Curb weight - definitive answer?

[JimD]

The added weight of a convertible is X shaped bracing under the car connecting the front suspension area to the rear suspension area. It is right in the middle, as low as it can be and be attached to the car. This bracing helps to make up for the rigidity loss of removing the top. Even with the bracing, my convertible is more flexible than a coupe would be. It is also a bit heavier, about the weight of a male passenger. Those are not advantages but the ability to lower the top on days like we had yesterday and will have today more than makes up for it (70s yesterday, upper 60s today and sunny).

With respect to handling, I drove a 135i couple when doing performance center delivery and that is my only real experience driving a 1 series coupe hard. I've also ridden in a 1M when it was driven really hard. The coupe is clearly more rigid and I like that rigidity, especially on a track. But with respect to handling, I do not think it makes the coupe corner better or otherwise quicker around a track. The direction of the flex is to make the wheels have better contact with the pavement, not worse. Corvettes are very flexible due to their method of construction but some of them are very fast track cars. Added weight is a disadvantage no matter how you add it but the way it is added in a bimmer convertible minimizes the effect on handling. Stated another way, a good vert driver will make his ride quicker than an average coupe driver around a track. I don't think the difference is really very large. It's easier to mess with the car to try and get quicker but I am confident the biggest thing holding my vert back from quicker times is me.

Jim

[BrokenVert]

Originally Posted by JimD

The added weight of a convertible is X shaped bracing under the car connecting the front suspension area to the rear suspension area. It is right in the middle, as low as it can be and be attached to the car. This bracing helps to make up for the rigidity loss of removing the top. Even with the bracing, my convertible is more flexible than a coupe would be. It is also a bit heavier, about the weight of a male passenger. Those are not advantages but the ability to lower the top on days like we had yesterday and will have today more than makes up for it (70s yesterday, upper 60s today and sunny).

With respect to handling, I drove a 135i couple when doing performance center delivery and that is my only real experience driving a 1 series coupe hard. I've also ridden in a 1M when it was driven really hard. The coupe is clearly more rigid and I like that rigidity, especially on a track. But with respect to handling, I do not think it makes the coupe corner better or otherwise quicker around a track. The direction of the flex is to make the wheels have better contact with the pavement, not worse. Corvettes are very flexible due to their method of construction but some of them are very fast track cars. Added weight is a disadvantage no matter how you add it but the way it is added in a bimmer convertible minimizes the effect on handling. Stated another way, a good vert driver will make his ride quicker than an average coupe driver around a track. I don't think the difference is really very large. It's easier to mess with the car to try and get quicker but I am confident the biggest thing holding my vert back from quicker times is me.

Jim

Thats a pretty good, more in depth, explaination of what I was trying to say earlier. But no matter how much you rationalize people wont get it. I can also verify this as fact. Ive taken 135 coupe owners at autox in my basically stock vert (all I have are wheels, tires, and a swaybar) When their cars had full coilovers, tunes, etc.
It comes down to the driver. But people with only a rudimentary understanding of physics never seem to get that.

And then you can put the top down and feel much better when I drop the top and all I can think to myself is these 250lbs are totally worth it

[chachacha28]

Originally Posted by carchrism5

Please do not comment on handling when you drive a vert. That's an oxymoron.

you are a douche bag.

/discussion

[AW128i]

Let's be honest, BMWs have never been lightweights! Even the E30 cars were around the 3,000 lb. mark from what I recall. From a purely technical standpoint, the real winner in the 1-series/3-series lineup (M cars excluded) is the 128i manual because it's the lightest car with just about perfect weight distribution. In theory, and with all else being equal, that car has the most potential for the best handling. But, we're talking fractions.

As for the coupe vs. convertible thing, the coupe is the lighter and torsionally stiffer car, which gives it an edge in handling, particularly on a less-than-smooth road surface. Again, however, we're talking fractions here. I will say that the convertible suspensions, being softer than their coupe counterparts, do not inspire the same level of handling confidence that their coupe brethren do. That being said, I wouldn't be completely surprised if the modern convertibles are just as stiff or stiffer than coupes and sedans from just a couple generations ago. Regarding the added weight of the convertibles, most of it is concentrated below and behind the rear seats.

[JimD]

If you said the weight is below and behind the seats I would agree with you but it is not behind the rear seats. It's been awhile since I climbed under mine but I am sure it is from the front suspension to the rear. It needs to mimic the lost stiffness from the top which, of course, starts at the top of the windshield in front of the front seats.

Convertibles that are designed as convertibles from the start can be stiff but they need big structures on the side. Look at a miata sometime. Really large tube type structure below the doors. But if you just cut the top off a coupe and add some braces under it, you are probably going to be less stiff.

Jim

[AW128i]

Well, there's certainly a good amount of additional bracing behind the rear seats, hence the non-folding rear seats. In addition, you have the top mechanism and controls there, plus the rollover mechanisms. I'm pretty sure this is the bulk of the reason why the convertibles have a rear weight bias and the coupes have a slight front bias.

[BrokenVert]

Originally Posted by AW128i

Well, there's certainly a good amount of additional bracing behind the rear seats, hence the non-folding rear seats. In addition, you have the top mechanism and controls there, plus the rollover mechanisms. I'm pretty sure this is the bulk of the reason why the convertibles have a rear weight bias and the coupes have a slight front bias.

