weight reduction ideas

[the1jbh]

Hey all, I could really use some advice on how to drop a good amount of weight in my miata. I know, the first thing I need to do, is trim off about 50Lbs from my body, but beyond that, I could really use some advice. I have already gutted, removed AC, removed driver and passenger windows and swapped out to light wheels. Any advice is appreciated.

[red986s]

Are you building an IT car?

[JeffYoung]

Other places to look --

Anything interfering with the dash bar, you can pull

Is a stock tank lighter than a fuel cell, or vicey-versa?

Vent windows

Carbon fiber seat v. fiberglass or alum

Exhaust

Bracketry

4 bolts holding the door on? Use three!

Paint is heavier than you think, strip the car down and paint it with a single coat of single stage

And so on....

[pitbull113]

removed driver and passenger windows I hope you have NASCAR style door bars or this isn't legal.
Remove the undercoatng.
Switch to manual rack and ditch p/s.

[TStiles]

The only time I had problems getting down to minimum in a miata was in the early days of SM , but that was before we could gut doors , and I did nothing but add a cage , suspension , rear end , exhaust , intake and go race. That was on an early 90 ( the lightest cars ) , but they've raised the weights.

I've done nothing but add weight to my 95 and I'm 195#

There's a guy who did a website about developing a lightweight miata , he weighed every potential part for removal and it's listed on the site .... Try googling lightweight miata. If that does not return the desired result , ask the question over at miatanet

Be aware that many of these weight reductions are non compliant with IT rules.

[red986s]

I hope you have NASCAR style door bars or this isn't legal.

Yep that's why I asked if he was building an IT car.

Give us some details on what you've removed/replaced. What do you want to do, road race, solo, track day?

[TStiles]

Here you go , note that much of this is non compliant , but it shows that this guy pulled 325# , you should have no problem getting a miata to make IT weight


44.00 replaced 16" chrome rims and tires with factory alloys
38.00 A/C
37.00 soft top
33.00 Passenger seat
27.00 Spare tire and jack
20.00 door windows, mechs, etc
10.75 Door and deck speakers
10.50 replaced headlights with midtenn fixed lights
10.00 replaced P/S with manual steering
8.00 Misc airbag stuff
6.00 replaced flywheel with shaved flywheel
6.00 replaced exhaust manifold with JR headers
6.00 deck lid
6.00 replaced '92 7-spoke alloys with '94 hollow spoke/pad
6.00 replaced catalytic converter with test pipe
5.50 wiper motor, arms, blades, bolts
5.00 replaced steering wheel with Grant GT wheel
5.00 deck/behind seats insulation
4.50 trunk hinges, springs, catches
4.25 bolts and rails for top
4.00 CD player, remote, harness
4.00 Front baby teeth
4.00 insulation under carpet
3.75 pax seat belt
3.75 AFM and square air cleaner
3.50 Speaker wires, +/- wires for amp, antenna
3.25 rear baby teeth
3.00 front air bag sensors, wires, bolts, covers
3.00 trunk ribs
2.50 replaced power windows with manual windows
2.50 plastic engine pan
2.25 Washer bottle, pump, hoses
2.25 dynamat under back shelf
2.00 Fuel line cover, battery cover
1.75 Charcoal canister, solenoid, hoses, harness
1.75 intake brace
1.50 Metal plate under steering wheel
1.50 AFPR
1.50 replaced radiator fans with low profile fans
1.50 replaced hood latch and cable with hood pins
1.25 front fender well liners
1.25 sill plates
1.25 behind seats carpet
1.25 Spare change (under the carpet)
1.00 cut front of cam cover and removed plastic
1.00 sunvisors (both sides)
1.00 rear fender well liners
1.00 soft top latches (car side)
1.00 fuel line cover (on tank)
0.75 Passenger side mirror
0.75 dual exhaust hanger
0.75 pax armrest
0.75 2x speaker covers
0.75 radio surround
0.75 drain tubes and collectors
0.75 Pax sunvisor
0.75 jute under seats
0.75 MSD
0.50 gas lid cable and switch
0.50 hardtop bolts and bracket
0.25 fuel filter cover
0.25 eyeballs and switch
0.25 antenna cable (radio to trunk)
0.25 throttle body brace
0.25 diagnostic connector/airbag bracket
0.25 gas canister bracket
0.25 l-pipe, hose, cover for gas canister
0.25 pillow block for alternator
0.25 radio antenna stalk
0.00 Cruise Control (not sure of weight)
0.00 Trunk carpet (not sure of weight)
0.00 Trunk "back" (not sure of weight)
0.00 rear exhaust heat shield (not sure of weight)
0.00 replaced hood prop with wooden dowl (due to fixed lights)
-1.50 ADDED BBK pulley
-1.50 Additional water in radiator
-3.00 Larger all metal radiator
-6.00 ADDED A/W IC (not sure of weight)
-8.00 ADDED intercooler water pump
-25.00 Jackson Racing Supercharger

320.75 Total weight removed

[G-Man]

I know it's the middle of the holiday feasting season, but there's no better way to reduce weight than off the driver (for the 90% of us who are "more than optimum weight.")

