Weight reduction? How do I add lightness?

[madjak]

Panel replacement gets expensive, and when you start cutting out structure you end up with panels flapping around. It's really only suitable for full race cars.

The best way to remove lots of weight from the car is to get the entire body sandblasted to reduce weight. The older cars used to have fairly thick panels and sandblasting could remove 40-50kg from the car easy before you start breaking through the skin. It also cleans off all the sound deadening, and clears out all the joints so you can seam weld. Obviously this weakens everything a decent amount so you can only do it if you plan on adding a full cage. The only downside is you have to strip and paint the car, but if you are very serious, you can then spray it with a nice thin single coat to get the weight out of the paint.

[Dan]

He's talking about removing the A/C and carpet, I don't think a bit of extra vibration from the boot not having the same reinforcement as stock is going to kill him

[3gress]

Would slide catch type panel pins mounted in the bootlid potentially eviscerate pedestrians according to the law? Any ideas on attaching a de- framed lid discreetly? I'd probably line the underside with some type of closed cell foam or rubber backing material. The hinge assemblies weigh a decent amount by themselves, i wouldn't miss them.

[hks_kansei]

Would depend.

Flush ones like the areocatch should be fine.
Regular old split pin style probably not.



depending on cost i'd look for these kind of things.
http://bullantperformance.com.au/dzus-fasteners/

I've seen a lot of cars use these for fibreglass panels etc, strong, and also flush mount and tiny.

[3gress]

Cheers for the link. The countersunk black panel washers on that site look promising. Painted body color they would be fairly inconspicuous. How reliable are dzus fasteners? I would'nt like to watch the news and see my bootlid stuck through someones windscreen.

[oztrackdays]

Horns are 1 kg+
Key is 1 Kg+
Lithium Phosphate Battery will save 9+ kg
Boot Pins Conversion 1 kg+

it's diminishing returns past a point for a road car.

[hks_kansei]

Cheers for the link. The countersunk black panel washers on that site look promising. Painted body color they would be fairly inconspicuous. How reliable are dzus fasteners? I would'nt like to watch the news and see my bootlid stuck through someones windscreen.

I'd expect them to be fine, i've seen them used to hold the engine covers on a lot of open wheelers etc.


My daily uses a very, very similar looking fastener to hold on the undertray, and they work brilliantly.
The only ones that have come loose are at the back there they've been dragged on abnormally tall speed bumps.

They screw in like a regular fastener, but right at the very end of travel there's a little lip they click over to lock them down and stop them rattling loose.



edit:
should probably note that i'm not plugging that site, it's just the first one to have come up on google with the fittings I was talking about.

[3gress]

Some of the more radical things i've done include removing entire hvac system, vents and controls, leaving only windscreen ducts with filterd air fed from original scuttle panel inlet. A blower fan and warm clothes would weigh less. Replace rear number plate light assemblies with lightweight led surface mount type strips. Same for rear boot mounted brake light. Swap side sills for strips of waterproof griptape. Replace necessary heat shielding with either punched alloy style shield or adhesive type heat shield mat. It all adds up. Roadside service membership and mates that owe favours negate spare tyre and jack! Lose central locking, boot lock etc etc.

[madjak]

He's talking about removing the A/C and carpet, I don't think a bit of extra vibration from the boot not having the same reinforcement as stock is going to kill him

I think once you go past that step of removing the ribs on the boot, door skins, cutting out the bonnet you are well and truely into race car territory and it's no longer streetable. Any cop following you will spot the boot flapping around and the car will now be a dedicated race car. Mine is still rego'ed and if it wasn't so loud I could drive it on the street. I don't want to wear the engine out though. I have carpet still, just no foam backing. All up the carpet is light and saves me from having to spray my interior. The exterior of the car still looks factory, except for the splitter. For me it's important that the car looks stock at first glance rather than a hacked up lightweight circuit car. Underneath it's still hacked up and lightweight... just doesn't look like it from the outside.

The boot might be ok with 4 hidden corner fixings, but hacking up doors, bonnets etc becomes risky.

[speed]

You can remove the casting marks, and a couple of lugs that aren't used... but most of the weight is removed from around the hub where there is a step for the brake shroud. You can grind all around the hub and remove the step and taper it to the back of the hub. There are some pics in my build thread.

I'm sure you can do the same with the calipers. Probably better to replace with Wilwoods if you are really concerned with weight... not quite as free though!

Thanks for that, you make it sound pretty easy. May suss out machining costs to reduce time and effort ;)

Courtesy of Keith Tanner.

Not a good idea if you have a big wing on the back

No big wing for me.. well not until I can steer better

I'd do it if i could find a decent way of securing it discreetly while still allowing access.

Why not just leave the hinge points and the catch area untouched then?

Not as light as removing it all, but lighter than stock, and would allow use of the original lock etc.

Definitely my kind of option

I figured the decklid being steel would be where the weight would be on the NA so I quickly looked into it.

According to this (http://clubroadster.net/vb_forum/16-gen ... ights.html) the weight of the NA boot is in lbs:
6.00 deck lid
4.50 trunk hinges, springs, catches
3.00 trunk ribs

Replacing the decklid with something like this (http://forum.miata.net/vb/showthread.php?t=516069) and then doing some modifications to the ribs for that last bit I'd think would be the way to go.

Wow, amazing how it all adds up but in reality I would probably leave the stock boot lid, hinges and latches

He's talking about removing the A/C and carpet, I don't think a bit of extra vibration from the boot not having the same reinforcement as stock is going to kill him

Agreed!

Horns are 1 kg+
Key is 1 Kg+
Lithium Phosphate Battery will save 9+ kg

it's diminishing returns past a point for a road car.

Only have 1 horn and agree.
Would be stoked with 100 kg drop.

Mind you most things I've done so far have added weight, such as adding F/I, roll bar and soon to go in torsen.

Would never had thought that I could save so much with a battery change. Thankyou OTD and Magpie!

Waiting for lightyear to reply to my PM as I thought CF hardtop, bonnet and headlight covers would all help and look cool on a red car but since the bonnet is alloy, I'm not too sure

Am selling some other cars to go towards a hoist, so maybe I should get that first and car engineered before I go too hard core

[3gress]

It just occured to me that removing the hinges would result in a potential horizontal guillotine blade aimed at the back of your head. Better that they stay.

[speed]

Yeah that doesnt sound good!
Am also concerned about taking too much out of the rear and distorting the weight distribution but I suppose most of the AC is up the front and I will have a heavier diff in the rear. Don't wish to over complicate but just a random thought.

[Dan]

Yeh, I think that is over complicating things.

Take weight out wherever you can and then balance it with setup.

Most of your weight loss should come out from around the center.

Sent from my SM-N9005 using Tapatalk

[speed]

Is this what corner weighting is all about? Never understood how that is achievable.

[madjak]

Corner weighting works by changing the preload on the springs. It's just like a cafe table with 4 legs and adjusters on each... except the car has little springs under each leg. You want the same pressure on each tyre so you compress the springs slightly to distribute the weight differently.

Of course you _could_ also do it by hacking out parts of your car! Not the easiest method though.