[NISFAN]

Seeing as I am on my Christmas break and have a chance to manually input all the engine power, weights, gear ratios, wheel sizes, etc into some software called CARTEST, I've come up with some interesting analysis.

Cars in database (so far):

1. F30 330D
2. F30 330D PPK
3. F30 335D xDrive
4. F30 335i
5. F30 335i xDrive

Note: Unless described differently...all cars M Sport spec, All cars ZF8, all cars sDrive, all cars 19", etc.

Also: Driver weight 90kg's with 20Kg of Fuel (which equates to about 28l of petrol or 24l Diesel), Dry tarmac, optimised Launch.

Here are a few 'virtual' acceleration plots.

The software can also plot usability in a certain gear, lap times for well known tracks, roll ons from x speed, etc. Just ask if you want me to do comparisons.

Attachment 954756

[teaston]

So it's saying the 330d is quicker than the 335d at anything over 1/2km? Surely that's not right?!

[derekh929]

Would the weight of AWD make that big a difference I can understand the better traction for initial few hundred metre , but looking at it in that example it would be 330d standard all the way

[Chrisnic]

The question is, what power outputs have been used in the calculations - BMW's or what they have measured on rolling roads? Ignoring xDrive for a moment I can't see an sDrive 335i which is both lighter and more powerful being such a small amount faster at getting to 1000m.

The results differ from what BMW quotes to 1000m as well.

330d 25.8 sec
E92 335i 24.4 sec

[NISFAN]

Originally Posted by teaston

So it's saying the 330d is quicker than the 335d at anything over 1/2km? Surely that's not right?!

I'm not sure why the 335d seems to struggle, perhaps the software is unkind in regards transmission losses for AWD. I will dig deeper into the set up files to see if I can spot anything obvious.

One thing to note though, this software (the way I have configured it) assumes optimum everything. So wheelspin control, gear change RPM's etc.

The xDrive cars also have a Launch control set at 3,500rpm, vs 2000rpm on the sDrives.

[NISFAN]

Originally Posted by derekh929

Would the weight of AWD make that big a difference I can understand the better traction for initial few hundred metre , but looking at it in that example it would be 330d standard all the way

The 335d is 90kg's heavier than a 330d sDrive. That is significant. Over 100kg's heavier than a 335i.

[NISFAN]

Originally Posted by Chrisnic

The question is, what power outputs have been used in the calculations - BMW's or what they have measured on rolling roads? Ignoring xDrive for a moment I can't see an sDrive 335i which is both lighter and more powerful being such a small amount faster at getting to 1000m.

The results differ from what BMW quotes to 1000m as well.

330d 25.8 sec
E92 335i 24.4 sec

I have used the dyno plots for Guy's (gtsussex) 335d and same for my 330d and 330d PPK (all same dyno, albeit Guy ran in AWD mode).

335i figures are from a different dyno done in the US, but I have seen similar results in the UK for 35i engined cars.

Car weights from BMW.

Note that the real output of a standard 330d is less than 30hp lower than a 335d. I need to check, but the torque band might be slightly better too. It is the amount of power under the curve for a set gear that determines performance.

Observation: The 335d uses similar ratios to the 330d, which might not be optimised for the engine output. Optimum gear change speeds for the 335d are around 4,500 in each gear. Quite a bit lower for the 330d.

[NISFAN]

Individual acceleration data for 335d and 330d shown below. I think it is showing the 330d as being a little faster than it is. Only perhaps 0.15 sec to 100km/h (62mph).

At the same token, it might be a little unfair to the 335d by a few tenths to 62mph.

Note that these are full launch runs. A 'mash the pedal' start won't produce the times, but imagine the 330d RWD will suffer less from wheelspin.

[Apl440i or 335d?]

Is there nothing on telly?

[PrinceBarin]

Great work NISFAN

When I get some downtime over Christmas I'll take a closer look. Meanwhile, how does this compare with the analysis on this site?: http://www.automobile-catalog.com

[matk]

Good stuff Nisfan, I know my 330 s drive is rapid anyway, the first solo spirited drive for a while today and come back with a massive smile on my face. Cannot wait to PPK it, I really think its going to set it off!

[NISFAN]

OK, I found the glitch that was affecting the xDrives. Basically....the software doubles up driveshaft and diff losses for AWD's. Whilst technically correct, the data I input was derived from Wheel horsepower, so it was having a bigger effect than it should have. I have now uploaded the files with modified AWD losses.

