Altaran's weight reduction journey

[Altaran]

Was this worth the trouble?

I am in the same boat. I have the aluminum front carrier but thought about going with the carbon-kevlar. Doing these requires a different front bumper. I need to buy a new front bumper, but switching to the carbon-kevlar carrier adds $300-$400 to the purchase. This is where the cost vs benefit kicks in for me.


Also which door and rear panels are those?

I did it when I converted from US to Euro bumper. The kevlar carrier is not that expensive. So you always have to consider that you have to get a different bumper. I used it to change some other things "while in there", such as removal of all unnecessary wiring and hoses (due to washer tank relocation and headlamp cleaning delete) , fog light delete and brake cooling install.

I actually don't know who made these panels, I found them on Kleinanzeigen (somewhat like a German craigslist). The seller did not know the manufacturer and there's also no logos or anything else to identify. I only paid 250 for all 4 panels so I didn't care too much.

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[Altaran]

Hey, for this mod did you use a custom mount/bracket for the e39 tank or did you buy? If so, can you provide a link? Thanks!

I bought a 3mm carbon fiber plate and cut it to the dimensions to fit into the drug bin. There's 3 threaded mounting points in there.

To hold the battery and the washer tank I used rivet nuts. For the high side mount on the tank I used a plastic cylinder with self made threaded bores to connect it to the CF plate and tank.

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[Altaran]

You can check Origin strut brace, one piece like Mason but made from Titanium

If you remove intake duct, make sure to make block off plate otherwise air will take easiest way and won't go thru rad

That looks good, I like it.

See pic below on the GTR reinforcements I was talking about. I need to get on the computer and spend some time with cad 😅

Both items combined should give some really good structure.

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[Gt4]

That looks good, I like it.

See pic below on the GTR reinforcements I was talking about. I need to get on the computer and spend some time with cad 😅

Both items combined should give some really good structure.

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GTR reinforcements were on my to do list also

[Altaran]

GTR reinforcements were on my to do list also

I'll let you know when I have something 😉

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[Mike RT4]

Just looked through your build.

Since yours is a genuine csl, you may not want to go all out like I have. But here's some more suggestions what you can do an still keep it streetable:
- relocate the battery to the drug bin in front (saves two really thick copper wires, more weight than you would think) As a RHD car, we don't get the same space like the LHD cars, so both bins are full - ABS on RHS and fuse box on LHS

- change the stereo to a lightweight system. I can't comment as I decided against it and ditched it completely, but Obioban has done this. I have the same AVIN 4 that he used for the same reason


- remove all obsolete cables from the wiring loom. I don't think bmw made a different one just for the CSL, so there should be a lot of unconnected stuff from options you don't have CSL has this done as standard - is part of the weight loss program - probably not as extreme as what Ian did, but a few kg

- if you convert to rear coilovers, you can get lighter upper control arms there as well as in front.You will see I already have coilovers these from the photos , so will look into the upper control arms

- liteglas front windshield, polycarbonate rear and side windows (relatively easy to reverse) That is a too extreme for me LOL

- depending on your NVH tolerance, you can remove sound deadening (supposedly the CSL had less than regular, but there should stimmt be some) The CSL has no sound deadening at all, just carpets, although I'm not sure about behind the dash.

- ditch the smg actuation and shift manually (sorry, had to say it 😜) It's what makes the CSL a CSL - I actually like the SMG on track, it gives the car a raw feel .

[cornerbalanced]

That looks good, I like it.

See pic below on the GTR reinforcements I was talking about. I need to get on the computer and spend some time with cad 😅

Both items combined should give some really good structure.

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Would happily purchase something like this from you when available!

[bigjae46]

Nice! 2570lbs is really light...that's about where I'm at right now.

There's a bunch of brackets and stuff you can remove. Airbag module, ebrake cable tubes, etc....that all adds up.







And for wiring...if you're willing to lose the windows and door locks...you can just unplug the GM5 module and start pulling wires out. If I had to do it again, I'd unplug other modules and drive it. Once you've unplugged all of the modules you're going to delete then pull the wires out.

[bigjae46]

That looks good, I like it.

See pic below on the GTR reinforcements I was talking about. I need to get on the computer and spend some time with cad 😅

Both items combined should give some really good structure.

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How do those plates attach to the firewall?

[Tbonem3]

I think you should make a batch of CF versions Jae, for forum purchasing.

[Altaran]

How do those plates attach to the firewall?

I don't know exactly, I haven't seen this up close. I'll have to visit bmw classic sometime and ask if they will pop the hood on the car they have there.

My thinking is to use L brackets to attach these reinforcements to the chassis, as there is no premade mounting items there. The brackets could be welded on or with chassis adhesive (like the CF roof). They have to be somewhat easily removable, otherwise no more access to the ECU compartment.

I would also combine this with a strut brace to avoid stacking plates above the struts.

In my case I also have to design the passenger side one so it goes around my battery poles.

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[DJAM3]

It's definitely bolted to some structure or bosses welded to the firewall

[Gt4]

I am shopping for a radiator and oil cooler and it seems like the Bimmerworld C&R radiator save 11lbs when fill and C&R oil cooler 2lbs

https://www.bimmerworld.com/Cooling/Radiators/BimmerWorld-C-R-Racing-LightWeight-E46-M3-Aluminum-Performance-Radiator-42mm.html

[Altaran]

I am shopping for a radiator and oil cooler and it seems like the Bimmerworld C&R radiator save 11lbs when fill and C&R oil cooler 2lbs

https://www.bimmerworld.com/Cooling/...ator-42mm.html

The description says:
"filled weight is a stunning 11# lighter than our 56mm radiator"
So they are referencing the weight loss to another one of their radiators, not the stock one. If you end up buying it, please measure the difference filled and unfilled.😃
But it seems it's out of stock and $1k for a radiator is definitely not cheap. I never really bothered looking for other radiators, most aftermarket units are larger and hence heavier. Since water temp is not an issue with our cars, I don't feel the need for more cooling. All it will do is make the thermostat open and close more often. Oil cooler is another topic 😉

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[Altaran]

One other thing I am considering for weight savings is titanium wheel bolts 🤔

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