BMW Garage BMW Meets Register Search Today's Posts Mark Forums Read

Go Back   BMW M3 and BMW M4 Forum > BMW F80 M3 / F82 M4 Technical Topics > Engine / Drivetrain / Exhaust / Bolt-ons

Post Reply
 
Thread Tools Search this Thread
      05-31-2013, 06:35 PM   #1
swamp2
Lieutenant General
 
swamp2's Avatar
 
Drives: E92 M3
Join Date: Sep 2006
Location: San Diego, CA USA

Posts: 10,201
iTrader: (1)

Lightbulb Updated BMW F82 M4 Performance Simulations-Predictions - Even Faster...

BIMMERPOST
     Featured on BIMMERPOST.com
Many of the regulars here will recall my advocacy of the principles of science/math (engineering really) to the enjoyment and understanding of vehicles. Some time ago I made some detailed predictions about the performance of the upcoming M3/M4. If you want to refresh your memory have a look at that thread from way back in late 2010 here. It showed a very quick new M3/M4!

With the new rumors on weight, redline and the not so new rumors on the torque and power I thought it was time to update my predictions. Stay tuned (or skip the details near the end if you are not so inclined) as I'm reasonably confident the car will be even faster than my prior predictions. No real surprise there as the new inputs to my physics based simulations are in essence more power and less weight. However, you'll probably be able to glean some things about the effect of the shapes of the power/torque curves on vehicle performance, the advantage of a high redline (disadvantage of a lower one...) and how we can extrapolate changes from the E60 M5 to F10 M5 to better understand what likely lies in store with the next generation M3/M4.

Relatively high torque, low (or even high) power, low redline engines as compared to low torque, high power high redline engines simply must be geared differently. The cars must delicately balance acceleration, peak speed in gears and utilizing the full rpm range. The former cars are great for more lazy driving with adequate torque to pass in higher gears whereas the latter have an addictive linear power band that is noisy, thrilling and takes more shifting to extract the total available performance. The new Ms are heading in the former direction, however, with good news that the new motor may rev “close to 8000 rpm”, they are not going to totally Corvette style power on us.

We can should be able extrapolate some of the changes from the E60 M5 to the F10 M5 to the M3, even though the new M4 will likely be lighter than its predecessor, unlike the progression of more weight in the M5. As far as engine and transmission we can extrapolate quite a bit. Both engine and transmission changes must go hand in hand and the changes for the M3/M4 are thus likely to be right in line with what happened with the M5 to accompany the lower displacement and forced induction. A bit unexpectedly the F10 M5 has more gear multiplication down low and less in its top gear. A wider overall range that impacts both off the line acceleration as well as providing increased fuel economy with a 7th a bit more like an overdrive gear. The F10 has about 5% lower gearing (higher gear ratio/torque multiplication) in first gear combined with a whopping 30% higher 7th gear (lower combined gear multiplication). Because the new M3/M4 will also have much more torque and peak torque will arrive at a much lower rpm its gearing should change in a very similar fashion.

I’m not also going to recall my prior statement that the new M3/M4 will require shifting at redline in all gears to extract maximum performance. The new M5 does not, only the first three shifts are done so in the M5. The rapidly falling torque curve means that you can get more thrust in a lower gear by shifting earlier for the higher gears. Basically when the force vs. speed graphs (second set below) cross before redline then the ideal shift will also be before redline. The higher the redline is, combined with this falling torque and 7 close spaced gears all lead to an inability to utilize the full rpm range in all gears. This obviously was not a problem in the current M3 because of the very flat torque curve up to high rpms (equivalently its very linear power curve). Based on this effort I also do not believe the car will have a redline "very close" to 8000 rpm. Or perhaps a slightly weaker but more confident statement is that the combination of power and torque curves that look like the ones in the M5, along with similar gearing changes like the ones I’ve chosen, do not yield significant performance improvements with a redline above about 7600. Thus my best guess is 7500-7700 tops. I really think “close to 8000” is more BMW marketing speak for a figure like I’ve mentioned.

Here are my predictions for speeds in gear comparing the existing DCT M3 on the left to the new M4 on the right:



Here are the force at the wheels comparisons. Many talk about the torque at the wheels, almost the same thing but one should really take the next step and convert that to a force. You can get an idea why folks talk about such turbo engines feeling a bit dead up top. It directly affects how much force gets to the wheels and the change to a downward slope can happen quite ubruptly (just like in the dyno itself). This is called jerk or surge and we humans are very tuned to feel this change in acceleration. The left is the existing car and the M4 is on the right.



