BMW tells Top Gear about upcoming M4

[lasovan]

"Turbocharged lightweight technology for M3 Coupe successor, coming your way 2014"

http://www.topgear.com/uk/car-news/b...upe-2013-07-12

Nothing really new, but worth reading nonetheless.

[myzmak]

was just about to post same link.....

will be fun to see them drive it....

will be more fun to drive it myself!

[fuddman]

If you believe the BMW fellow interviewed, then you would have to conclude BMW, in developing their new M series, is, for all intents and purposes, ignoring their competitors (MB, Audi, etc.). Instead, he says, the new M car they are bringing forward is being designed to beat their own current M3.
This is going to make the competition between car makers even more interesting, particularly between BMW and MB. That's because, fundamentally, MB appears to be headed in a different direction than BMW, engine wise anyway. In the car segment the interviewee is referring to, MB is moving forward with monster V-8's such as the one in the C63 AMG 507. BMW, on the other hand, is going to rely on the inline 6. On paper, at least, it would appear the new M cars are going to be over matched by the AMG cars.

[RMB]

I still have faith in the potency of the BMW multi-turbo I6. A GTR went twin turbo V6 and that seems to hold its own against mustang cobra V8's and Vette V8's. As you know and everyone else on the forum an engine and its output is only one aspect of performance and a lot of other things factor into the equation.

[solstice]

Talk is cheap, 3300 lbs or less otherwise it's a dissapointment. Their ambitions sounds very good though but this quote bothers me
"Slightly more lightweight"

I wish he had said "Significantly more lightweight". Maybe just a bad choice of word and that he meant significantly. The 1M is 3300 lbs with a very similar engine and without the focus on new lightweight materials in strategic areas around the car. The car looks "dynamic" and agile so hopefully it is 3300 lbs or less.

[bimmer]

Originally Posted by solstice

Talk is cheap, 3300 lbs or less otherwise it's a dissapointment. Their ambitions sounds very good though but this quote bothers me
"Slightly more lightweight"

I wish he had said "Significantly more lightweight". Maybe just a bad choice of word and that he meant significantly. The 1M is 3300 lbs with a very similar engine and without the focus on new lightweight materials in strategic areas around the car. The car looks "dynamic" and agile so hopefully it is 3300 lbs or less.

less than 3300lbs - impossible without CF. My guess around 3400 lbs, 450 and 400 torque, hydraulic steering,proper handbrake and nicer front face than 335. This is what I am waiting for... and the wait is killing me

[swamp2]

Originally Posted by solstice

I wish he had said "Significantly more lightweight". Maybe just a bad choice of word and that he meant significantly.

Yes, good observation, that stood out to me as well. I think it is factually correct. The new M4 will will be larger than the current E92 M3 and thus even given a good dose of weight reduction shaving anything off it countered by the growing size. Also electronics and wiring keep growing and safety components the same. The only way to achieve weight reduction beyond the large effort in the E92 M3 is money and BMW is more about profit than anything else. The will lower the weight just enough to maintain class leadership with a likely underrated engine, making the car seem a bit of an overachiever.

I also noted the apologist point of view that clients of the new M5 appreciate the increase and torque at low rpm. Sure what's not to appreciate about that. Of course they don't talk about the similar yearning for a high redline and power all the way to redline and disappointment in the turbo lag.

[solstice]

IMO you are cutting BMW to much slack on weight if you resign to that 3300 lbs is not doable. A Porsche 991 has all the latest tech and safety equipment and weigh in at just over 3000 lbs. if BMW's main design focus is now weight reduction for the F80 and they have admitted increase of lightweight materials as plastics and CF I don't see why 3300 lbs is a stretch for the admittably bigger car but 3300 lbs is a bigger number than 3000 lbs. Weight increase is not linear to size increase since not all parts grow with the exterior like the engine, tranny, front seats, wheels, and electronics for example.

I have a feeling that the F80 can shave the 200 lbs from the ~ 3500 lbs F30 335i purely by replacing steel with alu in certain weight critical areas even with the added beef to areas as brakes etc. I don't think the F30 is especially big on alu.

I don't care much if the F80 produces 390 or 490 hp but I will be dissapointed if it's 3500 lbs instead of 3300 lbs.

[swamp2]

Originally Posted by solstice

IMO you are cutting BMW to much slack on weight if you resign to that 3300 lbs is not doable. A Porsche 991 has all the latest tech and safety equipment and weigh in at just over 3000 lbs. if BMW's main design focus is now weight reduction for the F80 and they have admitted increase of lightweight materials as plastics and CF I don't see why 3300 lbs is a stretch for the admittably bigger car but 3300 lbs is a bigger number than 3000 lbs. Weight increase is not linear to size increase since not all parts grow with the exterior like the engine, tranny, front seats, wheels, and electronics for example.

