Remembered that I forgot to follow up to this thread when a BMW-related topic came up on my main forum. Sorry for being a few weeks late, lol

Well I looked it up. The N52 (R6) engine has a bore spacing of 91 mm (source: Automotive Engineering International, Jan 2005, page 28). So no, you CANNOT bore an N52 out to 90 mm because you cannot have a 1mm cylinder wall.


You cannot do that with a magnesium alloy block because it does not have the rigidity needed.
You cannot do that with aluminum either for the same reason.
Hell, you cannot even do that with iron.

The S38B38 3.8L engine you were referring to was....

Bore: 94.6 mm
Stroke: 90 mm
Cylinder wall: 5.4 mm
Bore Spacing: 100 mm

That is going to be a bit longer engine, and a 100 mm bore spacing gives a ton more headroom to play with than the M/N engines with their 91 mm bore spacings. And to have the rigiditiy needed in the engine for a scant 5.4 mm cylinder wall, they were using iron. The N52 as is has just a 6 mm cylinder wall (91 - 85 = 6) which is mighty thin. How thin is 5.4 mm, on iron?

http://www.bmwworld.com/engines/s38.htm

...and racing engines are not designed to last. They're designed to win races, and durability beyond the length of the race or how long the rules require them to last is not really a concern.

Please do not insult my intelligence by telling me that a 90 mm bore is possible on an engine that has a bore spacing of just 91 mm. That is nonsense, you obviously understand little about engine design and construction, and your credibility is now completely shot.

 

"I" and "L" can be used interchangably for "Inline" engines. Some say I6 and others say L6 and it's referring to the same thing. H means horizontally opposed.

here's a pic of Subaru's H-4 used in pretty much all of their cars. Add two cylinders and you have an H-6.

 

need to make a variable geometry turbo like the new Acura RDX or the new 911 turbo. Most turbo power curves are not good for a track, flat torque curves are ideal for the track. If a turbo car can be made to have the power of a turbocharged engine with the power curve of an N/A then yum

 

225kw / 400Nm apparently.

 

that equates to about 301 hp 295 torque, id like to see some power/torque curves whenever they are available

 

Strangely enough, the PR says 225kW/306hp, exactly the figure that IS350 puts out (I think it's intentional).

Lots more info on e90post:
http://www.e90post.com/forums/showthread.php?t=13204

N54 Bi-Turbo engine with HPI direct injection.
306HP, 400Nm available in range 1500 to 5800rpm. Max 7000 rpm. With full alluminium crankshaft casing, Bi-VANOS, electric water pump. 70kg less weight than 4.0L V8 NA engine. No turbo lag.

80-120kmh in 6.3s (330i in 8.2s)
0-100kmh in 5.7s (330i in 6.3s)

400Nm from 1,500 to 5,800rpm with no turbo lag (or so they claim). Very nice!

 

I'm sure some mags, particularly C&D, can do much better than that with the 335ci

 

Yeah, can't wait to see the "true" performance numbers of the new turbo 3. I would be very surprised if it can't beat the IS350's 5.1s from 0 to 60mph, particularly with a stick.

 

Question is, how much more would the price of the 335i be over the 330i.

The 335i could easily become a $50k car with some options.

 

306 thats it?? I was thinking more like 320-330 for sure with those Twin Turbos. Oh well. Its still going to be a beast like the IS350 however this will have a serious price hike over the IS. This has to be a 40-42K base car.

 

They wouldn't want it to have that much power, because then combined with the extra torque it'd be outrunning E46 M3s which would **** the snot out of them. One little chip though, and....

 

true. So customer will look at 335 and IS350, see 306hp, slower 0-60 time, and 5k-6k bigger price.
I think this will turn more customers to IS350 actually.

 

Is it just me or I am getting more impressed that the IS has 306hp with no forced induction?
I am sure though with some slight tuning and turning up the boost, this 3 can hit 350hp easy

 

First off, thanks for the explanation and picture!

And secondly, I wouldn't be surprised to see BMW do that. The reason I say this is the E46 330i sedan with Performance Package ran to 60 in like 5.5 or 5.6.... matching that of the E36 M3!
With a manual, and BMW's short gearing, I have a strong feeling this car will at the least match the IS350's acceleration numbers if not beat it. It may be able to even take it the E46 M3 right off the line... possibly.... but the E46 having a higher redline and more hp, it'll def take it on the top.

And I can't see BMW sitting around while and letting the IS350 being so much faster than the 3-series. So anyone know if we are indeed going to get this stateside?

 

unimpressed so with two turbos and direct injection it just matches the IS350 which is N/A and direct injection, 335 has some more torque tho