Where to remove weight from a track only car?
 

I figured we needed a thread on how to lighten up a miata, what others have done and what weight a track car can safely get down to.

Things i have removed:
AC
Power steering
front bumper support
Metal things between motor mounts and sub frame
Headlights/motors/relays and all related wiring
Everything behind the dash (heater core, ignition key thingy, all unnecessary wiring)
Carpet & all sound det is removed
Doors are pretty much fully gutted
OEM seat belts have been removed
Softop
Oem hood latch/cable ect.


Places i still want to remove weight:
Trunk lid skin
rear bumper (the pretty standard cut that alot of people do)
Exhaust (make a removable muffler via v-band)

I cant really think of anything else i have removed for the sake of lightness, maybe we can all ad to the list.

soft top
emissions components
ditch heavy wheels
hack up dash
start cutting away unnecessary sheet metal
removable cat to put in test pipe

Side mirrors and battery...

how about a plywood delete?

it *would* be sick to lay up some carbon fiber for your splitter.

should also add wiper motor and wiper arm delete to the list
possibly rear glass delete

OEM seats at 35lbs+ each. There are a whole bunch of little things that you can do that only net a pound or two, but add up. I put mine up on jackstands and just started looking at the car and if I didn't absolutely need it, then it got taken out.

I was at 2070 somewhat stripped with a rollbar, but since then I have taken about 150lbs or more out doing this.

2300+lb crew signing in from your GF's house.

Smaller fuel tank/fuel cell?
Ribbing inside the hood.
plexiglass windows

:bowrofl:

WHAT?! Fuck.

You need to keep labor in mind for all these things too. Mainly the lexan windows. I've said it before, and I'll say it again: Don't replace your HT glass with lexan unless it's broken. Between labor, the fact that you have to replace it every ~2 years, looks, fairly minimal weight savings (~5lbs?), and the whole weather tight thing, it's just not worth it.

Lexan triangle windows on the other hand, are great. Again not much weight savings, but very easy (aka, flat) to fabricate, and are great for NACA ducts. Those two ducts on my car bring in A LOT of air.

Snowboarder, if you haven't touched your rear bumper, get to it. Although you'll probably be adding weight back there for corner balancing purposes (remember FM's track dog raced with a spare tire in the trunk), there's a good 20lbs to be had. Here's a hint: once you're back there you'll notice you need the black plastic beam to hold the trunk on. Hack it up, it's fun and wasy (way easy). That 20lbs is an estimate with a crappy scale (weigh myself, hold stuff and weigh again, subtract), and I hadn't hacked up the tow hook mounts at all. They're a little ugly with the bumper cut.

I'd hope by the time you're getting to the point where you need the hood gutted, you've upgraded to a CF or fiber glass unit. That being said, I'll be gutting it and adding a cooper scooper eventually, ala (fuck, railz? slutz? I forget now).

We've been over this a million times, the risk vs. price is in no way worth it. You save some weight yes, but it's pretty much the least important spot to loose weight, beyond the fact that it's in the front. That and the risk of ripping it off and destroying it is way too high. If he keeps a jig saw, along with the battery powered drill I know we all have for removing wheels, as long as the rest of the car is fine, he can be up and running with a brand new splitter in the next session for $20. Only problem is it won't be painted until the next track day.:ohnoes:

parking/ebrake and parts
hood latch and cable
gutted doors (door bars on the cage right?)

Brake dust shields, fender liners, forgotten nuts and bolts...

Edit in exhaust shielding.

I've seen an APR CF splitter and a 12mm Birchwood splitter for an Elise in the same pattern. Any guess as to which one was lighter? ;)

The big weight in these cars is in the doors. If your doors support themselves, they are too heavy. Glass, quarterwindow support, window sliders, power window motors, the entire inner skin structure, hell the crash bar alone is like 4lbs a side. Get rid of ALL of it. I'll have to remove one of my doors sometime and weigh it compared to a power window, power mirror door.

-trunk hinges/latch
-headlights
-all glass except for windshield
-lexan windshield
-remove dashboard
-de-wire car (worth 15-20lbs)
-mufflers are for bitches
-seatbelt towers
-all crash structure and everything that crash structure attaches to
-fiberglass trunklid (I'm having one made that weighs <2lbs, stock lid is ~15lbs)

If you're talking about removing carpets, emissions, and HVAC in this thread, you're behind the curve. That's all easy to remove - the hard stuff is what you can't see or what nobody else thinks about.

Eh?

edit: I get it now, run nothing in the back or sides, and a lexan windshield?

It's amazing how heavy the trunk/lifters/hinges really are. Pretty damn easy to take off too.

