Wednesday, June 10, 2009
Tuesday, June 2, 2009
automotive formulas 2
Some formulas contain notation such as ^2 which means "squared" or ^3 which means "cubed"
Formulas for Calculating Performance
Ex: 8.4s (1/8 mile) X 1.5832= 13.2s (1/4 mile)
Convert between 1/4 mile and 1/8 mile ET's
1/4 mile ET = 1/8 mile ET x 1.5832 (thanks to Bobby Mosher for this formula)
1/8 mile ET = 1/4 mile ET / 1.5832 (thanks to Bobby Mosher for this formula)
Calculate 1/4 mile ET and MPH from HP and Weight
ET = ((Weight / HP)^.333) * 5.825
MPH = ((HP / Weight)^.333) * 234
Calculate HP From ET and Weight
HP = (Weight / ((ET/5.825)^3))
Calculate HP From MPH and Weight
HP = (((MPH / 234)^3) * Weight)
Formulas for displacement, bore and stroke
pi/4 = 0.7853982
cylinder volume = pi/4 x bore^2 x stroke
stroke = displacement / (pi/4 x bore^2 x number of cylinders)
Formulas for compression ratio
(CylVolume + ChamberVolume) / ChamberVolume
cylinder volume = pi/4 x bore^2 x stroke
chamber volume = cylinder volume / compression ratio - 1.0
displacement ratio = cylinder volume / chamber volume
amount to mill = (new disp. ratio - old disp. ratio / new disp. ratio x old disp. ratio) x stroke
Formulas for piston speed
piston speed in fpm = stroke in inches x rpm / 6
rpm = piston speed in fpm x 6 / stroke in inches
Formulas for brake horsepower
horsepower = rpm x torque / 5252
torque = 5252 x horsepower / rpm
brake specific fuel consumption = fuel pounds per hour / brake horsepower
bhp loss = elevation in feet / 1000 x 0.03 x bhp at sea level
Formulas for indicated horsepower & torque
horsepower = mep x displcement x rpm / 792,00
torque = mep x displacement / 150.8
mep = hp x 792,000 / displacement x rpm
mep = hp x 792,000 / displacement x rpm
mechanical efficiency = brake output / indocated output x 100
friction output = indicated output - brake output
taxable horsepower = bore2 x cylinders / 2.5
Formulas for air capacity & volumetric efficiency
theoretical cfm = rpm x displacement / 3456
volumetric efficiency = actual cfm / theoretical cfm x 100
street carb cfm = rpm x displacement / 3456 x 0.85
racing carb cfm = rpm x displacement / 3456 x 1.1
Formulas for tire size & their effect
effective ratio = (old tire diameter / new tire diameter) x original ratio
actual mph = (new tire diameter / old tire diameter) x actual mph
Formulas for g force & weight transfer
drive wheel torque = flywheel torque x first gear x final drive x 0.85
wheel thrust = drive wheel torque / rolling radius
g = wheel thrust / weight
weight transfer = weight x cg height / wheelbase x g
lateral acceleration = 1.227 x raduis / time^2
lateral weight transfer = weight x cg height / wheel track x g
centrufugal force = weight x g
Formulas for shift points
rpm after shift = ratio shift into / ratio shift from x rpm before shift
driveshaft torque = flywheel torque x transmission ratio
Formula for instrument error
actual mph = 3600 / seconds per mile
speedometer error percent = difference between actual and indicated speed / actual speed x 100
indicated distance = odometer reading at finish - odometer reading at start
odometer error percent = difference between actual and indicated distances / actual distance x 100
Formulas for MPH RPM gears & tires
mph = (rpm x tire diameter) / (gear ratio x 336)
rpm = (mph x gear ratio x 336) / tire daimeter
gear ratio = (rpm x tire diameter) / (mph x 336)
tire diameter = (mph x gear ratio x 336) / rpm
Formulas for weight distribution
percent of weight on wheels = weight on wheels / overweight x 100
increased weight on wheels = [ distance of cg from wheels / wheelbase x weight ] + weight
Formulas for center of gravity
cj location behind front wheels = rear wheel weights / overall weight x wheelbase
cg location off-center to heavy side = track / 2 - [ weight on light side / overall weight ] x track
cg height = [ level wheelbase x raised wheelbase x added weight on scale / distance raised ] x overall weight
Formulas for Calculating Performance
Ex: 8.4s (1/8 mile) X 1.5832= 13.2s (1/4 mile)
Convert between 1/4 mile and 1/8 mile ET's
1/4 mile ET = 1/8 mile ET x 1.5832 (thanks to Bobby Mosher for this formula)
1/8 mile ET = 1/4 mile ET / 1.5832 (thanks to Bobby Mosher for this formula)
