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      04-18-2008, 10:46 AM   #45
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Quote:
Originally Posted by ruff View Post
Porsche really deserves kudos for their emphasis on out of the box track readiness. Standard seats are manual adjustment and comfortable with good support. I would pay to have a manual seat option in the M3 over the heavy and less reliable electric chairs. Porsche is now offering carbon fibre buckets from the GT2 on all their cars. Expensive option, yet saves in the neighborhood of 40lbs on the chairs alone.

Porsche brakes are legendary for their fade free attributes. No need to opt for the over the top expensive ceramic option unless you are a track junkie with gobs of money.

The M division simply cut corners on their brakes, likely as an effort to keep costs down. I would of gladly paid more for multi piston/fade free brakes. Is the M division the only performance company to stay the course with single piston stoppers? The 1 series getting fitted with multi piston brakes should tells us something.

It appears BMW has finally ran the numbers and surmised they can make lots of money by offering performance parts. In theory this is exciting but in reality it will be more expensive for us the customers than if they simply offered the options straight from the factory as Porsche does. It will give the stealerships another avenue to bilk the customer with high installation costs and provide more room for intallation error.
Great post...

...wrong thread.
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      04-18-2008, 10:46 AM   #46
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Quote:
Originally Posted by lucid View Post
Wait, how much did that cost you? I need to enter the cost/benefit ratio in my benchmark table.
Lol, my grocery bills have been a little higher than normal since I eat a lot of fish now. Ha. Mercury be damned!
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      04-18-2008, 11:00 AM   #47
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Originally Posted by sayemthree View Post
empty the trucnk floor and tire goo kit
Yes, I noticed this other day. The sucker is heavy. I just weighed it:

The mobility kit: 1096 grams
The foam insert that holds the kit: 275 grams

I also weighed the front licence plate and its OEM holder part that I've been carrying in my trunk: 378 grams

Original post update with these numbers...
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      04-18-2008, 11:48 AM   #48
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Originally Posted by lucid View Post
Where did I mention any of that in my OP? I omitted those intentionally. I have no intention of tearing up the car like that. I am talking within reason considering this is a luxury car, which is obvious in what I posted.



Read my previous post. I would swap the seats only if I thought the swap can be done in reasonable time so that I can put the stock seats back on for whatever reason. Apart from that, if you think about the items I posted, you can see where I'm drawing the line.

Regardless, it would interesting to know how much the rear seats weigh for instance--not that I would remove them.

I would rather spend the money to lose 150lbs than gain 40hp on this car, but that ultimately depends on the cost of each. Have you driven it?
Sorry, I didn't mean to piss you off. I was trying to understand what you liked but I guess your original post explained it all.

I've driven the car and I'm interested in it because I want a luxury sedan with world class performance. It could be lighter but that would sacrifice some of the characteristics I paid 70K for. If I tried to make it a little lighter with after market parts it would sacrifice a lot more of the characteristics I paid for with very little weight gain (150 lbs, seriously). After market fit and finish is never close to factory for obvious reasons. If I was looking for a lightweight car I wouldn't buy an M3 (it's too big!) I'd look for a Lotus or an Ariel or I'd buy a frame from Factory Five and build my own. You will wind up with a car that looks like an M3 but will have the fit and finish and interior quality of a Subaru WRX STI but weigh a couple hundred pounds more. This car is brand new, are you really going to trust the very limited opinions you get on fit, finish and quality of after market body parts? I hope you loose the weight and retain the quality. The car is heavy because of it's size (you aren't addressing that) and it's quality. Carbon fiber body panels are lightweight but after market ones will not fit as good.

Best of Luck. I'll leave you alone.
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      04-18-2008, 11:53 AM   #49
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Quote:
Originally Posted by lucid View Post
Fortunately, I don't have that "problem".
Ok well for those of us that do, maybe you should add "Divorce" to your OP.

(kidding of course - love my wife very much! )
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      04-18-2008, 11:55 AM   #50
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Quote:
Originally Posted by jm1234 View Post
I've driven the car and I'm interested in it because I want a luxury sedan with world class performance. It could be lighter but that would sacrifice some of the characteristics I paid 70K for. If I tried to make it a little lighter with after market parts it would sacrifice a lot more of the characteristics I paid for with very little weight gain (150 lbs, seriously). After market fit and finish is never close to factory for obvious reasons. If I was looking for a lightweight car I wouldn't buy an M3 (it's too big!) I'd look for a Lotus or an Ariel or I'd buy a frame from Factory Five and build my own. You will wind up with a car that looks like an M3 but will have the fit and finish and interior quality of a Subaru WRX STI but weigh a couple hundred pounds more. This car is brand new, are you really going to trust the very limited opinions you get on fit, finish and quality of after market body parts? I hope you loose the weight and retain the quality. The car is heavy because of it's size (you aren't addressing that) and it's quality. Carbon fiber body panels are lightweight but after market ones will not fit as good.

