Announcement

Collapse
No announcement yet.

Altaran's weight reduction journey

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    Altaran's weight reduction journey

    So, since I have been asked to provide more details of my weight reduction built, here we go.

    To be honest, I was really surprised how low the weight actually turned out. I was expecting to be between 1250 and 1300kg. I ended up at 1166kg (unfortuantely there were still a couple of oil canisters in hidden in what used to be the battery compartment so it should be sub 1160kg.

    The individual wheel weights are:
    Front Left: 257,0kg
    Front Right: 299,5kg
    Rear Left: 301,0kg
    Rear Right: 308,5kg

    This makes a 47,7% Front and 52,3% weight distribution. When adding driver weight this improves by 1,3% more towards the rear.

    Since the engine was due for a rebuilt (~200k km on clock), it was going out anyways. Perfect timing to get to work. There are several damping mats in the engine bay towards the firewall and underneath the transmission tunnel. Not really needed >> toss them.

    On the interior side is where most of the weight is to be lost:
    - There is a large sound deadening mat on the firewall. If you like induction noise and don't like weight, then loose it
    - All the tar mats on the floor can go, this is really big weight savings. Some will go rather easy, others are a PITA. The forward mat on the tranny side and the mat between the rear seats and the trunk are the most annoying. There is a lot of chassis adhesive beneathe them so it's tough to separate. I used a head gun and plastic scrapers (click for reference). Another way is dry ice, I have not tested this myself so I cannot comment. Theres also another tarmat inside each door, so don't forget these :-)
    - Various interior trim elements also have damping elements in them. If you want to reuse them, throw these out for additional weight savings. I opted to use lighter CF door and rear side trim (manufacturer unknown, bought it used for cheal and got it refinished. The rear shelf cover is from Carboproject and the CSL center console obviously Karbonius. All CF elements on my car are in plain finish (1x1).
    - All trunk carpets and covers are also gone.
    - Removed all rear air ducting since theres no rear seats in my car.
    - Removed all airbags and the airbag ECU. If you got bucket seats and harnesses they are useless anyways. Also our cars are 20+ years old now, I would not trust cartriges that old.
    - Removed all AC components. This includes the heat exchanger and Aux Fan in front of the radiator. Should be some 20+kg weight savings in the very front of the car. I also removed the heat exchanger inside the blower module (Theres another one for the heater which I kept).
    - Removed all audio components (radio unit, amp, sub, all speakers and tweaters in the car)
    - Relocated battery from the rear to the drug bin inside the angine bay. I use a Lithiumax Restart 9 battery which weights about 1,5kg. By relocating to the front you can delete two very thick copper wires going through the entire car. I used the battery connectors from a 318i.
    - Swapped the MK20 ABS to MK60. This was a while in there project. Its much easire to redo the brake lines when the motor is out. There's a quality guide on this forum by heinzboehmer (click me) so won't go through all the details. I opted for option 3 on that guide. In addition I did not build a connector adapter that goes above the engine. Since I had the interior out and cable tree disassembled I built a whole new ABS wiring. Any wiring length saved is weight saved. I also opted for to use a standalone MK60 race unit (by MK Rennsporttechnik) which does not use the yaw sensor and only relies on wheel speed difference. This saves another 4-6kg. The wiring loom is also considerably lighter. This does not work plug and play with the standard cluster (I am sure it can be somehow made to work, I don't care though since I use an AiM Dash), has a different pinout than the E46 based MK60 ECUs, and you will loose DSC (who cares on a track car). You can also get the race software for a flashable CSL ECU, but you will not have the additional weight savings . Standard MK60 saves some 7kg over MK20 though.
    - Replaced the OEM interior air filter housing for a simle CF part (sourced privately, unfortunately NLA) - 4,6kg savings
    - Removed secondary air pump (a long time ago)
    - No clutch fan, I use a SPAL.
    - I have CF footplates, no carpets in the car.
    - Obviously CF Airbox is lighter than stock
    - Deleted the headlamp cleaning system, another useless element causing weight. Windshield washer tank was replaced with an e39 high intensity tank, which is located in the drug bin. I usually keep it empty since I don't drive the car in winter.
    - Upgrade from Xenon to Halogen lightim (you heard right: UPGRADED ) The Halogen units do not have the additional control units, so theres more weight gone. If you live stateside you can simply get H7 LED bulbs from Osram or Philips to fit into the Halogen housing, they are superior to Xenon lights. Unfortunately they are not yet roar approved for the E46 here in Germany (yet).
    - CF Roof is a must for our cars
    - The most time consuming element is to lighten the cars wiring loom. All wires leading to the the things I mentioned deleted above can be removed. I have a full box of wires removed. If you have buckets, you dont need seat wires. The HiFi wiring is really large, this accounts for the most wiring lost. When removing the airbag wiring, you can use the connecting pins going from the drivers side door to the interior to make your own mirror adjuster relocation kit for a CSL console. Saves some 100 bucks. Theres also some additional unconnected wiring from the factory that can simply be deleted. This is for options not fitted to the car, since BMW uses a standard loom for all 3 series.
    - I use Recaro PP Seats with CF Shell, which is 100% read legal. Currently I am using Burhart Mounts. Although I should be getting the new AnimalRacing Pulse Mounts for testing soon. They should be lighter and have the seating position correction. I will post a review when I get them (btw, these mounts also fit cobra and sparco shells)
    - Changed the front carrier from aluminium to carbon-kevlar. Also ligher, but not much.
    - Deleted the fog lights and stock wheel well venting. Went for proper brake cooling ducts.
    - I use the complete GT4 Aero from MK on my car (lip, canards, vented hood, fenders, trunk, wing - all out of CF). All parts are considerably lighter than stock. They are motorsports parts not for show and shine, so dont expect perfect clearances.
    - My suspension components are overall 17kg lighter than stock: TTX Dampers with monoball strut mounts (from BRT Automotive), front DTM Control Arms from AKG (the 7075 version), rear lower AKG control arms, rear upper Millway control arms, MK bumpsteer adjusted from toe arms.
    - CF driveshaft is lighter than OE
    - Titan7 TS5 forged wheels at 8,2kg vs 11,23kg OE front and 12,23 OE rear.
    - AP Racing 6-pod front and 4-pod rear is also considerably lighter than stock (forged Al vs cast steel)
    EDIT:
    - Forgot about the Aux Water Pump in the engine bay, I swapped to the regular 3 series unit (also used in CSL), which deletes one Electric Motor and is hence lighter. No negative effects on water temp, when driving it's at 80° ± 3°.

