hythe

I'm getting horrible flashbacks of Kenneth Williams in one of the "Carry on" movies...

big_ipaq

No, this is not it. All components are the same, there is no more aluminium in 530i than in 550i except in the engine and transmission. So must be something different.

I am curious how much more weights 5.0l V8 compared with 3.0l L6. The best compromise IMHO, if no other way, would be to add some dead weight in the back of the heavier models to compensate, but I am not sure this is needed. So the engineers surely found a way to compensate for the heavier V8.

Has anyone weighted his E60 on both ends?

dlevi67

Well, the official difference 530i -500i is 160 kg (150 with auto). Part of this is additional equipment (seats!) which sits in the middle of the car anyway. Part of this (larger transmission shaft, differential) sits at the back, and as I said I suspect V8s are mounted further back in the engine bay than I6s. I think this can relatively easily account for 50-60 kg of the needed 80.

I don't know where they could have added the ballast, TBH - I had an E39 V8, and I can assure you there was no ballast there - nor any place to put it, unless they filled up some of the box sections in the chassis with cement.

Bring on the scales...

big_ipaq

Actually, as I wrote above, 170 kg. Surely, I am talking about European version, no options. I doubt the seats are different in the two versions. Transmission is accountable, but I am sure we're not talking about 80 kg. More than this, gearbox is still in the front of the car.

hythe

It does seem fairly self-evident that a V8 is shorter than an I6, so sits further back in the engine bay. I wonder if BMW go to more effort around items like the radiator, which sit right in the nose - could save a few lbs there with more exotic materials for the more expensive models.

My Alpina probably has horrible weight distribution with that big supercharger and intercooler sitting in the nose. Mind you, as a Touring, that helps - still leaves it with a very high polar moment of inertia...

big_ipaq

Why is it obvious that a V8 is shorter than an I6? The V organization means you have 8 cylinders but not head-to-head, right? Is the offset of each cylinder pair close to zero, or more close to a full cylinder diameter?

This can be part of the explanation, but I guess because of the heavier european diesels I6 engines (525d, 530d, 535d), there must be something else...

dlevi67

Offset is practically zero. So, length of engine is equivalent to 4 cyl or little more.

See here for diagram

I'm starting to think that we are making unnecessary complications here. I've actually taken a look at CarFolio, and came up with the following:

525i (2005 MY): 1550 kg, 49.8% front = 772 kg front axle weight, 778 rear
535d (2005 MY): 1735 kg, 52.5% front = 911 kg front axle weight, 824 rear

difference = 139 kg front, 46 kg rear. I think 46 kg is within the realm of possibility for a heavier diff/transmission/brakes/suspension, slight differences in engine mounting position, battery size and position etc.

hythe

Sounds about right...

On big-ipaq's question, I believe it depends (generically) on the angle of the vee - hence, the VW VR6 engine isn't particularly short, as it's almost an I6 - whereas a 90 degree V8 will have zero offset.

VTbound

Almost zero, it can't be zero. THe minimum offset is the thickness of the journal bearing on the crankshaft.

See here:
http://www.realoem.com/bmw/partgrp.do?mode...hg=11&fg=20

hythe

Fair point.