weight reduction ideas

JeffYoung said:
"Hardware items (nuts, bolts, etc.) may be replaced by similar items performing the same fastening function(s)."
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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.
 
tderonne said:
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.
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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.
 
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The "hardware is free" rule shows up in the engine, transmission/final drive and suspension sections, but not in body/chassis.
 
JeffYoung said:
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.
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So you believe in the 'replaced with air' thought process. I do not.
 
Rules NERD Alert!!!!!

Once again you all have gone off on a tangent. The op wants to know how to lighten his Miata.
 
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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.
 
"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?
 
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.
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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...
 
JeffYoung said:
"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?
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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.
 
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the1jbh said:
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.
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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.
 
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.
 
the1jbh said:
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.
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Go on the diet AND replace the bolts. Then you're getting somewhere.
 
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