I'm looking to lose 15 pounds which will make my car faster, and more importantly, make my whole life better. I'll feel better, be healthier, be stronger, better endurance in the heat, better off at/on track, endurance is better, etc., etc., etc. - all of this contributes to a better life on and off-track.

[lateapex911]

Other places to look --

Anything interfering with the dash bar, you can pull

Is a stock tank lighter than a fuel cell, or vicey-versa?

Vent windows

Carbon fiber seat v. fiberglass or alum

Exhaust

Bracketry

4 bolts holding the door on? Use three!

Paint is heavier than you think, strip the car down and paint it with a single coat of single stage

And so on....

Some of that's kinda grey, isn't it? (Not that I really care, but..)
1-Anything? That implies that i could pull my entire HVAC box. I don't think that's the case. I notched mine for my cross car tube, which runs behind the dash.
2- bracketry. Depends. I know some who have cut every welded on bracket for things they no longer needed off the car,. The exhaust system is a good example, but I think thats pretty gray.
3 deleting bolts on required items? Where does it say you can??

yes I know, 'hardware is free', but I don't think that means just remove it.
It means that you can use stainless or aluminum or alternatives instead of stock.

[red986s]

I'm sitting at 2275 lbs: NA Miata, 1/2 tank, 170 lbs driver. Didn't do anything outside the GCR.

[Knestis]

This is the New IT™, Jake. I was noodling it over this morning and thinking that we're at a point where a sprint-optimized Pablo could essentially start with NO wiring harness, and just add the very few bits that are necessary anymore.

And I've got this bracket that supported the rear seat, which can be removed...

http://www.it2.evaluand.com/gti/images/firesys1.jpg

...the bit that the fire bottle is bolted to. (This was Pablo I, bless his wadded up soul.)

Washer/wiper/light stalks can come out, as can the light switches. Replacing engine/gearbox mounts won't make much difference, movement-wise, compared to what I've currently got but it would be a great weight-saving opportunity on the front end of the car.

That's the beginning of the list based on most recent rules tweaks and interpretations but I've got some other ideas that can be requested - hatch struts (and brackets), trim panels around the cowl (big PITA on a Golf) and of course their brackets, and since we have the engines located correctly now, we've got to address the safety and longevity problems associated with stock shifter bushings.

It's a potentially busy winter!

K

EDIT - if you can replace a ferrous bolt with a titanium or aluminum version, you can use a plastic one. If you can use non-metallic materials, you can use air. I was reminded about this when I saw a post on the Sandbox about doing that with engine mounts. Air is certainly not "rigid."

[Robbie]

Lithium batteries are under 10 pounds and are about 250 dollars.

[JeffYoung]

Sure some of that is grey.....

Heater box needs to stay but if there are metal structures in the way of the dash bar, you can cut them to allow the bar to pass is what I am saying.

On bracketry, the point is that if the rules say "x" can be removed, "x" includes the bracketry. Don't leave that shit in there!

Bolts are probably the grayest of the gray areas, but if you follow the well-settled-from-before-my-time rule that "free bushings" meant "air bushings" on the back of a RX7, then "free hardware" means have it. That's not creep or a new interpretation or anything. It's following what the Elders of ITCSion have been doing for years.

All that stuff is still on my car. I run 100 lbs over and need to put me, and the car, on a diet.

[the1jbh]

Its a 96 miata, being built for ITA.

[the1jbh]

I do have Nascar bars on both driver and passenger side.

[red986s]

Great! Welcome to the craziness!

Sounds like you've got a lot it out already. Couple of things I thought of and you may have already done.

exhaust system
undercoating

I like TStiles list you could look that over. You should be pretty close.

[TStiles]

Its a 96 miata, being built for ITA.

I'm 195# and I make weight with 40# ballast , 3 gallons of fuel , heavy battery , 13# wheels , and nothing special in the lightening department.

