Front downforce on road cars is messed up

  • Thread starter Sander 001
  • 14 comments
  • 2,446 views
It doesn’t make sense on how some cars have front downforce and some don’t.

The Ferrari 458 had front downforce in GT5/6 but it doesn’t have any in GT Sport. :confused:

The flagship Ferrari’s Enzo and LaFerrari have zero front DF even though they have large air channeling and front spoiler designs, F1 style splitters! :confused::confused:Meanwhile, The Lamborghini Aventador has 50 front DF even though it has a much simpler front. The McLaren F1 is simpler still and it has 200 front DF! The Xbow also has 200 front DF, seems the manufacturer’s PR department gives them a write up on the car mentioning downforce and PD is obliged to give the car DF.

Doing a bit of research, the Enzo is supposed to have loads of frontal DF and the LaFerrari even has active aero elements in the front among other things! :crazy: Even without doing any research, common sense tells that there’s absolutely no way these 350km/h high tech wind tunnel designed machines would not have any front downforce whatsoever. Or any modern supercar.

I’ve been racing more often in N600 classes and even with the reduced power, the lack of control at any moderate speed makes driving these things basically ridiculous. You’re standing on the brake with both feet almost more than you’re touching the throttle:boggled:

PD please:ill:
 
14,341
United Kingdom
Not so Great Britain
I think this could just be down to the fact that you only see two numbers that relate to what is otherwise a set of complex equations.

Personally, I wouldn't take it mean that the Enzo has 0 number of front downforces, and 200 rear downforces... I'd take it that the car physics model has xxxx units of downforce in total evenly spread across the front and rear, on top of which there is an additional 200 units at the rear... so lets say the car has 1000 downforces inherent in it's design, so 500 front, 500 rear... except the car actually generates more at the back... so there is effectively this +200 rear figure, so the car actually had 500/700.

So the question then becomes, why do some cars have additional figures front and rear. Well, I suggest that the inherent car physics model number of downforces (xxxx above), is proportional to the cars Cd or CdA values. It could be cars with a lower CdA cannot mathematically achieve a high front or rear downforce number, without the boosting of the figures we see in the tuning screen. I'm not stating this as a fact but I think it holds up with the Enzo and MacF1 examples.

.. but like I say Aero is complex, the fact that the tuning screen units are dimensionless is telling. Consider for a moment that 200kg of downforce is entirely speed dependent, air pressure dependent, and headwind dependent... so whatever units they are in the tuning screen, they aren't likely to be kg or N. In vehicle dynamics, *I believe* such things are talked about as Coefficients of Lift... much the same way as coefficients of drag... and that the actual values for 'downforce' a.k.a. negative lift are generated using the same equations... so it would make more sense for them to actually be related to cL.

..

There's also intuition vs expectation vs perception vs experience at play here.
 
3,954
Philippines
Laguna
Alpha_Cipher1
I think this could just be down to the fact that you only see two numbers that relate to what is otherwise a set of complex equations.

Personally, I wouldn't take it mean that the Enzo has 0 number of front downforces, and 200 rear downforces... I'd take it that the car physics model has xxxx units of downforce in total evenly spread across the front and rear, on top of which there is an additional 200 units at the rear... so lets say the car has 1000 downforces inherent in it's design, so 500 front, 500 rear... except the car actually generates more at the back... so there is effectively this +200 rear figure, so the car actually had 500/700.

So the question then becomes, why do some cars have additional figures front and rear. Well, I suggest that the inherent car physics model number of downforces (xxxx above), is proportional to the cars Cd or CdA values. It could be cars with a lower CdA cannot mathematically achieve a high front or rear downforce number, without the boosting of the figures we see in the tuning screen. I'm not stating this as a fact but I think it holds up with the Enzo and MacF1 examples.

.. but like I say Aero is complex, the fact that the tuning screen units are dimensionless is telling. Consider for a moment that 200kg of downforce is entirely speed dependent, air pressure dependent, and headwind dependent... so whatever units they are in the tuning screen, they aren't likely to be kg or N. In vehicle dynamics, *I believe* such things are talked about as Coefficients of Lift... much the same way as coefficients of drag... and that the actual values for 'downforce' a.k.a. negative lift are generated using the same equations... so it would make more sense for them to actually be related to cL.