I've got my oem truck lid down to about 7 or 8lbs after making it pretty much just a skin and it sits on some pins.

cut any welded on bolts and replace hardware with light weight hardware.

yeah 20 bucks is pretty compelling. can't touch that with cf. material cost back of the envelope calc looks to me in $150-170 range (for prepreg). i mentioned because its more weight on the very front, and you already have some weight up there from the IC.

I'm crushed. crushed.

Excess bolt length.Trim them down to 2-3 rounds of thread sticking out,then a DROP of low strength lock-tite.Grind down all of the flashing on the block,trans& diff.Im really thinking of cutting the trunk floor out and riveting/bonding an Aluminum plate in.
(G)

What areas are considered "safe" for lightning holes as well?

I have yet to totally rip everything off and really look at it.

What can be removed and/or new material be riveted/welded in a better area for reinforcement?

I wonder if removing my soft-top will not help my corner balancing considering the front is super heavy?

I think removing the soft top, but then adding weight lower for a lower c/g will work better... the further from the center of the car, the less total over all weight to get your corner weights.

From an article on the iRacing forums, in NASCAR, they could make the cars really light weight, but due to their weight requirements.. they bond tungsten (sp?) to the bottom of the gearbox, so any weight it does have is as low as possible and still ends up weighing 3800 lbs

remove weight, add downforce.

Have you guys read this faq?
http://lightweightmiata.com/forum/in...863&topic=72.0

I wish I didn't weigh 188lb.

...

I didn't see it mentioned and I know most of this forums about keeping it cheap BUT the v8 roadsters front subframe is supposedly good for 10 lbs ....right where you'd want to lose it.

You could also look at using aluminum or nylon hardware for all non-critical connections (e.g. - fenders, dash, etc.). There's a couple motorcyle vendors that sell a lot of lightweight metric hardware in alu/Ti. Not really worth the effort IMO.


-Zach

Wha...? This post is two grammar errors away being warned, and only one idiotic statement.

Why the hell and who the hell would someone want to make a new harness? Dozens of people have documented their miata race car build, and do no such thing. Snowboarder is the first and only I know of that's done anything but just use the stock harness and cut out unneeded wires. And I think all he did was cut the harness where it went through the bulkhead and put a connector there.

Seriously, WTF. Myself, Savington, Keith's Targa build, FM's Track Dog build, Bbundy....Who's advising this!?!

...

I fucking know you can trim down the harness and make it lighter, I've done it. Your original post, if you can read, suggests making a completely new one yourself, not modifying the original, as everyone else does.

In my years I've seen many efforts to lighten a race vehicle, some included whaleing bolts and or rifle drilling some parts. If you don't understand the term whaleing, think of a bolt that fits a bushed bore. It could be an alternater bolt or a PPF, the part of the bolt that does not need to be the bushed size can be reduced. Yes it is alot of work to chuck a bolt in a lathe to remove a few grams, but it does add up.

I don't think anyone on this forum has that kind of money.

Trey, it doesn't take $$ it takes friends.

...

We know, and we don't think that's intelligent. It's significantly easier and cheaper to trim the stock harness down.

sorry

ill sell my car and re-do it the way you guys want :)

Inflate the tires with helium

Try not to be such a dumbfuck on the forum.

To be fair, he was getting an exorbitant amount of shit for something which is pretty fucking common outside of this forum.

There's something to be said about the custom harness in my Dad's vette - no looming and everything is tightly bound and zip tied every 4 inches. In 40 seconds you can trace any wire back to the fuse box which is mounted right on the dash.

If you really wanted to minimize wiring weight in any vehicle/product/house the goal is to bundle components which are 'communicating' with each other as close as possible in order to minimize wire length. I have not messed around too much with the harness under the dash, but I assume Mazda made compromises for the sake of packaging and maintenance which results in a harness which is longer than actually needed in a gutted track car.

We're probably taking grams here of course.

-Zach

better yet, inflate the tires with vacuum. no mass!

Sounds awesome.

Fat fuck.. haha

Helium>no mass......considering no mass=no inflation :idea:

I am surprised no one has mentioned the area between the steering wheel and the driver's seat.

I swapped to a Canadian Non Airbag column and combo switch and dropped ~4 lbs. The column is lighter the mounting bracket is lighter and there is no knee bolster metal backup plates under the dash.

My car is still heavy it weighed 2283 with no fuel in it and the hard top off. At Packwood national tour this last weekend.

Bob

I was talking about the sort of padding which resides under the shirt.. :vash:

I was actually going to mention that as well... Also loosing some organs and extremities might help as well.

At least you discovered the shift key and the "." key.

