DASHOCKER

iTrader: (2)

I read what makes sense in the thread from those with knowledge about the cars.. Thanks. Commence...

LexFather

So you read my posts. Thanks

DASHOCKER

iTrader: (2)

Do chickens have lips? Anywho, folks take a look at the precision that goes into the production of M engines. Here is the the E92 M3 motor being assembled

http://youtube.com/watch?v=EcvD_VaJ2UE

Koma

iTrader: (3)

Cool vid, thanks for sharing that!
Are all M engines hand built? I didn't watch the video with sound, the girlfriend is napping.

picus

I just want to chime in about the 335i engine issues. AFAIK, there are no real actual *engine* issues. If anyone can clue me in on that let me know. The two issues that have come up are the hp fuel pump (resolved) and the oil/coolant overheating, which I believe is also resolved. BMWNA has offered me a secondary oil cooler (I got one of the cars without one), but my car has been running so well I am hesitant to mess with it.

The N54 engine may or many not have problems, I still think it's too early to tell. The most miles on a 335i now can't be much over 40k tops.

Och

iTrader: (3)

Well, technically you're right, the 335 does not have engine issues, but overheating issues that are caused by insuficcient cooling, which in turn caused by lousy engineering. With all that overheating these engines are guaranteed to start blowing head gaskets, having sludge issues, seizing, and then some.

greyBLITZ

iTrader: (2)

Wow, thanks very much for all the responses, I'm glad to see so much interest. Also, on another note, I notice that lately it seems most companies are aiming for the 100HP/liter mark which has been seen in the 7th gen. Celica, and the RSX, etc. So what is stopping the 1UZ or 3UZ and future engines from achieving something like that? Just for comparison, what is the difference between the 1UZ/3UZ and the engine in the Celica and RSX that makes them have so much more output per liter?

Och

iTrader: (3)

Well, if you look at Celica, RSX, S2000, M3, you will see that
1) These engines have rather high compression rate.
2) They make the power at high RPMs.
3) They have no low end torque whatsoever.

So if you take an engine with 400hp and 300lb/ft, and even it out, it becomes 350/350.

picus

OK, well if it happens then you'll be right, until then you're just speculating. The overheating issues aren't exactly common.

greyBLITZ

iTrader: (2)

Right! So maybe that is the secret to such high power ratings since it is always measured as peak HP? Someone mentioned that the M's don't have much of an impressive low-end torque rating. I know the 1UZ/3UZ has an amazingly flat torque curve. So do you guys think the reason that it's maxHP is so much lower, is due to the fact that they have compromised in order to achieve a very flat and uniform torque curve?

Also, how much difference does the individual throttle bodies yield? And how about the BMW variable valve timing technology? Is the Double Vanos the name of it?

GSteg

iTrader: (15)

Yes. Double Vanos is BMW's teminology for variable valve timing. The valve timing is not only for the intake valves, but also the exhaust valves too.

Usually you're able to shift your powerband depending on how you design your engine. Lexus acheived a flatter torque curve that's suitable for city driving. No one wants a very peaky powerband in a heavier luxury car.

The individual throttle body itself isn't rocket science. Instead of one throttle body for the whole car, you now have one for each cylinder. The benefits of having individual TB is less pumping loss, allowing you to restore some power that's loss by using a manifold that connects to 1 throttle body. Sharper throttle response are not uncommon with ITBs. However, just like a regular intake manifold, the throttle bodies must be tuned correctly. Having a TB too big will net in low end loss, but you might gain top end power. Having the throttle bodies too small may be easier for city driving, but you will have restriction on the top end.

A lot of cars do not come with ITB due to cost and complexity.

Och

iTrader: (3)

LOL, not common? Give me a break.

Och

iTrader: (3)

Well, HP rating is always the peak HP, unless the manufacturer decides to underrate it, for example Supra, Skyline, etc, which were rated at 280hp, but in reality had well over 300.

As far as 1US/3UZ goes, it has a flat torque curve just like most engines out there. I wouldn't say they compromise HP to achieve flat torque curve, I would say that cars like M3, S2000 compromise the torque curve to achieve flat HP. They don't really start to pull until after 4000RPMs, but the good thing about it is that they have a really high redline so their power range is very good, and they are amazing to drive around a track while keeping the engine spinning fast. However it is not very useful in city driving, because you wont be launching the car at 4000rpms and redlining it every time.

[/QUOTE]
Also, how much difference does the individual throttle bodies yield? And how about the BMW variable valve timing technology? Is the Double Vanos the name of it?[/QUOTE]

I think GSteg explained it very nicely, I would just like to add that individual TB's, as well as other complex components, can become tuning/maintenance nightmares as the car gets older.

Och

iTrader: (3)

Says the guy who thinks X5 is a sports car.

doug_999

All cars (especially first year cars) have issues - and as I've said, the more tech in the car, the more issues. Alas, you and your buddies (TRD, Och, etc.) love to make BMWs sound like they have tons of issues - alas, even at #18 they are still more reliable than average and yes, BMWs have more technology.

So do BMW have more issues than Lexus - yes, but please quit with the all BMWs have "major issues" campaign - you do a disservice to people like the OP and when they find out you are wrong, they no longer trust your posts.