Best of Luck. I'll leave you alone.
Having been down this road, I agree completly.
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      04-18-2008, 12:01 PM   #51
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I'm not so sure. I have not done any weighing of brake components but consider these facts.

-The OEM brake caliper is aluminum.
-The OEM rotors are composite and floating with aluminum hats for less thermal stress and less weight.
-Rotating mass is bad indeed but having sufficient mass in your braking system is crucial for not cooking things.
-BBKs are just that BIG. This means larger and potentially heavier calipers and larger diameter and again potentially (likely) more rotor mass.

I am quite keen to hear about an apples to apples weight comparison of the OEM brakes vs. Brembo.

Then go for Mov'it ceramic... far superior to anything else...
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      04-18-2008, 12:05 PM   #52
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Quote:
Originally Posted by OC kid View Post
A cursory check has shown the opposite, the stocks are already pretty light. As lucid mentioned, I would expect only ~10-15 lbs. with all four swapped out.

If you go to 18s the tires will be lighter as well, I believe. And you would be reducing unsprung weight . . .
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      04-18-2008, 12:11 PM   #53
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Quote:
Originally Posted by jm1234 View Post
I've driven the car and I'm interested in it because I want a luxury sedan with world class performance. It could be lighter but that would sacrifice some of the characteristics I paid 70K for. If I tried to make it a little lighter with after market parts it would sacrifice a lot more of the characteristics I paid for with very little weight gain (150 lbs, seriously). After market fit and finish is never close to factory for obvious reasons. If I was looking for a lightweight car I wouldn't buy an M3 (it's too big!) I'd look for a Lotus or an Ariel or I'd buy a frame from Factory Five and build my own. You will wind up with a car that looks like an M3 but will have the fit and finish and interior quality of a Subaru WRX STI but weigh a couple hundred pounds more. This car is brand new, are you really going to trust the very limited opinions you get on fit, finish and quality of after market body parts? I hope you loose the weight and retain the quality. The car is heavy because of it's size (you aren't addressing that) and it's quality. Carbon fiber body panels are lightweight but after market ones will not fit as good.
You have a point about fit&finish, but it is overemphasized. If you are selective, you won't have trouble finding quality parts. You can definitely get aftermarket wheels that are on par, if not better, with stock wheels in quality. Check out the CF bootlid VS has out. Looks and fits great. I most likely will leave the seats alone, so the interior will be untouched. The seats are the only mod on that list that would change the characteristic of the car really.

Some stock parts weigh what they weigh because of cost considerations. BMW is trying to keep the MSRP low. For instance, the GrouppeM titanium exhaust system looks great, and I am sure it would work well as well. Couldn't BMW ship the car out with titanium exhaust? Of course, but would most people want to pay for it? No.

Obviously, the car is heavy because it is big. That is the main cause. Fine, but so what? The option is not to buy a Lotus because I don't want to be driving in a Lotus around on the streets. I want this car to weigh as much as a E46 M3, and there is no such car out there with an engine comparable to the E92 M3 engine. Dropping this engine into a E46 M3 would be great, but that ain't gonna happen. Not worth it. So, exploring the bolt on/off weight reduction approach makes sense to me personally, but it all depends on cost in the end, which is I posted this thread and asked the questions I asked...
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      04-18-2008, 12:13 PM   #54
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Quote:
Originally Posted by MVF4Rrider View Post
Then go for Mov'it ceramic... far superior to anything else...
Way too little ratio of performance per dollar. What you get from ceramics in order are:

longevity (great benefit)
weight (good benefit)
fade resistance (small benefit)
brake power (little to no benefit)
cost (outrageously high)
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      04-19-2008, 11:51 AM   #55
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Ok well for those of us that do, maybe you should add "Divorce" to your OP.

(kidding of course - love my wife very much! )
Well, that would blow the cost all to hell. Of course, it would reduce the weight to zero since you'll be losing the car to the ex.
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      04-19-2008, 11:55 AM   #56
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Stock wheels are forged, right? So to get lighter and just as strong wheels, would be big bucks. It's worth it for some, especially if you're going for looks. But for saving weight, plus the fact that it is unsprung weight and affects rotational mass, a few pounds would make a difference. I just don't know what is out there yet in E9x M3 fitment, looks, strength and weight.
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      04-19-2008, 11:58 AM   #57
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If you go to 18s the tires will be lighter as well, I believe. And you would be reducing unsprung weight . . .
Why would tires be lighter? To keep the same rolling diameter the tires need to be bigger, i.e. higher sidewalls. This makes the tire heavier. What is wanted is lighter wheel and tire combo. Smaller wheel, heavier tire and vice versa. Going to smaller wheels does not automatically make the combo lighter.
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      04-19-2008, 01:40 PM   #58
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Originally Posted by ersin View Post
Why would tires be lighter? To keep the same rolling diameter the tires need to be bigger, i.e. higher sidewalls. This makes the tire heavier. What is wanted is lighter wheel and tire combo. Smaller wheel, heavier tire and vice versa. Going to smaller wheels does not automatically make the combo lighter.
Very true. The 18 inch tires are in fact 1-2 lbs heavier than the 19s. It makes me think that perhaps the difference between the cast 18s and forged 19s might indeed be a wash.
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      04-19-2008, 03:15 PM   #59
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I can't find it now but somebody posted weights of wheels and tires. I'll keep searching for it.
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      04-19-2008, 04:21 PM   #60
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I can't find it now but somebody posted weights of wheels and tires. I'll keep searching for it.
The stock 19" wheel weights are in the first post. 23/26.5 lbs F/R.

