Is it faster to create a light car with a small engine or a heavy car with a huge engine?

Thought it was common sense. The lighter something is, the easier it is to get going. While momentum makes a difference, in the racing world you don't want something that weighs 100 tons but has 10,000bhp, mainly because you won't be able to get it to go around turns or anything, it may be hell on straightaways, but thats all it would be useful for.

Traction wise don't look at LFS though (if you are), tires never slide as much as they seem to in LFS.

Light is the best way to go, it takes less horsepower to get it going, and that lower weight really helps going around corners, and also because it uses less horsepower it improves gas mileage too.

It's impossible to say definitively either way without knowing all of the circumstances but almost always it's going to be the light car with the small engine. If the power to weight ratios are the same for the light and heavy cars then the light one should be quicker round an average lap. Extra power at the expense of weight gives you better top speed (unless the car is gearing limited) and better acceleration (where traction allows), but the lighter car should have better cornering speeds, better braking and better low speed acceleration.

edit: Additionally, if you're in a racing series where there's a minimum weight restriction then the lighter car will allow you to use more ballast weight which you should be able to place anywhere you like, allowing you to adjust the weight distribution of the car.

it largely depends on the track

for a simple comparison look at the wrs from fz5 vs lx6 which are a pretty good example
on track fighting for position however things can look vastly different and depend a whole lot on where the longest straight is

Light car with a huge engine...

Quote from XCNuse :

Traction wise don't look at LFS though (if you are), tires never slide as much as they seem to in LFS.

I thought LFS had too much grip atm - i mean 1.2 G on cheap-o road_normals?

Quote from ethan520 :

Is it faster to create a light car with a small engine or a heavy car with a huge engine?

Colin Chapman once said "add lightness, reduce complexity"

Weight is the enemy in racing.

Quote from Jakg :

I thought LFS had too much grip atm - i mean 1.2 G on cheap-o road_normals?

I get 1.2G peak in my road car. That's about right. The peak doesn't mean you have grip at that moment. You can generate these big peaks by throwing it into a roundabout and lifting.

Lightness is the key

Quote from Shotglass :

it largely depends on the track

Yep, it entirely depends on the track or the type of race. A 200bhp 200kg car would destroy a 1000bhp 1000kg car on a tight and twisty circuit, but wouldn't have a hope around a high-speed oval (assuming they were both equally aerodynamic).

Thrust SSC weighed something like 10 tonnes remember

Quote from Jakg :

I thought LFS had too much grip atm - i mean 1.2 G on cheap-o road_normals?

Take XFR with the softest slicks and try to turn around with full lock from a stand and see what happens.

...every sim seems bugged under around 10 MPH - i always ignored this because rarely am i ever under 10 MPH

For the expected behaviour you need to use a realistic diff, use an open diff and don't you suddenly find all the low speed tire scrubbing problems magically disappear?

Quote from Jakg :

I thought LFS had too much grip atm - i mean 1.2 G on cheap-o road_normals?

That's INSTANTANEOUS g force, NOT the AVERAGE g-force numbers you see from production car skidpad tests.

Quote from ajp71 :

For the expected behaviour you need to use a realistic diff, use an open diff and don't you suddenly find all the low speed tire scrubbing problems magically disappear?

Genius it works!

Locked is dead, long live LSD! Thank the maker.

Quote from XCNuse :

Genius it works!

Hehe FYI XCNuse RL cars scrub the same way roughly as cars in LFS with Diff's =) I hav e a viscus LSD in my car and I scrub all the time in low speed situations =)

There are lots of formula to lightness.
HERE GOES.

Lightness = Easy Manuverbility
Lightness = Save lots of fuel
Lightness = Nippy and good handling

Err I can't think of any more...

Quote from sweetreid :

Locked is dead, long live LSD! Thank the maker.

Lolz Locked hasn't been dead yet. MWUAHAHAH! I am still using Locked. By the way the clutch load preset is set 400-500 NM at best. It's almost as Locked Diffs!

Don't be silly and say:

Quote :

Locked is dead!

Which LSD are you talking about by the way? Is it the Clutch Pack LSD or Viscous LSD? :haha:

Quote from Viper93 :

Hehe FYI XCNuse RL cars scrub the same way roughly as cars in LFS with Diff's =) I hav e a viscus LSD in my car and I scrub all the time in low speed situations =)

My car's turn lock comes to early for me to get any scrubbing heh, my car has like maybe 25 degrees of steering lock, it isn't pretty. Actually I doubt it even has that much.

what is even better is a light car with a big engine (trust me) thats way you can keep up with skylines on the straights if not faster, then as the twisty bits come along..bye bye skyline

Quote from pearcy_2k7 :

what is even better is a light car with a big engine (trust me)

Nooooo, I can't get my head round that, that just doesn't make sense. Really? What a revelation! Thanks!

Well its not a good idea to put something like a v8 or any heavy engine in a car such as the elise the weight distribution goes out the window,.

Quote from pearcy_2k7 :

Well its not a good idea to put something like a v8 or any heavy engine in a car such as the elise the weight distribution goes out the window,.

Putting an all-aluminum small block V8 in an Elise would not change the weight distribution dramatically...

I bet it would, the Elise is a Lotus, meaning it has many years behind its technology and placements as Lotus always has since the days of Jim Clark.
I bet anything besides probably 200 lbs in the front drivers' seat dramatically changes the COG.

Keep in mind the Elise engine already is an aluminum block.

Not to mention, where would you put the 4 more cylinders?

Quote from XCNuse :

...

Not to mention, where would you put the 4 more cylinders?

In the boot?