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      03-27-2019, 07:56 PM   #56
MachinesWithSouls
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Drives: 2022 M3 6MT
Join Date: Apr 2015
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2022 BMW M3  [10.00]
Quote:
Originally Posted by Max Well View Post
Quote:
Originally Posted by SoManyBlueCars View Post
I'm sorry, I don't mean to make fun here at all. But I see everyone going bananas here for the moonroof delete option. Wut?
You're in an SUV. You don't notice it in an M3 if it has a moonroof, and you're sure as hell not going to notice it in these things. These are great trucks that handle well for what they are, but I can't imagine anyone tracking this, so really, get the roof folks.
Yeah... so, where to start...

You begin by making a disclaimer about not wishing 'to make fun here at all.' OK, we're listening. Then you proceed with comments, "in these things", and "these are great trucks"... And then topping it off with the usual and mundane, "I can't imagine anyone tracking this, so really, get the roof folks."

Probably not the ideal way to be taken seriously on the X3M/X4M Forum which is frequented by those interested in BMW's Performance Engineering, and how best to maximize such in the vehicles we drive, track or no track. Many of which are M2, M3, M4, and M5 Drivers.

Some estimated numbers:

Your M3: HP 425, roof width 42", roof length 60", roof surface area 2520 sq in, wt Al Roof 21.3 lbs, CFRP roof wt 8.7 lbs, ht 56.1", est CG 20.8", vehicle ht above CG 35.3", AL roof moment 62.5 ft-lbs, curb wt 3630, SSF 1.505, wt moon roof ~27.1 lbs, moon-roof moment 132.7 ft-lbs, Wt (lbs)/HP 8.5. (Rough numbers)

The X3M Comp: HP 503, roof width 44", roof length 80", roof surface area 3520 sq in, wt Al Roof 29.7 lbs, CFRP wt 12.1 lbs, ht 65.7", est CG 24.4", vehicle ht above CG 41.3", AL roof moment 102.3 ft-lbs, curb wt 4620, SSF 1.351, wt moon roof ~126.6 lbs, moon-roof moment 485.9 ft-lbs, Wt (lbs)/HP 9.2. (Rough numbers)

Not sure these numbers mean much to you, but they tell a very different story about the actual Physics involved, and how replacing the X3M's moon roof with even OEM Al makes a far greater composite difference to the handling and dynamics of the X3M Comp as it would to the smaller-roof'd, lower and wider slung M3 - quite counter to your generalizations. You can try to make the argument 'are you going to track it, if not then you won't notice a difference', but you do realize how hollow that sounds on a Forum filled with BMW Enthusiasts?
You know, they just did a test on the grand tour, with the Aston, Bentley and M850, against some ancient Renault that barely ran. The concept was simple - in real world conditions, those amazing cars were no faster that the old Renault because of traffic and pedestrians and lights, etc.

I mention that because no one ever NEEDS the speed. We want the speed. But how much speed do we need?

On a track, if you're a good driver, you may notice the weight difference slightly, and it MIGHT gain you a tenth of a second. But then, why buy a car that's so high off the ground, with so much space and a hatch. It seems silly to embrace the practicality of the car, then shun a feature based on weight reduction.

All your fancy calculations mean nothing to me because you're talking about how a car feels at the limit - which is very high in both my M3 and an X3M - and not how a car feels on a road, where these will live 99% of the time. And since a good driver in an X3 can beat a bad driver in an M3, that 50 pound difference just seems even more trivial.

And lastly, if you've driven An X5M on the track (I have at the performance center) you'd know they are absolutely amazing cars. But all the fancy electronics and wide tires cannot hide the fact that you are asking over 2 tones of metal to move around a track. Stepping firmly on the gas causes the nose to point to the sky.

Least you think I limit this criticism to X guys - I make fun of M3 guys too, when they say the car handles "so much better"
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