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

[jmarino21]

Being an engineer myself, plus fucking one on this thread. Impressive!

[eMvy]

Originally Posted by swamp2

It might be a more approachable reply to not dismiss something as "garbage" without providing some ideas as to specific concerns.

Exactly. Thanks for all of your work on this, and from a fellow engineer,

[Carl L]

Originally Posted by ron_jeremy

Look at the M3 history.
E30M3:190-230hp
E36M3: 286-321hp
E46M3: 343hp
E92M3: 420hp

The E36 and E46 had about the same hp, but the latter was faster and better.
My guess is that the power will be pretty much like what we saw in E92M3, about 420-430, official that is.
We all know BMW are pretty modest, so 450 is likely in the ballpark.
But then again, we will see a significant bump in torch, so it will be easier and more of a daily driver with the low end torch, and faster than the excisting M3.

A fair enough post, but not sure how these official figures support your point. With the smallest power bump being 22 PS, that means that officially the F80 will be at least 442PS (like Swamp, I've been touting 440-460 for the past year). M3post may be correct with 415PS, but I doubt it. We'll find out soon though.

Swamp, great work bud and seems to all make good sense. A lot of the naysayers are guys who won't be in a position to get one of these next year. Very excited for the weight loss.

[ASAP]

Originally Posted by swamp2

It might be a more approachable reply to not dismiss something as "garbage" without providing some ideas as to specific concerns. Cars get faster, this is normal and we have not seen much slowing of this progression.

This is clearly not as fast as a 2011-2012 GT-R. I've seen low 11s reported for that car.

It's all about power and weight. If this car gets 450 hp and has a weight in line with my ESTIMATE. It simply WILL be this fast.

So it will go from a reported 12.7@113 to over 120?

The new m5 does 12.0@119... my FBO on E85 335i barely traps 120 and you are saying this new m3 will do it no problem? My car dyno'd 430 whp which is almost 500 crank hp if you count a 15% auto drivetrain loss, then how do you figure a 430-450 crank HP car will do this? Even with a 100lb advantage this will be impossible... the only current sub 100K cars that can do this are the C6 Z06, Mustang gt500, Nissan GTR and Viper...

You need to recalculate your numbers asap man... lol

[bimmerjph]

Originally Posted by Moo

BMW probably won't allow official 0-62 times to be faster than current M5 or M6.

According to BMW the E92 was quicker than the E60 and the E46 was quicker than the E39.

[FormulaMMM]

Originally Posted by ASAP

So it will go from a reported 12.7@113 to over 120?

Is this sort of performance increase unprecedented in your view?

E36 M3 -- 14.2-.6 @ 93-98 mph.

E46 M3 -- 13.3-.5 @ 103-106 mph.

E9X M3 -- 12.5-.7 @ 113-115 mph.

I know a similar power increase is reportedly not in store for the F80, but less weight, likely superior launch control, power characteristics more favorable to straight line acceleration. 120 mph trap doesn't strike me as crazy. History indicates that it's not.

[Zebra99]

Originally Posted by ASAP

So it will go from a reported 12.7@113 to over 120?

The new m5 does 12.0@119... my FBO on E85 335i barely traps 120 and you are saying this new m3 will do it no problem? My car dyno'd 430 whp which is almost 500 crank hp if you count a 15% auto drivetrain loss, then how do you figure a 430-450 crank HP car will do this? Even with a 100lb advantage this will be impossible... the only current sub 100K cars that can do this are the C6 Z06, Mustang gt500, Nissan GTR and Viper...

You need to recalculate your numbers asap man... lol

No respect for mathematical genius....that's okay, we'll see when official times get posted by members.

And btw, it's his educated guess based on vague information currently available. Can almost call it an opinion really.

Lets see your mathematical justification....

[swamp2]

Originally Posted by Skullbussa

Very entertaining post.

There is no way this car is going to trap 120 in the quarter mile. That is C6 Z06 territory which is far faster than this car will ever be.

And I am curious who is snapping off 4.1 second runs to 60 in E92 M3s? Even if you take traction out of the picture, I don't think there is the power/weight ratio for that to happen.

Guys, guys, do a bit of homework. Please think a bit more before you type and do nothing but A-B comparisons with knee jerk reactions...

C6 Z06s have trapped as high as 128, just a hair under 129. You must understand statistics a bit. There are numbers from magazines, numbers from local drag strip track rats, number from manufacturers and numbers from average every day Joe owners. The simulations take out ALL traction, weather and driver variables, meaning the results tend to be closer to the best possible results. Just like every other car in history the new M4 will trap at a variety of different values. Just like my prior comments about the 0-60, the 1/4 mi traps will vary and (reasonably big) IF my weight AND power values are accurate the car should trap at or above 120.

As to sun 4 second 0-60 it was done by Car and Driver magazine. For a link and a better idea of what statistics mean for the current E92 M3 have a look here at the performance "database" we have put together.

