Altaran's weight reduction journey

[Gt4]

Nice progress getting those mats out and the surface clean! Though I still see a lot of wires that need to go 😜

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I only removed the audio wiring harness so far. And don’t plan to go all out for next season.

[Mike RT4]

There's pics of all the components up on insta, I tagged the manufacturers in the description.
The reason for the dampers is performance. They have the shortest reaction time on the market (0,5mm stroke to build up full damping afaik).
The aftermarket control arms and toe arms are:
- correct bumpsteer, which happens more on lowered cars due to different arm angles
- better overall adjustability: each rod can be adjusted as well as the strut mounts. This is not only camber and caster, but also position of the wheel relative to the car. Front wheels can be pushed out to the front (1cm or so depending on your wheels) thereby increasing wheel base and improving handling.
- lightweight: all parts are forged aluminum (grade 7075) and considerably lower weight than stock.

Generally it's possible to convert to full monoball with stock control arms. So if you are going for a milder setup retaining factory kinematics, this may be easier. Generally speaking more adjustability means also more ways to screw up the setup 😉

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Would be nice to see some better photos when you have time, plus to hear what you think to the mods once you have tested on track. Do you experience any additional road NVH?

[Altaran]

Would be nice to see some better photos when you have time, plus to hear what you think to the mods once you have tested on track. Do you experience any additional road NVH?

The suspension setup has been in the car for 5 years so I have already had several trackdays on it. Track performance has been nothing short of phenomenal. Car is incredibly stable on both axles. The dampers react incredibly fast, ironing out any uneven track surface. Taking curbs on full throttle doesn't even unsettle this car. Steering input is translated precisely and feedback is great. Just as a mechanical car should feel like.

When I installed the he suspension I still had full interior. There may be a minor increase in NVH, but it was barely noticeable for me.
Now the car is on a full diet, so it is more like a GT4 racecar with license plates. If NVH is a topic, don't strip it 😉

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[Gt4]

Altaran, I think you will have to do this to get the M3 as light as possible

https://www.youtube.com/watch?v=HUNSZnlA1sM&pp=ygUaY2FyIHBvd2VkZXJjb2F0aW5nIGNoYXNzaXM%3D

[Mike RT4]

The suspension setup has been in the car for 5 years so I have already had several trackdays on it. Track performance has been nothing short of phenomenal. Car is incredibly stable on both axles. The dampers react incredibly fast, ironing out any uneven track surface. Taking curbs on full throttle doesn't even unsettle this car. Steering input is translated precisely and feedback is great. Just as a mechanical car should feel like.

When I installed the he suspension I still had full interior. There may be a minor increase in NVH, but it was barely noticeable for me.
Now the car is on a full diet, so it is more like a GT4 racecar with license plates. If NVH is a topic, don't strip it 😉

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Ah, cool, I thought they were a recent addition.

In that case, how much do the compression struts decrease the steering lock by?

I like to have a bit of fun (when possible) and I would be concerned that the reduction in lock would mean the difference between “saving” the car compared to spinning off backwards into the scenary 😱😞🤪?

I have read that these kits can reduce the steering angle so road use / parking can be a ball ache (58 point turns)🤪🤷♂️?

My car is nowhere near as extreme as yours, but I am always looking for improvements👍. I have some of the parts already that your car has, and mine is currently sitting at around 1380kg (it’s in the build section). Any suggestions would be gratefully received👍.

[Altaran]

Altaran, I think you will have to do this to get the M3 as light as possible

https://www.youtube.com/watch?v=HUNS...IGNoYXNzaXM%3D

Not a bad idea. But I think I am done for now taking my car apart 😅

I'll keep this in mind if I ever start on the m3 gtr Project. 😉

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[Altaran]

Ah, cool, I thought they were a recent addition.

In that case, how much do the compression struts decrease the steering lock by?

I like to have a bit of fun (when possible) and I would be concerned that the reduction in lock would mean the difference between “saving” the car compared to spinning off backwards into the scenary 😱😞🤪?

I have read that these kits can reduce the steering angle so road use / parking can be a ball ache (58 point turns)🤪🤷♂️?

The struts are not the issue. With the DTM Style control arms you have to put steering angle limiters on your rack. Since they have a straight cross rod, it limits how much steering angle until your wheel hits it. How much depends on what wheel setup you are running.
MK has a control arm design where you can still retain steering angle. It's not quite as light as the DTM style, but still considerable savings compared to stock and it has adjustable caster.

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[Altaran]

My car is nowhere near as extreme as yours, but I am always looking for improvements👍. I have some of the parts already that your car has, and mine is currently sitting at around 1380kg (it's in the build section). Any suggestions would be gratefully received👍.

