Weight reduction

Real tech discussion on design, fabrication, testing, development of custom or adapted parts for Pontiac Fieros. Not questions about the power a CAI will give.

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whipped
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Post by whipped »

Series8217 wrote:
whipped wrote:Why not just chop the bottom? That's a good amount of weight right there. It'd probably be the equivalent of building the whole thing out of fiberglass... and then you don't have to worry if you need to carry lead bricks back there, or worry about the fiberglass melting and tossing your tools down the highway..

:thumbleft:
Chop the bottom of the trunk and add a peice of sheet metal across?
Yes/kindof/maybe.

In the middle of the trunk there is a "step". Cut off at that line, and yeah put some sheet metal in. I used 1/8" aluminum and screwed it in... but whatever works. :p
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Series8217
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Post by Series8217 »

Yeah, I have a plywood board screwed in there right now.. It's just not as big as it could be considering there's a good foot and a half of depth at least before i get to the muffler.

alltrbo wrote:Are there mini-starters available? any aluminum water pumps available (or are they)? Aluminum heads are nice, just saving 5lbs each/wheel is another 20, are there lighter tubular control arms? How much do you save with coilovers, etc... 10lbs here and 8lbs there adds up, like I said.
You can get a mini starter off a newer 60/V6. I also saw one on a Shortstar in the 'yard that seemed to fit the 60/V6. It weighed a few lbs less than the normal one.
Held, RCC, and WCF make tubular controls arms. You can lose some weight there. Coilovers save a pound... maybe. There just isn't much you remove.
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Post by p8ntman442 »

Series8217 wrote: You can get a mini starter off a newer 60/V6. I also saw one on a Shortstar in the 'yard that seemed to fit the 60/V6. It weighed a few lbs less than the normal one.
My aluminum 2.8 has webbing where the cast block dosent, so the stock starter does not fir, I had to get a newer style gm one that was considerably smaller, probably shaved 2-3 lbs. Between that and the battery, thats some weight. But I weigh 180 lbs, and could easily slim down to 170 if I didnt drink so much, which would be a lot better on the wallet than a new starter and battery.
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bryson
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Post by bryson »

I just decided to bump this back up -- this summer I plan on making another header, so I will probably use that time to cut the trunk out and hopefully make a fiberglass replacement, or something simpler and lighter out of sheet metal. I've dropped a ton of cash into the engine/trans already and don't want to spend a whole lot more. Making fiberglass parts (front bumper, maybe a dash, trunk). I'm looking into making tubular control arms. I have access to a mill here, so I should be able to notch the tubes pretty easily.

So: lighter wheels, brakes, suspension components, lighter decklid and hood, trunk, interior stuff, smaller battery....Ignoring engine choices, what else can you guys think of? How heavy are the seats and stock dash? Would you guys be concerned about making the rear window out of lexan then putting it back in the stock weatherstripping? I've heard that the flexibility of lexan can actually cause the windows to get sucked out at speed. Most people rivet the windows in to prevent this -- I bet that rivets at the top and bottom of the window would be hidden pretty well by the roof's overhang and the decklid.

Hmm...I already replaced the rubber hoses that I have run to the front of my car for the intercooler with stainless hardlines. Any places where rubber coolant lines could be replaced with hardline might shave a couple lbs. Can anyone think of cars with pretty light brake calipers? Or, aftermarket rotors and calipers could be used. How about aluminum spindles? Maybe Corvette stuff could be adapted, but then you have kind of an awkward bolt pattern.

Has anyone tried replacing the door bars with tubular stuff?
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Post by crzyone »

I believe the stock seats are 30#+ each. Going to racing seats is bound to save 15# per seat.

I would get rid of the door bars completely and weld in an aluminum rollcage if I was getting serious about loosing weight. Gut the interior.

The blower motor in the trunk can be taken out.
The heater motor up front.
Take out the trunk and stock support and weld in a tubular steel strut brace.
Heat shields and insulation in the engine bay
Remove dash, keep guage pod.
Tubular control arms

Corvette 12" rotors are a bit heavy but the calipers are light as a feather. Plus you get to replace the big heavy iron fiero caliper bracket with a light weight chunk of aluminum for the vette adapter.