Congrats on the win, dude. That was a squeaker! Have fun with those new Hoosiers!

i'm planning on making a harness from scratch, but since the car has a nissan motor and aim dash, its mostly an exercise in throwing out everything except for lights.

i was looking at these as possibilities:
http://www.amphenol-aerospace.com/circular_hd38999.asp
http://www.fuzeblocks.com/


old s13, do u have any pics of your (i'm assuming) drift s13 harness? i'd like to see that.

That first link has some really sweet plugs, i did a similar thing in my 1990 and love it!

Are you wanting to make the dash appear stock?

Here is what I did. Remove the passenger side air bag, unbolt the lid, and then glue the lid back to the dash. It will look bone stock. I removed the driver side as well, but I assume you will have an aftermarket wheel. The passanger air bag is seriously heavy. You can do the same thing to the glove box, remove the outer skin, and bolt the bottom hinge back to the dash. The latch is attached to the skin, and you will still be able to latch it, and when you are finished it will look stock. You can then put components that need adjustment like ecu or my Electromotive under the dash for easy access.

After I removed all of the a/c and heater components, unnecessary wiring, airbags, and glove box; the dash wieghed about 15 lbs or so. It was a lot work, but looks much better than an aluminum dash. All of my gauges still work too.

When I removed the dash to strip it, it was all I could do to muscle it out by myself. When I put it back in, the difference was incredible.

If you have an early year Miata, one of the motor mounts is a heavy cast peice. Replace it with a later year stamped steal one. I cut holes in both of my motor mounts to make them lighter. I will get a pic of it.

Another trick is to get rid of the fancy alternator tensioner, and cut the bracket in half. I will get a pic of that too.

I removed the parking brake, and even cut out the brackets that held the cable under the car. (I wish I had not done that) Get hood pins, and get rid of the cable and brackets under the dash and hood, and get rid of the hood prop. Hood props belong in the tow vehicle with your tools.

If I think of other things I did, I will post them.

Toss the headlight motors?

It seems you could easily fabricate a manual method to raising and locking the headlight frame in place (assuming you still have yours) e.g. - a removable pin.

In fact, if my memory serves me right there's a guy with the user name 'Adore' who removed his motors but has some sort of manual method to raising and locking his lights.

-Zach

Never knew about the glove box idea. I like it since I never use my glove box at all.

One thing my car still has is the parking brake. I lost the front brakes last year (back when they were stock) at Thunderhill and the e-brake kept me from going into a tire wall. No matter what it weighs, for me it's a safety item.

I went on this "park brake salvation" train a few months ago at about 130mph. If I didn't have that brake, I'd be in a different car today at the least. Suddenly the "stupidity" of a drum brake inside the rotor like a Mustang or Lexus doesn't sound so "stupid" if you ask me.

Yeah the e-brake would not be a good thing to get rid of in my opinion.
In the CMRA (motorcycle road racing) they require all bikes to have rear brakes even though most people, even the fast guys, never touch them. It is effectively an emergency brake unless you have God-like riding skillz.

I can't do it because I'm old and uncoordinated, but I know one top driver that uses the E brake for control. I see no mention of this above.

because this thread isn't about driving technique, it's about removing weight.
i removed lbs. worth of brackets and bolts under the hood. including the washer bottle and heavy bracket that held it and the fuse box. i now just have a small alum. tab holding the fuse box. also part of my winter remodeling will include replacing my heavy steel i/c pipes with an aluminum otr pipng setup, and replace the cat-back exh. pipe with aluminum.

on the wiring, i wish i could have this guy make me a new harness!

http://rywire.com/store/replacement-...ess-p-245.html

Just wondering is that true of the top level riders like moto gp. Sorry to get off topic lol

Some of the stuff I have done in my street car...
swap in 1.6 dash
remove radio
remove air bag system
remove wiring for above
remove power antenna
remove power steering
remove hood latch and cable, replace with pins
remove cruise control
remove cockpit brace, replaced with rollbar + weight, I know
drilled holes in cast A/C bracket
remove windshield sprayers/reservior
replace fuse box bracket w/aluminum tube
radio bracket behind dash removed
removed defroster wiring
probably other stuff I forgot

some time in the future I'd like to look into a lighter drivers seat, and manually raised/lowered headlights. I require A/C for a street car so that's not going anywhere.

More pics of these please.

Attachment 195195

This is a crude pic, since this was taken I have got everything bolted down and made a nice filler panel from ABS to cover the wiring below.

tucks it out of the way nicely, leaves room to mount something like aftermarket coils, etc. I guess the the "nawwwsss" overflow bottle saves an ounce or two, so does ditching the charcoal canister.

Attachment 195196