Weight of Unoptioned 1987 F-Body Combinations
Model Base Weight
IROC-Z 305 5.0 5-Speed 3250
Formula 305 5.0 5-Speed 3383
IROC-Z 350 5.7 Automatic Overdrive 3341
GTA 350 5.7 Automatic Overdrive 3476

Anyone know why an 87 IROCZ 305 5 speed is 133 pounds lighter than an 87 Formula 305 5 speed? Ditto for 5.7 liter cars. 133 pounds.

 

Yeah that doesn't make sense.... I thought Formulas were "omg teh lightest!!!!11!"

 

probably the rear spoiler those foam things are heavy.

 

True... forgot about that. I don't tend to think about it since my Formula has never had one since I've owned it. And it's getting replaced with a fiberglass 4th-gen replica so I should be able to maintain weight savings.

 

Hmmm.... very interesting....... muhahahahahahaha... All those, Formulas are the lightest thirdgens.....

J/k - Who knows anyway...

 

87 are you sure your Camaro is a B4Z not a B4C (Police Interceptor)? Just never heard of a B4Z.

 

the aerowing spoiler is rubber actually, mine cracked, its probably a good 30lbs or so
i imagine the hideaway lights add a few more lbs
i dunno what the weight difference would be but i know the iroc's front bumper support has large holes on both sides for the fog lights (i think) and my formula one was pretty solid
just a few little things i could think of off hand.. beats me where the other 90lbs is :P

edit: did the formula and iroc-z differ in standard equipment? i know the formula comes pretty loaded

 

Very close guess... the one I have sitting out back weighs in at 24lbs.

 

You'll have to get out your secret fbody decoder ring for b4z. ;>)

 

Moving...

 

B4Z= IROC package

 

The Pontiacs almost always weigh more than the Chevys.

The Formulas are about the lightest of the V8 Pontiacs.

All of those numbers look pretty believable to me, for dry weight (no gas, no driver, no cargo, minimum options, etc.)

 

With the Pontiac you get more car for the money. I'm guessing some of weight might be better interior parts or insulation. Only guessing. Haven't been in a bird to see if the plastic is a rattly as a Camaro. For sure can't be worse than Camaro.

 

I don't know about "better" interior parts, or "more car for the money"; but certainly "more" something or other. Mostly appearance and "comfort" type things, nothing functional like drive train or suspension or chassis. In fact, the Camaro is mostly better in that regard; lower restriction air intake, "wonderbar", a few other things. The only thing I can think of that the Birds have in that area that's arguably "better" is that more of them came with the 9-bolt, and even that is kind of subjective. Same for exterior trim. More, heavier, etc.; "better" is a little harder to pinpoint. The Firebird has a lower drag coefficient, but that's about it.

Every Firebird I've ever been in was about as rattle-prone as a Camaro, not really noticeably better or worse. The things that rattle, like T-tops, hatch glass, A-pillar molding, door guts, seat hinges, etc. etc. etc. are all pretty much the same.

 

Yeah. I initially meant to be kidding around when I typed "more car for the money" hoping to maybe rattle a bird owner or two. It seems some guys take the "Formula lightness" issue pretty seriously. Then got my self sidetracked and believing there might be potential for better interior. Birds do look a bit more plush inside, but probably share the same plastic with Camaro.

 

My 89 formula 350 weighed in at 3300 lbs with ttops almost a full tank and all..

The Leather seats in the birds weigh 60lbs driver and 40lbs pass

I have never weighed the camaro stuff..The same??

 

Seat weight sounds about right.... they're exactly the same, except for the seat covers; same power motor, same tracks, same shells, same foam, everything the same except the "styling" on the outermost layer (stitching pattern)

 

im saying though, an 'unoptioned' formula still comes standard with alot of stuff, I think standard is power windows, power locks, power mirrors, a/c, etc.. im assuming its the same with the iroc but that should probably be taken into consideration those things add up
some interior parts are shaped different, dash, center console, seats, door panels but i dont think it adds up to different quality or any noticable weight difference
again i dont know about the iroc but the formula came standard with the ws6 package which would add some weight
another thought someone might want to verify those weight numbers, i dont take the technical page as being total fact
133 between both the 305's and the 350's doesnt sound right
beings that the difference between the formula and gta were more then just engine and tranny, gfx and more standard options shouldve come with the gta which should add up to more then a 2lb difference between the 2 sets of cars

 

a buddy of mine and i weighed his bone stock 85 iroc and my 86 iroc and both cars weighed 3480.