    When removing the carpet, check the rear footwell closely for rust. I had a bunch, its not visible from underneath. But it was at the point where some metal broke off easy when being touched.

    Here's some things I have not done yet that can lead to further weight savings:
    - Liteglass Windshield (5kg lighter) - will do this when I have a rock chip in my windshield since then its free with insurance.
    - Macrolon rear side and rear windows
    - Swap from roll bar to welded cage and then go CF doors (but with window lift for sure). This will probably be a zero sum game in terms of weight but lead to increased overall stability. When you have a cage you can also start cutting out sheet metal and replace it with CF plates, since you have the cage for stability...
    - CF front dash console. The stock unit does carry considerable weight, but theres no 100% CF replica yet. I heard theres some work in process on this but nothing sure yet.
    - CF Al reinforcement plate (under the car), CF mid pipe hangers, and CF rear 3 point brace. (minor savings).
    - Complete Air blower and ducting delete. saves more than 20kgs. I would not do this unless its a competition car. When removing all insulation and carpets, the cabin heats up a lot. If you delete venting, it may save weight but it will not be such a fun driving experience anymore. Same goes for CF doors with fixed windows.
    - CF Rear quarter panels, Karbonius makes those. Quite the cost factor though. I'd rather start a V8/V10 swap at that point...

    Click image for larger version  Name:	IMG_20230123_122310.jpg Views:	13 Size:	130.6 KB ID:	275791

