Weight Reduction.

[Stevin]

Good Day guys.

I've been thinking about this for a while, and I've thought of everything I can take out of the car that isn't necessary for a track car.

This is what I've come up with, which I guess is the usual.

Seats
Carpets, roofliner, parcel shelf,
Sound Deadening
Air con
Bootliner

This is also what I plan on removing
Bonnet and Bootlid (replaced with CF pieces)
Windows, except rear window and windscreen (replaced with Lexan)

Radio antenna, and wiring

Then more radicle things that I plan on doing once the cage is in.
Fuel Cell in the boot
Cut Away inner structure in the doors.

I can't think of much else, but I know there must be more I can do ?

Oh yeah, there is no sunroof in the car.

[northloop]

Brackets for seats.
Floor studs for wiring.
Door electrics (electric windows, central locking)
Inner door skin
Fan and cooler for air con unit (heavy)
Rationalise the wiring, wires are heavy
Heater / matrix
Most of the dash board
Seat belts - replace with harness
Centre console
Interior lights
Front fogs if fitted.
Any un-necessary options like cruise control
Bonnet brackets (heavy)

pretty much everything which isn't necessary to make the car run .......

It is possible to become very anal with this sort of thing and start putting small batteries in, removing electrics and starting the car using a jumper etc etc. But to be honest I think that is a bridge too far.


Hope this is of help.

Gary

[Stevin]

Thanks guy man.

Quick question... I I was thinking when I do the cage I should start pulling all the unnecessary wires out... not before ?

My thinking is that I'm more than likely going to have to move the fuse box... so might as well remove them right upto the fusebox ?

Also also the Handbrake will come out... dont need that.

Oh also does anyone know if there is a writeup on how to remove the aircon ? I've removed the little condenser bottle on the front right, but thats all ATM... as I'm not sure what and where to remove other than the compressor.

I figured once the car gets caged, I'll remove the blower motor and heater core, as the dash will have to come out then anyways.

[northloop]

If you buy a cage which is going to go to the front suspension legs then the fuse box will have to move, as you say. If you take the heater out and associated wiring then you have a little more space to re-house the fuse box.

With regard to the aircon there is an auxillary fan at the front of the car and cooler which are used solely for the air con unit. These are very heavy and can come out.

This is my build thread and shows some of the parts coming out.

http://www.e30zone.net/modules.php?name ... ic&t=59472

[1an]

removing the hadbrake? how do you intend on stopping the car moving when it is parked?

[JimmyC]

put it in gear

[1an]

suppose that is one way, also i suppose it depends if the car is going to be a road car or purely a track car.

[Stevin]

Well, it will have it's roadworthy certificate... but it's not going to be driven much on the road.

By law we have to have a handbrake, but we dont have a yearly mot or anything like that, so it will never have a problem.

Also with the brakes I plan on using in the rear It will be a bit of work 2 get the Handbrake 2 work... so why bother.

Oh, I'm using E46 M3 rear Callipers and disc's

The cage I'm using is going to be a custom build, but it will go through to the front strut housings, and tie into the diff carrier, might even re work the rear shock housings for added strength fo the coilovers.

Northloop... thank you for the link, awsome car you have going there !

[JimmyC]

pull the cage into the rear beam mounts aswell

Remove all the underseal- thats alot of wieght!!

[Mox3d]

I was going to suggest removing as much underseal as you can. It's a lot of work with a hotgun and scraper though. Takes me usually a week and it's pretty tedious but is it worth it in the end ? Probably if your car is going to be 100% race/track. Otherwise, no.

And if you do this you will want to keep the thing super CLEAN and not let and crap build up in the catchment areas because obviously you will lose all underside protection from stones/dirt etc. Basically the more race oriented you make a car the more required subsequent maintenance you're effectively dialling in.

[Stevin]

Rear Beam Mounts ?

[JimmyC]

Rear Beam Mounts ?

where the rear beam mounts to the shell

The studs pass through the inside of the car, you can tie the cage into these, as you will with the diff mounts in the boot

[Weeman]

I've done mine, seats carpets, door cards, OMP seats, harnesses, electric aerial, stereo and speakers, but I've not tackled the roof lining or tar yet. Central locking and electric mirrors will be staying, I'm not gonna be going silly, as its road legal too

[Simon13]

that was an alpina once wasn't it?

[Stevin]

Rear Beam Mounts ?

where the rear beam mounts to the shell

The studs pass through the inside of the car, you can tie the cage into these, as you will with the diff mounts in the boot

Ahh, yes. I was planning on that.