I have a feeling that the F80 can shave the 200 lbs from the ~ 3500 lbs F30 335i purely by replacing steel with alu in certain weight critical areas even with the added beef to areas as brakes etc. I don't think the F30 is especially big on alu.

I don't care much if the F80 produces 390 or 490 hp but I will be dissapointed if it's 3500 lbs instead of 3300 lbs.

A comparison against a smaller car (Porsche) isn't fair. The Porsche is a bit wider but much shorter than a 3er. Also it's greenhouse is much smaller - the width between driver and passenger, "rear seat" room and overall interior volumes are entirely incomparable. Thus the Porsche isn't lighter because Porsche does a much better job at weight consciousness, it's simply basic math.

Weight increase is probably generally linear with volume (say overall max WxHxL). The best data I could find shows how well weight scales with wheelbase x width. I'm confident you could add height into the comparison and thus compare weight vs. volume and it would be pretty well linear. Yes there is plenty of variation around a perfect line but there is still a linear fit here with good R^2 value (goodness of fit).

The E9X M3 already offered aluminum in place of steel on many large weight components (subframes) as compared to the base model. Without a major migration into the unibody (which isn't going to happen) I'm just not sure how much room is left...

The real question is how well have they done getting composites much less expensive so the bean counters will allow more very light weight carbon fiber and other composites into the car.

Weight will be a big test here for BMW M with this car. We will see if they have the same double speak like they did with the M3.

BMW said "increased use of light weight materials", "light weight design" and "lighter components". What it all ended up meaning was simply less weight increase rather than a lighter vehicle.

[Technic]

Originally Posted by bimmer

less than 3300lbs - impossible without CF. My guess around 3400 lbs, 450 and 400 torque, hydraulic steering,proper handbrake and nicer front face than 335. This is what I am waiting for... and the wait is killing me

I bet that it will be 3500lbs, or about 70-90 lbs less than the E92 M3. Or about the same weight savings of the F32. 450/400 sounds about right.

Anything radical (lots of CF and aluminum) and BMW will take the M3 out of the $60-$70,000 market because they will have to price it accordingly.

[solstice]

The E90 is a great car but it's hardly a good example of weight control. A 335i was just about under 100 lbs lighter than the much larger E60 535i. The E60 535i with a 3 liter TT just as the F80 is speculated to have had a ~3650 lbs curb weight. It's also a significantly larger car than the F30 and the HW it carries is not weak, it's the same as the 360 hp 550i.

The E90 M3 can be forgiven being a bit porky due to it's engine. An 8400 rpm or higher V8 has never and will never again be available at inflation adjusted price point as the E9X M3. The F80 will have no such exotic engine and need another party trick. To me that is low weight. 3300 lbs is not such a stretch or expensive as you make it out to be. I bought my E60 535i with sport package, cold weather package, leather and upgraded audio for just over $50k. This included things as ars and the aluminum front end and suspension parts.

[bimmer]

M4 will be 100lbs less than F32, and new M3 100lbs than F30. BMW please give us 450hp/400tq and 8000rpm.
I am just worry about steering wheel being electric (no feedback). Whatever BMW do, it will not touch 911 territory. However, there is a lot of complains about 911 steering being numb. I will gladly pay a little gas penalty for e92 steering feel.

[swamp2]

Originally Posted by solstice

...
The F80 will have no such exotic engine and need another party trick. To me that is low weight. 3300 lbs is not such a stretch or expensive as you make it out to be.

Carbon fiber is the composite that provides strength stiffness and potentially the largest weight savings. Unfortunately, it is also extremely expensive. Have a look at this discussion thread from over a year ago where we debated early weight rumors for the car. In that thread (post #57) I showed how it would cost BMW about $1k to save 300lb using carbon fiber. That number may be closer to $1k for 500lb as well, it all depends on how inexpensive BMW has been able to purchase and manufacture composites. Keep in mind this is not $1k in the PRICE of the car, but $1k of COST, that will be significantly multiplied many times over for PRICE. Given that the raw material itself (carbon fibers) are probably still the controlling cost factor, I doubt they've had any great breakthroughs on cost. In short, the conclusion from that thread is that a 3200 lb car is extremely unlikely, I also believe 3300 is as well for the same reason.

