F80 M3 Engine?

[Conza89]

Rumour has it, the next M3 will have a turbo inline 6, I think it's almost to the point of fact?

Anyway, since the last car had a glorious 414bhp V8, I wanted to try and create a likely replacement, but turbocharging is a whole new world of learning, to which I'm confused.

I'm aiming for 450bhp / 335 KW, torque I'm not concerned about, it'll have loads.

I'm thinking 3.4 litres would be a logical jump from 3.2 of the E46's motor, but the rumour mill also suggests the N55 will be used, but I doubt this as turbocharged in the M135i it produces 315bhp, or 100 short of the old V8.

Any suggestions as to likely components would be great, I'm starting with this...

[RobtheFiend]

Considering the fact that a 3.2 liter BMW engine can be tuned to over 425 hp without turbo, do you really think that 400-450 with a pair of turbos would pose a problem?

A 2 liter Mitsu Evo has 280 hp from the factory, that means 140 per liter, so a 3 liter engine at the same trim level would produce 420 hp.

[Conza89]

Considering the fact that a 3.2 liter BMW engine can be tuned to over 425 hp without turbo, do you really think that 400-450 with a pair of turbos would pose a problem?

A 2 liter Mitsu Evo has 280 hp from the factory, that means 140 per liter, so a 3 liter engine at the same trim level would produce 420 hp.

A couple of problems here

Firstly, the 3.2 litre engine tuned to 425bhp, NA, is clearly a race engine, and wouldn't be viable for production, or the longevity needed for production.

Secondly, 140bhp per litre is substancial, and when you increase the amount of cylinders, you also increase the amount of ineffiency throughout the whole motor, so assuming you could just multiply it out to 3 litres / 6 cylinders from 2 and 4 is not accurate for that reason.

So my original questions goes to, neither of these points, but rather, based on a likely 3.0-3.4 litre inline 6 turbo, what would be likely parts that will be used, and a settings range (1.2 bars of boost, ect).

[RobtheFiend]

The Medium BMW straight six (2.3l - 3.25l), is maxed out at 3.3 liter. A 3.4 would require the use of the big I6 (3.3l - 3.8l). That one is much heavier and longer.

"140 hp per liter is substantial" ? WTF?

400 hp from 2 turbos, do you even know how small those turbos can be?

You only need a pair of Garrett GT2058 ; 36.1/52.2mm compressor , 47mm turbine 72 trim.
The turbos on a Nissan RB26DETT is GT28 size.

[oppositelock]

Considering the fact that a 3.2 liter BMW engine can be tuned to over 425 hp without turbo, do you really think that 400-450 with a pair of turbos would pose a problem?

A 2 liter Mitsu Evo has 280 hp from the factory, that means 140 per liter, so a 3 liter engine at the same trim level would produce 420 hp.

I have no idea what you're trying to say here, as you're contradicting yourself. Nevertheless, the next gen turbo M3 will no doubt be lower revving and hampered by stricter fuel economy and emissions standards. 450 hp sounds completely reasonable. AMG's new M157 direct injected turbo motor barely puts out 100 hp per liter in it's highest state of tune.

[RobtheFiend]

How am i contradicting myself? Please describe.

[oppositelock]

The OP's proposed engine is a 3.4L liter with 450 hp, producing a respectable 132.4 hp per liter. Then you throw out the Evo example with a virtually identical 140 hp\L to prove.....what exactly? That a theoretical M3 should make exactly 476 hp instead of 450? I don't get it. The contradiction here is the idea that 132 hp/L sucks, but 140 is OMG super awesome. Not sure why this imaginary 26 horsepower deficit bothers you.

[RobtheFiend]

I never said 140 hp/l is super awsome, it is NOT super awsome.

What i ment with my first post is; if a 3.2 liter N/A can be made to reach over 420 hp, it would be easy peasy to get a 3 - 3.2l turbo to that level.
There is no need to move up to 3.4l.

Read Wikipedia. The larger M5 engine is what you need if you gonna go to 3.4 liter. The 3l engine used in the M135 probably maxes out at 3.25l.

I used the Evo engine as an example, because most people here know what that is.

And using the Evo as basis, you get 3l 420 hp. End.

Its an example, nothing else, so chill.

[oppositelock]

As I said, I had no idea what you were trying to say. Back on topic, then.

[RobtheFiend]

????

[Kretus]

Well, considering that the production N57S diesel engine is a 2993cc engine wich produces 376HP, I don't think BMW would have any trouble making 450HP out of the N55 petrol one. Perhaps if they use 3 turbo's instead of 1...

[RobtheFiend]

Isn't the N55 a dual turbo?

[T16]

Nope, the N55 is a single twinscroll turbo, the N54 was the twin turbo one.

[Daffyflyer]

Wonder if the fuel pumps still expensively explode..

[oppositelock]

Wonder if the fuel pumps still expensively explode..

They'll just be a scheduled maintenance item, along with blasting the intake valves with walnut shells every other oil change.