    Click image for larger version  Name:	IMG_20230123_130841.jpg Views:	13 Size:	152.5 KB ID:	275792 Click image for larger version  Name:	IMG_20230123_130848.jpg Views:	13 Size:	150.0 KB ID:	275793
    Click image for larger version  Name:	PXL_20230325_211538370.jpg Views:	13 Size:	232.0 KB ID:	275807 Click image for larger version  Name:	PXL_20230401_132814342.jpg Views:	13 Size:	152.9 KB ID:	275797 Click image for larger version  Name:	PXL_20230408_150929930.jpg Views:	13 Size:	208.9 KB ID:	275802 Click image for larger version  Name:	PXL_20230803_185134359.jpg Views:	13 Size:	246.9 KB ID:	275808 Click image for larger version  Name:	PXL_20231009_140702728.jpg Views:	13 Size:	110.1 KB ID:	275794 Click image for larger version  Name:	PXL_20231010_140720751.jpg Views:	13 Size:	168.6 KB ID:	275798 Click image for larger version  Name:	PXL_20231010_140748502.jpg Views:	13 Size:	203.4 KB ID:	275804 Click image for larger version  Name:	PXL_20231010_145314195.jpg Views:	13 Size:	175.1 KB ID:	275799 Click image for larger version  Name:	PXL_20231010_165939189.jpg Views:	13 Size:	83.3 KB ID:	275795 Click image for larger version  Name:	PXL_20231024_163207187.jpg Views:	13 Size:	179.7 KB ID:	275805 Click image for larger version  Name:	PXL_20231026_180325454.jpg Views:	13 Size:	169.2 KB ID:	275801 Click image for larger version  Name:	PXL_20240723_144422217.jpg Views:	13 Size:	146.9 KB ID:	275796 Click image for larger version  Name:	PXL_20240818_133527255.jpg Views:	13 Size:	139.8 KB ID:	275803 Click image for larger version  Name:	PXL_20240818_133548761.jpg Views:	13 Size:	149.0 KB ID:	275800
    Click image for larger version  Name:	PXL_20240818_133725249.jpg Views:	13 Size:	211.3 KB ID:	275809
    Attached Files
    Last edited by Altaran; 08-18-2024, 10:02 AM.
    2002 E46 M3 TiAg Coupé >> full tracktool conversion @m346gt
    2000 986 Boxster S >> ice cream getter
    Past: E46 330Ci, 944S2, 996 C4S

    #2
    happy now, Gt4?

    EDIT:

    Here's the finished interior pic. didn't upload before somehow. More info regarding car mods is on IG @m346gt

    Click image for larger version

Name:	PXL_20240818_133511770.jpg
Views:	561
Size:	160.8 KB
ID:	275811
    Last edited by Altaran; 08-18-2024, 08:52 AM.
    2002 E46 M3 TiAg Coupé >> full tracktool conversion @m346gt
    2000 986 Boxster S >> ice cream getter
    Past: E46 330Ci, 944S2, 996 C4S

    Comment


      #3
      2570.59 LBs

      That's light as hell. Must be a blast to drive.
      2004 Dinan S3-R M3
      2012 Dinan S1 X5M

      Comment


        #4
        Kül
        DD: /// 2011.5 Jerez/bamboo E90 M3 · DCT · Slicktop · Instagram
        /// 2004 Silvergrey M3 · Coupe · 6spd · Slicktop · zero options
        More info: https://nam3forum.com/forums/forum/m...os-supersprint

        Comment


          #5
          Originally posted by 9kracing View Post
          2570.59 LBs

          That's light as hell. Must be a blast to drive.
          So far I can't complain, especially with the engine being +60hp over stock. Though I have only done some test drives on roads and have not yet been on the track.

          Especially the breaking power is ridiculous with the lower weight. Can't weight to see cornering speeds on the track with tires on proper temp.
          2002 E46 M3 TiAg Coupé >> full tracktool conversion @m346gt
          2000 986 Boxster S >> ice cream getter
          Past: E46 330Ci, 944S2, 996 C4S

          Comment


            #6
            That is amazing! So light.
            Phoenix Yellow e46m3 Build Thread
            Japanrot Red E46 330i Msport k24/dct/turbo Build Thread

            Comment


              #7
              This is dope. I regret not removing that sound insulation from behind the dash when I had mine all apart! Mostly for the induction noise...

              Thanks for detailing all this!
              Build thread: Topaz Blue to Shark Blue

              Comment


                #8
                Originally posted by Altaran View Post
                happy now, Gt4?

                EDIT:

                Here's the finished interior pic. didn't upload before somehow. More info regarding car mods is on IG @m346gt

                Click image for larger version

Name:	PXL_20240818_133511770.jpg
Views:	561
Size:	160.8 KB
ID:	275811
                Too long to read, fuck it!!

                Just kidding! Great thread/posts. Thanks for posting.

                I won’t ask for exterior pics cause you previously mentioned why you don’t want to post some and I understand.