Just a bit of an update, I removed my Bootlid, hinges, torsion bars, antenna and antenna bracket.

put a CF single skin CSL style Bootlid, with pins... saves 11kg over the std stuff.

Nice.

Who u askin if it was an Alpina ?

[MJG]

Nice to know about the 11kg bootlid saving, that's a lot! I didn't think about all the hinges etc. I'll probs keep mine on hinges but really strip down everything else.

If it's a 4dr then you should gut the rear doors (and fronts, if you have door bars on roll cage) and just leave them a shell. Even making fibreglass doors with plastic windows would be best bet.

BTW your pic of sideways e30 looks great

You should remove your main beam headlights then strip the excess plastic bracketry that holds it in. Also remove the innards from the bumpers, including the heavy metal mounts and then just cable tie on the hollow shell, also would hole-saw the shell too so you just have a mesh bumper silhouette that is basically useless but doesn't look stupid like it does with no bumper.

[northloop]

Surely you need to have a reasonable amount of weight over the driven wheels or you will struggle to get drive?

[Stevin]

I guess so... I guess thats why I plan on running a fuel cell in the boot right up against the rear bulkhead over the rear axle.

That should save some weight 2, with the removal of the wheel well

[handpaper]

I was repairing the rear valance on mine the other day, and thought:
"Take out the spare wheel well, and with a little sheet metal work I could build a diffuser in here...."
Worth a try? At what speed would it become useful?

[northloop]

When I put the fibre glass bonnet on the front of mine I thought of the good work I was doing, loosing up top, up front weight and helping weight distribution. I was about to fit the boot too until I considered I might be un-doing some of the work I had done upfront.

[Stevin]

I figured an 11kg saving is still an 11kg saving.... I know it might not be the best for weight distribution, but I figured with the removal of the aircon, and installing a CF bonnet it would bring the weight distribution back to a fairly std spec.

Although I will only be able to find this out once I get the coilovers on and corner weight the car.

[northloop]

Yeah but standard weight is bad Stevin. From what I know the 325 is reknowned for being nose heavy due to the heavy iron lump.

[Stevin]

Ok, yes... but I think I could still make it handle well with adjustability of the suspension.

[MJG]

Do what race car people do, remove every last bit of weight possible, then if handling issues follow you can always add ballast in key areas like right against the subframe mounts in the back (low down, over back axle).

Ideally you don't want ANY weight over the ends of the axles as that adds resistance to your car turning so making it less responsive.

Regarding the wheel well and diffuser idea, I removed my spare wheel well on my old e28 and replaced it with a sheet of thin steel. Saved quite a few kgs too. The diffuser idea though is a bit pointless really, a diffuser on a race car is the final part of the under-car aerodynamics package. If you made a full under-car fibreglass/carbon fibre tray which was smooth and flat, which then led to the diffuser, then that could help, but if not then it wouldn't really do anything imo.

[Mox3d]

If you made a full under-car fibreglass/carbon fibre tray which was smooth and flat, which then led to the diffuser, then that could help, but if not then it wouldn't really do anything imo.

The gearbox and diff would need additional cooling also

[stratos]

Adding ballast to race cars is only done to bring the weight up to the minimum specified by the regulations. It does not increase traction or help with handling problems.

[MJG]

Yeah but they do put it low down in proper places to get the corner weighting right, correct? But I agree sorry, the main reason is just for regs.

[Stevin]

Do what race car people do, remove every last bit of weight possible, then if handling issues follow you can always add ballast in key areas like right against the subframe mounts in the back (low down, over back axle).

Ideally you don't want ANY weight over the ends of the axles as that adds resistance to your car turning so making it less responsive.

Regarding the wheel well and diffuser idea, I removed my spare wheel well on my old e28 and replaced it with a sheet of thin steel. Saved quite a few kgs too. The diffuser idea though is a bit pointless really, a diffuser on a race car is the final part of the under-car aerodynamics package. If you made a full under-car fibreglass/carbon fibre tray which was smooth and flat, which then led to the diffuser, then that could help, but if not then it wouldn't really do anything imo.

I would think that if u removed the spare wheel well, and cut a section out of the rear valance it would help with reduced drag, as the air wont be trapped behind the valance ?

[MJG]

Yeah that's true, but the diffuser won't do anything.

[Lloydie38]

I weighed mine and it now weighs 1020kgs

See my site at http://whitetrack325i.webeden.co.uk/ and that gives you a breakdown of what the interior weighs etc.

Bonnet and Boot next after the 35KG cage goes in this weekend