Very intersting interviews (in PDF) with the directors at BMW M! - The Unofficial BMW M5 Messageboard (m5board.com)

Gustav · 14th March 2002, 04:40

I re-post it because it's very itnersting, describing in detail why BMW doesn't use turbos:

Check out these articles for very intersting reading on M cars from the M People themselves:

http://195.27.218.10/bmwe/products/a...ntwicklung.pdf

http://195.27.218.10/bmwe/products/a...elopment_E.pdf

Rcihter, owner of the E39 M5 Touring:

http://195.27.218.10/bmwe/products/a...nterview_e.pdf

Chassis development on the M3:

http://195.27.218.10/bmwe/products/a...fahrwerk_e.pdf

Interiour design:

http://195.27.218.10/bmwe/products/a...w_Design_E.pdf

Adam · 14th March 2002, 13:06

Cheers gustav very very interesting!
all the best
Adam

kgk · 14th March 2002, 13:12

Hello Gustav,

I failed to find their arguments convincing.

If you look at it, the power that the engine develops must roughly scale like this:

power = rpm * displacement * pressure.

(You'd meter fuel for the "effective volume," the product of the displacement and pressure [where pressure would be normalized to one atmosphere].)

Now, look at their arguments:

1. rpm is good.

Yes, of course it is. But rpm is *VERY* expensive.

2. displacement is heavy.

Yes, of course it is---so one has to be moderate in terms of the displacement, since this is a big stick. Is the M5 engine too big/heavy? Nah, it is probably fine.

3. "[turbo] pressure hurts the car's spontaneity"

Oh, they're saying I'd rather feel every nuance of the gas pedal and not destroy some other car in a drag race? ARE THEY CRAZY?! Of course I want to go faster, "spontaneity" be damned!

But, note that they did not mention twin-screw superchargers. Why are these missing, you ask? I fear that these are not mentioned because they are quite spontaneous and can deliver monster power.

(I lost all of my respect for these BMW "white papers" when I read one that explained why it was a good idea to have the low-power lamps be gas discharge (HID), but the high beams had to be halogen. What a piece of marketing trash!)

So, here is the recipe:

IF YOU'RE NOT USING FORCED INDUCTION, YOU'RE THROWING AWAY POWER.

That's the reality---and given that I'm not wasteful, I want more power! So, are you going on record as saying that you want *LESS* power, but more "spontaneity?"

M5Laser · 14th March 2002, 18:03

wow!! Where do you find these articles!? You always find the coolest stuff... where is it coming from??

My view about forced induction is, more power, the better!

chazzy · 14th March 2002, 18:07

Quote:

Originally posted by kgk
IF YOU'RE NOT USING FORCED INDUCTION, YOU'RE THROWING AWAY POWER.

I agree ... Mercedes is rapidly moving on with engine designs that cost a lot less money to develop, generate more horsepower, and have greater fuel efficiency. I think BMW will eventually have to do it to be reasonably competitive.

Quote:

Originally posted by kgk
(I lost all of my respect for these BMW "white papers" when I read one that explained why it was a good idea to have the low-power lamps be gas discharge (HID), but the high beams had to be halogen. What a piece of marketing trash!)

So are you saying that halogens are better for low beams or HIDs are better for high beams? I flash my high beams all the time and if they were HID, they would not be nearly as effective.

KKelly · 14th March 2002, 18:46

KGK,

If that is truly your opinion, why did you buy an M5?

I can guarantee you that the term "drag race" is not often used at Motorsport. If high revving engines are so expensive, why are the next generation of Mercedes s/c cars so damn expensive?

There is a lot of power left in the E39 and some room for more displacement. I don't think you are going to see anyone go beyond 475-500hp for many different reasons, including fuel efficiency, regulation, insurance, etc. The E39 can easily achieve that without forced induction.

I have been in two highly modified turbo cars, Supra and '95 S4, and didn't like the power delivery in either car. For the type of driving that //M cars are known for, such an engine would destroy the balance of the car. The power comes on suddenly and with tons of drama. I know a Mercedes would be more refined but I am still too young (and will always be) to drive a Mercedes.

Has anyone considered for the moment that Mercedes was forced to go to s/c's because their flagship was decidely slower than the E39 M5? They keep just slapping big engines with superchargers in their cars. Not interested. I do think Mercedes is well aware that their market is also not as interested in cars with a more edgy nature.

Certainly BMW is not alone in their philosophy of high-revving na engines. Ferrari, Toyota, and Honda are also headed in the same direction.

One thing I have noticed is that Audi hasn't yet shipped its RS4 or RS6 over to the States. It may be difficulty to get those cars Federalized due to emissions and charge a competitive price. Mercedes doesn't have to charge a competitive price.

M5Ted · 14th March 2002, 21:44

I completely agree with KKelly. One of the things that make M cars so special are their engines. The smooth, constant power delivered from the M engines makes a huge difference in road racing. Sure, for strait line you are always going to get more power out of a turbo/supercharged car, but power delivery is more important. I have driven a few S4s, WRXs and a K04ed GTI 1.8T and with all the power is great, but I can't imagine racing them. "Instant on" power mid way through a turn will cause the car to become unbalenced and much harder to control. Don't get me wrong, the S4, WRX and GTI are awsome cars, but BMW has a special product and I don't think they should change it.

Ted
'95 M3
ex 1988 M5

Johnny D · 15th March 2002, 00:19

Interesting reading, anything on the M5??