0-62 Acceleration times for various E89 models including prediction for remapped N20 engined versions

[Anonymous]

There was a post requesting a prediction on the impact of a remap on the acceleration times.

Also there was a debate of the impact / how a gearbox affected acceleration.

This data is the last/latest published by BMW for the various models from the most recent European Spec E89 brochures.

I've then used the 'real world calculator' that mcbutler found https://www.carspecs.us/calculator/0-60 and used it to both re-calculate the BMW official numbers based on their declared masses and flywheel BHP to cross check them.

Whilst not a perfect fit, the more powerful/heavier the car the closer the fit..to within 0.1 of a second in many cases.

The figures shown are the BMW official numbers except for the 280/295 which are predictions, which lie in the part of the graph with the highest degree of correlation.

The calculator is not based on pure maths but calls on a database of published data which it integrates in some fashion.

Of course its only one figure, it would be great if the manufacturers provided 0-100mph / standing 1/4 etc

A few observations:

1) The shift from 2-3 for many Zs occurs around the 60 mph mark..in general the autoboxes have to shift 3 gears to a manual's 2 in most cases. An extra shift either a manual or slower auto box has a bigger impact.
2) We don't know the methodology used by BMW and whether that's consistent over time. For eaxmple..did they just max out in a lower gear to avoid a time wasting shift if the 0-62 was their only goal.
3) The only standardised data available is the limited 0-60 0-62 figures from BMW, there are many figures from many sources but they don't cover enough models to be used as basis of prediction
4) I've calculated a figure for a 280 and 295 BHP remap as various suppliers claim various outputs.
5) At 50 mph a car only needs about 10bhp to overcome drag, so these figures are mostly driven by mass, bhp, torque, initial launch and time to change gear. Drag and rolliing resistance aren't major factors at this end of the speed range and probably relatively similar.

Version Gearbox BHP Weight 0-62 Date

18i 6 Speed Manual 156 1470 7.9 2016
18i 8 Speed Auto 157 1495 8.1 2016
20i 6 Speed Manual 184 1470 6.9 2016
20i 8 Speed Auto 184 1495 6.9 2016
23i 6 Speed Manual 204 1480 6.6 2010
23i 6 Speed Auto 204 1480 7.3 2010
30i 6 Speed Manual 258 1470 5.8 2010
30i 6 Speed Auto 258 1505 6.1 2010
28i 6 Speed Manual 245 1480 5.7 2016
28i 8 Speed Auto 245 1500 5.5 2016
280 6 Speed Manual 280 1480 5.4
280 8 Speed Auto 280 1500 5.1
295 6 Speed Manual 295 1480 5.2
295 8 Speed Auto 295 1500 4.9
35i 6 Speed Manual 306 1580 5.2 2016
35i 7 Speed DSG 306 1600 5.1 2016
35is 7 Speed DSG 340 1600 4.8 2016

I'm sure there will be plenty of analysis..

 

[Smartbear]

Good correlating Pete
Rob

 

[enuff_zed]

Regardless of whatever nitpicking comes along, plus the actual real-world importance of such figures, I think you should be thanked for taking the time and effort to produce all this.
I appreciate it.

 

[r4row]

Good effort well done

 

[Zed Baron]

Thats interesting

 

[kinger]

Well done, good job

 

[Beeacon]

This is a really good estimate, though it might be worth putting in the remapped 35i and 35iS figures of 370-380hp if that can be found, as a lot of people have theirs Stage1+ mapped (Stage 0=35i 306hp, Stage 1= 35iS 340hp, Stage 1+= ~370-380hp).

 

[Anonymous]

This is a really good estimate, though it might be worth putting in the remapped 35i and 35iS figures of 370-380hp if that can be found, as a lot of people have theirs Stage1+ mapped (Stage 0=35i 306hp, Stage 1= 35iS 340hp, Stage 1+= ~370-380hp).

The Bondarmatic based on the same logic predicts as follows: 35i Manual 4.5 sec, 35i DSG 4.3 sec, 35is 4.2 sec..

 

[enzed4]

Excellent - thanks for taking the time to do this

 

[mcbutler]

The calculator was an interesting find, however it could do with a field to enter torque directly as it has more influence on acceleration than BHP.
My stage 1 mapped 35i is 378 BHP and 411 lb/ft and I would bet good money that its somewhere in the 4 sec bracket..

A lot of work put into the post on this, very interesting

 

[Anonymous]

The calculator was an interesting find, however it could do with a field to enter torque directly as it has more influence on acceleration than BHP.
My stage 1 mapped 35i is 378 BHP and 411 lb/ft and I would bet good money that its somewhere in the 4 sec bracket..

A lot of work put into the post on this, very interesting

Sadly it’s not that simple, it’s a complex series of calculations that needs the gearbox ratios, the final drive ratio, wheel sizes and a series of decisions about shift points plus to drag up the past a time prediction for how long each gearshift will take plus a complex launch prediction..

The generalisations are...when comparing any two cars

The flatter and broader the torque curve the better or if not flat, a highly optimised set of gear ratios to allow up shifts to drop back onto the rising curve before the torque peak..

The faster the gear change the better

I did look at it but it’s too complex for me...given that the engines , gearboxes, final drives are broadly similar the first order approximation was close enough for me..

 

[Nictrix]

What makes the 28i auto faster than the manual when the rest of the models the manual is faster than the auto?
Other than the 35 models.

 

[flybobbie]

I might be able to get 6.6 in my 23i, if the gearbox was any good.

 

[mr wilks]

I might be able to get 6.6 in my 23i, if the gearbox was any good.

Revel in your relative lightness

 

[sunnydays]

The calculator was an interesting find, however it could do with a field to enter torque directly as it has more influence on acceleration than BHP.
My stage 1 mapped 35i is 378 BHP and 411 lb/ft and I would bet good money that its somewhere in the 4 sec bracket..

A lot of work put into the post on this, very interesting

You will be in the low 4s. One of my old 35is cars that was running stage 1+ clocked 4.1s. Your 35i will be putting out similar power I would imagine

 

[Tarzan]

The fastest are the red ones :driving:

 

[Anonymous]

What makes the 28i auto faster than the manual when the rest of the models the manual is faster than the auto?
Other than the 35 models.

The E89s with the 6HP has a shift time around 700-800ms per gear..the initial launch management was less sophisticated and lock up was achieved at higher rpm ..the net effect was that for the 6HP equipped cars the auto was always slower than the manual..the mechatronics were an earlier design

On the other hand the 8HP benefited from two extra gears so a closer set of ratios allied to a 200ms or less shift speed plus much better launch control and torque converter lock up with a more sophisticated ECU management during the shift , ie keeping the engine on the boil..

So the 8HP progressively shows a progressive advantage the greater the power output being controlled..it breaks even on the 20i gets ahead with the 28i and would show a little more with a remap..

As speed climbs that advantage is lost in the gross overall time..

That’s why the ZF 8HP seems to come alive with the remap..it’s shifting through the close ratios faster and more frequently than the 6 speed manual.. There are some other refinements in shift speed ie variable shift time in sports+ mode which I assume was used for the 0-62..

The DSG boxes show the same logic with even faster shift speed

These days you’ll see several people who are reprogramming the ZF8HP for much reduced shift times..

 

[Maybach_man]

The guy who mapped mine altered the gearbox 'map' as well.

 

[Anonymous]

The guy who mapped mine altered the gearbox 'map' as well.

On the 0-62 sprint with one or two changes it may shave off another 100ms or so

 

[Busterboo]

On the 0-62 sprint with one or two changes it may shave off another 100ms or so

That'll make shopping quicker.