I think we need to get 50# off the legal weight :happy204:

You should be golden with a 96

[GKR_17]

[QUOTE=JeffYoung;330580]
Bolts are probably the grayest of the gray areas, but if you follow the well-settled-from-before-my-time rule that "free bushings" meant "air bushings" on the back of a RX7, then "free hardware" means have it. That's not creep or a new interpretation or anything. It's following what the Elders of ITCSion have been doing for years.
[QUOTE]



"Hardware items (nuts, bolts, etc.) may be replaced by similar items performing the same fastening function(s)."

Certainly not a reasonable argument to say an "air bolt" performs the same function as a metal version.

No go on the lightweight battery also.

[JeffYoung]

Good point.

So try this.

I replaced 4 bolts with 3. 3 hold the door on just fine.

Arguably legal.

I don't do it, but I think this is exploiting a grey zone, and not illegal. I wouldn't ding someone for doing it.

[tom91ita]

four hollow bolts would weigh the same as 3 solid bolts. and be legal.

we shaved the bolt heads (took ~1/2 off the top) and drilled out the engine to tranny bolts for the winning $2009 challenge Team "Gutty" CRX. if you trim the top off the heads, you have to be VERY careful when engaging with the wrench to keep from rounding off the head.

it saved ~ 1/2 pound for the 5 main bolts and fit the theme of the car being gutted for light weight.

[tderonne]

"Hardware items (nuts, bolts, etc.) may be replaced by similar items performing the same fastening function(s)."

You skipped a very important part when you quoted this rule....

The section(s) it's in. It appears in the engine section and transmission final drive section. Nowhere does it say ALL the fasteners in the car can be replaced.

[Ron Earp]

The section(s) it's in. It appears in the engine section and transmission final drive section. Nowhere does it say ALL the fasteners in the car can be replaced.

Is it written in the GCR that rules in a section only pertain to the items in that section? I know it is implied, sure, but is it stated? All sorts of fasteners get replaced in IT cars. I suspect a strict interpretation would result in illegal cars.

Make sure your engine is legal. Transmission, brakes, drive line, and suspension too. Race above minimum weight. Have fun.

[JeffYoung]

The "hardware is free" rule shows up in the engine, transmission/final drive and suspension sections, but not in body/chassis.

[Andy Bettencourt]

Good point.

So try this.

I replaced 4 bolts with 3. 3 hold the door on just fine.

Arguably legal.

I don't do it, but I think this is exploiting a grey zone, and not illegal. I wouldn't ding someone for doing it.

So you believe in the 'replaced with air' thought process. I do not.

[red986s]

Rules NERD Alert!!!!!

Once again you all have gone off on a tangent. The op wants to know how to lighten his Miata.

[lateapex911]

I understand the OP wants to know how to lighten his car.
But, I feel some of the advice being given is erroneous, or could be taken in ways it might not have been intended, resulting in a car that, perhaps, he's not happy with.

So, as this is a discussion board, I think it's reasonable to discuss wether the suggestions are actually legal.

If I'm going to suggest something, I'm CERTAINLY not going to suggest something thats not legal. Now, I might say, "I see a lot of XYZ, and strictly speaking, it's not legal, but I'm not going to protest anyone over it". But thats informational, not a statement of: "do this".

So, some legal thoughts:


Radiators are free. You can choose a lighter radiator, and you can control the size and capacity. less water is less weight, if the resulting system meets the required cooling capacity.
Exhausts are free, to a degree. Different materials can be used in the header and exhaust to save weight. And remember, they need not run the entire length of the car.
Smarter cages with less parts. Elegance in engineering can be safer and lighter.
The seat is a significant area of possible savings.
Battery must be of appropriate group size. I went and weighed all the legal options and use the lightest.
Air tubes and filters. often i see people bolting on some long aluminum tube. There are lighter options.
We nor allow alternate engine mounts. Certainly some stock mounts can be replaced with lighter versions.
Somebody mentioned fuel cells. Often the cell is lighter than the stock tank. But be beware, the filler hoses, valves, breather tubes, and mounting brackets can be deal killers. Design carefully or you add weight. not appropriate for this car, but the rules give some latitude to placement of the cell too.
Personally, I do not subscribe to the "remove stamped on brackets/rivnuts/etc on the body when allowed systems are removed" line of thinking. For example, I wouldn't remove a stamping under the dash that mounted the now removed section of the HVAC box that housed AC componentry. That's me. I'm not sure how such a protest would play out.
As mentioned by many, undercoating and sound deadening can get stripped. It adds up.
Wire harnessing for optional items such as rear wipers can go.
Wheels. Some can weigh 5 pounds each over others. And it's unsprung weight and rotational. Triple win.
Tires too! Again, there can be significant differences.
Any part you put on the car. Brackets, for example. Steel? Why? What's wrong with aluminum?
Any allowable air device, like airdams, should be considered carefully. I see guys using all sorts of stuff, garden edging, and so forth. I've seen airdams add over 10 pounds IN FRONT of the front axle. The arm moment is even higher.
Fuel. I see guys just running gallons extra, because their gauge is busted and they don't want to figure it out. 3 gallons is about 20 pounds.
Gravel. I've vacuumed pounds out from cars. (not mine!), after an off. Stuff gets everywhere. Tape close the holes and openings in the 'frame' etc. No sense carrying a lot of crap around, especially if it rattles.

