F80 M3 and F82 M4 Dyno and Weight: Comparison Time

[CanAutM3]

Originally Posted by swamp2

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.

I agree that there is an actual time needed for one clutch to engage while the other disengages. However, while this process is being done, there is still power transmitted to the rear wheels, hence no interruption in forward acceleration. If I am not mistaken, shift times in CarTest do interrupt forward acceleration. So inputting a shift time of zero would be more representative, wouldn't it? Further, IIRC from your own testing, the accelerometers never showed negative acceleration during a DCT shift (as would on a 6MT), did they?

[flinchy]

Wow... So the <1500kg the reviewers quote is over 100kg off reality... And it's NOT lighter than the e9x m3....

[Sedan_Clan]

Originally Posted by flinchy

Wow... So the &lt;1500kg the reviewers quote is over 100kg off reality... And it's NOT lighter than the e9x m3....

It IS! Read the thread fully. The US curb weight is accurate and previously weighed E9X's were in the 3700 lb. range.

[m3rxn]

[spool twice]

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 .

the n55/n54 can handle up to E50 safely without a complete reflash. Anything higher will require a reflash. However, Terry@bms has always stated than gains above an E60 mixture isnt as significant as adding E30-E50, so the most "potential" in gains happens in the smaller mixture of ethanol, and decreases exponentially in gains the more you add. This mainly applies to stock fueling. Terry will find ways to add an external line booster that the JB4 can control to boost fueling needs without reflashing (though, reflashing is always recommended for best performance).

[bruce.augenstein@comcast.]

Originally Posted by Sedan_Clan

It IS! Read the thread fully. The US curb weight is accurate and previously weighed E9X's were in the 3700 lb. range.

We'll get a good handle on this as full instrumented tests continue to roll out. Right now, it looks as if the new cars are slightly less ponderous than the E9X cars, but not by anywhere near what BMW marketing says. At least not in U.S. trim.

The lightest E9X six-speed car I've seen (tested by Car & Driver) came in at 3552 pounds full of fuel, with the Competition Package and not much else. If memory serves, the lightly optioned DCT cars come in at around 3600 pounds (Car & Driver and others).

Judging by just the single road test I've read in Motor trend, the new cars will come in just a bit lighter than those C & D cars mentioned, but not by a bunch ( a few pounds at most), and certainly far away from the 80-kilo lie that the BMW marketing mavens have come up with.

Still, lighter is better, even if it's by a teensy bit.

[monkawekrue]

beautiful cars.

[speeddeacon]

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.

Here's the scenario: you're sitting at a red light on a lonely stretch of highway when lo and behold a new 911 Carrera S rolls up beside you with a hot chick driving. She gives you the look and you immediately start fiddling around to activate launch control but the light turns green and she disappears into the night because you didn't find launch control in time. Or you rev the engine to about 4 grand and drop the clutch when it goes green and you smoke her, preserving your ego. Of course you could just floor the DCT and use lack of launch control engagement as an excuse should she happen to still beat you.

[gthal]

Originally Posted by flinchy

Wow... So the <1500kg the reviewers quote is over 100kg off reality... And it's NOT lighter than the e9x m3....

Originally Posted by Sedan_Clan

It IS! Read the thread fully. The US curb weight is accurate and previously weighed E9X's were in the 3700 lb. range.

This has got to be one of the most frustrating and pull your hair our threads EVER on this forum

[flinchy]

Originally Posted by Sedan_Clan

It IS! Read the thread fully. The US curb weight is accurate and previously weighed E9X's were in the 3700 lb. range.

no... it's not

i've found non-stripper DCT idrive ones weighed at ~3550lb WITH DRIVER

the kerb weight for the 'pure edition' stripper here in australia was ~3450-80lb... again, with driver afaik.

i worked out, that given accurate scale measurements of an F82 vs E92 with similar options (so the E92 has CF roof), the E92 inc driver and half tank of fuel was over 200lb lighter...

so unless the measurements are inconsistent or incorrect..

Originally Posted by gthal

This has got to be one of the most frustrating and pull your hair our threads EVER on this forum

i guess, plenty of people unable to add and subtract? haha

[flinchy]

Originally Posted by spool twice

the n55/n54 can handle up to E50 safely without a complete reflash. Anything higher will require a reflash. However, Terry@bms has always stated than gains above an E60 mixture isnt as significant as adding E30-E50, so the most "potential" in gains happens in the smaller mixture of ethanol, and decreases exponentially in gains the more you add. This mainly applies to stock fueling. Terry will find ways to add an external line booster that the JB4 can control to boost fueling needs without reflashing (though, reflashing is always recommended for best performance).

should change the fuel scalar at ~E20. i wouldn't go above E10 personally.

the thing with E60 not giving gains, is the HPFP can't keep up at high power. you can't give it enough fuel to make power

dual HPFP's you'll be able to make GOOD power on E85, no meth ever needed!