The next key point is underrating, the 335i was, the 1M was and now the F10 M5 is as well. The M5 is likely to be underrated by about 20-30 hp. Given its weight and performance there really is no other reasonable explanation. I’ve this same CarTest physics based acceleration simulation software to model a plethora of cars performance and I’ve done so using the F10 M5 as a baseline to provide better M3/M4 predictions. Just based on the claimed ~400 ft lb of torque in the new M3/M4 and a redline near 8000 rpm, as well having a torque curve that looks anything like the F10 M5, “about the same power” as the current M3 is just not possible. I’m estimating the quoted power of the car to be 420-430 hp but actual power will be more like 440-460. For the included simulations I’ve decided on 450 hp. I have however, varied the power and weight like in the prior post and effort linked to above to provide a more reasonable range of performance figures. The complete range of simulations I’ve used is certainly not shown.

Here are the torque and power curves I have used:



Here are the basic inputs into the simulation:



Weight: My prior estimate was around 3590 lb (wet without driver). For three reasons, one stronger and two weak I am revising that estimate down.
  1. BMW reports weight in the US with 165 lb (75 kg) added for driver and cargo. 3700 is about right for a typical US E92 M3, which translates to about 3550 (wet without driver). BMW will probably be saving at least 100 lb compared to the current car meaning a figure of about 3450 (wet without driver) is reasonable. The 100 figure is very roughly justified again in the post mentioned near the beginning of this one.
  2. Ongoing rumors insist we’ll see a significantly lightened vehicle.
  3. Less weight = more performance = an more exciting post.

Like I said, one stronger and two weak…

For completeness sake the software has a place to add the drivers weight and I have used 160 lb. Guess 165 might be better from a standards perspective, but what's 5 pounds among friends.

Acceleration curves: turquoise for the new M4 and purple of the E92 M3. These also show a fairly dramatic difference in what you feel at high rpms. First gear is obviously quite dramatic in the new car, a huge overall advantage for the M3. Despite the undesirable roll off in acceleration, even at its worst point (right before shifting) it remains with more acceleration than all except right around the peak of the existing car!



Last but not least the full comparison, first column is E92 M3, second is my initial prediction mentioned above and last is the current effort.



Summary of predictions:
  • 0-60 mph: 3.5 - 3.7 s
  • 0-100 mph: 8.2 - 8.4 s
  • 0-200 kph: 12.4 - 12.6 s (for our metric friends!)
  • 1/4 mi time: 11.9 - 12.1 s
  • 1/4 mi trap: 120 - 123 mph
  • Top speed: 193 - 197 mph (of course true, not indicated, indicated will be over 200 mph)
  • Nurburgring Nordschleife lap time (SportAuto): Low 7:5X (will greatly depend on choice of tires)

Hope you enjoy the predictions. Like all work of this type, garbage in garbage out. There are a lot of assumptions in such simulation. If the actual car differs significantly from these inputs then the predictions will be correspondingly off. However, if the inputs are close to actuals, I'm highly confident the car will indeed have this level of performance. Will this be enough to keep the car on the top of the competitive heap?

Last edited by swamp2; 05-31-2013 at 10:06 PM.
swamp2 is offline   United_States
0
Reply With Quote
      05-31-2013, 09:14 PM   #2
RMB
Lieutenant
 
RMB's Avatar
 
Drives: '11 Cayenne S
Join Date: May 2012
Location: Virginia

Posts: 569
iTrader: (0)

Garage List
Very interesting and thanks for the information. I plan on picking up the new M4 when it comes out so I am very interested in reading about its potential performance improvements.
RMB is offline   United_States
0
Reply With Quote
      06-01-2013, 10:11 PM   #3
Needsdecaf
Everything's Bigger in Texas!
 
