Weight savings cost/benefit benchmarks

MTROIS wrote

Hey Lucid, what is your "form" right now? With the food savings program you might even gain money...that you can then spend on the parts!

I no longer have cycling form of any kind. When you refuse to train on a cold rainy day, you know that you're done with racing, but I have kept my weight in check.

MTROIS wrote

Also, any risk of altering the balance of the car with the various mods??

This must become a consideration if you remove a lot of weight away from the center of mass of the car. It would take a drastic reduction though for you to notice it. Maybe someone who has stripped a car for the track can chime in?

I have the Dixis Titanium exhaust which weighs in at 7.8kg. That includes the H pipe as well.

Working Out:
Cost: $50 a month.
Weight Savings: 10-50 lbs approx
Value: Priceless.

Arsenal wrote

I have the Dixis Titanium exhaust which weighs in at 7.8kg. That includes the H pipe as well.

How much did you pay for it? Did you weigh the stock exhaust & H pipe after you took them out?

Updated OP with weight data on front and rear seats.

Thanks Lucid!

BMW-M-Mexico wrote

Thanks Lucid!

Thanks BMW-M-Mexico for supplying the front seat weights.

Now what would be really cool is a graph that had an the x axis the stage. A stage would be adding the most bang for the buck option in the list that has not yet been "added". The actual x axis value would be the cumulative amout of weight saved. The y axis would be amount required to get to that cumulative stage. What would be cool about this is you could simply pick you desired amount to spend or weight to be saved and find the other value. Ok pretty nerdy... but useful nonetheless! Thanks for maintaining this very useful topic.

nice thread!

swamp2 wrote

Now what would be really cool is a graph that had an the x axis the stage. A stage would be adding the most bang for the buck option in the list that has not yet been "added". The actual x axis value would be the cumulative amout of weight saved. The y axis would be amount required to get to that cumulative stage. What would be cool about this is you could simply pick you desired amount to spend or weight to be saved and find the other value. Ok pretty nerdy... but useful nonetheless! Thanks for maintaining this very useful topic.

+1, that would be nice!

Great tread!!!

This can help when I actually decide to start modding...

swamp2 wrote

Now what would be really cool is a graph that had an the x axis the stage. A stage would be adding the most bang for the buck option in the list that has not yet been "added". The actual x axis value would be the cumulative amout of weight saved. The y axis would be amount required to get to that cumulative stage. What would be cool about this is you could simply pick you desired amount to spend or weight to be saved and find the other value. Ok pretty nerdy... but useful nonetheless! Thanks for maintaining this very useful topic.

I thought about such a represantation, but there is actually a third dimension to it, which is "livability", so it is really a 3D chart. I like your "stage" idea, but this livability dimension makes it somewhat difficult to identify squential stages. In simple terms, the cheapest mod you can do for weight reduction is back seat removal, but it is not practical. However, if we limit your stage idea to modifications that do not take anything away from the stock functionality of the car, then it would work.

lucid wrote

I thought about such a represantation, but there is actually a third dimension to it, which is "livability", so it is really a 3D chart. I like your "stage" idea, but this livability dimension makes it somewhat difficult to identify squential stages. In simple terms, the cheapest mod you can do for weight reduction is back seat removal, but it is not practical. However, if we limit your stage idea to modifications that do not take anything away from the stock functionality of the car, then it would work.

I would take, enjoy appreciate and likely use whatever you chose to put together.

At the end of the day some 20% of M3 drivers may track their cars but 100% of us would if the circumstance arose drag or drag off the lights.

I don't see the sense in doing the large amounts of mods to loose 150lbs, not dollar wise or the fact of spending a month of Sunday's putting it back together so to be able to get warranty work done.

A vast number of M3 owners have changed wheels at a cost of around $3,000 with a saving of around 17lbs and also swapped out exhaust systems for around $2,500 with some 33lbs saving but with gains between 10-15 in HP.

So we all can get a 50lbs weight saving on mods that we all do and not cause problems with warranties, we also get 10-15hp gain. You would be better off putting a PowerChip in next to get another 40hp for $1-2k.

