F80 M3 and F82 M4 Dyno and Weight: Comparison Time

[Sedan_Clan]

Originally Posted by 330indy

Well we now know this 3300 lbs hype was/is BS.
A page from BMW mag/ Spring-Summer

[fusionchicken]

Originally Posted by swamp2

These particular results assume equal drivetrain losses between the cars. Although this technically isn't true, it is obvious from prior real world performance numbers (E9X M3, F10 M5, etc.), that there are solid performance gains despite some additional losses for the mechatronics. If you think about how much power is required to move a clutch and move a syncro it surely isn't much power, regardless of being moved by a human or by hydraulics. Yes the M-DCT system moves those parts very fast but still, very little power is required. Thus I believe the losses are only insignificantly higher in the M-DCT.

I definitely agree that DCT is better and more consistent at launching from a dig, but it looks like once moving, at least for the E9x chassis, DCT and MT with similar options / mods seem relatively equal. I can only attribute this to the 3 pedal car putting more power to the ground (if there's something else I'm missing I'd be glad to be enlightened), and of course having a competent MT shifter is vital. I'm curious if the video below could be a representation for the F8x chassis as well.

[gmd2003]

Originally Posted by GoKimiGo!

That's something that has caught my eye with these dyno runs. I'm guessing timing is being adjusted. Unfortunately this is something that plagues turbocharged vehicles. Doesn't make a difference for a street car but will have an affect when at a road course in moderate to high temps.

Given the fact that I always take dyno results with a grain of salt, I must admit that I'm impressed with the numbers this thing is putting down on 91 pump. I wonder what 93 will make or e85 for the brave ones who go that route.

Can't do E85 without full ECU control to adjust fueling and that isn't happening any time soon if ever . Just basic piggybacks for now and hopefully some with CAN control in the future . Even the JB4 with CAN control on the N54 needs an ECU flash to do E85 .

[Never Convicted]

Originally Posted by fusionchicken

I definitely agree that DCT is better and more consistent at launching from a dig, but it looks like once moving, at least for the E9x chassis, DCT and MT with similar options / mods seem relatively equal. I can only attribute this to the 3 pedal car putting more power to the ground (if there's something else I'm missing I'd be glad to be enlightened), and of course having a competent MT shifter is vital. I'm curious if the video below could be a representation for the F8x chassis as well.

Also pretty much says that all the guys who got the ZCP pretty much wasted their money.

[antzcrashing]

The badge inside the instrument cluster is so cheesy, cant believe bmw does that

[Sedan_Clan]

Originally Posted by antzcrashing

The badge inside the dash is so cheesy, cant believe bmw does that

Why? It just replaced the static/imprinted ///M logo found in other ///M cars. The only digital ///M logo that remains visible while driving is the smaller one located under the tach. The larger one displays at start up (..as does the ///M splash screen on the iDrive).

[antzcrashing]

Originally Posted by Sedan_Clan

Why? It just replaced the static/imprinted ///M logo found in other ///M cars.

Every m car has a cheesy M badge inside the instrument cluster. Big and chrome like this? Pretty lame

[Sedan_Clan]

Originally Posted by antzcrashing

Every m car has a cheesy M badge inside the dash? Big and chrome like this? Pretty lame

Big and chrome? What are you talking about?

[GoKimiGo!]

Originally Posted by gmd2003

Can't do E85 without full ECU control to adjust fueling and that isn't happening any time soon if ever . Just basic piggybacks for now and hopefully some with CAN control in the future . Even the JB4 with CAN control on the N54 needs an ECU flash to do E85 .

I'm aware of what'd be involved, but I have a feeling it won't take very long. The tuner community is very persistent.

[swamp2]

Originally Posted by bruce.augenstein@comcast.

Coupla points here. First (and on direct point), the power you need to shift isn't the direct issue. The power you need to drive an oil pump to xx psi is what you need to look at. One might assume the oil pressure will be fairly high, since speed is of the essence for the shift. Probably still not a ton of power, but...

Second, in your post showing comparison numbers between the stick and DCT, you used three tenths of a second for shift speeds. Way back when, we looked at shift speeds with an accelerometer, and deduced that two tenths was the actual shift speed, across a couple of speed-crazed drivers (with me being one). Best shifts were in the .18 -.19 second range, but two tenths seemed close enough.