Drives: Porsche Tractor
Join Date: Feb 2011
Location: The Woodlands, TX

Posts: 1,819
iTrader: (0)

Impressive analysis.
Needsdecaf is offline  
0
Reply With Quote
      06-02-2013, 01:46 AM   #4
buildbright
Captain
 
buildbright's Avatar
 
Drives: 335i BMW F30 Sedan
Join Date: Sep 2012
Location: Tampa, FL

Posts: 907
iTrader: (0)

I agree. The f30 chassis and new transmissions are great for acceleration. There is already a 11 sec 335i. I predict with a jb4 and some other goodies the new f80 should be a 10 second car.
buildbright is offline  
0
Reply With Quote
      06-02-2013, 06:45 PM   #5
BigMacSmallFries
Second Lieutenant
 
Drives: '15 M3, '11 GT3 RS
Join Date: Aug 2010
Location: Toronto, Ontario

Posts: 252
iTrader: (1)

Thanks for posting, but 8.3 seconds to 100mph?! An LP560 4 wheel drive/550hp/3400lbs does it in 8. I hope you're right!
BigMacSmallFries is offline  
0
Reply With Quote
      06-02-2013, 09:13 PM   #6
CanAutM3
Brigadier General
 
CanAutM3's Avatar
 
Drives: 2015 M4 DCT
Join Date: Jan 2012
Location: Montreal

Posts: 3,831
iTrader: (0)

Garage List
2015 BMW M4  [4.50]
2006 Audi S4  [0.00]
I always enjoy reading your inputs and analysis, thanks for taking the time and sharing .

I am hoping the the gearing on the new M3/M4 will be adapted to always keep the car in the power plateau (6 to 7.6k in your assumption) and only 7th gear with taller gearing for fuel economy. If that were the case, every gear could be pulled to redline yielding a very smooth acceleration curve. It should help reduce the feeling of "acceleration drop-off" nearing redline. I guess it is wishful thinking on my part .

Last edited by CanAutM3; 06-03-2013 at 06:04 PM.
CanAutM3 is offline   Canada
0
Reply With Quote
      06-02-2013, 09:19 PM   #7
bimmerjph
Lieutenant Colonel
 
bimmerjph's Avatar
 
Drives: 2002 BMW 325i
Join Date: Oct 2011
Location: Tennessee

Posts: 1,968
iTrader: (0)

What software are you using?

BTW great post. Thanks for the predictions!
bimmerjph is offline   United_States
0
Reply With Quote
      06-03-2013, 03:07 AM   #8
swamp2
Lieutenant General
 
swamp2's Avatar
 
Drives: E92 M3
Join Date: Sep 2006
Location: San Diego, CA USA

Posts: 10,201
iTrader: (1)

Quote:
Originally Posted by bimmerjph View Post
What software are you using?

BTW great post. Thanks for the predictions!
Thanks, as mentioned in the post it is called CarTest.
swamp2 is offline   United_States
0
Reply With Quote
      06-03-2013, 03:18 AM   #9
swamp2
Lieutenant General
 
swamp2's Avatar
 
Drives: E92 M3
Join Date: Sep 2006
Location: San Diego, CA USA

Posts: 10,201
iTrader: (1)

Quote:
Originally Posted by BigMacSmallFries View Post
Thanks for posting, but 8.3 seconds to 100mph?! An LP560 4 wheel drive/550hp/3400lbs does it in 8. I hope you're right!
8.4 was the top end of the range I predicted. A very quick search revealed the Lambo has done 7.8 s 0-100 mph. A 0.6 second gap is pretty significant!

Quote:
Originally Posted by CanAutM3 View Post
I always enjoy reading your inputs and analysis, thanks for taking the time and sharing .

I am hoping the the gearing on the new M3/M4 will be adapted to always keep the car in power plateau (6 to 7.6k in your assumption) and only 7th gear with taller gearing for fuel economy. If that were the case, every gear could be pulled to redline yielding a very smooth acceleration curve. It should help reduce the feeling of "acceleration drop-off" nearing redline. I guess it is wishful thinking on my part .
Your welcome.

No matter how 7th is geared the large drop off in acceleration is pretty well inevitable as the accelerative force basically follows the torque curve. Now if the torque curve (shape or redline) were more S65-ish, as stated, this drop off would not occur. Of course that is NOT the same as saying torque is more important then power... But that is a whole different discussion.

I really don't think this car will be a shift at redline in every gear type of car, but at least it should for the first few shifts and that more important than the latter ones for sure. Given the more F10 M5-ish torque curve and gearing and a 7600-ish redline, something has to give and that something is not shifting at redline.
swamp2 is offline   United_States
0
Reply With Quote
      06-03-2013, 05:44 AM   #10
Levi
Brigadier General
 
Levi's Avatar
 
Drives: Alfa Romeo
Join Date: Jul 2009
Location: Prague

Posts: 3,264
iTrader: (0)

M3/M4 will be fast, as I previously predicted. Your numbers are quite there swamp. But that doesn't tell how good the M3/M4 will be. GTR also is very fast, but not more fun than a Cayman, MP4-12C is also very fast, but hasn't got the feeling of a 458.
Levi is offline   Czech_Republic
0
Reply With Quote
      06-03-2013, 08:26 AM   #11
fatmike91
New Member
 
Drives: bimmerless
Join Date: Jun 2013
Location: NJ

Posts: 5
iTrader: (0)

Very interesting. Could you model how a lighter M3 would perform?