[swamp2]

Originally Posted by CanAutM3

Thanks for doing this

If we assume DCT, why the interruption in acceleration on gear shifts? Also, why so much wheel spin and lost acceleration going into 2nd? If the car was able to pull 1g in first gear without losing traction, there is no reason it cannot pull 0.75g in second gear. I am guessing that we don't see benefits of the gearing due to assumed shift times and tire slippage shifting into 2nd...

Let me explain why I selected those gear ratios. I reduced 1st gear because I don't think the tires would be able to sustain 1.2g in real life, so I reduced it to slightly above 1g. I also adjusted the spacing between gears 2 to 6 so that the engine always remains in the power plateau, which should yield better theoretical acceleration.

No problem. This is the kind of instant A to B comparisons that actually give the best results using such techniques (relative change more than absolutes).

I agree about the 1.2 g, it is quite high. That being said if the next generation of the Michelin Pilot is out by that time, who knows, just like cars tire tech continues to march on.

Pretty sure the interruption in acceleration is wheel spin.

Again despite the existence of a power plateau, as long as the force curves vs. speed and across gears do not overlap, it still provides better acceleration to shift at redline after a period of rapidly dropped torque.

Originally Posted by CanAutM3

Agreed that it all comes down to power. Peak power is a great way to quickly assess overall performance. But ultimate performance is about average power produced during an acceleration run, not only peak power. IMO, this is why the power plateau will make the M3/M4 performance impressive.

But not nearly as impressive if the plateau did not exist in the first place due to the turbo and or Valvetronic systems not being able to breathe like a high performance NA engine can!

[swamp2]

I have slightly modified your statement. Cheers.

Originally Posted by Moo

BMW probably won't allow official 0-62 times to be faster than current M5 or M6 on official written BMW specs from marketing

[swamp2]

Thank you to jamarino21 and eMvy, background is an essential element in appreciating certain contributions.

[smashhell]

Think all you guys are forgetting one big competitor. The C63 AMG.

The current one already has 481HP and 443lb torque. It will do 0-60 in 3.7 and 1/4 mile in 12.1 at 120mph.

I will be truly disappointed if the new M3 won't break 500HP. It's competition the next C63, next RS4/5, and many many other cars will put the M3 in the dust if this happens.

http://www.caranddriver.com/reviews/2012-mercedes-benz-c63-amg-coupe-instrumented-test

[swamp2]

Originally Posted by ASAP

So it will go from a reported 12.7@113 to over 120?

The new m5 does 12.0@119... my FBO on E85 335i barely traps 120 and you are saying this new m3 will do it no problem? My car dyno'd 430 whp which is almost 500 crank hp if you count a 15% auto drivetrain loss, then how do you figure a 430-450 crank HP car will do this? Even with a 100lb advantage this will be impossible... the only current sub 100K cars that can do this are the C6 Z06, Mustang gt500, Nissan GTR and Viper...

You need to recalculate your numbers asap man... lol

No 430 will not, 450 should, WITH THE WEIGHT I HAVE ASSUMED. Not sure where the 430 number is coming from here...

I think you have missed the contributions and large amount of effective hp that M-DCT is good for. There are many threads on this topic but M-DCT may be good for at least 20 perhaps in some cases and some metrics good for close to 50 hp.

Also have a look at my prior comments about ranges and statistics. Single figures do not make good comparisons.

Every component on each generation of car evolves, chassis stiffness, suspension, suspension hook up ability, parasitic drive train losses (these evolve slowly...), tires, etc. Again for the nth time, consider these numbers a range to cover the best reported times.

[swamp2]

Originally Posted by Zebra99

And btw, it's his educated guess based on vague information currently available. Can almost call it an opinion really.

Lets see your mathematical justification....

Both excellent points. Like I've said many times before and also in the OP, garbage in, garbage out. The inputs here are not unreasonable but are absolutely ASSUMPTIONS at this point.

[swamp2]

Originally Posted by smashhell

Think all you guys are forgetting one big competitor. The C63 AMG.

The current one already has 481HP and 443lb torque. It will do 0-60 in 3.7 and 1/4 mile in 12.1 at 120mph.

I will be truly disappointed if the new M3 won't break 500HP. It's competition the next C63, next RS4/5, and many many other cars will put the M3 in the dust if this happens.

http://www.caranddriver.com/reviews/...trumented-test

Well prepare for a guaranteed disappointment. The car just will not have 500 hp.

Despite the AMGs rapid improvements in the handling department and on track performance the M has most often bested competitors on a road course but not always at the drag strip. Probably not much different this time around...

[ASAP]

Originally Posted by swamp2

No 430 will not, 450 should, WITH THE WEIGHT I HAVE ASSUMED. Not sure where the 430 number is coming from here...

I think you have missed the contributions and large amount of effective hp that M-DCT is good for. There are many threads on this topic but M-DCT may be good for at least 20 perhaps in some cases and some metrics good for close to 50 hp.

Also have a look at my prior comments about ranges and statistics. Single figures do not make good comparisons.

Every component on each generation of car evolves, chassis stiffness, suspension, suspension hook up ability, parasitic drive train losses (these evolve slowly...), tires, etc. Again for the nth time, consider these numbers a range to cover the best reported times.