Engine choice is definitly a big facor for weight. Obviously there is a huge difference between an ecotec and a 3800sc. Thinwall exhaust piping could save 20# or so. It would on my setup with dual exhaust.

I believe the Muncie 4 speed is the lightest manual trans, around 90lbs.

Sorry if any of these are repeats, just off the top of my head.
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Post by The Dark Side of Will »

bryson wrote:Can anyone think of cars with pretty light brake calipers? Or, aftermarket rotors and calipers could be used. How about aluminum spindles? Maybe Corvette stuff could be adapted, but then you have kind of an awkward bolt pattern.

Has anyone tried replacing the door bars with tubular stuff?
Wilwood calipers are light, but don't have dust boots.
Rotors with aluminum hats are lighter than one piece rotors and you can also get teh uber secksie full floating rotors.
Street Dreams already makes aluminum lowering knuckles. They're not FEA optimised and could probably still lose a bit of weight, but the assembly is 4# lighter than stock per corner, yet includes larger wheel bearings and multiple bolt circles.
Last edited by The Dark Side of Will on Sat Apr 29, 2006 8:53 pm, edited 1 time in total.
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Post by teamlseep13 »

crzyone wrote:I believe the stock seats are 30#+ each. Going to racing seats is bound to save 15# per seat.

I would get rid of the door bars completely and weld in an aluminum rollcage if I was getting serious about loosing weight. Gut the interior.

The blower motor in the trunk can be taken out.
The heater motor up front.
Take out the trunk and stock support and weld in a tubular steel strut brace.
Heat shields and insulation in the engine bay
Remove dash, keep guage pod.
Tubular control arms

Corvette 12" rotors are a bit heavy but the calipers are light as a feather. Plus you get to replace the big heavy iron fiero caliper bracket with a light weight chunk of aluminum for the vette adapter.

Engine choice is definitly a big facor for weight. Obviously there is a huge difference between an ecotec and a 3800sc. Thinwall exhaust piping could save 20# or so. It would on my setup with dual exhaust.

I believe the Muncie 4 speed is the lightest manual trans, around 90lbs.

Sorry if any of these are repeats, just off the top of my head.
No aluminium roll cage please, unless you just want it to look good. Stick to 4140 or 4340 tubing. The aluminum in tube form doesnt have the tensile strength for a roll cage.
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Ecotec swap taking much too long...
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Post by bryson »

The Dark Side of Will wrote:
bryson wrote:Can anyone think of cars with pretty light brake calipers? Or, aftermarket rotors and calipers could be used. How about aluminum spindles? Maybe Corvette stuff could be adapted, but then you have kind of an awkward bolt pattern.

Has anyone tried replacing the door bars with tubular stuff?
Wilwood calipers are light, but don't have dust boots.
Rotors with aluminum hats are lighter than one peice rotors and you can also get teh uber secksie full floating rotors.
Street Dreams already makes aluminum lowering knuckles. They're not FEA optimised and could probably still lose a bit of weight, but the assembly is 4# lighter than stock per corner, yet includes larger wheel bearings and multiple bolt circles.

Do you know what wheel bearings are used? I'm interested in a set (I'm guessing they sell front and rear) -- how much are they, and do they even make them for the '88?
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Post by bryson »

Eh, just looked it up. Only fronts, only 84-87. I'm going to start another thread on lowering the rear of the '88.
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Post by The Dark Side of Will »

I oughta know... I came up with the concept and designed that hub. The bearings are '92 Z28 Camaro.

Yes, '84-'87 fronts only. At least you're not the typical Fiero owner who faints in shock after looking at the price.