[Sedan_Clan]

Originally Posted by flinchy

no... it's not

i've found non-stripper DCT idrive ones weighed at ~3550lb WITH DRIVER

the kerb weight for the 'pure edition' stripper here in australia was ~3450-80lb... again, with driver afaik.

i worked out, that given accurate scale measurements of an F82 vs E92 with similar options (so the E92 has CF roof), the E92 inc driver and half tank of fuel was over 200lb lighter...

so unless the measurements are inconsistent or incorrect..

So you've found a U.S. non-stripper DCT ///M3 in Australia???? There have been a few examples that weighed somewhere in the 3550 range, but there are far more examples of E9X ///M3's weighing in the 3650-3700 range (...and links to magazine tested and weighed E9X's have been included in this thread). Let's keep in mind that most of these F8X's are fully loaded or nearly fully loaded. We have yet to see what a stripper/low-optioned car weighs.

[gthal]

Originally Posted by flinchy

i've found non-stripper DCT idrive ones weighed at ~3550lb WITH DRIVER

the kerb weight for the 'pure edition' stripper here in australia was ~3450-80lb... again, with driver afaik.

No offense but that is BS... a non-stripper, DCT WITH driver at 3,550.... That would mean the car was 3,400 without driver and that E9X does NOT exist unless it was modified after BMW built it.

Originally Posted by Sedan_Clan

So you've found a U.S. non-stripper DCT ///M3 in Australia???? There have been a few examples that weighed somewhere in the 3550 range, but there are far more examples of E9X ///M3's weighing in the 3650-3700 range (...and links to magazine tested and weighed E9X's have been included in this thread). Let's keep in mind that most of these F8X's are fully loaded or nearly fully loaded. We have yet to see what a stripper/low-optioned car weighs.

Exactly... so now we are comparing completely stripped cars in Australia with US built cars with options and DCT.

The one thing we know... the F8X weighs less than an E9X when equipped the same way. We now also know that a complete Australian stripper weighs less than a well equipped US car

[flinchy]

Originally Posted by gthal

No offense but that is BS... a non-stripper, DCT WITH driver at 3,550.... That would mean the car was 3,400 without driver and that E9X does NOT exist unless it was modified after BMW built it.



Exactly... so now we are comparing completely stripped cars in Australia with US built cars with options and DCT.

The one thing we know... the F8X weighs less than an E9X when equipped the same way. We now also know that a complete Australian stripper weighs less than a well equipped US car

yeah i was surprised too, but unless you can prove that the scales were out of cal, that's where it lies.

the opposite is true, we know that F8x and E9x with similar options, the F8x weighs more (marginally, at least...).. the proof is here on these very forums.

Originally Posted by Sedan_Clan

So you've found a U.S. non-stripper DCT ///M3 in Australia???? There have been a few examples that weighed somewhere in the 3550 range, but there are far more examples of E9X ///M3's weighing in the 3650-3700 range (...and links to magazine tested and weighed E9X's have been included in this thread). Let's keep in mind that most of these F8X's are fully loaded or nearly fully loaded. We have yet to see what a stripper/low-optioned car weighs.

uh no, that's not what i said

i said the STRIPPER DCT in australia (aka the 'pure' edition') weighs <3500lb.. and a non-stripper (idrive, whatever else) is ~100lb more on the scales.

>(...and links to magazine tested and weighed E9X's have been included in this thread).

yes, and you remember some have weighed in at <3600lb.. i believe it was C&D?

>Let's keep in mind that most of these F8X's are fully loaded or nearly fully loaded. We have yet to see what a stripper/low-optioned car weighs.

i'm comparing it to the one in the OP, which has the same weight as an E92 with driver and half a tank (larger tank mind you!) with CF roof, DCT, upgraded stereo, whatever else... with no driver, 1/4 tank, couple more options... remember, the E92 weight i'm quoting is non-stripper with a 176lb driver, and ~30lb more fuel.

the F82 has to get to say 3450lb stripper (again, i believe inc average weight driver and a half tank) to be lighter than an E92 stripper.

[gthal]

Originally Posted by flinchy

yeah i was surprised too, but unless you can prove that the scales were out of cal, that's where it lies.

the opposite is true, we know that F8x and E9x with identical options, the F8x weighs more.. the proof is here on these very forums.

There is also proof of E9X cars in the 3,700 lb range without a driver.

So, I think you need to post a picture of something to prove 3,550 for an E90 with DCT with decent options WITH a driver or it is simply not credible IMO. Nothing personal but I just don't see it as even remotely possible given it would be a one of a kind car.

[flinchy]

Originally Posted by gthal

There is also proof of E9X cars in the 3,700 lb range without a driver.

indeed, and i'm sure there will be proof of F8x fully loaded full tank of fuel in the same range

not to mention the vert weighing.. what was it? 4100lb (not really useful info for this comparison, but still, M4 vert >4000lb)

Originally Posted by gthal

So, I think you need to post a picture of something to prove 3,550 for an E90 with DCT with decent options WITH a driver or it is simply not credible IMO. Nothing personal but I just don't see it as even remotely possible given it would be a one of a kind car.

https://www.google.com/search?q=e92+...on+kerb+weight

that's the pure edition, 1580kg kerb weight = 3480lb. still porky imo haha.

as far as i can tell that's actually *without* driver. i can't find an accurate source though.. some claim with, some claim without. doesn't seem to be a real 'standard' here...

the 3550 i found googling 'e92 m3 kerb weight' and there was a few results from here, plus elsewhere.

there's results of non-stripper (i believe fairly optioned even) E92 M3's without driver at 3550lb on another forum.

