BIMMERPOST M3/M4 First Ride Notes, Impressions and More Tech Details

[Alpina_B3_Lux]

Originally Posted by BlackJetE90

You have read through the marketing to get the real numbers.

Pull from other post, thanks to Swamp.

The apples to oranges BS with the weight obviously continues and thanks for all of the non-sheeple who were very quick to point of the BS marketing of car weight without driver. It's great that Jason clarified 3300 without driver with 90% fuel. That means apples to apples is:

3305 lb (i.e. less than 3306 lb) + 68 kg (driver) + 7 kg (cargo) = 3470 lb

Now the CSiC brakes are almost for sure included here despite being an option because that is just how BMW marketing rolls. No CSiC brakes should add about 20 kg. Thus

E92 M3 = 3704 lb (US curb weight with driver, gas, cargo)
F82 M4 = 3514 lb (US curb weight with driver, gas, cargo)

Other considerations: The average weight of the driver really should not be 68kg - realistically it should be set at 80kg at least.

Also, from what I remember the vast majority of buyers of the E9x M3 opted for a DCT which will again be quite a bit heavier than the MT version. Add a few options that everyone chooses (like satnav, better audio system etc.) and you'll rather be at 3600 at least.

Still, it's good that BMW makes an effort to reduce weight. I'm not really enthusiastic about the power figure though.

Alpina_B3_Lux

[Dackelone]

Originally Posted by CanAutM3

"In "Sport" and "Sport Plus" settings, the turbochargers are "pre-tensioned," which means that they keep spinning at a high rate of speed even after you have taken your foot off the throttle."

Any hint on how they do this?

I suspect it is done thru the electronic wastegates.

[CanAutM3]

Originally Posted by Dackelone

I suspect it is done thru the electronic wastegates.

The waste gates can reduce the intake charge by bleedding off excess pressure. I don't see how they can add energy to the system when the throttle (valves in our case) are closed...

The waste gates may be part of a more elaborate system to maintain the momentum of the turbos off throttle, but I don't believe they can do it just by themselves.

[Needsdecaf]

Originally Posted by clar

People, stop swooning over the 3300 lbs claim. Nothing is said on the options to achieve that weight. The most telling fact in the article is that it's around 80 kg lighter than the equivalently equipped E9x M3. That means only 80 kg savings! I had expected more. Maybe specifying the carbon ceramics would save some more.

Only 80 kilos? Seriously, the car is larger has more tech (hidden stuff like safety) and you complain it's ONLY 80 kilos lighter? An F30 is a LOT bigger than an E90. Just those 80 kilos took a lot of effort.

[Needsdecaf]

Originally Posted by 330indy

And what's up with cylinder deactivation to slow the revs?

Not to slow revs, to drop revs.

Likely that the anti-lag system uses some form of waste gate pressure or, less likely, some WRC style post cylinder detonation to keep the turbos on boil. But that would prevent the engine from dropping revs during gear changes. So somehow they are deactivating cylinders to get the engine to slow normally when you lift.

Pretty trick, would explain all the pops and farts in the videos.

[Lorde]

Slowing revs is the same as dropping revs. He is correct.

[Mikecom32]

Originally Posted by Needsdecaf

Not to slow revs, to drop revs.

Likely that the anti-lag system uses some form of waste gate pressure or, less likely, some WRC style post cylinder detonation to keep the turbos on boil. But that would prevent the engine from dropping revs during gear changes. So somehow they are deactivating cylinders to get the engine to slow normally when you lift.

Pretty trick, would explain all the pops and farts in the videos.

My bets are on a WRC style antilag, but the new version that is more intelligent. I believe some (all?) manufacturers switched to a system that controls the air/fuel entering the turbo (inlet bypass type antilag). This provides a more constant pressure than the "retard the timing and let it ignite in the exhaust manifold" method, and is much easier on the turbos and other exhaust components.

Also, since they're doing cylinder deactivation (letting the fuel go unburnt to the turbocharger?) and they say the system will only be active for short periods of time, my guess would be antilag of this sort.

[Bubbles]

Looks like a beast of a car. BMW seemed to hit on an issue that I always struggled with at the track: HEAT

On a side note, I hope they improved/redesigned fuel pump for this car.

[DASHOCKER]

I may buy my first m car.. Seriously..

