OK I remember a thread where some guy was talking about loving huge amounts of HP and of course the forum experience kicked in and everyone started telling him that in a Fiero you don't need huge HP numbers in order to kick other cars' @$$ because of the power-to-weight ratios....... Anyways I got to thinking and what what kind of numbers would a Fiero have to be putting down in a 3800SC Fiero to have have similar PTW ratios and kick the pants off say Z06's, Vipers, new Challengers, LSX trans ams, etc........?

Well, obviously gearing and drag and traction are a factor, but just google the cars, find out thier power and weight, then divide weight by power. An L67 in a Fiero is probably near 10:1 Pretty respectable. Some lambos are 4:1, but your average car is 20:1+

got to remember that fieros aren't as light as many people think, the 84 base coupe is 2464lbs (lightest of all the fieros). I had some guy swear that fieros were under 1500lbs lol.. Man would that be nice So a 84' 2.5 has a power to weight ratio of 25:1 (95hp, 2464lbs), and my 87 GT has a 20:1 (135hp, 2708lbs)

[This message has been edited by kawana (edited 11-14-2008).]

With a ZZ4 SBC my power to weight ratio is 8.02:1

A new Z06 is 6.29:1
Challenger is 9.74:1
Viper is 5.75:1
LSX Trans Am is 10.21:1

To beat a new Z06 you would need around 425 hp
A viper or a ZR1 would require at least 500 hp

These are only going by power to weight ratio's based on flywheel horsepower. Gearing, drag, drivetrain loss, and traction make a huge difference as well.

As an example a stock 2008 Corvette has a power to weight ratio of 7.32:1 and runs 0-60 in 4.0 seconds and 1/4 mile in 12.4 seconds. (Car and Drive magazine) My car has 8.02:1 and runs 0-60 in 3.9 seconds and 12.3 in the 1/4 mile. So even with a slightly higher ratio I am .1 seconds faster due to traction, gearing, and/or drivetrain loss.

Yup, you can add power or you can subtract pounds to get where you want to go.

Not sure how much you can lighten a Fiero, but it's a bit funny to always hear about the huge horsepower plans everyone has, while no one talks about ripping out the air conditioning system or shaving a couple of hundred pounds off the car, which would be like adding quite a few BHP.

My 3.4 conversion into an old British car works so well because although the engine only puts out around 200 BHP, a Fiero GT would need to produce around 280 BHP just to match it for P/W. Of course the Fiero accelerates better off the line, being a mid-engined car with better traction. Naturally all that makes me want to add a turbo to the light car too. Let's see, the Fiero would then need to have an engine up in the 425 BHP range.... of course finding space for a turbo would be a bit problematic....

[This message has been edited by BillS (edited 11-15-2008).]

quote Originally posted by BillS: Yup, you can add power or you can subtract pounds to get where you want to go. Not sure how much you can lighten a Fiero, ......

There are lots of ways. You can start be getting rid of anything you don't need. Like you said, A/C is not needed. It depends on how far you want to go. I have seen some autocross cars with no doors just using the skin. They had a roll cage with a diagonal tube for protection instead of the heavy door. You should be able to get in the low 2000s getting rid of the interior, spare tire, A/C, etc. If you want to get extreem you can go for a tube chassis like I did. The tube chassis SD4 cars were about 1800 lbs with driver according to one of the drivers I know. Pretty light. Some of those motors were making around 400 hp. The GT 1 cars were required to be 2450 with 500 hp for that racing class (4.9 lbs/hp). My car is 2147 plus driver (me). My conservative weight to power ratio is 3.6 lbs/hp given that the engine is making 645 (the actual dyno number) and me with equipment is 200 lbs. After my mods, I am sure it is making more than that. I can feel it.

It just depends how far you want to go. You can click the link in my signature if you want to see details.

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Paul

For a full history of my IMSA Build: http://www.cardomain.com/ride/789315
HHP Adjustable Sway bars for ALL MODELS: https://www.fiero.nl/forum/Forum4/HTML/036556.html

Rrunner your car is amazing it takes a long time to read all of that.

quote Originally posted by BillS: Yup, you can add power or you can subtract pounds to get where you want to go. Not sure how much you can lighten a Fiero, but it's a bit funny to always hear about the huge horsepower plans everyone has, while no one talks about ripping out the air conditioning system or shaving a couple of hundred pounds off the car, which would be like adding quite a few BHP.

Theres not a whole lot you can take off a fiero. Im still not sure why my fastback weighs in at 2700lbs, and the 84 coupe weighs in at 2464. WHere is that 244lbs hiding? If i were making a completely race oriented fiero (but didn't want to go full tubeframe), i would ditch the power windows, and install lexan, gut the interior, lightweight rims, remove HVAC and all related parts, remove door innards etc.. but If you want to keep it streetable, theres not ALOT you can do,

quote Originally posted by kawana: Theres not a whole lot you can take off a fiero. Im still not sure why my fastback weighs in at 2700lbs, and the 84 coupe weighs in at 2464. WHere is that 244lbs hiding? If i were making a completely race oriented fiero (but didn't want to go full tubeframe), i would ditch the power windows, and install lexan, gut the interior, lightweight rims, remove HVAC and all related parts, remove door innards etc.. but If you want to keep it streetable, theres not ALOT you can do,

You could start with an '84, without any options and then do an engine swap. Also you could replace interior pieces (and other items) with more light weight parts. Many cars do this. Several of the body panels look the same on the ZR1 and the Z06. However there is much more carbon fiber on the ZR1. An aluminum flywheel, and lighter rims/tires will help the rotating mass, unsprung weight and overall weight of the car. Again, it depends what you want. Some people don't want to trade the looks of a fastback (as well as other options) for a lighter weight car. That's fine. I suppose that is why everyone talks HP. The other thing to consider is the purpose of the car. IF it is inteded to go in a straight line, then the weight is not as critical. With enough HP, even a brick can fly. But it becomes more important when you want to turn.

Just some thoughts.

Ya, i was thinking of using an 84 as a project sleeper, but i hear that engine swaps are more of a PITA in them because of the wiring, but i might have heard wrong.

Throw a turn into the mix and nearly all cars mentioned are faster regardless of power.

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