Landracing Forum

Tech Information => Technical Discussion => Topic started by: Bruno on April 29, 2009, 11:54:41 AM

Title: So where on the car is the best location to add weight?
Post by: Bruno on April 29, 2009, 11:54:41 AM

so I want to add some lead to the front, and rear of my 1990 corvette,  in regard to the rear where is the best place to locate the ballast ? in front or behind the rear axle?  The easyest place is behind the rear axle, just not sure one would want the weight that far aft?

Title: Re: So where on the car is the best location to add weight?
Post by: panic on April 29, 2009, 12:25:30 PM

Thanks for not reading this.

Title: Re: So where on the car is the best location to add weight?
Post by: SPARKY on April 29, 2009, 01:37:27 PM

Before I added any weight to any car ( I would put in on race car scales) but especially a Corvette----I would talk to someone is is running a similar car---some have NOTORIOUS lift

Title: Re: So where on the car is the best location to add weight?
Post by: Bruno on April 29, 2009, 02:58:49 PM

I am primarly concerned about traction,

Title: Re: So where on the car is the best location to add weight?
Post by: McRat on April 29, 2009, 03:03:47 PM

1 pound after the axle will give you more than 1 lb worth of traction.  Say wheelbase is 10 ft.  Put 100 lb at 2 feet after the axle, it puts 120lb weight on the rear tires, and removes 20 lb from the front tires.

Title: Re: So where on the car is the best location to add weight?
Post by: interested bystander on April 30, 2009, 12:25:44 AM

Other than putting it LOW, this brings up the topic of POLAR MOMENT OF INERTIA regards where to locate weight in the North and South diections.

 I'm curious as to knowledgable Landspeed racers opinions on Elmo vs Bonnevile as to  high? or low?
Are the two venues different. I.E. driving El Mirage you may need to be a sprint car driver therefore low polar moment, but Bonneville, accelerating  over several miles, ya might want a stabilizing high polar moment. You're both times trying to defeat the Spin Gods, but does it take a differnt approach??!!!   

Title: Re: So where on the car is the best location to add weight?
Post by: Stainless1 on April 30, 2009, 10:11:24 AM

Why not run it without any or minimal weight to start, after you weight it and know what the corners are doing.  Then you can see how it feels.  Make and take provisions for adding weight... Think about frame torque from the motor when you start to add weight.  You may not want the weight balanced...
Or just add a bellypan made of 3/8 to 1/2 inch steel and go racing...  :roll:

Title: Re: So where on the car is the best location to add weight?
Post by: sabat on April 30, 2009, 11:38:06 AM

Quote from: panic on April 29, 2009, 12:25:30 PM

Thanks for not reading this.

Why do you do this?

Title: Re: So where on the car is the best location to add weight?
Post by: SPARKY on April 30, 2009, 06:27:08 PM

 :evil: BPD?  :evil:

Title: Re: So where on the car is the best location to add weight?
Post by: McRat on April 30, 2009, 06:55:40 PM

I'd have to say you should always add weight to the car instead of the driver.  If I don't lose some weight, I'll have to use Crisco to get my firesuit on.   :cry:

:-D

To avoid spinning, I'd say always keep as much weight as possible between the tires, and keep the nose heavier than the rear, but I'm just guessing at that.  "Outboard" tires would have the most "leverage" against the weight of the car to resist spinning, and a heavy nose will naturally try to go into the wind.