[Never Convicted]

Originally Posted by CanAutM3

Yes you are: marketing hype

No offense, but that's crap. You're clutching at straws here. Go to other manufacturers sites. C7 is 3298 lbs. CURB weight. 991S is 3120 lbs. CURB weight. RS5 is 4012 lbs CURB weight. GT-R is 3818 lbs. CURB weight. Then you speculate on how much options will add, like ANYONE, EVER got any of the others without options. And you think that BMW is acting in some sort of misleading vacuum? Maybe they should weigh it with 4 bodybuilders with their barbells in the trunk to satisfy you.

It's amusing that basically the same crew on here is convinced that BMW lost it's way, has gone downhill, is marketing driven, RIGHT AFTER you bought your cars. Amazing how much better timing you had, no matter that it covers every MY to the present.

[BMV///M3]

Looking forward to it.....I'm relatively new to BMW seeing how this is my first 335. At the time of purchase I justified not looking into the M as "its not practical"...haha. Now I want one.

All goes according to plan and I should be picking one of these up 2015.

Though one quick gripe, am I the only one who really really dislikes the Nav? It just looks like an "attachment". The way its encased on our e92 is so much better IMO. It really bothers me.

[Bigiggs]

I am a bit surprised no one has touched on the electronic diff. Any opinions on this diff vs that in the e90/92?

[Lorde]

Originally Posted by Bigiggs

I am a bit surprised no one has touched on the electronic diff. Any opinions on this diff vs that in the e90/92?

Potential Torque Vectoring? The test drivers did note it was easier to break the rear loose, catch, correct, and do it over again in the opposite direction. I'm intrigued.

[Mavus]

Amazing vehicle! There is no single four door sedan that comes close to F80 M3. After some tuning and mods it will be insane but I will wait couple of years until LCI.

[MrBeranek]

Looks very promising. If there´s no M2 significantly lighter than the M4, then we have a winner. Just wondering, if the weight specs are according to DIN or according to EU. The latter (being under 1500 kg) would be absolutely fantastic.

[positiveions]

When I said it would redline about 7500, people doubted me. Haaa, Guess I am right.

[Needsdecaf]

Jens, any update on this?

Thankfully, the straight-six sound in the M3/M4, familiar to E36 and E46 drivers, is all natural; no artificial sound actors (read: no Active Sound) are fitted. Note about Active Sound: we asked and were told by one of the engineers that there was absolutely no artificial sound feature, but others have written today that the M3/M4 will use the speakers to amplify the sound. A request for clarification is in at BMW and we should have an answer by tomorrow morning.

[Remonster]

Originally Posted by Bigiggs

I am a bit surprised no one has touched on the electronic diff. Any opinions on this diff vs that in the e90/92?

Shoul be the same as the one in the F10 M5 or at least very similar, a mechanically locking diff that's controlled by an electric motor so it can vary its lockup or even open entirely as needed. There are times when an LSD is unnecessary and can cause understeer (tight low speed corners) or even reduce stability (braking in some situations) so an electronically controlled diff is really he ultimate type of diff if you ask me.

[AlteredBe4st]

excellent coverage. thank you

[DopeM3]

Thank you!

[ozinaldo]

Originally Posted by CanAutM3

I have to disagree with this statement. IMO, shifting at 6000RPM, especially in the lower gears, will leave some performance on the table...

To maximize acceleration, you need to keep the revs in the fat portion of the power curve, not the torque curve. Without knowing gearing, it is difficult to assess exact numbers, but any shift that brings the revs below the power plateau (guessing from about 5500RPM to 7300RPM based on the press release graph) will not leverage the maximum performance potential.

On another note, the press release quote "Its peak torque soars far beyond 500 Newton metres (369 lb-ft), outstripping the figures recorded by the outgoing BMW M3 by well over 30 per cent.". This means "well over" 383 lb-ft (295 x 1.3).

Generally speaking, in most gears, shifting at 6000 or a bit over than that mark will leave the driver in the "fatter" portion of the power curve compared to shifting at 7000. You would like to keep a 1M between 4000 to 6000 rpms to receive the optimum results. That's where max torque and max power meets and holds; if you want a single number, 5000 is probably the sweetest spot in the whole rpm range.

I do shift close to rev limiter sometimes just to check if the car is really making the max speeds of each gear (as a way of indirect engine check-up)

[pkimM3r]

Dont you want to shift so that in the next gear you have hit peak hp and tq: Eg shift into second at 6k, engine will be at around 4k where hp and tq are still increasing vs shifting at 7.5k where engine will be at 5.5k where hp and tq are already at peak power? It may feel faster since tq is still increasing but its not at max tq. Just a thought.