I knew I wasn't crazy (Re: E92 M3)

[Tave]

Right. Theoretically, I get what you guys are saying, but from an engineering/practical perspective, I just don't think it works like that. Engine length is never the only independent variable in construction.

[sportyaccordy]

No I don't.

BMW 3-Series - 180.60 inches

Mercedes C-Class - 178.40 inches

Audi A4 - 180.00 inches

They're all almost exactly the same size, regardless of engine configuration/hood length. What does that tell me? Mercedes and Audi probably use the space they save on the front end to increase interior room or trunk volume. Which, of course, is an advantage for those automakers in its own right.

You can't compare the A4's length to the Bimmer's- it's essentially a FWD car.

Putting a V6 in a Bimmer (YUEEEEECCHHCHHHHH) could go two ways: one, they could keep everything behind the A-pillar the same, throw in the V6 and shorten the car by about a foot (wow) or they could put that foot back into the passenger cabin and trunk.

Now what I CANNOT explain is why the E90's competitors, all with V6s, have about the same interior room. Either they are all idiots, BMW is a collective packaging genius, or a combination of both. I'll start another thread later looking at the 5 vs. the E vs. the M... this is a good topic of discussion.

[Raza]

You can't compare the A4's length to the Bimmer's- it's essentially a FWD car.

How is it "essentially a FWD car" when even the FWD cars have longitudinal engines?  Hell, even my FWD Passat has a longitudinal engine.  Proportions should be similar to a RWD car.

[Raza]

Is I-6 good for mid-rear configuration or is V6 better. One more thing despite the I-6 being longer I think BMW 3.0 liter I-6 in E90 is the lightest 6 cylinder engine compared to the Honda 3.2 liter or Nissan 3.5/3.7 liter.

An I6 is probably too long to make for a small mid engined car.  Most mid engined cars come with four cylinder engines (inlines) or boxers that are transversely mounted.  The Clio did with a V6, but the larger, more expensive MR cars have longitudinal mounted engines, like in the Murcielago, which is huge.  Mounted transversely, I doubt it would work, but they could definitely do it longitudinally, though, as I understand it, that's a more complicated and costly setup that could result in a larger car than necessary. 

Not sure though. 

I still don't see the advantage of an I6 anyway, though. 

[sportyaccordy]

How is it "essentially a FWD car" when even the FWD cars have longitudinal engines?  Hell, even my FWD Passat has a longitudinal engine.  Proportions should be similar to a RWD car.

Packaging-wise it's similar to a FWD car... look at the overhang. RWD cars like the G35, 335i all have the center of the front wheels waaaaaaaaay ahead of the midline of the motor. Audis, not so much (at least not for the current A4/S4/RS4).

[SJ_GTI]

I just did a simulation of a 3.7L "M3"... 9000RPM, 400HP, 3400#, tight gearing on CarTest2000... similar performance to the real deal in the straight line, but mine cornered better, lapped Laguna Seca 1.6 seconds faster, and would sip less fuel with better gearing...

Plus I'm sure a 9000RPM L6 wouldn't sound too bad...and beating the RS4/C98 with less HP and more finesse would have been sweet too. But w/e

That sounds like a pretty good simulated engine.

Now back in the real world, BMW made 400 HP with a 4.0L V8 that was about 40 lbs lighter than their 333 HP 3.2L I6. I don't see the benefit of them using this theoretical I6.

[sportyaccordy]

I don't see the benefit of them using this theoretical I6.

Using their magnesium/aluminum 6 would have saved another 80#. So the weight I used for the car was off.

[Champ]

Are you getting to 3.7L by bore or stroke?  Seems like if you did stroke it would be hard to rev that up to 9grand!

[sportyaccordy]

Are you getting to 3.7L by bore or stroke?  Seems like if you did stroke it would be hard to rev that up to 9grand!

My performance simulator isn't that advanced. However there are 2.4L motors from the latest Honda Accord that have been built to rev to 8.5K w/pretty standard components. I'm sure with titanium con-rods and all that BS they could bore and stroke (more bore though) the 3.0 to 3.6L no problem.

Keep in mind the 3.6L from the old 360 Modena only revved to 8500 and made 425HP in the
Challenge Stradale. I'm sure the better balanced L6 could do the same and rev a little higher.