ED: 3550 with Options:
-19" wheels
-M-DCT
-EDC
-Nav (Tech. Package)

1/4 tank of fuel.


i really am curious as to the weight of a full stripper F82 though.

<3450lb w/o driver would be pretty awesome.

[gthal]

Originally Posted by flinchy

https://www.google.com/search?q=e92+...on+kerb+weight

that's the pure edition, 1580kg kerb weight = 3480lb. still porky imo haha.

as far as i can tell that's actually *without* driver. i can't find an accurate source though.. some claim with, some claim without.

the 3550 i found googling 'e92 m3 kerb weight' and there was a few results from here, plus elsewhere.

Actually, what you said (and I quoted above) was ...

i've found non-stripper DCT idrive ones weighed at ~3550lb WITH DRIVER

So this is a non-stripper, DCT, iDrive car... WITH a driver. Are you saying this is a "pure edition" car or is that something different?

Bottom line... put a car on a scale and weigh it and let us know the options. I think you will find they are closer to 3,650 without a driver than 3,480... having said that, I'm not familiar with the "pure edition."

[flinchy]

Originally Posted by gthal

Actually, what you said (and I quoted above) was ...



So this is a non-stripper, DCT, iDrive car... WITH a driver. Are you saying this is a "pure edition" car or is that something different?

allegedly.. yes, non pure ediiton. again, according to SOME people.

could have been scales way out of calibration, but there's a handful of other people saying about the same?

will have to get a similarly optioned E9x and F8x side by side same day same scales hahaha.. put to rest the debate, because you can find a variance of what.. 3500-3800lb with E90/92 M3's... depending on options, scales, driver/no driver.. 1/4 tank, half tank.. cf roof, non cf roof... what's the variance of F8x so far? we've got about 3560-70lb with a few options (not FULLY loaded though?), have there been any confirmed lower? what about higher? what's the upper limit for the F8x? Apples to apples stuff.

this is beginning to sound like dynojet vs other dyno debate haha

considering a 335i weighs less than that (quoted kerb weight with similar options, stock (steel?) roof), yet the N54+turbos etc. weighs MORE than an s65..?.. talking purely engines being the difference, the 335i should weigh slightly more.

[swamp2]

Originally Posted by CanAutM3

I agree that there is an actual time needed for one clutch to engage while the other disengages. However, while this process is being done, there is still power transmitted to the rear wheels, hence no interruption in forward acceleration. If I am not mistaken, shift times in CarTest do interrupt forward acceleration. So inputting a shift time of zero would be more representative, wouldn't it? Further, IIRC from your own testing, the accelerometers never showed negative acceleration during a DCT shift (as would on a 6MT), did they?

But again, the performance advantage is independent of anything about the car or engine, it is only about the shift being faster.

My actual test results were not very conclusive, despite some care in the choice of the accelerometer and DAQ. There was some evidence in that data arguing for a truly zero shift time when it comes to simulation (in the S modes). There was also evidence for a drop in acceleration qualitatively like a MT shift.

Using 50 ms seems like a conservative approach (i.e. not to incredibly pro M-DCT, which I am). Now that being said the performance improvements in times to speed will only change by the difference in those shift times 50 ms to 0, i.e. 0.05 seconds which is insignificant.

[swamp2]

Guys, keep in mind the almost mind numbing array of weight specifications listed in the sticky here in this section. BMW's optimistic 1500 kg / 3300 lb thing was an empty fuel tank, no driver at best. That being said I also agree that having an E9X M3 at 3550 with driver is pretty well impossible.

[spool twice]

Originally Posted by flinchy

should change the fuel scalar at ~E20. i wouldn't go above E10 personally.

the thing with E60 not giving gains, is the HPFP can't keep up at high power. you can't give it enough fuel to make power

dual HPFP's you'll be able to make GOOD power on E85, no meth ever needed!

The Brazilian sold and operated N54/N55's are coping fine with the country's mandatory E25 with the very same fueling system as the euro/USDM models. Maybe the MSD80 DME has more legroom for fueling needs, as its boost targets are load based? I hope the S55 DME works in a similar fashion.

I agree with you, the dual HPFP will be able to make good power some blends of E85. The need for a line booster may not be neededfor mild mixtures , but at this moment, I think Terry is the only one who can report fuel trims as he's experimenting more and more with E85, but no fuel trim logs have been reported (yet). Can't wait for results from him soon.

[CanAutM3]

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.

See this post.

On the E9X chassis, a DCT car will be faster due to the faster shift times in most scenarios. But I agree with you, there are more losses with the DCT and the E9X DCT made up for it through better gearing.