[Andy Bettencourt]

Rules NERD Alert!!!!!

Once again you all have gone off on a tangent. The op wants to know how to lighten his Miata.

Not really. Some have suggested 'replacing' something with nothing. Not legal. A service to the OP.

[JeffYoung]

"Not legal" in your opinion.

I've got no dog in this fight, but I'd say this:

1. The whole "air bushing" deal was hashed out here at length years ago and I certainly remember most/all (maybe not Dewhurst) agreeing that "free" meant fire away with your air bushings.

2. I'll grant you the hardware rule is a bit different. Still, using 3 similar bolts to replace 4 that perform the same fastening function seems far more within the rules than, say, adding a MAP sensor when the rules didn't allow that.

3. Jake, no provision in the ITCS to allow you to tape holes in the chassis. Illegal. Right?

[tom91ita]

not sure they were mentioned but radiator fans are largely unnecessary although convenient. or lighter alternates exist if you want one.

Under 3.c Engine Cooling Systems:




Cooling fans may be removed or replaced. Electrically operated
fans with manual or automatic actuation may be fitted.


for me, the fuel cell question also comes down to how much fuel do you have to carry to keep the fuel pump primed. the cell typically needs much less (by 3-4 gallons in some cars/courses).

EDIT: do you have an aluminum underpulley that is just the single for the alternator? smaller degree but like Jake, said, less weight and less rotational mass. same with pressure plate and clutch disc...

[Andy Bettencourt]

"Not legal" in your opinion.

I've got no dog in this fight, but I'd say this:

1. The whole "air bushing" deal was hashed out here at length years ago and I certainly remember most/all (maybe not Dewhurst) agreeing that "free" meant fire away with your air bushings.

2. I'll grant you the hardware rule is a bit different. Still, using 3 similar bolts to replace 4 that perform the same fastening function seems far more within the rules than, say, adding a MAP sensor when the rules didn't allow that.

3. Jake, no provision in the ITCS to allow you to tape holes in the chassis. Illegal. Right?

It just seems pretty obvious that when the rule says you can replace something, that 'something' actually has to be tangible. '3 bolts for 4'? I am not sure how you would arrive at a conclusion that the 4th missing bolt was performing any function of the one it 'replaced'. I submit the only way it would be legal is if the item you were attaching was free, then it would define it's method of attachment.

So to edit: Find the lightest hardware you can if you want to add up ounces. Otherwise, lots of great ideas in here about cages, wheels, mirrors, exhausts, fuel cells, undercoating, etc. It's amazing what we try and add back in with Data boxes, cool suit systems, hooks and hangers, video systems, etc.

[RacerBowie]

Hey all, I could really use some advice on how to drop a good amount of weight in my miata. I know, the first thing I need to do, is trim off about 50Lbs from my body, but beyond that, I could really use some advice. I have already gutted, removed AC, removed driver and passenger windows and swapped out to light wheels. Any advice is appreciated.

While these guys are all bitching about minutia, let us know where you are. I'm sure someone can get together with you and take a look.

Miatas are relatively easy to get to weight, so this shouldn't be that hard.

[dickita15]

Miatas are relatively easy to get to weight, so this shouldn't be that hard.

it would be even easier if we added 100 pounds. :D

[the1jbh]

No worries on me pulling the old "replace it with air" bit. If I get so anal that I am removing bolts to remove weight, then I'll just go on a diet and drop a few pounds.

[Ron Earp]

No worries on me pulling the old "replace it with air" bit. If I get so anal that I am removing bolts to remove weight, then I'll just go on a diet and drop a few pounds.

Go on the diet AND replace the bolts. Then you're getting somewhere.