Total weight needed?

[38flattie]

I'm hoping for a little help here. I've searched, but haven't founf what I'm looking for.

On a car build looking at a target of 180 mph, and a frontal are of 20.86 sq.ft, what kind of total weight should I be looking for? Is there a formula for this?

I found a ballast formula, but it only helped with weight on the drive wheels.

Any help is appreciated.

[jl222]

I'm hoping for a little help here. I've searched, but haven't founf what I'm looking for.

On a car build looking at a target of 180 mph, and a frontal are of 20.86 sq.ft, what kind of total weight should I be looking for? Is there a formula for this?

I found a ballast formula, but it only helped with weight on the drive wheels.

Any help is appreciated.

  As light as you can and still keep it on the ground
  Depends on what class you run and if you can have a spoiler and how much lift your body style has.
  Chapperrall racing figured out years ago that cars rear suspensions go into droop at about 160 mph [depending on style] and
added spoilers to their race cars.
No spoiler or wing more weight, or both. Maybe start heavy and take out if needed.
  We are about 4800 lbs with 3000 lbs on rear tires but at 180 mph would not need that much.

                             JL222

[Jonny Hotnuts]

At 180 mph any car with +20' fa wont have any issue with traction unless the car is entirely made from carbon fiber and rolling resistance is not a significant factor at these speeds.

Basically....I would say dont worry about it.

~JH

[Peter Jack]

I'd build with normal race car type materials, not trying to add additional weight or make anything extra light. At the same time include mounts where extra weight can be added. That way if you do require ballast you can bolt it on in the location it will do the most good and you won't have to use a huge amount as the car isn't ultra light to start with. Good Luck!

Pete

[38flattie]

Thanks guys!
It will be BVGALT.

[Stan Back]

Here's your answer . . .

"I'd build with normal race car type materials, not trying to add additional weight or make anything extra light. At the same time include mounts where extra weight can be added."

One way to consider doing that is to box the frame and segment it so you can add weight inside the rails later if needed.

Stan

[Jonny Hotnuts]

Here's your answer . . .

"I'd build with normal race car type materials, not trying to add additional weight or make anything extra light. At the same time include mounts where extra weight can be added."

One way to consider doing that is to box the frame and segment it so you can add weight inside the rails later if needed.

Stan

Also good if you need a place to hide your shine if the police are on your tail.  All things considered BVGALT racers are known to be prolific moonshine drinkers.

~JH

[38flattie]

Here's your answer . . .

"I'd build with normal race car type materials, not trying to add additional weight or make anything extra light. At the same time include mounts where extra weight can be added."

One way to consider doing that is to box the frame and segment it so you can add weight inside the rails later if needed.

Stan

Also good if you need a place to hide your shine if the police are on your tail.  All things considered BVGALT racers are known to be prolific moonshine drinkers.

~JH

I've been known to resemble that remark! That's why I started with a '38 Chevy-the frames are factory boxed.

[Jonny Hotnuts]

I've been known to resemble that remark! That's why I started with a '38 Chevy-the frames are factory boxed.

I got me a 38 chev as well.

http://sphotos.ak.fbcdn.net/hphotos-ak-snc3/hs175.snc3/20260_1308270942904_1114496579_31002776_5228789_n.jpg

[Stan Back]

"'38 Chevy-the frames are factory boxed."

Yabut -- you need to put dividers in there (along with access holes with caps) so, say if you use shot, you can pour it in and keep it in place where you put it.

[Peter Jack]

SURPRISE!!! ------- IT'S GREEN.

Pete

[hotrod]

I found a ballast formula, but it only helped with weight on the drive wheels.

Any help is appreciated.

If you use that formula and figure out how much weight you need on the drive wheels to get traction sufficient to use the power you expect, then it is a simple matter to figure out the total car weight once you decide what weight split you want to use front to back.

Suppose you want to use 65% of your weight on the rear wheels and need 3000 pounds of weight on the rear wheels.

Then the corresponding front tire weight would be  (3000/65 ) x 35 = 1615.4  pounds on the front wheels to get a 35/65 weight balance and 3000# on the rear wheels.

Total vehicle weight = 4615.4 lbs
To maintain stability you don't want to get too far from a 50/50 weight split or the front end will be so light you won't be able to keep the nose down unless you have some way to add aero down force in the front.

Larry

[jl222]

  Hey Larry thats sounds like our 222 Camaro 

            JL222

[38flattie]

Hotrod, if I use that formula, and use a 53/47 split, I come up with 2322Lbs on the front, 2619Lb on the rear, and a total car weight of 4941lbs. Does that sound right? Everyone told me I'd need a heavy car, but that heavy?

The 53/47 split came from Pat Riley's car, after he made corrections. It's the only car that I knew of like mine I could referance.

[RichFox]

5000 pounds sounds heavy to me. If you were building a 300mph roadster I would understand your concern with weight. Your choice of motive power guarantees enough weight forward. Just build the car without trying to make it light or heavy. Adding weight is easy. Taking out built in weight is hard. The Giants are killing 'em.