.

I'm thinking keep it under 650WHP with the appropriate turbo and you should be ok. We'll see.

I'm not worried about the rods, the crank is

Honda guys make 1100 whp on an open deck...granted thats with cast iron sleeves but still an aluminum block.

I don't think the open deck is an issue on a motor that all iron

[n54gte]

Imagine having cams and ported heads on the n54...

[wgknestrick]

Originally Posted by 135Pats

Crank is still forged IIRC. Rods and Pistons are cast, albeit a very high quality cast.

The notion of the N55 being weaker than the 54 is to this point complete speculation. At BIG power is it more likely to throw a rod? Yea, probably. But I for one am done calling the N55 'weak' just because the tuning sucks. Motor hasn't had a chance to shine yet.


I think you are kidding?

Tuning isn't the main thing holding the N55 back. A lot of N55s still have BEF + JB4 as tuning options.

It's the lack of "serious" turbo kits (Pure's N55 stage2 is still a great option for most, but not close to 600whp land). When a stock frame turbo is the biggest (non custom fabbed) option out there, there are marketplace problems.

The main question is which is the more reliable engine once modded to 500-600whp? I am going to speculate that the correct answer is not the one with forged pistons, but the one that isn't misfiring left and right, throwing fuel into the oil.

I don't think we've seen much to worry about on either engine that the mechanical parts are structurally "weak". Its the functional parts (coils, injectors, oiling system) that have let it down in certain cases.

Detonation and poor oiling kill just about every make of engine anyway.

[Nugget]

Originally Posted by wgknestrick

Tuning isn't the main thing holding the N55 back.

Yes it is.
No one can reliably run much over 20psi at the moment without encountering unexplained 'misfires'.

[3000GT MR]

Originally Posted by 135Pats

It's just the relative relationship between "forged" and "quality". I agree it's over stated. The motor will hold whatever it'll hold, who knows. A few dyno pulls at 850WHP show that it's an ox, but would it run like that for 40K miles? I doubt it, and at some point the open deck is going to be an issue.

I'm thinking keep it under 650WHP with the appropriate turbo and you should be ok. We'll see.

I'm not worried about the rods, the crank is

I heard there might be a 4 digit number rolling around out there.....

[135Pats]

Originally Posted by Milan

Honda guys make 1100 whp on an open deck...granted thats with cast iron sleeves but still an aluminum block.

I don't think the open deck is an issue on a motor that all iron

The 54 is sleeved as well I believe. I'm not sure how we aren't seeing cylinder float but i'm not complaining. Perhaps the design of the water jacket helps, IDK.

Originally Posted by Nugget

Yes it is.
No one can reliably run much over 20psi at the moment without encountering unexplained 'misfires'.

Yep. Hardware really isn't holding the 55 back at this point. You guys need fuel control, lots of it. Isn't E85 a big issue on that motor?

Originally Posted by 3000GT MR

I heard there might be a 4 digit number rolling around out there.....

I do know a certain someone from GA with a large enough turbo to do that

Exciting times for our platform!

[3000GT MR]

Originally Posted by 135Pats

I do know a certain someone from GA with a large enough turbo to do that

Exciting times for our platform!

Its closer to your neck of the woods than mine.