                Still amazed with the weight! It’s the same weight as my E30 318is with a M42 engine and low options…

                I built an E46 M3 ZCP track car back in 2015-2016 and I had a build thread on RIP M3forum.net. I didn’t put that car myself on scales but new owner told me it’s around 2750lbs but don’t remember if it was before or after he did more mods to that car like CF driveshaft, …I did a lot of the stuff list above but I guess it’s all the small details combined that makes the difference.
                2002 BMW E46 M3 TiAg 6mt Track car project
                2006 BMW E46 M3 Individual Estoril blue/Black 6mt
                2024 Toyota Land Cruiser Black

                Comment


                  #9
                  There is huge weight savings in the wiring. When I removed all the factory harness from my car I estimated about 45lbs. I made a harness consisting of m22759/32 wire and the engine and chassis harness combined are about 6-8lbs with all connectors attached. If you’re really stupid like me you can go full autosport connectors for extra weight savings.

                  Click image for larger version

Name:	IMG_0935.jpg
Views:	583
Size:	173.1 KB
ID:	275860
                  Attached Files

                  Comment


                    #10
                    Just start my old laptop to get some pics of previous track car builds…

                    Here is an idea to remove more weight. You can get rid of the rear window motors and make custom brackets to hold them in place with a carriage bolt and flat bar:
                    2002 BMW E46 M3 TiAg 6mt Track car project
                    2006 BMW E46 M3 Individual Estoril blue/Black 6mt
                    2024 Toyota Land Cruiser Black

                    Comment


                      #11
                      Nice work! That weight is impressive.

                      Originally posted by Altaran View Post
                      - All the tar mats on the floor can go, this is really big weight savings. Some will go rather easy, others are a PITA. The forward mat on the tranny side and the mat between the rear seats and the trunk are the most annoying. There is a lot of chassis adhesive beneathe them so it's tough to separate. I used a head gun and plastic scrapers (click for reference). Another way is dry ice, I have not tested this myself so I cannot comment. Theres also another tarmat inside each door, so don't forget these :-)​
                      Dry ice for the tar sound deadening works amazingly well. Much, much easier than with a heat gun (and way less messy). Stripped all of it out of a racecar in ~1hr with this method.
                      2002 Topasblau M3 - Coupe - 6MT - Karbonius CSL Airbox - MSS54HP Conversion - Kassel MAP - SSV1 - HJS - PCS Tune - Beisan - MK60 Swap - ZCP Rack - Nogaros - AutoSolutions - 996 Brembos - Slon - CMP - VinceBar - Koni - Eibach - BlueBus - Journal

                      2012 Alpinweiss 128i - Coupe - 6AT - Slicktop - Manual Seats - Daily - Journal

                      Comment


                        #12
                        Originally posted by Gt4 View Post
                        Just start my old laptop to get some pics of previous track car builds…

                        Here is an idea to remove more weight. You can get rid of the rear window motors and make custom brackets to hold them in place with a carriage bolt and flat bar:
                        On the e46 compact there was a manual rear window mechanism:


                        I am not 100% sure if it fits our cars, but this may be worth a try as well.

                        I will leave those motors in for now. With the bucket seats and the roll bar it would be a pain to open them manually. The other option is to get vented rear windows and glue them in.

                        Gesendet von meinem Pixel 7 mit Tapatalk

                        2002 E46 M3 TiAg Coupé >> full tracktool conversion @m346gt
                        2000 986 Boxster S >> ice cream getter
                        Past: E46 330Ci, 944S2, 996 C4S

                        Comment


                          #13
                          Originally posted by heinzboehmer View Post
                          Nice work! That weight is impressive.



                          Dry ice for the tar sound deadening works amazingly well. Much, much easier than with a heat gun (and way less messy). Stripped all of it out of a racecar in ~1hr with this method.
                          Nice! That's definitely on the list when I do this next time.
                          How did you make dry ice work with the mats that are on a vertical surface?

                          Gesendet von meinem Pixel 7 mit Tapatalk

                          2002 E46 M3 TiAg Coupé >> full tracktool conversion @m346gt
                          2000 986 Boxster S >> ice cream getter
                          Past: E46 330Ci, 944S2, 996 C4S

                          Comment


                            #14
                            Awesome. There is no better mod than lightness.

                            2005 IR/IR M3 Coupe
                            2012 LMB/Black 128i
                            2008 Black/Black M5 Sedan

                            Comment


                              #15
                              Originally posted by Obioban View Post
                              Awesome. There is no better mod than lightness.
                              Hey, I sent you a pm. I hope that you can help.

                              Comment

                              Working...
                              X