..

There's also intuition vs expectation vs perception vs experience at play here.
This is a very believable argument, and I would almost agree with you, if only it explains why the Vulcan handles as it is right now :(
I'm repeating the Vulcan over and over not because I like it, but because it's the car where the flaws of the aero system really shows. Maybe it's an outlier?

But overall, well said 👍
 
811
United Kingdom
United Kingdom
I'm pretty sure if it says zero then it means none rather than baseline.

Based on how the cars drive anyway. The Vulcan has massive downforce I.R.L but clearly is not modelled with anywhere near realistic downforce in the game - the braking in particular is a world apart.
 
1,689
United States
NY
SavageEvil
It doesn’t make sense on how some cars have front downforce and some don’t.

The Ferrari 458 had front downforce in GT5/6 but it doesn’t have any in GT Sport. :confused:

The flagship Ferrari’s Enzo and LaFerrari have zero front DF even though they have large air channeling and front spoiler designs, F1 style splitters! :confused::confused:Meanwhile, The Lamborghini Aventador has 50 front DF even though it has a much simpler front. The McLaren F1 is simpler still and it has 200 front DF! The Xbow also has 200 front DF, seems the manufacturer’s PR department gives them a write up on the car mentioning downforce and PD is obliged to give the car DF.

Doing a bit of research, the Enzo is supposed to have loads of frontal DF and the LaFerrari even has active aero elements in the front among other things! :crazy: Even without doing any research, common sense tells that there’s absolutely no way these 350km/h high tech wind tunnel designed machines would not have any front downforce whatsoever. Or any modern supercar.

I’ve been racing more often in N600 classes and even with the reduced power, the lack of control at any moderate speed makes driving these things basically ridiculous. You’re standing on the brake with both feet almost more than you’re touching the throttle:boggled:

PD please:ill:

I have an idea, it think that most of these "super car" manufacturers throw out these buzzwords but don't give context. Do they state when those DF claims become applicable? Don't just assume DF claims apply across the board, more than likely those are peak claims and not what you can do normally at all. Folks don't buy super cars to race them, just because folks do doesn't mean they were built for that. Off the show room floor cars are only going to perform as well at it's designed to within a given spectrum.

Those numbers you threw out like 200 front DF for the McLaren and such sounds pretty high doesn't it? At what speed does it reach that 150, 220 or at 240mph? The numbers are the max amount of pressure it can generate at whatever speed it reaches that peak. Street cars generate positive lift at speed anyway, which is why some of them come with a lip spoiler at the rear end for highway cruise comfort and mileage range, generate lift but not too much to cause instability. Either way all vehicles pushing through air generate lift by nature, the Bernoulli Effect causes this it's also by taking advantage of this phenomenon which allows aircraft so large to fly. You should wonder less about those numbers since super cars like all other land borne vehicles will generate lift at speed due to air flowing underneath it at all times. Why are wind tunnels used for these cars, to reduce aero drag as much as possible they want that 0-60 time, majority of buyers aren't going to be racing their cars at any length at all, hence the exteriors are muted and don't sport the usual race car menagerie of canards, spoilers and duct work. My bet is on neutral DF at best and some downforce at higher speeds but there is a limit due to the muted design. All in all the aero work is going to be relatively pointless for racing around tracks since much of it is gained at higher speeds than the mechanical grip can cope with.

TL;DR Downforce claims in the game are just that and without context should be taken as the peak limit at relatively high speeds. Race cars look fancy outside due to needing the generate DF as quickly as possible so why would a street car be able to generate it faster or at the same pace when it's not even built with that in mind. Those numbers are honestly useless unless you are doing top speed runs where you can lose control due to lack of grip from positive lift that generates automatically as the car increases speed.
 
