Dynamic weight transfer calc

Question - why does my stove-hot FWD car lift its rear wheel when I hammer a turn, yet my mate's old Alfa sits f lat and goes 'round quick

Robert's Simple Weight Transfer calculat Works for anything with 4 wheels! <-- the formula <-- the example

Weight transfer = ( Lateral acceleration acceleration x Weight x Height of CG ) / Track width For example, an '82 Alfa Romeo GTV Tipo 116 is cornering at 0.85 g.

Assuming its track width is 1600 mm , height of CG is 500 mm and it weighs 1250 kg with a 70kg driver, then we can calculate the weight t Assuming the car has a perfect 50:50 weight dist ribution between front and rear, which it does (wi th gearbox and clutch at rear) then we c Therefore you can see the outside wheel has far more influence on handling than the inside wheel. This explains why we'd prefer unequal Lateral acceleration Track width CG height Weight Therefore your WT is… Weight distribFront

Rear 

Variables 0.85 <--insert Lateral G - try changing this to simulate sl Use G-meter or take a gues 1600 <--insert Track width mm (a relatively wide track is Look up your spec sheet! 500 <--insert C of G height in mm (low slung sports car Another guesstimate, but g 1250 <--insert weight in kg (extra mass equals extra wor Look up your spec sheet! A 332.03 kilograms (total weight transfer from side to side given these variables) 0.5 0.5 1 <-- Must = 1

Weight per side (static) per wheel

front rear 

625 312.5 312.5

The RESULTS! Look here for the figures - Weight per side (dynamic) This is why your nose-heavy FWD car understeers -->

per wh wheel

If 50:50 front:rear balance, car will handle neutrally If nose-heavy will ultimately understeer 

f rro ont (L (LOADED) front (UNLOADED)

per wh wheel

This is why your nose-heavy FWD car lifts a rear wheel -->

rear (L (LOADED) rear (UNLOADED)

478.52 ie outside front wheel 146.48 ie inside front wheel 478.52 ie outside rear wheel 146.48 ie inside rear wheel

OK, this is not every factor. Look at tyre compound, too. Chassis stiffness. Think about weight per kg spread o Enjoy!

er?

ransfer is 332 kg. an see that each inside wheel shoulders 146.48 kg while the outside has to suffer 478.51 kg. Give or take. length non-parallel double wishbones, because it has the least camber change on the outside wheel. Camber change is bad. ! Mostly from 0.7 to 0.85, sedans to sports cars on radials t a tape measure and go to height of engine, then come down 2/3rds height of engine, give or take dd yr own weight to see the effect!

test calculations! kg Dynamic Total weight loaded 957.03 Tot otal al wei weigh ghtt unlo unload aded ed 292.97

50:50 dist 332.03 332 .03 wt 625 wt side

957.03 loaded side 478. 47 8.52 52 pe perr whee wheell 292.97 unloaded side 146.48 146.4 8 per wheel wheel er the increased contact patch when you fit those big wide tyres - maybe that's why wet-weather driving is sooo

exciting?