Corner Weights ??
Thread Starter
Le Mans Master
Joined: Apr 2000
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Corner Weights ??
Any opinions? Still need to read it thru myself.. Application to C5?
http://www.grassrootsmotorsports.com/cornerweight.html
http://www.grassrootsmotorsports.com/cornerweight.html
Le Mans Master
Joined: Aug 2000
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From: Austin Texas
Re: Corner Weights ?? (MelloYellow)
This is standard (track) race car setup often called scaling the car. If every chassis was perfectly square and every spring was exactly the same length and had exactly the same spring constant, then scaling would not be necessary.
To scale a car (from Race Car Engineering by vanValkenburg circa 1985) you perform an approximate alignment of the 4 wheels--you will perform a final alignment after scaling--this is to get the wheels close enough so that scaling and alignment are (approximately) independent functions (which they are not in the general case). The car (with the weight of the driver in the drivers seat) is them placed on 4 scales one under each tire (usually replaced by a metal wheel at this point to increase the sensitivity of the scales, and the shocks are also removed or set on their loosest settings). The springs are shimmed/adjusted so that each left tire has the same weight as its right counterpart. After scaling, the suspension goes through a full alignment procedures, and may go through the scaling procedure again.
Scaling increases the balance of the car and also increases its sensitivity to changes in tire pressures, driving styles,...
To scale a car (from Race Car Engineering by vanValkenburg circa 1985) you perform an approximate alignment of the 4 wheels--you will perform a final alignment after scaling--this is to get the wheels close enough so that scaling and alignment are (approximately) independent functions (which they are not in the general case). The car (with the weight of the driver in the drivers seat) is them placed on 4 scales one under each tire (usually replaced by a metal wheel at this point to increase the sensitivity of the scales, and the shocks are also removed or set on their loosest settings). The springs are shimmed/adjusted so that each left tire has the same weight as its right counterpart. After scaling, the suspension goes through a full alignment procedures, and may go through the scaling procedure again.
Scaling increases the balance of the car and also increases its sensitivity to changes in tire pressures, driving styles,...
Thread Starter
Le Mans Master
Joined: Apr 2000
Posts: 7,248
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Re: Corner Weights ?? (MitchAlsup)
Thx, Thought they might be talking about scaling.
Has anyone done this? Normally people seem to feel it's a waste of time on the street and marginal for the track, eh? Expensive?
Any good techniques to measure Bump Steer when aligning?
[Modified by MelloYellow, 1:36 PM 2/5/2002]
[Modified by MelloYellow, 8:58 PM 2/5/2002]
Has anyone done this? Normally people seem to feel it's a waste of time on the street and marginal for the track, eh? Expensive?
Any good techniques to measure Bump Steer when aligning?
[Modified by MelloYellow, 1:36 PM 2/5/2002]
[Modified by MelloYellow, 8:58 PM 2/5/2002]
Race Director
Joined: Sep 1999
Posts: 12,422
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From: CONCORD NC
Re: Corner Weights ?? (MelloYellow)
You MUST have adjustable sway-bar links to do this correctly. Disconnect the sway bars (one link front and rear is enough) and get the car on a set of scales. It is simply a matter of adjusting the rear spring hanger bolts until you get within 10 lbs cross weight. At this point, you must adjust the end links on thw sway bars to hook them up WITH THE CAR RESTING ON THE WHEELS. If you don't you are simply binding the suspension back up.
I do this after ever suspension change, alignment, or weight change.
Dave
I do this after ever suspension change, alignment, or weight change.
Dave