Youre a bit misinformed, and the info is in this thread.


The top mechanisms are below the rear seats, you pull out the cushion and there they are.

The rear seats dont fold because there is an x brace there to tie the upper and lower sides of the car together. Its just some light steel in reality, not really that heavy.

Admitted the rollover bars are slightly bulky.

[fusion01]

Originally Posted by ezeedee

you are a douche bag.

/discussion

I actually chuckled at his comment, I thought it quite witty and I'm not sure it was too be taken TOO seriously. In my mind, if you're wanting to track your car and that is one of it's primary functions, you will opt for the coupe, not the vert. Of course it's down to driver skill but weight reduction + added rigidity + same driver = better times.

[fusion01]

Originally Posted by fourtailpipes

i could very well be wrong about the placement of the ballast, but there's no getting around the fact that the total delta is more than double the weight of a cute girlfriend.

anyone have a way of getting to the weight of a sunroof versus sunroof delete? that's what i REALLY want to know!!!

I heard sunroof is in the region of 16kg.

[BFD99]

Mine weighed 3530 with me in it, I weigh around 165lbs.

[fusion01]

The coupe's weight really isn't a biggie. Just researched the Golf R (4wd) and that's only about 11kg lighter (1521 kg vs 1532 kg). Add a tune and the car has serious power to weight and in my experience is nimble enough on the track with no complaints! I'm interested in seeing what the new 135i hatch (F20) will weigh and following onto that the 235i next year.

[WhatsADSM]

I know this is a bit of a thread resurrection but thought the information would be nice for the next person who is curious on the real stock weight of these cars (I found this thread while searching for info on the e82).

In any case I just bought my "new to me" 135i. It's a 2011 DCT car with minimal options (not easy to find). The only options are M-sport package and HK audio, literally nothing else besides the standard stuff. On my way home with the car I stopped off at a certified CAT scale and paid to have it weighed. Not perfect but within reason, and I'm sure once I do coilovers and a corner balance I can check back with more exact numbers.

2011, DCT, M-sport package and HK audio only. 2/3rds of a tank of gas:

[Esteban]

Anybody know how much power seats weigh vs manual?

[WhatsADSM]

Originally Posted by Esteban

Anybody know how much power seats weigh vs manual?

It's not a huge difference I thought I read somewhere like 15 pounds. I believe that it for both but again not 100% sure on that so don't quote me. FWIW mine are the manual sport seats.

[m981addicts]

Originally Posted by BrokenVert

ok, but like I said most of the weight is low in the car, below your ass low. It really only hurts acceleration substantially, I think .2 or .3 seconds to 60.

And thats a good one. Havent heard that kind of weight estimate before



its about 50 lbs at the tippy top of the car

One heck of a cute gf with that top!

[Matticus91]

Originally Posted by WhatsADSM

I know this is a bit of a thread resurrection but thought the information would be nice for the next person who is curious on the real stock weight of these cars (I found this thread while searching for info on the e82).

In any case I just bought my "new to me" 135i. It's a 2011 DCT car with minimal options (not easy to find). The only options are M-sport package and HK audio, literally nothing else besides the standard stuff. On my way home with the car I stopped off at a certified CAT scale and paid to have it weighed. Not perfect but within reason, and I'm sure once I do coilovers and a corner balance I can check back with more exact numbers.

2011, DCT, M-sport package and HK audio only. 2/3rds of a tank of gas:

Picture doesn't work

[PDXE82]

I've weighed my 2013 135i DCT with all options/packages but park distance on a local truck scale. Came out to just over 3400lbs. Don't remember how full the gas tank was.

[Captain Blood]

Originally Posted by BrokenVert

Wrong captain.

[WhatsADSM]

Originally Posted by Matticus91

Picture doesn't work

Yea was posted up to photobucket before they started charging $$.

Here is another copy:

[xQx]

Originally Posted by carchrism5

Please do not comment on handling when you drive a vert. That's an oxymoron.

At risk of feeding the trolls, sure, verts handle badly from the factory, but they don't always have to be that way.

Sure, the vert has a weight surcharge but it's only 120kg - or about the same as a weight surcharge of carrying one (average american ) passenger. Get a good diet, run half a tank of feul and ditch the engine cover, cowls and get a CF bonnet and you'll be basically the same weight as the E87.

The good thing for the vert is all that weight is down low. Most of it's bracing below the floor or behind the back seats, and weight of the ragtop sits in the boot (rather than in the coup where it's nice and high above your head) - which means all the extra weight nice and low, and neatly between the four wheels. The 1er coup has about a 52f/48r weight distribution - a manual vert is 50.3f/49.7r.

If you drop some good shocks and nice stiff swaybars into a vert, you should have a car that's got a center of gravity which is lower and further aft than the coupe - ie. a better platform for balanced handling.

[Suprgnat]

Originally Posted by xQx

Sure, the vert has a weight surcharge but it's only 120kg - or about the same as a weight surcharge of carrying one (average american ) passenger.

DAMN! Play nice! I feel the...

[inevitab1e]

Anyone know how much lighter the 135is version weighs? Supposedly has a lighter suspension. Maybe 50lb less than normal 135i?