What's more important? More power or less weight?

[djroadboy]

Something for all you clever folks to discuss.

Lets say you are limited to 200bhp/tonne to race in a particular series..

Would it be better to have 140 bhp and a 700kg weight or 180 bhp and a 900kg weight?

I am all for lightweight but you need power to overtake/defend positions. So which is more important?

Dan

[P I Staker]

Adding power makes you faster on the straights, subtracting weight makes you faster everywhere.

[Mikey G]

P I Staker said:

Adding power makes you faster on the straights, subtracting weight makes you faster everywhere.

True, less weight means the tires and suspension work less, makes the whole car more efficient so to speak.
More power just means you can throw a bigger hammer in a straight line...

[djroadboy]

But its not just about ultimate lap times in a race situation though is it? Obviously it varies from circuit to circuit but there's no point in being quick everywhere through lightweight if you get mugged down every long straight through lack of power.

Dan

[Gwagon111]

As a chap who never amounted to much, once said, "add lightness".

[Scuffers]

depends....

some cars are more sensitive to weight than others, and some have more aero issues than others

the first have more issues with weight being added, the latter will make better use of more power.

If your talking the Elise, suffer the weight, if you can get more power to use.

only downside to this is in longer races, you will be heavier on tyres/brakes.

[coppice]

I do remmeber watching a fascinating battle which iluustrated this point - at Croft between a monster Ford Falcon (I think- Aussie V8 with approx 600bhp and 1500kg to drag around)and a 500 kilo 250ish bhp Seven. The Falcon won by a nose but there was nowt in it.

[RegMolehusband]

A lighter car can take big chunks of time out of a heavier car under braking and turn-in (based on my Caterham hillclimbing experience).

Edited by RegMolehusband on Sunday 28th October 09:07

[New POD]

djroadboy said:

Something for all you clever folks to discuss.

Lets say you are limited to 200bhp/tonne to race in a particular series..

Would it be better to have 140 bhp and a 700kg weight or 180 bhp and a 900kg weight?

I am all for lightweight but you need power to overtake/defend positions. So which is more important?

Dan

[Corpulent Tosser]

djroadboy said:

Would it be better to have 140 bhp and a 700kg weight or 180 bhp and a 900kg weight?


Dan

IMO 140bhp and 700Kg

With the same power/weight ratio there would be little in it on the straights, but the lighter car could brake later, carry more corner speed and enter the straights faster.

Of course all other factors would have to be equal, but that would certainly be the way I would go.

[Ferg]

Surely with identical power to weight you will never get mugged on the straight? Aerodynamics is the only factor making much difference in that situation. Light weight is best.

[RealSquirrels]

less weight and less drag.

[GreigM]

Depends on the circuit/gearing also - if you're at Spa or Silverstone with long straights the extra power (and gearing to use it) is important, but somewhere like Oulton which is more about handling then the weight loss will be a bigger advantage.

[IforB]

A while ago, in gp bike racing, there were some who decided to go for lighter bikes with a bit less power. On single lap with no traffic, they were fast. In a race, they were rubbish as the bigger, heavier and more powerful bikes simply sat in the way and runined their advantage. Once the bigger bikes opened the throttle, they disappeared off into the distance down the straights.

So from that point of view, for a laptime, lightness is key, for racing you need both, but more power is always good.

[djroadboy]

Some interesting points. I guess it very much does depend on the circuit and the car/aero. I suppose in reality its about finding the right balance between the two.

Scuffers, the original discussion I had was about the Elise but led into this more general discussion. Very good point about tyres & brakes in longer races. Congrats on your Time Attack result btw. That was something I thought about with regards to this. Clearly the lower weight of Jamie's car was an advantage but looking at how slow it was through the speed traps I would have thought you'd have been a sitting duck on the straights in a race situation.

Have fun in Oz! :-D

Dan

[AJS-]

Surely it would depend on the circuit mostly? Monza or Silverstone you'd probably want the power, Monaco or Singapore light weight.

On balance I'd probably go for light weight - you can exit corners faster and brake later, which makes defending positions a lot easier. Also for longer races you will be easier on tyres, brakes and fuel.

[zac510]

Depends upon the torque curve too

[SlipStream77]

AJS- said:

Surely it would depend on the circuit mostly? Monza or Silverstone you'd probably want the power, Monaco or Singapore light weight.

On balance I'd probably go for light weight - you can exit corners faster and brake later, which makes defending positions a lot easier. Also for longer races you will be easier on tyres, brakes and fuel.

^^This

[wildman0609]

it also depends on the type of race. for endurance racing the lighter less powerfull car would be more fuel efficient and need to stop to refuel less than a heavier more powerful car.

[Scuffers]

djroadboy said:

Scuffers, the original discussion I had was about the Elise but led into this more general discussion. Very good point about tyres & brakes in longer races. Congrats on your Time Attack result btw. That was something I thought about with regards to this. Clearly the lower weight of Jamie's car was an advantage but looking at how slow it was through the speed traps I would have thought you'd have been a sitting duck on the straights in a race situation.

kind of depends... if you have enough of a braking and corner speed advantage, short of the 'faster' cars running 3-4 wide in the braking zones, you will still be able to run away after a couple of corners.

problem with most cars is aero, as in drag, as in weight has nothing to do with drag, you just need power.

other issue is there is weight and weight, add 50Kg's to the roof of a car, you will notice the difference, add it to the floor, probably not, all that happens is you work the tyres and brakes more.

this kind of thing really comes down to what the car is and who your competition is, but I would suggest if your running to a P/W limit, then making the engine produce your target power as low down the rev-range as possible, then staying at this level for the rest of the rev-range is the way forward, ie. so you at max power (allowable) all the time, this has a huge difference unless you have a 7-8 speed sequential etc.