Weight savings cost/benefit benchmarks

[roastbeef]

has anyone figured out a way to do a quick opening valve at the bottom of the windshield washer reservoir to drain it for the track (and fill it back up after)? seems like an easy way to ditch 8-10lbs.

[Richbot]

It'd be trivial to put a hole in tank and put a 3/8" pvc tap in it with some sealing glue and a check valve to just push with a screw driver or something g when you want to drain it through the liner. Whether it holds up to long term use would be a question

[macdude357]

Originally Posted by roastbeef

has anyone figured out a way to do a quick opening valve at the bottom of the windshield washer reservoir to drain it for the track (and fill it back up after)? seems like an easy way to ditch 8-10lbs.

Maybe just keep a minimal amount in the resevoir (ie enough for a few uses, then partially refill when it's out)?

[roastbeef]

Originally Posted by macdude357

Maybe just keep a minimal amount in the resevoir (ie enough for a few uses, then partially refill when it's out)?

i kinda already keep it at a minimum.

[Datka]

So yesterday I removed front passenger seats from my e92m3 and 135i.
M3 seats are with power/heated and 135i is manual, no power/heated.
Removed them right before the track season here, just for track days.
Very easy to remove, just unbolt 4 bolts and unplug the unit.
I was shocked how heavy the non powered seat was, if not the same, maybe 2 pounds lighter than powered one.
I think its about 65 pounds or so.
Going to remove rear seats too and about 110 pounds will be gone just like that.
Cheapest go fast mode I have ever done

[Richbot]

...and now I don't want manual seats anymore, thanks for curing me of that

[Datka]

....lol, the reason I bought 135i(I got both cars brand new)w/ manual seats was because I thought they were significantly lighter...

[Richbot]

I bet the lower seating position is nice to have, and it's one less thing that can short and cause a battery drain, so still worth it knowing what I know about BMW's and long-term ownership, heh

[-BEASTMW-]

Originally Posted by Datka

I was shocked how heavy the non powered seat was, if not the same, maybe 2 pounds lighter than powered one.
I think its about 65 pounds or so.

Originally Posted by Richbot

...and now I don't want manual seats anymore, thanks for curing me of that

Originally Posted by Datka

....lol, the reason I bought 135i(I got both cars brand new)w/ manual seats was because I thought they were significantly lighter...

I dunno about the 135i seats, but BMW says the manual M3 seats are 22lbs lighter per pair:
"The new Manual M Sport Seats (M3 Sedan, Coupe) offer the same adjustments as the previous electric seats but with manual adjustment in order to save weight (approximately 5kg per seat) and expense when power memory seats are not required. Lumber support and seatback side bolters remain electrically adjustable. Power Seats remain standard in the M3 Convertible."

Has anyone measured how much lower you can supposedly sit with the manual seats? My E90 has the manual ones but I don't have a power seat to compare to.

At any rate, it is indeed one less thing to break. My E39 M5's driver seat stopped working in one direction most of the time, which forced me in into an uncomfortable driving position until it decided to work again or I got it fixed. And that's not even the infamous E39 "twisted seat" issue in which one side's adjustment teeth would strip and so one side of the seat back would move but not the other. At least a couple hours to DIY that fix.

[Datka]

Just looked it up. The weight of non powered 135i front seat is 66.14 pounds.
I believe its heavier than e9x m3 powered seats.
I had no idea they were so heavy. Now I am thinking to remove the driver seat too

[-BEASTMW-]

Originally Posted by Datka

Just looked it up. The weight of non powered 135i front seat is 66.14 pounds.
I believe its heavier than e9x m3 powered seats.
I had no idea they were so heavy. Now I am thinking to remove the driver seat too

That is crazy heavy. Exactly double what my stock Honda S2000 seats weighed. I was actually kind of pissed because I replaced those with name brand carbon one-piece race seats and only saved 6lbs per seat!

[roastbeef]

BATTERY
Stock: 27.250 kg (60.02 lbs) -- 90 Amp/Hr (note; my oem battery weighed 55.4lbs)
http://bmwfans.info/original/E92/Cou...1/ill-61_2091/
Voltphreaks vph900 (7 lbs)
https://p10.secure.hostingprod.com/@...products_id=80
Cost: $1000
Weight savings: 48 lbs
cost/benefit: $20/lbs

[Down_Shift]

Idrive, window motors, windows.

Front and rear windshields.

Scrape away deadening after you remove the carpets.

M3 and BMW badges + side grills and led markers. 1.6lb. Free.


Divorce. Weight savings- varies depending your type. Cost- YMMV.

[SpartaEvolution]

Sparta Evolution Saturn 6 piston 380x34 (F) 4 piston 355x32 (R) Kit
Sparta Evo Saturn (F) caliper assembley: 12.2 lbs with pads & adapter
Sparta Evo (F) rotor assembley: 19.5 lbs
Sparta Evo Saturn (R) caliper assembley: 8.2 lbs with pads & adapter
Sparta Evo (R) rotor assembley: 19 lbs
Cost: $3990 + shipping (assume $4100 total)
Weight savings: 18 lbs (for all 4 corners)
cost/benefit: $230/lb
($460/lb when calculated the same way as the other brake kits)

[Richbot]

Burger Motorsports cowl/cabin filter housing deletes - 1,076 grams (filter replacement thingies from Burger weigh 207 grams, stock parts weigh 1283 grams total).

Cost: $69 shipped

Cost/benefit: $29.11/lb or, removing any weight from the front of this car: $priceless/lb

[roastbeef]

Originally Posted by Richbot

Burger Motorsports cowl/cabin filter housing deletes - 1,076 grams (filter replacement thingies from Burger weigh 207 grams, stock parts weigh 1283 grams total).

Cost: $69 shipped

Cost/benefit: $29.11/lb or, removing any weight from the front of this car: $priceless/lb

I did this. It's about 8lbs... fun to do, too!

[Richbot]

Its only 8 lb if you take the whole cowl off

[roastbeef]

Originally Posted by Richbot

Its only 8 lb if you take the whole cowl off

You're taking about these things?

[Richbot]

Yes. I weighed those. They weigh in at 640 grams each, including the OEM filters, +- a couple grams. So unless yours were full of water, you didn't lose 8 lb if that's all you removed

You can also use the cowl filter delete thingies to remove the entire cowl and hood seal over the rear of the engine (which includes the plastic covers for the MC/ABS, etc. and keeps water off of some stuff but for a track car who cares), and zip tie the main engine harness up out of the way. I didn't do that, but that's supposedly another 5-6lb of crap

[Shredicus]

Engine and ancillary delete will remove a full 450+ lbs. off the front off the car

[SYT_Shadow]

Originally Posted by Richbot

Burger Motorsports cowl/cabin filter housing deletes - 1,076 grams (filter replacement thingies from Burger weigh 207 grams, stock parts weigh 1283 grams total).

Cost: $69 shipped

Cost/benefit: $29.11/lb or, removing any weight from the front of this car: $priceless/lb

I did this on one car and now inside it smells like exhaust fumes all the time

[Richbot]

Must have a leak ? No change at all on my car.