Calculate 1/4 mile ET and MPH from HP and Weight
ET = ((Weight / HP)^.333) * 5.825
MPH = ((HP / Weight)^.333) * 234
Calculate HP From ET and Weight
HP = (Weight / ((ET/5.825)^3))
Calculate HP From MPH and Weight
HP = (((MPH / 234)^3) * Weight)
Formulas for displacement, bore and stroke
pi/4 = 0.7853982
cylinder volume = pi/4 x bore^2 x stroke
stroke = displacement / (pi/4 x bore^2 x number of cylinders)
Formulas for compression ratio
(CylVolume + ChamberVolume) / ChamberVolume
cylinder volume = pi/4 x bore^2 x stroke
chamber volume = cylinder volume / compression ratio - 1.0
displacement ratio = cylinder volume / chamber volume
amount to mill = (new disp. ratio - old disp. ratio / new disp. ratio x old disp. ratio) x stroke
Formulas for piston speed
piston speed in fpm = stroke in inches x rpm / 6
rpm = piston speed in fpm x 6 / stroke in inches
Formulas for brake horsepower
horsepower = rpm x torque / 5252
torque = 5252 x horsepower / rpm
brake specific fuel consumption = fuel pounds per hour / brake horsepower
bhp loss = elevation in feet / 1000 x 0.03 x bhp at sea level
Formulas for indicated horsepower & torque
horsepower = mep x displcement x rpm / 792,00
torque = mep x displacement / 150.8
mep = hp x 792,000 / displacement x rpm
mep = hp x 792,000 / displacement x rpm
mechanical efficiency = brake output / indocated output x 100
friction output = indicated output - brake output
taxable horsepower = bore2 x cylinders / 2.5
Formulas for air capacity & volumetric efficiency
theoretical cfm = rpm x displacement / 3456
volumetric efficiency = actual cfm / theoretical cfm x 100
street carb cfm = rpm x displacement / 3456 x 0.85
racing carb cfm = rpm x displacement / 3456 x 1.1
Formulas for tire size & their effect
effective ratio = (old tire diameter / new tire diameter) x original ratio
actual mph = (new tire diameter / old tire diameter) x actual mph
Formulas for g force & weight transfer
drive wheel torque = flywheel torque x first gear x final drive x 0.85
wheel thrust = drive wheel torque / rolling radius
g = wheel thrust / weight
weight transfer = weight x cg height / wheelbase x g
lateral acceleration = 1.227 x raduis / time^2
lateral weight transfer = weight x cg height / wheel track x g
centrufugal force = weight x g
Formulas for shift points
rpm after shift = ratio shift into / ratio shift from x rpm before shift
driveshaft torque = flywheel torque x transmission ratio
Formula for instrument error
actual mph = 3600 / seconds per mile
speedometer error percent = difference between actual and indicated speed / actual speed x 100
indicated distance = odometer reading at finish - odometer reading at start
odometer error percent = difference between actual and indicated distances / actual distance x 100
Formulas for MPH RPM gears & tires
mph = (rpm x tire diameter) / (gear ratio x 336)
rpm = (mph x gear ratio x 336) / tire daimeter
gear ratio = (rpm x tire diameter) / (mph x 336)
tire diameter = (mph x gear ratio x 336) / rpm
Formulas for weight distribution
percent of weight on wheels = weight on wheels / overweight x 100
increased weight on wheels = [ distance of cg from wheels / wheelbase x weight ] + weight
Formulas for center of gravity
cj location behind front wheels = rear wheel weights / overall weight x wheelbase
cg location off-center to heavy side = track / 2 - [ weight on light side / overall weight ] x track
cg height = [ level wheelbase x raised wheelbase x added weight on scale / distance raised ] x overall weight
automotive formulas 1
The formula is Pi X the radius squared Time the stroke X number of cylinders
so on a 350 Chevy
3.1417 X 4 X 3.48 X8 = 349859
formula for displacement
(BORE)X(BORE)X(STROKE)X(.7854)X(NUMBER OF CYLINDERS)
EXAMPLE: 4x4 x 3.48 x .7854 x 8= 349.848576 round up 350ci
(Area of cylinder) x (stroke of engine) x (number of cylinders)
so...
(bore size/2)^2 x pi x stroke x 4
(pi = 3.142)
Surface area of piston x length of stroke x number of cylinders
Surface area = Radius square x pi
radius = 1/2 diam
Take a single cylinder's dimensions...
Length of piston stroke (h) in cm.
Internal Radius (r) of cylinder in cm.
Volume (cc) = π x r² x h.
cc x 4 = Volume of the 4 cylinders.
(Simple example: Stroke = 15cm. Radius = 4cm.