[Uli_HH]

As I posted before, my information about the weight of the F8x says:

• F80M3 - EU-Empty = 1.483kg = 3.269lbs
• F82M4 - EU-Empty = 1.495kg = 3.296lbs

This weight reduction is reached by:

1. making all doors/folds out of aluminum instead of steel ( like F30 )
2. making internal supporting structure out of industrial carbon composite instead steels ( like F30 )
3. making some/many suspension components out of industrial carbon composite istead aluminium ( like F30 ) - (link) saving overall 35kg /77lbs. only in this part

The new engine would be al little bit heavier than the S65 V8 ... also according to my informations!

Greets Uli_HH

[Tåst]

Wow 1500kg sounds really good. I am waiting best M-car until e46.

[bmwm3redblack]

Originally Posted by Uli_HH

As I posted before, my information about the weight of the F8x says:

• F80M3 - EU-Empty = 1.483kg = 3.269lbs
• F82M4 - EU-Empty = 1.495kg = 3.296lbs

This weight reduction is reached by:

1. making all doors/folds out of aluminum instead of steel ( like F30 )
2. making internal supporting structure out of industrial carbon composite instead steels ( like F30 )
3. making some/many suspension components out of industrial carbon composite istead aluminium ( like F30 ) - (link) saving overall 35kg /77lbs. only in this part

The new engine would be al little bit heavier than the S65 V8 ... also according to my informations!

Greets Uli_HH

Why f82 is heavier than f80 4 door????

[solstice]

I think they will keep it at 3300 lbs even if that is rounded to the closest hundred lbs, I.e 3349 lbs which I'll give them a pass at

[Uli_HH]

Originally Posted by bmwm3redblack

Why f82 is heavier than f80 4 door????

As you say "4 doors" ... the lightweight parts from F80 and F82 are identical ... like the F82 the F80 also gets an carbon roof ... so what counts are two more doors made of aluminium.

According to my informations the posted weights are for an stock car with more stock features than the F9xM3 ... and with M-DCT, but without CCBs.

[Tåst]

Originally Posted by Uli_HH

As you say "4 doors" ... the lightweight parts from F80 and F82 are identical ... like the F82 the F80 also gets an carbon roof ... so what counts are two more doors made of aluminium.

According to my informations the posted weights are for an stock car with more stock features than the F9xM3 ... and with M-DCT, but without CCBs.

So whit manual weight is about 1450kg, this is light car compare to Audi S4 saloon 1,730 kg (3,814 lb) or huge RS5 1,800 kg (3,968 lb).

[solstice]

Official weight is like starting MSRP, pretty much no cars sold are at this number but it gives us a reference point.

[mkoesel]

Uli, what do you mean by "internal supporting structure"? Can you give some examples of which parts fall into that category?

My thoughts about CF for the F80 is that it will be used primarily in cosmetic areas like the roof is on today's M3, such as a deck lid, hood, etc. I would expect the rest of the weight savings to come from heavier use of aluminum in the chassis vs. the F30.

I should add - we may also see some CF in the chassis such as perhaps the driveshaft or other easily-formed parts. I am not so sure about the suspension or subframes, but who knows. The question is whether production costs are low enough to mass produce complex parts like that at a pricepoint that will support a $70k vehicle.

[Uli_HH]

Originally Posted by mkoesel

Uli, what do you mean by "internal supporting structure"? Can you give some examples of which parts fall into that category?

My thoughts about CF for the F80 is that it will be used primarily in cosmetic areas like the roof is on today's M3, such as a deck lid, hood, etc. I would expect the rest of the weight savings to come from heavier use of aluminum in the chassis vs. the F30.

I should add - we may also see some CF in the chassis such as perhaps the driveshaft or other easily-formed parts. I am not so sure about the suspension or subframes, but who knows. The question is whether production costs are low enough to mass produce complex parts like that at a pricepoint that will support a $70k vehicle.

"internal supporting structure" meens parts such as transmission tunnel, engine rear wall, rear wall of the trunk, rear shelf and so on ... parts which normally form the backbone of a steel body, but which are not located in crash zones ...if you make some of this parts of carbon composite instead of steel, you can save many pounds of body weight without too great costs.

And of course, if you speak of lightweight construction at the F8x , you should forget the high-gloss carbon parts ala E92M3 carbon roof quickly and rather look at the body of the i3.
We are not talking about "handmade" visible carbon parts but of industrially produced carbon composite with much less demands on the surface quality, because these parts would be painted and used on not visible parts of the car.

Greets Uli_HH