811
United Kingdom
United Kingdom
You should wonder less about those numbers since super cars like all other land borne vehicles will generate lift at speed due to air flowing underneath it at all times. Why are wind tunnels used for these cars, to reduce aero drag as much as possible they want that 0-60 time, majority of buyers aren't going to be racing their cars at any length at all, hence the exteriors are muted and don't sport the usual race car menagerie of canards, spoilers and duct work. My bet is on neutral DF at best and some downforce at higher speeds but there is a limit due to the muted design. All in all the aero work is going to be relatively pointless for racing around tracks since much of it is gained at higher speeds than the mechanical grip can cope with.

TL;DR Downforce claims in the game are just that and without context should be taken as the peak limit at relatively high speeds. Race cars look fancy outside due to needing the generate DF as quickly as possible so why would a street car be able to generate it faster or at the same pace when it's not even built with that in mind. Those numbers are honestly useless unless you are doing top speed runs where you can lose control due to lack of grip from positive lift that generates automatically as the car increases speed.

Wind tunnels are not used to optimise 0 to 60 times - aero becomes important at higher speeds.

And yes a downforce number will indicate a vertical force at a certain speed. But that doesn't mean that it's completely irrelevant at anything less than that peak speed. If one car makes 400kg downforce at 150 mph and another car makes 200kg downforce at 150 mph, then the first car will make more downforce than the second at any speed, it just won't be 400kg.
 
3,021
United States
Theresa, Wisconsin
Wind tunnels are not used to optimise 0 to 60 times - aero becomes important at higher speeds.

And yes a downforce number will indicate a vertical force at a certain speed. But that doesn't mean that it's completely irrelevant at anything less than that peak speed. If one car makes 400kg downforce at 150 mph and another car makes 200kg downforce at 150 mph, then the first car will make more downforce than the second at any speed, it just won't be 400kg.

The above is correct. One of the biggest reason manufacturers use wind tunnels is to reduce Cd to help cars get the best possible fuel economy. The way the EPA numbers work for example Ford as an entire company must average a certain predetermined fuel economy for the whole sales base each year. These are not real numbers but if Ford has to average like 20 MPG for every car sold it means they need to sell 3 Focus's for every F350 they sell to maintain the EPA mandated fuel mileage average. Back in the early 90's at one of the tech classes I attended they claimed it took about 5HP for some of the smaller cars to maintain 55 MPH on a flat road with the windows up, the biggest enemy being wind resistance, that really starts taking a lot of HP to overcome at speed in excess of 80MPH.
 
729
Brazil
Brazil
I can only imagine this being like it is for these cars for balancing reasons, even though it makes no sense at all and causes more harm than good.
 
1,202
I think they were challenged with balancing the higher performing N-Class cars against Group 3. Since many of these cars are capable of reaching horsepower numbers that Group 3 simply can't, they were reined in by having lower downforce levels and less consistent driving characteristics overall.

There's definitely a couple of hidden variables that we don't have access to for each car in the game, and I would say the most obvious examples would be the Tomahawk Group X cars having astounding levels of grip and downforce at high speeds despite the game telling us they're locked at a lowly 450/750 split.
 
3,138
United States
Connecticut
Ridley-X4
I think they were challenged with balancing the higher performing N-Class cars against Group 3. Since many of these cars are capable of reaching horsepower numbers that Group 3 simply can't, they were reined in by having lower downforce levels and less consistent driving characteristics overall.

But why balance higher-end N-series cars against those in Gr.3 when they're not really meant to race against each other? Hopefully they'll tinker with the DF in general in a future patch.
 
811
United Kingdom
United Kingdom
But why balance higher-end N-series cars against those in Gr.3 when they're not really meant to race against each other? Hopefully they'll tinker with the DF in general in a future patch.
Agree. They don't race together. So why even try to balance? If that's the reason. I'd suggest it's more just incompetence / ignorance on PD's side.
Vulcan and FXX aren't even road legal anyway, they are track only, so why are they N's in the game?
 
1,202
But why balance higher-end N-series cars against those in Gr.3 when they're not really meant to race against each other? Hopefully they'll tinker with the DF in general in a future patch.
That would just be my guess for general online racing against strangers or friends.

Vulcan and FXX aren't even road legal anyway, they are track only, so why are they N's in the game?
Haven't track specials usually been handled weirdly by PD anyways? The Zonda R was classified as a full race car and even has comparable downforce.