3.142 x 4 x 4 x 15 = 754cc per cylinder.
754 x 4 = 3,016cc = A 3 Litre engine).
so on a 350 Chevy
3.1417 X 4 X 3.48 X8 = 349859
formula for displacement
(BORE)X(BORE)X(STROKE)X(.7854)X(NUMBER OF CYLINDERS)
EXAMPLE: 4x4 x 3.48 x .7854 x 8= 349.848576 round up 350ci
(Area of cylinder) x (stroke of engine) x (number of cylinders)
so...
(bore size/2)^2 x pi x stroke x 4
(pi = 3.142)
Surface area of piston x length of stroke x number of cylinders
Surface area = Radius square x pi
radius = 1/2 diam
Take a single cylinder's dimensions...
Length of piston stroke (h) in cm.
Internal Radius (r) of cylinder in cm.
Volume (cc) = π x r² x h.
cc x 4 = Volume of the 4 cylinders.
(Simple example: Stroke = 15cm. Radius = 4cm.
3.142 x 4 x 4 x 15 = 754cc per cylinder.
754 x 4 = 3,016cc = A 3 Litre engine).
MV F4
MV F4
Engine
Type Four cylinder, 4 stroke, 16 valve
Bore x Stroke 76.0 mm x 55.0 mm
Displacemet 998.3 cc
Engine Management / Induction Weber Marelli 5SM ignition-injection integrated
System; induction discharge electronic ignition,
“Multipoint” electronic injection
Clutch wet, multi - disc
Transmission Cassette type; 6 speed constant mesh
Cooling System Liquid cooled, water-oil heat exchanger
Chassis
Type TIG welded CrMo steel tubular trellis
Aluminum alloy side plates
Wheelbase 55.40”
Overall length 79.01”
Overall width 26.97”
Seat height 31.87”
Curb weight, without fuel 414.5 lb. (F4 1000 R) / 416.7 lb. (F4 1000 R 1+1)
Fuel capacity 5.5 gal. (1.0 gal. reserve)
Fairings Thermoplastic
Suspension
Front 50 mm “UPSIDE - DOWN” telescopic hydraulic
Fork with rebound-compression damping
And spring preload adjustment
Rear Progressive, single shock absorber with rebound
And compression (High speed / Low speed)
Damping and spring preload (hydraulic control)
Brakes
Front Dual 320mm floating with steel braking band and
Aluminum flange; Radial-type with 4 piston calipers
Rear Single 210mm cross-drilled steel disc; 4piston caliper
Wheels / Tires
Front wheel 3.5” x 17.0” aluminum alloy
Front tire 120/70 ZR-17
Rear wheel 6.0” x 17.0” aluminum alloy
Rear tire 190/55 ZR-17
Performance*
Max. power 174 hp @ 11,900 RPM
(limit 13,000 RPM)
Max. torque 81.8 lb./ft. @ 10,000 RPM
Max. speed 187.0 mph
Engine
Type Four cylinder, 4 stroke, 16 valve
Bore x Stroke 76.0 mm x 55.0 mm
Displacemet 998.3 cc
Engine Management / Induction Weber Marelli 5SM ignition-injection integrated
System; induction discharge electronic ignition,
“Multipoint” electronic injection
Clutch wet, multi - disc
Transmission Cassette type; 6 speed constant mesh
Cooling System Liquid cooled, water-oil heat exchanger
Chassis
Type TIG welded CrMo steel tubular trellis
Aluminum alloy side plates
Wheelbase 55.40”
Overall length 79.01”
Overall width 26.97”
Seat height 31.87”
Curb weight, without fuel 414.5 lb. (F4 1000 R) / 416.7 lb. (F4 1000 R 1+1)
Fuel capacity 5.5 gal. (1.0 gal. reserve)
Fairings Thermoplastic
Suspension
Front 50 mm “UPSIDE - DOWN” telescopic hydraulic
Fork with rebound-compression damping
And spring preload adjustment
Rear Progressive, single shock absorber with rebound
And compression (High speed / Low speed)
Damping and spring preload (hydraulic control)
Brakes
Front Dual 320mm floating with steel braking band and
Aluminum flange; Radial-type with 4 piston calipers
Rear Single 210mm cross-drilled steel disc; 4piston caliper
Wheels / Tires
Front wheel 3.5” x 17.0” aluminum alloy
Front tire 120/70 ZR-17
Rear wheel 6.0” x 17.0” aluminum alloy
Rear tire 190/55 ZR-17
Performance*
Max. power 174 hp @ 11,900 RPM
(limit 13,000 RPM)
Max. torque 81.8 lb./ft. @ 10,000 RPM
Max. speed 187.0 mph
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