Weight Reduction vs. Power

[light driver]

Last night I made a little experiment on "Expert level" seasonal race on Twin Ring Motegi...(The easiest Expert thing ever). I took my sweet little BMW 2002 Turbo, and gave it 477pp with max weight reduction, 902kg, and 299hp, no turbo added. No aids except abs1. Quite easy win... Then I thought about THIS thread and my own post a little further up above...So changed the car like this: Got rid of the stage 3 weight red, switched it to Standard, but kept the bonnet and window light parts on. Now the BMW weighed 1065kg. Turned the power up to 322hp by adding "high turbo" to bring it back to 477pp... And raced again...The car was way slower in its heavier stage, and much more difficult to drive. Didn`t even bother to complete the race. No doubt, light weight was the best by far on the BMW 2002 Turbo...No way the extra 23hp could compensate for the extra 163kg. Even on a relative high speed track like T R Motegi...First time I actually bothered to make this test. Result was clear...Still think it was the other way round in GT5...

Oh wait...There are a few cars, or at least one in GT6 which benefits from higher weight and more power with it.. Suzuki GSXR-4 off course, and probably a few more... But NOT my BMW 2002 Turbo...

 

[Sharpie]

"You can't make up for light weight. You can add power or take off weight. Taking off weight's a little better." - Jay Leno

From a true car enthusiast

 

[stuff1138]

@light driver great test!

Extremely light weight cars (Caterham, GSXR-4, etc) tend to be sprung tighter than a "light" road car such as the 2002. Adding power to something light will always make it accelerate quicker assuming that the rubber will stay in contact with the road surface. The drive wheels of an extremely light, tightly sprung car with a ton of power will deflect and skip/hop because of the torque loads they are under and the fact that there is litte opposing force pushing them against the road surface so the car becomes unstable. In a straight line this can cause massive wheel spin to the point that car never hooks up and just spins in circles. While cornering, more of the cars weight, and therefore more grip, is on one drive wheel's contact patch. This extra grip to one side causes the other drive wheel to start losing grip, then deflect and the car becomes unstable. Since the car is so light and the forces are so great (because of the massive power to weight ratio) without "alien" reaction times it will be very hard to recover without losing a ton of time or complete control of the car.

Some things you can try to counter this without adding weight are; loosen the springs for the drive wheels; tighten up the damper rebound for the drive wheels; loosen the damper bound for the drive wheels; use grippier tires and of course add down force. Adding weight should really be a last resort because once you start doing that the car starts to become harder to stop. An identical car weighing 900kg will take less energy to stop than a car weighing 1000kg allowing you to brake later, carry more speed in the corners and accelerate earlier out of the corners.

Weight distribution is important too. A 50/50 split can definitely positively affect the handling of a car but if you can keep the car under control with a wonky weight distribution and a good suspension tune you can probably still be quicker with a lighter car than a heavier car. This isn't always true but when possible aim for this. There's a reason why they put a minimum weight limit on a race car and not a maximum.

 

[Skarmory]

i just reduce them all to minimal weight and throw on power upgrades until i reach the race restriction

less weight is a must on the heavier cars, otherwise they turn like barges