Last, does your software allow for powershifting?

If so, it would be interesting to compare a two-tenths, powershifted MT against a 55-pound heavier (according to BMW) DCT. Not trying to prove anything here (DCT will still be quicker), but just curious.

A good bracketing study to explore for sure.

I don't believe CarTest does allow power shifting. Either way there are no options other than shift time AND engagement time. Also, I do believe that 0.3 second shifts are much more realistic for a moderately adept MT operator.

So if we adjust the total of shift time + engagement time down to 0.2 seconds, and make the MT car only 55 lb lighter, along with about 1% less loss (specifically 5 hp less at redline in 3rd gear) it becomes a near total performance wash. The MT car traps a hair faster but crosses a hair later (pretty well total equity for all practical purposes). Because the sims also show equality on 0-60 but the MT about 0.2 seconds quicker to 100 mph, and because these are inconsistent with quoted BMW figures (including standing 1 km), it tells me the modeling assumptions are not correct, too much loss difference or too short of shift times or both. Well either that or simply deny that the BMW figures are real (or perhaps only real for largely unskilled drivers). Also see comments below on a wide range of measured results for the E9X M3.

[swamp2]

Originally Posted by fusionchicken

I definitely agree that DCT is better and more consistent at launching from a dig, but it looks like once moving, at least for the E9x chassis, DCT and MT with similar options / mods seem relatively equal. I can only attribute this to the 3 pedal car putting more power to the ground (if there's something else I'm missing I'd be glad to be enlightened), and of course having a competent MT shifter is vital. I'm curious if the video below could be a representation for the F8x chassis as well.

One video does not offer any firm conclusions. Way too many variables not held equal. How many contests are there for closely comparable cars where about half of the videos show car A as the winner and half car B? The primary variable here are total weight the other driver skill. Look at the E9X performance "database", you will see the trend that the M-DCT cars are faster.

[Boostin FD]

I don't know if mineral white is worth the extra $550. I kind of like how much whiter Alpine white is.

Is it really worth it?

[GrussGott]

Originally Posted by Boostin FD

I don't know if mineral white is worth the extra $550. I kind of like how much whiter Alpine white is.

Is it really worth it?

Subjective of course, but the opinions seems to go like this:

Mineral White:
1.) MW makes the lines easier to see
2.) MW is much "deeper"
3.) MW is more special and looks more expensive

Alpine White:
1.) AW makes the lines easier to see
2.) AW is more "pure"
3.) AW looks more sporty

After going to a dealership and looking at both on an M3/4 and then comparing to MW on a 43x convertible ... I concluded that AW is more to my taste.

I think if I wanted a more 'deeper' and special light color I'd go moonstone

[Fedorov]

Such nice cars! I'm JEALOUS!!!!!

[modkrazy]

Originally Posted by nick380

Wow absolutely crazy, I love how bmw underrates their engines. It's almost as if you are always getting more than you paid for haha.

Well, EAS uses an ego-boosting dyno, as they always seem to read quite high compared to pretty much everyone else. Even with 20-30whp less, though, still very impressive.

[CanAutM3]

Originally Posted by swamp2

A good bracketing study to explore for sure.

I don't believe CarTest does allow power shifting. Either way there are no options other than shift time AND engagement time. Also, I do believe that 0.3 second shifts are much more realistic for a moderately adept MT operator.

So if we adjust the total of shift time + engagement time down to 0.2 seconds, and make the MT car only 55 lb lighter, along with about 1% less loss (specifically 5 hp less at redline in 3rd gear) it becomes a near total performance wash. The MT car traps a hair faster but crosses a hair later (pretty well total equity for all practical purposes). Because the sims also show equality on 0-60 but the MT about 0.2 seconds quicker to 100 mph, and because these are inconsistent with quoted BMW figures (including standing 1 km), it tells me the modeling assumptions are not correct, too much loss difference or too short of shift times or both. Well either that or simply deny that the BMW figures are real (or perhaps only real for largely unskilled drivers). Also see comments below on a wide range of measured results for the E9X M3.