Tirerack says 24/25 lbs F/R for the stock tires.
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      04-19-2008, 04:29 PM   #61
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Quote:
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The stock 19" wheel weights are in the first post. 23/26.5 lbs F/R.

Tirerack says 24/25 lbs F/R for the stock tires.
Are those 19" tires? Then what are the same weights for the 18s? It would be nice to know. I'm betting there is not too much difference. I still can't find that post but IIRC they had both weights in there.
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      04-19-2008, 04:45 PM   #62
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Are those 19" tires? Then what are the same weights for the 18s? It would be nice to know. I'm betting there is not too much difference. I still can't find that post but IIRC they had both weights in there.
From tirerack:

18" BMW spec PS2s: 24/27 lbs
19" BMW spec PS2s: 24/25 lbs

http://www.tirerack.com/tires/Spec.j...D64YR8SPORTPS2
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      04-19-2008, 05:18 PM   #63
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From tirerack:

18" BMW spec PS2s: 24/27 lbs
19" BMW spec PS2s: 24/25 lbs

http://www.tirerack.com/tires/Spec.j...D64YR8SPORTPS2
Cool. From this thread, wheel weights are

18" 23.2/24.9, say 23/25
19" 23.6/26.1, say 24/26

So, all up weights with PS2 are:

18": 47/52
19": 48/51

Yep. Pretty close. So, let's say for all practical purposes there is no weight savings whether you get BMW 18s or 19s. After-market wheels/tires would have to beat this to realize a weight savings. Pretty hard to do without spending big bucks (i.e. high quality forged wheels).


Cheers.
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      04-19-2008, 05:23 PM   #64
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Quote:
Originally Posted by ersin View Post
Cool. From this thread, wheel weights are

18" 23.2/24.9, say 23/25
19" 23.6/26.1, say 24/26

So, all up weights with PS2 are:

18": 47/52
19": 48/51

Yep. Pretty close. So, let's say for all practical purposes there is no weight savings whether you get BMW 18s or 19s. After-market wheels/tires would have to beat this to realize a weight savings. Pretty hard to do without spending big bucks (i.e. high quality forged wheels).


Cheers.
I am confused. On that thread, GregW reported that he weighed his 19" wheels + tires at:

47/51.5 lbs

and used the tirerack tire specs to deduce:

23/26.5 lbs for the wheels

Is that what you are referencing?

The example I used in the OP, Morr mono-forged VS8 wheels, are supposed to be pretty solid (in quality and strength). And they are supposed to weigh ~ 20/23 lbs and cost ~$2500. Would save about 13 lbs total.

Also, does anyone have weight data on the driveshaft? (I am assuming there is very little weight or rotational inertia reduction to be had there with a quality CF shaft).
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      04-19-2008, 05:41 PM   #65
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Quote:
Originally Posted by lucid View Post
I am confused. On that thread, GregW reported that he weighed his 19" wheels + tires at:

47/51.5 lbs

and used the tirerack tire specs to deduce:

23/26.5 lbs for the wheels

Is that what you are referencing?

The example I used in the OP, Morr mono-forged VS8 wheels, are supposed to be pretty solid (in quality and strength). And they are supposed to weigh ~ 20/23 lbs and cost ~$2500. Would save about 13 lbs total.

Also, does anyone have weight data on the driveshaft? (I am assuming there is very little weight or rotational inertia reduction to be had there with a quality CF shaft).
Sorry, that was Greg W's original post. See post #74 here.

Drive shaft? Are you serious? Is that not a major undertaking? I didn't think anyone made these anyway. But not a bad idea. Not only would you be getting lighter mass, but also lighter rotating mass -- should increase throttle response.
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      04-19-2008, 05:46 PM   #66
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Drive shaft? Are you serious? Is that not a major undertaking? I didn't think anyone made these anyway. But not a bad idea. Not only would you be getting lighter mass, but also lighter rotating mass -- should increase throttle response.
I am just curious, not serious!

No way am I going to replace the driveshaft of a car that is under warranty.

I thought there were some CF options available for the E46 M3 though?
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