So that's 50lb weight saving, plus a total 50hp gain to do what 100% of us may do and that is drag someone and still have something that resembles a M3, comfortable and 99% oem.

If I was going to do ALL the mods to a M3 I would rather wait for a CSL. A lot of BMW dealers from Australia are in Germany this week and my dealer believes their will be a CSL. He's back in 2 weeks, so I will wait until then before I start destroyng the M3 for that extra 100lbs.

watrob wrote

At the end of the day some 20% of M3 drivers may track their cars but 100% of us would if the circumstance arose drag or drag off the lights.

I don't see the sense in doing the large amounts of mods to loose 150lbs, not dollar wise or the fact of spending a month of Sunday's putting it back together so to be able to get warranty work done.

A vast number of M3 owners have changed wheels at a cost of around $3,000 with a saving of around 17lbs and also swapped out exhaust systems for around $2,500 with some 33lbs saving but with gains between 10-15 in HP.

So we all can get a 50lbs weight saving on mods that we all do and not cause problems with warranties, we also get 10-15hp gain. You would be better off putting a PowerChip in next to get another 40hp for $1-2k.

So that's 50lb weight saving, plus a total 50hp gain to do what 100% of us may do and that is drag someone and still have something that resembles a M3, comfortable and 99% oem.

If I was going to do ALL the mods to a M3 I would rather wait for a CSL. A lot of BMW dealers from Australia are in Germany this week and my dealer believes their will be a CSL. He's back in 2 weeks, so I will wait until then before I start destroyng the M3 for that extra 100lbs.

Modding cars isn't supposed to be logical or make sense. It is a work of passion.

BMW said no CSL, maybe one will come, but in the meantime we have what we have.

lucid wrote

How much did you pay for it? Did you weigh the stock exhaust & H pipe after you took them out?

I paid 5400. I did not weigh the stock exhaust but Dixis website says the stock exhaust weighs at 25kg

Sticky wrote

Modding cars isn't supposed to be logical or make sense. It is a work of passion.

BMW said no CSL, maybe one will come, but in the meantime we have what we have.

+1 Sticky!

Remove the V-8 and cut a hole in the floorboard for the feet, weight savings - 445lbs

Hey Lucid,

What do you think about a (delta power-to-weight ratio)/(cost) parameter? This way, we can compare whether it is more cost effective to add power or to simply reduce weight.

If I get back down to my birth weight of 7 lbs 2 oz....my car will be so much faster. Isn't every 10 lbs = 1 hp? I'd gain about 16 hp.

Good post!

My suggestions:

Fuel: running with full tank vs. running with 1/2 tank
Suspension: KW V3 is for example slightly heavier then stock
Speakers: There are some lightweight options available
Amplifier: Genesis is best know for this
Tires: depending on make and model they can vary by as much as 3 lbs.
Nitrogen: I believe there is a small gain to be had filling tires with this
Bolts/nuts: changing all bolts and nuts on the car with titanium or magnisium.
Remove hidious stickers under the hood, on the door jams and sun visors.
The ultimate wheels for weight saving would be Dymags.

Great info in this thread. I knew when I bought this car that I would not be willing to go to great lengths to reduce the weight, so with that in mind I began my weight savings crusade with the option boxes.

E92 instead of E90 - 20 lbs (wasn't considering E93)
CF roof instead of steel MR - 55lbs (11 lb roof + 44 lb MR)
6MT instead of M-DCT - ~44 lbs (?) don't remember the exact figure
Forged 19s instead of 18s - very minimal but rotational
No nav/idrive or packaged options - unknown

I did skip cloth seats for leather, and added EDC even though it added some weight. It also helped that I wanted the above items too, but would have been willing to add some weight if I didn't.

It would be nice to shave an additional 50-100 lbs and try to get closer the the E46 M3 weight. The right combo of wheels, brakes, exhaust and a light weight battery might get half of that but beyond those mods I doubt there is much else I would be willing to sacrifice.