I am not surprised if the numbers between DCT and 6MT are quite close on the F8X. I have been speculating for some time that the DCT would not provide as much benefit on the F8X. The DCT more likely has an edge from launch (more consistency) due to the electronics better managing traction (which Cartest can probably not simulate). The Auto Motor & Sport 6MT and Sport Auto DCT acceleration times are pretty evenly matched.

Try doing it again with zero shift times for DCT. It might improve the simulation results.

[modkrazy]

Originally Posted by GrussGott

Subjective of course, but the opinions seems to go like this:

Mineral White:
1.) MW makes the lines easier to see
2.) MW is much "deeper"
3.) MW is more special and looks more expensive

Alpine White:
1.) AW makes the lines easier to see
2.) AW is more "pure"
3.) AW looks more sporty

After going to a dealership and looking at both on an M3/4 and then comparing to MW on a 43x convertible ... I concluded that AW is more to my taste.

I think if I wanted a more 'deeper' and special light color I'd go moonstone

I'm a huge fan of Alpine White, but when time comes for me to get one of these, I'm going Tanzanite or another dark blue; there are some lines I don't want to see, lol.

[CanAutM3]

Originally Posted by bruce.augenstein@comcast.

a 55-pound heavier (according to BMW) DCT.

I still think the F8X DCT is more likely 89lb (40kg) heavier than the 6MT as is published in the official BMW press release. The DCT was 45lb heavier on the E9X, they made the 6MT 26lb lighter on the F8X and they took a beefier DCT from the F1X for the F8X (18lb). I however still wonder why it shows only a 55lb heavier curb weight on the US website.

[Sedan_Clan]

Originally Posted by modkrazy

Well, EAS uses an ego-boosting dyno, as they always seem to read quite high compared to pretty much everyone else. Even with 20-30whp less, though, still very impressive.

So how do you explain BMS' nearly identical numbers on a separate dyno?

[MParallel]

Originally Posted by Needsdecaf

Mineral White >> Alpine White. Look at the difference in depth and luster in those pics.

I find AW the nicet color. Don't like the shifts in coloy because of the metalic.

Great pics nonetheless.

Which had me laughing out loud though, the brand name of the spacers. What's up with everyone wanting a German name?

Macht Schnell may sound cool for English people, but when you know it's German for "Makes fast", it looks like a joke.

[fusionchicken]

In regards to 6MT vs DCT, this post came from another thread reviewing a 6MT car:

Originally Posted by A418t81

Again , I noticed no degradation in performance against the DCT down the long back straightaway at SPA and that included 3 shifts. The power was instantly there after a shift with no perceptible pause. In fact when you shift fast it actually thumps the diff. The DCTs never pulled me during or immediately following a shift. Every time I was beside one coming out of the hairpins I would slowly and consistently pull away down the straight. YMMV but I had no issues with post shift power disruption.

Link to thread: http://f80.bimmerpost.com/forums/sho....php?t=1003540

Originally Posted by swamp2

One video does not offer any firm conclusions. Way too many variables not held equal. How many contests are there for closely comparable cars where about half of the videos show car A as the winner and half car B? The primary variable here are total weight the other driver skill. Look at the E9X performance "database", you will see the trend that the M-DCT cars are faster.

I definitely agree one video is not conclusive at all, and on the street with random encounters the DCT will win 99% of the time, as MT drivers competent enough to run with a DCT car are very few.

[swamp2]

Originally Posted by CanAutM3

I am not surprised if the numbers between DCT and 6MT are quite close on the F8X. I have been speculating for some time that the DCT would not provide as much benefit on the F8X. The DCT more likely has an edge from launch (more consistency) due to the electronics better managing traction (which Cartest can probably not simulate). The Auto Motor & Sport 6MT and Sport Auto DCT acceleration times are pretty evenly matched.

Try doing it again with zero shift times for DCT. It might improve the simulation results.

The benefit is from the time savings from shifting, that's it. There is nothing car, engine, etc. specific about the benefit.

A DCT shift time is clearly not zero. I typically use between 30-50 ms which according to some testing I did long ago (not entirely conclusive) along with various claims from manfacturers, seems very reasonable. Just another approximation anyway since it seems from feel that shift times vary not only by Drivelogic mode but by throttle position, simiarly in one mode and at WOT the shift times even vary from gear to gear. That has to do with the rpm drop getting smaller as the gears go up.