[Champ]

Seems like you'd just need to get too exotic with it for it to be practical.? They can just make a V8 with a little less engineering effort and achieve the same.

Sounds like you should apply to BMW, since you have some good ideas and I am sure they never thought they could make a good ~420hp 6cyl. :P

[MexicoCityM3]

That sounds like a pretty good simulated engine.

Now back in the real world, BMW made 400 HP with a 4.0L V8 that was about 40 lbs lighter than their 333 HP 3.2L I6. I don't see the benefit of them using this theoretical I6.

Maybe they should have bored, stroked and boosted the hell out of the MINI engine to put in the M3 and then we?d have gotten a lightweight 4.0L 450+ hp engine (according to my latest simulations.). Those BMW engineers truly suck.

[Raza]

Maybe they should have bored, stroked and boosted the hell out of the MINI engine to put in the M3 and then we?d have gotten a lightweight 4.0L 450+ hp engine (according to my latest simulations.). Those BMW engineers truly suck.

...speaking of bored, isn't this topic of theoretical useless engine configurations a little tired?  Can we please go back to the issue at hand?

Mustangs, and why they rock.

[1 BAD 7]

Lets say my some miracle they even come up with a 3.7L I-6 making 400hp weighing some 20 Ibs less then the 414hp 4.0 liter V8. What happens when in next 4 year Audi and MB decide to up the game to 480hp plus cars. Unless BMW goes supercharger/turbocharger which they will not do with M cars. They would have to go back to a V8. Becasue there is only so much you can do with NA V6 before it is way over stressed and too complicated and expensive to make.

Just take example of F-1 right now most upper class teams are sticking with the V8 except for couple that have a turbo V6 and they are no where near as sharp or quick as the leading V8's. I think overall BMW took the right direction with the V8 the more they learn from developing those lightweight and high reving  F-1 V8's the more they will be able to improve the next generation of V8's.

My performance simulator isn't that advanced. However there are 2.4L motors from the latest Honda Accord that have been built to rev to 8.5K w/pretty standard components. I'm sure with titanium con-rods and all that BS they could bore and stroke (more bore though) the 3.0 to 3.6L no problem.

Keep in mind the 3.6L from the old 360 Modena only revved to 8500 and made 425HP in the
Challenge Stradale. I'm sure the better balanced L6 could do the same and rev a little higher.

[sportyaccordy]

Lets say my some miracle they even come up with a 3.7L I-6 making 400hp weighing some 20 Ibs less then the 414hp 4.0 liter V8.

Stop right there.

It would weigh about 80# less.

Also keep in mind the 911 GT3 makes about 400HP from a 3.6-3.8L flat 6. Definitely not the F6 in a Subaru Legacy but also not exactly out of this world. With 400HP in a 3300# chassis the M3 would have had a decisive advantage over it's competition.

Champ, one day. Or perhaps, with my crazy ideas, I'll just build my own car

[565]

Now what I CANNOT explain is why the E90's competitors, all with V6s, have about the same interior room. Either they are all idiots, BMW is a collective packaging genius, or a combination of both.

Road and Track has those wonderful diagrams for the cars and where their engine and drivetrain parts are.? The 3.0 inline six, doesn't look impossibly large inside the BMW engine bay.? In fact it doesn't look much longer than the larger V6 engines of the competitors, due to probably careful packaging of the accessory parts of the engine.? The actual length of the block is only 1 factor in the overall length of a fully dressed engine.

I hope these pictures show up.? Tell me if you can see them or not.

[red_shift]

Road and Track has those wonderful diagrams for the cars and where their engine and drivetrain parts are.? The 3.0 inline six, doesn't look impossibly large inside the BMW engine bay.? In fact it doesn't look much longer than the larger V6 engines of the competitors, due to probably careful packaging of the accessory parts of the engine.? The actual length of the block is only 1 factor in the overall length of a fully dressed engine.

I hope these pictures show up.? Tell me if you can see them or not.

Thanks man

[Raza]

Can we address why you use different letters?

Inline = I
V = V
Boxer/Horizontally Opposed/Flat = H

[sportyaccordy]

I can see them. I imagine BMW placed all the accessories on the side of the L6, as opposed to in front like the V6's. Perhaps the L6 isn't dead after all