 

The difference in weight is auto vs. manual tranny.


My '88 IROC weighed in at 3205lbs with 1/3 tank of gas.

 

That info sounds like it came from the article "Family Feud" in Automobile back in May of 1987 (sheesh thats 17 years ago) anyway, If I remember right, the authors clearly stated that the Formula was the "most fun to Drive"

'nuf said

As for your question, I think the weight difference comes in the Formula has the added weight of the headlights, and spoiler as mentioned before. Also keep in mind the WS6 package has heavier swaybars than the IROC.

John

 

I guess I can see a standard Formula weighing a little more due to the headlight motors, better insulation, larger rear spoiler, and higher content of standard equipment. (V8's and a/c go hand in hand with the Pontiac). The bottom line though, is once these cars are optioned out like they typically are in the real world, the weight difference is negligable.

and FYI..in response to an earlier comment...I wouldn't say the addition of a wonderbar on an IROC was result of better engineering, it was just an alternative to the bigger and better swaybars that the Firebird WS6 cars had

 

Camaro's did go after speed and handling a little more with their intakes, weight, less content, and suspension. Regardless, the WS6 cars were set up for good handling and a compliant ride compared to the IROC's all-out lateral G, rough riding setup. This is why they consistently hit .9-.92g's while the Firebirds stayed behind a little, but were more "comfortable" on the streets.

 

Well not to turn this into another "who's stronger Superman or the Hulk" debate over which F-body is supreme, but the same options were pretty much available on both cars, so I dont see the Camaro as a road racer stripper vs. a bloated over-optioned Firebird.

And both cars turned roughly the same g's varying only slightly in the .87-.90 range, depending on what mag you're reading. So even though the Firebird was slightly softer over the bumps(although they ride pretty damn hard to me), you'd have to have a pretty sensitive posterior to notice any difference in handling.

I'll give you the 5hp or so advantage the Camaro had with the better air intake set-up(in the earlier years anyway), but again we all know that 5 hp isn't worth squat on the street.

Bottom line, the cars are close enough in performance that the outcome is up to the driver.

 

Very well stated You get the cookie

 

Very well stated You get the cookie

 

I notice the differences. But to your post.

 

If the rear spoiler weighs that much, I wonder how much my 88 Special apperance spoiler weighs? It looks big. In that case I wonder how rare it is as well. I have heard so much about the spoiler over the past few years that it makes me think to hard and then my head hurts, lol.

 

if you stripped them to their guts, no interior ect, and just have the outer shell, i could see the wing, and popup lights adding weight... the combo of more front air dam, the air intake snorkle and canister, and nose bracing could weigh SLIGHTLY more...


but im still missing 75lbs somewhere.

interior the console probly weighs more being two piece...
everything else is pretty close... i donno what the bracing holding the dash looks like but it cant be that much...


minimal options perhaps?

 

Wheels! it's gotta be the wheels. I have both an IROC and a TA. They both came with 16" stock wheels. My TA is an 86 and has the 16" formula wheels cause the crosslace ones didnt come out yet. I definatly think the formula's wheels are heavier cause ive had to carry both kinds up and down my basement stairs. Plus look at the surface area that the formula's wheels take up. Does somebody know how much they weigh? What about the quarter panels? The firebird's are a bit bigger. Maybe the weights were taken with a rear drum/peg leg IROC and a rear disc/posi formula?

 

Also don't forget that the front end of the 'birds are about 3-4 inches longer than the Camaro's. The fenders themselves are longer with more metal in them, plus more supports for the front bumper also. That's probably where the more weight comes into play.

 

no my point was both 'sets' of cars differed by the same amount, but were comparing, 2 irocs, and a formula and a gta, theres alot of differences between formula and gta and the only real weight difference being accounted for is the tranny

 

Those Firebird aluminum 5-spokes (not GTA crosslace) were really heavy weren't they? I heard they were the heaviest of all 3rdgen wheels.

If true, thats probably at least 60lbs over the IROC right there.

 

I just weighed my rims, the 84-87 WS6 rims used on the Formula and Trans AM weigh in at 25#, and the Formula rims from 88-92 weigh 21#.

I doubt the IROC rims weigh 10# each.

John