450 crank translates to 382 WHP assuming a 15% drivetrain loss but since BMW underrattes their cars I will give u 395 WHP... at 3450 LBS, that will not run 120, sorry... That DCT would have to be magic. For reference, my friend dynod 425 in a DCT 335is and hit 120.4 barely... This was with very lightweight wheels too on one of the fastest tracks in the country...

[smashhell]

Originally Posted by ASAP

450 crank translates to 382 WHP assuming a 15% drivetrain loss but since BMW underrattes their cars I will give u 395 WHP... at 3450 LBS, that will not run 120, sorry... That DCT would have to be magic. For reference, my friend dynod 425 in a DCT 335is and hit 120.4 barely... This was with very lightweight wheels too on one of the fastest tracks in the country...

See above:

The C63 AMG with performance pkg will break 120 mph in 1/4 mile. It's $70k.

The Vette C06 also does 11.8 at 120. It starts at $76k.

The GT500 does it in 11.5 at 126mph. It starts at $60k.

I'm pretty sure the next base Vette with 460HP, 450lb torque, weights 3300lbs will break 120mph as well. And that starts at $50k.

Add those to your sub 100k cars that does 120.

Point is as much I love BMW, they are pretty behind in the HP game.

[swamp2]

Originally Posted by ASAP

450 crank translates to 382 WHP assuming a 15% drivetrain loss but since BMW underrattes their cars I will give u 395 WHP... at 3450 LBS, that will not run 120, sorry... That DCT would have to be magic. For reference, my friend dynod 425 in a DCT 335is and hit 120.4 barely... This was with very lightweight wheels too on one of the fastest tracks in the country...

I believe that current E92 M3s are not overrated and are running about 11-12% loss. One very solid source of truly accurate loss information is the Rotortest Research Institute, rri.se, check it out. This is what a real repeatable dyno capable of absolute predictions looks like... I trust other Mustangs and Dynojets and the like about as far as I can throw them...

Let's get to the main point here though with another approach. Your guesses/observations are fundamentally rooted in a cars power to weight ratio, correct? Have a look at the "state of the art" in predictions of trap speeds based on power to weight alone. Generally speaking it is much less accurate than a physics based simulation approach used in my OP but it still offers some definite insights and you might relate to it better. LRT best fit regression. Now if you are better at curve fitting large, complex data sets, IN YOUR HEAD, than this formula, feel free to let me know. However, I doubt it. Humans tend to get pretty good at such curve fitting and extrapolation but you CANNOT ON AVERAGE beat the formula. That basically the definition of the curve fit formula...

For a 440 crank hp E92 M3 (give me 25 hp on top of 414 for DCT, that is a minimal number) with a weight with driver of 3700 lb. The formula above predicts an trap speed of 113 mph. Not bad for a quick first pass formula, eh!? The best time for a stock E92 M3 in the database I referred to earlier is about 115 mph. Let's say the formula is under predicting by 2 mph (you could also figure out if that a higher power figure is better, which in this case might indicate some underrating). For the sake of simplicity I'll stick with this approach. The formula certainly can not predict each and every car perfectly, with this simple model so many variables are not accounted for. However, it captures the simplest dominant effect of power to weight ratio.

Next for the M4 lets use 475 hp (450 actual + 25 for DCT benefits), with a weight with driver of 3600 we get 117 mph from the formula. You might personally have a gut feel that this number is "just about right". However, giving the same +2 mph of difference between observation and predictions for the current E92 M3 we then arrive at 119 mph. Hmmm....

Maybe 120 mph really isn't too unreasonable.

Maybe we'll also never see 123 out in the real world. As a small aside though I have noticed that trap speeds from CarTest are not its strongest prediction capability. I've received some valid criticism of my prior work on the forum where trap speeds are a bit under predicted compared to the best achieved results from real tests. Note that 113 mph and change from CarTest for the current E92 M3 whereas 115 is a better best figure! It is all coming together for you?

I do hope there is some of this getting through to you, it's actually some really good stuff in my humble opinion.

[Peahi]

Thanks for the hard work! Putting numbers up always adds to the quality of the discussion.

[Holset]

Nice analysis swamp2.

Regarding about shifting at redline or lower to get as much acceleration as possible ,some of you guys must understand that even if the engine does not produce peak power at redline it can still be better to shift at this point.
Because when you shift up obviously the rpms will drop and your power output may be higher in this point as oppose to shifting at lower rpm where peak power is but land on lower power in the next gear.

The goal is to use as much average power as possible to the ground not just shift at peak engine power.

If its best to shift at redline or lower depends on the engines power delivery and on how the gearing is set up it may be diffrent for certain gears as clearly swamp2 understand.

[flinchy]

You got at least one key thing wrong

F10 m5 not shifting at redline?

You dont shift at peak tq you shift at the point where tq effective (counting final drive and gear ratio) is higher in higher gear

M5 you ALWAYS shift at redline

[flinchy]

Originally Posted by swamp2

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!

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.

The thing is.. Torque IS power.. Power IS torque

Going by the graph an data you yourself provided.. It WILL be a shift at redline every gear, as it carries more power/torque there than you'll gain with the longer multiplication