[BEAR-AvHistory]

The 50/50 is add copy & about as real as the M40i having 382BHP

The BMW Tech Spec document lists 2, 3 & 4 as:

4 Cylinder @ "Weight, unladen, to DIN/EU kg 1420 / 1495 (1430 / 1505)

4 cylinder @ "Weight, unladen, to DIN/EU kg 1430 / 1505"

6 Cylinder @ "Weight, unladen, to DIN/EU kg 1555 / 1630"

US does not get the 2 small 4 cylinder.

All have a rear weight bias which is a good thing.

[TAZ007]

Originally Posted by BEAR-AvHistory

The 50/50 is add copy & about as real as the M40i having 382BHP

The BMW Tech Spec document lists 2, 3 & 4 as:

4 Cylinder @ "Weight, unladen, to DIN/EU kg 1420 / 1495 (1430 / 1505)

4 cylinder @ "Weight, unladen, to DIN/EU kg 1430 / 1505"

6 Cylinder @ "Weight, unladen, to DIN/EU kg 1555 / 1630"

US does not get the 2 small 4 cylinder.

All have a rear weight bias which is a good thing.

Agree, since that is where the rubber meets the road.

[kyrix1st]

Your quoted figures do not seem to suggest weight distribution, but the DIN/EU standardized weights(in kg) for the whole car.

Originally Posted by BEAR-AvHistory

The 50/50 is add copy & about as real as the M40i having 382BHP

The BMW Tech Spec document lists 2, 3 & 4 as:

4 Cylinder @ "Weight, unladen, to DIN/EU kg 1420 / 1495 (1430 / 1505)

4 cylinder @ "Weight, unladen, to DIN/EU kg 1430 / 1505"

6 Cylinder @ "Weight, unladen, to DIN/EU kg 1555 / 1630"

US does not get the 2 small 4 cylinder.

All have a rear weight bias which is a good thing.

[Yamatokh]

Originally Posted by kyrix1st

Your quoted figures do not seem to suggest weight distribution, but the DIN/EU standardized weights(in kg) for the whole car.

I think you are right.

This is what I found in Google:

EU kerb weight is easily calculated from the DIN weight. Quite simply, EU kerb weight is always 75kg more than DIN. The European Union adds this 75kg ballast to account for a driver and a small amount of luggage.

So those are not weight distribution, but rather weights based of different standards.

[BEAR-AvHistory]

Originally Posted by kyrix1st

Your quoted figures do not seem to suggest weight distribution, but the DIN/EU standardized weights(in kg) for the whole car.

My bad. Am surprised the weight distribution is listed in the web site is 50.6 / 49.4.

50/50 is an good number compared to most cars which are very nose heavy but not as good as rear weight bias. Rear bias creates a more agile car but risks oversteer issues.

Expect that distribution goes along with the built in understeer to kept the customers out of trouble in corners.

[DPelletier]

I've also seen the 50.6/49.4 for the M40i or something very similar; close enough to call it 50/50.

The extra weight of the 6 cyl at 105kg is 7% of the cars weight so to make a real negative impact, that weight would need to be centered at or forward of the front spindles.......and it isn't. As Bear AvHistory illustrated, it's quite likely that the extra weight is split between the front and rear with a small bias towards the front but not enough to change the distibution a significant degree.

If you don't want/need the extra power of the M40i, go with the 4 cyl but don't do it for percieved better balance/increased handling prowess or you are likely to be disappointed.

2 cents,
Dave

[Geradeaus]

One of my favorite videos for the sDrive 30i can be used to extrapolate some things about the 40i:

https://www.youtube.com/watch?v=AJIFDlOwJ_s&t=1s

At 9:51 a chart is displayed that shows the 30i with a 50.38 front to 49.62 rear balance.

At 10:16 you can see the huge amount of space in front of the four-cylinder engine. I'm assuming that that space is used to hold the two additional cylinders of the B58. You can also see that that space is in front of the strut towers.

At 10:53 Mark talks about the mid-ship design with the engine behind the strut towers. The B58 adds the two additional cylinders in front of the strut towers in addition to two additional radiators behind the grill.

The weight difference between the two models is about 230lbs or roughly 7% of the total car's weight. And, that weight is mostly ahead of the front axle. I would guess the M40i weight distribution is more along the lines of 57/43 than 50/50.

At 15:00 Mark talks about driving autocross in the M2 and the 30i and the differences between power vs. balance. I found it very interesting that the fastest times were in the 30i. It would be very interesting to see a comparo of the 30i and the 40i on the same course.

[DPelletier]

Originally Posted by Geradeaus

The weight difference between the two models is about 230lbs or roughly 7% of the total car's weight. And, that weight is mostly ahead of the front axle. I would guess the M40i weight distribution is more along the lines of 57/43 than 50/50.

.

Not a chance. Go back to post #9 where the B58 Supra has 52/48 and explain how on earth the Z4 could possibly be that much different?


Dave

[Geradeaus]

Originally Posted by DPelletier

Not a chance. Go back to post #9 where the B58 Supra has 52/48 and explain how on earth the Z4 could possibly be that much different?


Dave

Originally Posted by DPelletier

Not a chance. Go back to post #9 where the B58 Supra has 52/48 and explain how on earth the Z4 could possibly be that much different?
Dave

I guess I'm just bad at math? Adding 7% to the 50 makes no sense as that creates a difference of 14%. I needed to divide the 7% and add 3.5 to the front. How about 53.5 front vs 46.5% rear? Got it to within 1.5% of the Supra.

More cross bracing for the convertible? Only one cylinder in front of the strut tower?

[TAZ007]

Originally Posted by Geradeaus

I guess I'm just bad at math? Adding 7% to the 50 makes no sense as that creates a difference of 14%. I needed to divide the 7% and add 3.5 to the front. How about 53.5 front vs 46.5% rear? Got it to within 1.5% of the Supra.

More cross bracing for the convertible? Only one cylinder in front of the strut tower?

Don't forget the turbo intercooler and the three rats in a ball.