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)
- 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.
- 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
- if you convert to rear coilovers, you can get lighter upper control arms there as well as in front.
- liteglas front windshield, polycarbonate rear and side windows (relatively easy to reverse)
- depending on your NVH tolerance, you can remove sound deadening (supposedly the CSL had less than regular, but there should stimmt be some)
- ditch the smg actuation and shift manually (sorry, had to say it 😜)

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[Nate047]

I had a professional chassis builder fix it. The driver side was still good enough to be fixed by grinding off the rust. The passenger side hat to be cut out and replaced. He used a metal sheed and bent it to have the same contoure as stock and ground the welds so they're less visible. So other than the new underfloor finish, you would not recognize that this was welded in.

The motorsport ABS is essentially only different software. You can get it flashed into any MK60 Ecu that is flashable (like CSL). The standalone units are usually based on flashable e90 units, as those are cheap to come by unlike the E46 CSL units. Thats why DSC doesn't work. In your case the easiest thing would be to get a flashable e46 unit as it would be plug and play from your existing unit. Since I converted from MK20, I had to go the long way anyways.

I have not tracked yet, but from road testing its quite notieable how much later the ABS starts interfering. Considering stock ABS software is programmed for a 1,6 ton car with full accessories, early 2000s suspension, and tire setup, its obvious there's some room to be gained with modified cars. When getting the software done, you specify your car's parameters so its specifically tailored to your car. The ABS interaction is also harder, but this is a choice. There is one pin on the connector which is used as a ground switch. When activated the ABS interaction becomes smoother, which is better for road users. For track/race usage, you want to feel the ABS kick in so you get a feeling how much braking you can do without starting to loose traction.

Nice, thank you for the thorough response. Did you have a lot of track time in the car when it was still MK20?

My car is at an interesting place, I had to rush to put it back together because we were moving house. So now I have to decide if I leave well enough alone and just run the MK20 for a while, or if a simple stock MK60 retrofit "the easy way" is worth doing. I already have the parts from a MK60 donor car, so I would only need to spend a small amount more, and would have minimal down time to make this happen.

How much did the motorsport ABS end up costing in total? I feel like that's overkill for me at this point, but I'm curious.

[Gt4]

Looking at your engine bay, you can possibly do the following:

-cut the OEM bracket to remove the SAP mounting points
-replace OEM strut brace by a one piece design for more rigidity
-get rid of OEM intake duct on top of radiator and make a block off plate so air flow is force to go thru the radiator cause with Evolve intake no need for this air duct

[bmw m3 s50]

S
- Changed the front carrier from aluminium to carbon-kevlar. Also ligher, but not much.

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?

[Altaran]

Nice, thank you for the thorough response. Did you have a lot of track time in the car when it was still MK20?

My car is at an interesting place, I had to rush to put it back together because we were moving house. So now I have to decide if I leave well enough alone and just run the MK20 for a while, or if a simple stock MK60 retrofit "the easy way" is worth doing. I already have the parts from a MK60 donor car, so I would only need to spend a small amount more, and would have minimal down time to make this happen.

How much did the motorsport ABS end up costing in total? I feel like that's overkill for me at this point, but I'm curious.

Yeah, I have done a lot of tracking over the years on this car. From my experience the MK20 is not a bad system. Just like any other street abs, it leaves some margin, so it kicks in too early. This will likely still be the same with a factory type MK60.

A factory MK60 upgrade is still worth it. When relocating the hydraulic block underneath the master cylinder you eliminate a lot of brake line length. This makes a very noticeable effect in the brake bedal, it's feels much less numb and more.direct than before. And this is not due to the race abs software, that only makes a difference when it kicks in.

If your car is close to factory in weight, does not have significant aero upgrades (CSL parts do not count as significant), way better suspension, or at least semi slick wheels, installing a race ABS probably isn't worth it.

In your case I'd recommend doing the MK60 swap with a factory unit. I would buy the competition/CSL unit, which is reprogrammable. Yes it's expensive but it will likely only increase in price, so you won't have a net worth loss. And it gives you the possibility of a later upgrade to race with a simple software flash.

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[Altaran]

Looking at your engine bay, you can possibly do the following:

-cut the OEM bracket to remove the SAP mounting points
-replace OEM strut brace by a one piece design for more rigidity
-get rid of OEM intake duct on top of radiator and make a block off plate so air flow is force to go thru the radiator cause with Evolve intake no need for this air duct

Still thinking about putting a catch can in the car, that's the only reason why the sap bracket is still there 😅

I may get another strut brace. Still debating whether to cage or not though. Another solution would be to manufacture gtr type connectors from the domes to the firewall increasing rigidity.

Yes, removing the intake duct is definitely a good idea. Since I have direct air supply from the LH Brake duct with a y splitter I don't need it.

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[Gt4]

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

[e46mpwrd]

- 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.

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!