The second glitch, affected both 335d and 330d. In joining up the dots on the horsepower graph, the software uses spline averaging. As anyone knows when using spline, it works well for arcing type graphs, not for S shaped graphs that (especially the 335d) both 330d and 335d had. It had given the 330d a bulge above it's actual power, which was making the 330d a little faster than it should have. I have smoothed the curve to give a more realistic figure for both engines.

[NISFAN]

Prefer lap times to drag times?

[gatsojon]

Very interesting NISFAN and thanks for posting.

As this is purely theoretical, can you do a 335d s-drive, assuming the 330d s/x weight delta?

[PrinceBarin]

Originally Posted by NISFAN

Prefer lap times to drag times?

Cool. How about around the Top Gear test track?

[NISFAN]

Originally Posted by gatsojon

Very interesting NISFAN and thanks for posting.

As this is purely theoretical, can you do a 335d s-drive, assuming the 330d s/x weight delta?

Good idea

I've kept the additional 20kg's weight of the 35d engine (extra turbo and oil cooler ???) but taken off 70kg's of AWD gear.

Perhaps a clue as to why there is NO 335d sDrive

[NISFAN]

Originally Posted by PrinceBarin

Cool. How about around the Top Gear test track?

No TG test track unfortunately Although I would imagine the xDrive would gain back some of the weight disadvantage in the standing start.

[Apl440i or 335d?]

How much more does the x-drive weigh?

Parkers says its only 20kg heavier? I can't believe that!

How can the 330d ppk be faster than the theoretical 335d s drive?

[NISFAN]

Originally Posted by Apl335d

How much more does the x-drive weigh?

Parkers says its only 20kg heavier? I can't believe that!

How can the 330d ppk be faster than the theoretical 335d s drive?

Weight is from the BMW site (EU weight, which I stripped out to get basic car weight).

335d = 1705kg's
330d = 1615kg's

BMW Technical pages

Believe it or not, the 330d PPK actually has a better power/torque shape than the 335d. The 9hp extra that the 335d gives occurs at a much higher revs where engine torque is lower. It is also hamstrung by using the same diff ratios as the 330d.

These graphs can be seen here.335d dyno run

[Apl440i or 335d?]

Originally Posted by NISFAN

Weight is from the BMW site (EU weight, which I stripped out to get basic car weight).

335d = 1705kg's
330d = 1615kg's

BMW Technical pages

Believe it or not, the 330d PPK actually has a better power/torque shape than the 335d. The 9hp extra that the 335d gives occurs at a much higher revs where engine torque is lower. It is also hamstrung by using the same diff ratios as the 330d.

These graphs can be seen here.335d dyno run

Thanks, not seen that thread before

[Irnbrukid]

Originally Posted by NISFAN

Weight is from the BMW site (EU weight, which I stripped out to get basic car weight).

335d = 1705kg's
330d = 1615kg's

BMW Technical pages

Believe it or not, the 330d PPK actually has a better power/torque shape than the 335d. The 9hp extra that the 335d gives occurs at a much higher revs where engine torque is lower. It is also hamstrung by using the same diff ratios as the 330d.

These graphs can be seen here.335d dyno run

Is the theoretical 335d Sdrive not 1635kg?

So the graphs are really just a theoretical times for your car standard and PPK'd & GTsussex's car, and some graphs from a 335i.

Why don't you put all the BMW published figures in, to see the times? As we know not all cars produce the same power as published.. some better some worse.

I know from the times I've seen the 335d posts the same 0-1000m time as the M135i (23.8), and it's definitely faster than the 330d. I think that's a better measure since it's over a better distance.. 0-60 times are not a great measure

[NISFAN]

Originally Posted by Irnbrukid

Is the theoretical 335d Sdrive not 1635kg?

So the graphs are really just a theoretical times for your car standard and PPK'd & GTsussex's car, and some graphs from a 335i.

Why don't you put all the BMW published figures in, to see the times? As we know not all cars produce the same power as published.. some better some worse.

I know from the times I've seen the 335d posts the same 0-1000m time as the M135i (23.8), and it's definitely faster than the 330d. I think that's a better measure since it's over a better distance.. 0-60 times are not a great measure

Yes the theoretical 335d sDrive has a basic weight of 1635kg's (330d 1615 +20kg's)

I used real figures because the BMW figures are nuts. Set by marketing by the looks of it.

Yes 1km is a better yardstick than 60mph, that's why I included it.