The curb weight (not wet w/o driver) of my 1999 328i was under 3200.

I'd be curious what these charts would like like with a 3200lb (or 3300lb) car.



/
fatmike91 is offline  
0
Reply With Quote
      06-03-2013, 09:19 AM   #12
ILC32
Lieutenant
 
ILC32's Avatar
 
Drives: 1993 Porsche RSA
Join Date: Aug 2005
Location: Somewhere

Posts: 580
iTrader: (0)

Very interesting. 450 hp is consistent with what I was told quite some time ago by a confidential source. I don't claim to know what the current hp target is, but it will be interesting to see how things ultimately turn out, especially with respect to the actual (as opposed to specified) output .
ILC32 is offline  
0
Reply With Quote
      06-03-2013, 11:52 AM   #13
swamp2
Lieutenant General
 
swamp2's Avatar
 
Drives: E92 M3
Join Date: Sep 2006
Location: San Diego, CA USA

Posts: 10,201
iTrader: (1)

Quote:
Originally Posted by Levi View Post
M3/M4 will be fast, as I previously predicted. Your numbers are quite there swamp. But that doesn't tell how good the M3/M4 will be. GTR also is very fast, but not more fun than a Cayman, MP4-12C is also very fast, but hasn't got the feeling of a 458.
I strongly agree with you on this!
swamp2 is offline   United_States
0
Reply With Quote
      06-03-2013, 12:00 PM   #14
swamp2
Lieutenant General
 
swamp2's Avatar
 
Drives: E92 M3
Join Date: Sep 2006
Location: San Diego, CA USA

Posts: 10,201
iTrader: (1)

Quote:
Originally Posted by ILC32 View Post
Very interesting. 450 hp is consistent with what I was told quite some time ago by a confidential source. I don't claim to know what the current hp target is, but it will be interesting to see how things ultimately turn out, especially with respect to the actual (as opposed to specified) output .
As discussed quite a few times all of the rumors of; nearly 8000 rpm redline, close to existing power, a torque curve like the M5 and about 400 ft lb of torque are almost an impossible combination, something is inconsistent in this set of characteristics. I think power "about the same" will be the thing that will not be correct from that list (well and as stated about "near" 8000 rpm redline as well).

However, looking at torque per liter in the F10 M5, if it kept its ratio there but had 3.0 liters, it would only about about 350 ft lb, not closer to 400...
swamp2 is offline   United_States
0
Reply With Quote
      06-03-2013, 12:08 PM   #15
ASAP
Breaks My Wallet
 
ASAP's Avatar
 
Drives: 2009 Baby BMW
Join Date: Sep 2012
Location: 703

Posts: 1,285
iTrader: (0)

1/4 mile trap speeds 120-123?

what kind of garbage is this? Faster than an F10 M5? As fast as a 2011-2012 GTR?
__________________
2009 135i 6AT
E40 PTF Protune, AR Dp's, 5" ETS FMIC, BMS DCI
ASAP is offline   No_Country
0
Reply With Quote
      06-03-2013, 12:08 PM   #16
FogCityM3
Lieutenant Colonel
 
FogCityM3's Avatar
 
Drives: M3 (E90)
Join Date: Feb 2012
Location: San Francisco

Posts: 1,537
iTrader: (0)

Very nice, as usual. Based on your numbers, 7.67 weight/power ratio (acutally mentioned by one of the mods/insider guys a while ago as being similar to M3 GTS) would be in line with the M5, which was not the case w/ last generation. From a marketing perspective, especially since the M3 will be a 4 door, wonder whether BMW will not care about cannibalization (of the M5 and M4 w/ M6) if straight line performance equals M5/M6.