What's mysterious about lowering the rear of an '88?
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Series8217
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Post by Series8217 »

crzyone wrote:Corvette 12" rotors are a bit heavy but the calipers are light as a feather. Plus you get to replace the big heavy iron fiero caliper bracket with a light weight chunk of aluminum for the vette adapter.
He already has an 88... so the 12" vette rotors only add 2.9 lbs per corner, and the corvette calipers would weigh MORE than the stock 88 calipers. The 88 calipers are light as heck, easily enough to make up for the slight increase in rotor weight.
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Post by eHoward »

My favorite carroll smithism was *knocks on roll bar* "aluminum roll bar? A lot of my friends died in cars with aluminum roll-cages." *walks away*
teamlseep13 wrote:
No aluminium roll cage please, unless you just want it to look good. Stick to 4140 or 4340 tubing. The aluminum in tube form doesnt have the tensile strength for a roll cage.
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Post by GM-TPI »

I think APC makes a "snap together" roll cage, but it might just be for the Honda boys :la:
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Post by bryson »

The Dark Side of Will wrote:I oughta know... I came up with the concept and designed that hub. The bearings are '92 Z28 Camaro.

Yes, '84-'87 fronts only. At least you're not the typical Fiero owner who faints in shock after looking at the price.

What's mysterious about lowering the rear of an '88?
You designed that? :afrocool: Awesome -- Did you use software that analyzes stresses, or did you just base the design off the stock unit?

I know drop spindles can be used in the front to lower the car and maintain suspension geometry, but is there any way to lower the rear without changing geometry? Unless, of course, you changed it to make it better :bootyshake:

I have heard that the 84-87 front end weighs significantly less than the 88's front. Is there a way to get the weight savings of the earlier front end with the suspension geometry of the 88?
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Post by bryson »

Bump up

plus: how realistic am I in wanting to make my street-driven Fiero 2400-2500lbs? Lighter wheels, lighter suspension stuff (mimick slalom suspension), CF decklid/hood, lexan rear window, fiberglass trunk, no spare or jack or washer fluid, short front bumper (possible trimming of heavy metal bumper), lighter dash and seats, minimal insulation and light carpet....

That's all I can think of right now...
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Series8217
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Post by Series8217 »

bryson wrote:Bump up

plus: how realistic am I in wanting to make my street-driven Fiero 2400-2500lbs? Lighter wheels, lighter suspension stuff (mimick slalom suspension), CF decklid/hood, lexan rear window, fiberglass trunk, no spare or jack or washer fluid, short front bumper (possible trimming of heavy metal bumper), lighter dash and seats, minimal insulation and light carpet....

That's all I can think of right now...
I'm in the mid 2600s with a 3.4 DOHC. Did you look at my thread? Do the same to yours and you should be in the low 2500s if not high 2400s.. Doing all that extra stuff (CF parts, fiberglass dash, light seats) will let you install a stereo system and perhaps some other goodies without getting out of the 2400s.
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Post by bryson »

*edit* -- The thread you posted in the first page? I'm checking it out now. I have a GT, though, so that may make a difference.
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Post by The Dark Side of Will »

bryson wrote:
The Dark Side of Will wrote:I oughta know... I came up with the concept and designed that hub. The bearings are '92 Z28 Camaro.

Yes, '84-'87 fronts only. At least you're not the typical Fiero owner who faints in shock after looking at the price.

What's mysterious about lowering the rear of an '88?
You designed that? :afrocool: Awesome -- Did you use software that analyzes stresses, or did you just base the design off the stock unit?

I know drop spindles can be used in the front to lower the car and maintain suspension geometry, but is there any way to lower the rear without changing geometry? Unless, of course, you changed it to make it better :bootyshake:

I have heard that the 84-87 front end weighs significantly less than the 88's front. Is there a way to get the weight savings of the earlier front end with the suspension geometry of the 88?
Yes, the early suspension is significantly lighter. If you want good geometry and light weight, design and build your own... or maybe adapt Corvette or Miata front suspension.

Don't lower the rear more than ~1". If you want to improve the geometry, especially on the '88's, raise the inner pivots of the lateral links/control arms.

I didn't analyze stresses on the hub. I just made it as beefy as it could practically be. In hindsight, the only other thing I'd do to it would be to add a feature onto which an ABS reluctor could be pressed.

The knuckle, OTOH, has a lot of dead weight and I think could lose another pound or maybe even two via FEA. The spindle can be drilled hollow to save a large fraction of a pound per corner as well.
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