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...
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...
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