Last edited by FogCityM3; 06-03-2013 at 04:10 PM.
FogCityM3 is offline  
0
Reply With Quote
      06-03-2013, 12:28 PM   #17
solstice
Colonel
 
Drives: 2015 M3 6MT
Join Date: May 2013
Location: Seattle

Posts: 2,225
iTrader: (0)

Nice to see that experience and theory now matches up. I said before that all turbo cars I've owned and driven make optimal power in the midrange not at redline. And the footage from testing at the ring indicates short shifting to keep optimal power delivery. Last time I posted this someone jumped at me saying that with 100% cofidence this was wrong and that redline shifting was going to be optimal, was that you . ( Even with all this data I'm not 100% confident of anything with this new car but I think it's likely that it will behave like other turbo cars). Impressive work nevertheless swamp2, thanks!
solstice is offline  
0
Reply With Quote
      06-03-2013, 12:51 PM   #18
rs_philly
Private
 
Drives: 335xi Monaco Blue
Join Date: Jun 2010
Location: Philadelphia

Posts: 63
iTrader: (0)

415HP?

Thanks for the detailed analysis - it looks very thorough.

The last set of rumors (for at least 6 months) say the power will likely be similar to the E90/92, but torque qill be in the 395-400 lb-ft range. What would the performance numbers look like if you ran the simulation with 415 HP?
__________________
08 335xi Monaco Blue, '14 MCSc British Racing Green II
05 330Ci Convertible ZHP, Imola Red (sold)
00 540 sport, Orient Blue (gone, RIP)
rs_philly is offline   United_States
0
Reply With Quote
      06-03-2013, 01:18 PM   #19
vladberca
Brigadier General
 
vladberca's Avatar
 
Drives: '09 jetta tsi 6mt
Join Date: Oct 2009
Location: Craiova

Posts: 3,598
iTrader: (0)

I don't think BMW will keep the same power for the new M3/M4 because for the F10 M5 it was increased with about 10%.
I assume that 450hp is a safe number that we can expect
vladberca is offline   Romania
0
Reply With Quote
      06-03-2013, 01:25 PM   #20
VCMpower
Banned
 
Drives: 2010 Dakar, 2013 Fire Orange
Join Date: Jan 2010
Location: Victoria B.C.

Posts: 941
iTrader: (0)

Reasonable doubt. Gavel drop. I feel the only info they can assure of is, less time a the fuel station, if you stay out of boost!

Last edited by VCMpower; 06-03-2013 at 01:38 PM.
VCMpower is offline   Canada
0
Reply With Quote
      06-03-2013, 01:42 PM   #21
Palle
Enlisted Member
 
Drives: 1er
Join Date: Dec 2012
Location: Frankfurt

Posts: 45
iTrader: (0)

sounds great!!!! thanks a lot!
Palle is offline   Germany
0
Reply With Quote
      06-03-2013, 01:48 PM   #22
PSTM3
Private First Class
 
PSTM3's Avatar
 
Drives: GT-R, CTS-V Coupe, 750i
Join Date: Apr 2012
Location: Phoenix,AZ

Posts: 190
iTrader: (0)

Awesome stuff.
PSTM3 is offline   United_States
0
Reply With Quote
Post Reply

Bookmarks

Tags
2014 bmw m3, 2014 m3, 2014 m3 engine, 2014 m3 forum, 2014 m3 weight, 2014 m4 engine, 2014 m4 weight, 2015 bmw m3, 2015 bmw m4, 2015 m3, 2015 m3 engine, 2015 m4 engine, 2015 m4 weight, bmw f80, bmw f80 forum, bmw f80 forums, bmw f80 m3, bmw f80 m3 s55, bmw f80 m3 sedan, bmw f82, bmw f82 forum, bmw f82 forums, bmw f82 m3, bmw f82 m3 coupe, bmw f82 m3 forum, bmw f82 m4, bmw f82 m4 coupe, bmw f82 m4 s55, bmw f83, bmw f83 m3, bmw f83 m4, bmw m forum, bmw m forums, bmw m3 s55, bmw m3 s55 engine, bmw m4, bmw m4 coupe, bmw m4 coupe forum, bmw m4 forum, bmw m4 forums, bmw s55, bmw s55 engine, bmw s55 motor, bmw spy, bmw spy photo, bmw spy photos, bmw spy pic, bmw spy pics, bmw spy video, bmw spy videos, f80, f80 forum, f80 forums, f80 m3, f80 m3 engine, f80 m3 forum, f80 m3 forums, f80 m3 motor, f80 m3 s55, f80 m3 sedan

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -5. The time now is 12:57 AM.




f80post
Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST