Mechanical grip vs Aero grip

[legatoblues]

A hot topic in modern racing is the amount of grip cars should have.

"Less grip, get them sliding around and working hard!" says one camp.

"More grip, give the drivers the confidence to push!" says the other.

But I don't really recall hearing much discussion about the relationship between mechanical grip and aero grip.

High downforce cars have trouble when running in dirty air, but wouldn't this be negated by an increase in mechanical grip, either through larger / stickier rubber, or some change to the overall setup?

Early-mid 2000's F1 had some pretty big issues with dirty air (iirc)...could this be an example of what I'm talking about, with reduced mechanical grip (the grooved tyres) having a negative impact on the racing?

The GT500 cars in Super GT have plenty of downforce but seem fine behind other cars, likely due to the grip provided by having an open tyre war.

On the other hand, as Indycar increased the downforce levels on the DW12 without making any other changes, racing seemed to suffer at all tracks (but especially the shorter ovals) compared to the brilliant racing frequently seen before the aero increase.

Am I missing something here, or is mechanical grip just not mentioned as much as downforce?

vs

 

[TenEightyOne]

You'd probably get a good discussion going on this in the F1 2017 Technical thread. I can tell you that in F1 the engineers/commentators often talk about mechanical grip, particularly at circuits like Monaco where the speeds (and therefore available downforce) are very low.

 

[twitcher]

It's an interesting conversation. Not going to pretend for a minute that I have the answers, but...

With all the talk from FIA and Manufacturers about wanting road relevence, why is the current formula do dependant on massive wings and appendages sticking out of the cars for providing downforce, none of which have any relevance to road cars. In fact, most manufacturers of super cars and hyper cars have moved away from massive wangs, instead focusing on underbody downforce and active aero.

Speaking of active aero, why is it banned? Active aero is the future, and has applications to road cars. Most Hypercars today have active aero...so why not on an F1 car?

Speaking of active, what's with the fuss over the suspension? Again, active suspension is the future, and has massive applications to road cars (automated or not), yet it's illegal in F1.

So, active aero and active suspension are illegal, yet have road car relevance. Massive wings, monkey seats, T-wings, shark fins, etc, are ok, but are things we will never in a million years see on a road car.

Me thinks the powers that be might be purposely driving this sport into the ground

Edit:
Just a note to add to the convo, keep in mind that the Evo is a TA car, not a racecar. It is in no way shape or form designed to race wheel to wheel with other cars, it is designed to run in clean air setting lap times (sound familiar?)

 

[LMSCorvetteGT2]

You'd probably get a good discussion going on this in the F1 2017 Technical thread. I can tell you that in F1 the engineers/commentators often talk about mechanical grip, particularly at circuits like Monaco where the speeds (and therefore available downforce) are very low.

Unless it rains then they try to give a bit more down force.

 

[Liquid]

Good god, what on earth is that Lancer-looking car and what series is it from? It looks utterly ridiculous.

 

[AudiMan2011]

Good god, what on earth is that Lancer-looking car and what series is it from? It looks utterly ridiculous.

Looks like an Australian Time Attack car.

 

[05XR8]

Looks like an Australian Time Attack car.

Exactly that.

 

[Scaff]

A hot topic in modern racing is the amount of grip cars should have.

"Less grip, get them sliding around and working hard!" says one camp.

"More grip, give the drivers the confidence to push!" says the other.

But I don't really recall hearing much discussion about the relationship between mechanical grip and aero grip.

High downforce cars have trouble when running in dirty air, but wouldn't this be negated by an increase in mechanical grip, either through larger / stickier rubber, or some change to the overall setup?

Early-mid 2000's F1 had some pretty big issues with dirty air (iirc)...could this be an example of what I'm talking about, with reduced mechanical grip (the grooved tyres) having a negative impact on the racing?

The GT500 cars in Super GT have plenty of downforce but seem fine behind other cars, likely due to the grip provided by having an open tyre war.

On the other hand, as Indycar increased the downforce levels on the DW12 without making any other changes, racing seemed to suffer at all tracks (but especially the shorter ovals) compared to the brilliant racing frequently seen before the aero increase.

Am I missing something here, or is mechanical grip just not mentioned as much as downforce?

vs

In very simplistic terms the reasons why open wheel cars have more issues with dirty air is because they are open wheel cars.

While they are able to generate stupid levels of downforce via aero, they are also creating a high degree of drag and air disruption from the four large tyres having limited aero management.

Closed wheel cars have significantly lower issues with this and as a result suffer less with regard to dirty air.

Its also not something that would change with greater mechanical grip either, as once aero grip comes into play its the dominant factor by a low way (and you are not going to get modern aero levels of grip out of tyres alone).

 

[Lewis_Hamilton_]

Speaking of active aero, why is it banned? Active aero is the future, and has applications to road cars. Most Hypercars today have active aero...so why not on an F1 car?

Speaking of active, what's with the fuss over the suspension? Again, active suspension is the future, and has massive applications to road cars (automated or not), yet it's illegal in F1.

So, active aero and active suspension are illegal, yet have road car relevance.

Just a guess on my part so don't take it as truth. I would think two main reasons would be to keep costs down for the lower budget teams, the second being a safety concern. F1 cars with lots of active aero parts would likely just be too fast.

 

[Scaff]

Just a guess on my part so don't take it as truth. I would think two main reasons would be to keep costs down for the lower budget teams, the second being a safety concern. F1 cars with lots of active aero parts would likely just be too fast.

These two and the removal of tech that can be considered driver aids.

The argument from back in the day for both was it made it too easy.

 

[TenEightyOne]

the second being a safety concern. F1 cars with lots of active aero parts would likely just be too fast.

There's an additional safety concern involved in that. Let's say there's a high-speed-but-tightening corner (possibly at Sepang) where adjustment of the active aero is required to get the car through at the highest possible velocity. Lap after lap the driver has to put faith in the active aero (just as he or she has to in every other aspect of the car). An active-aero failure could easily be catastrophic... and quite possibly more likely given that it's not a pre-stressed fixed-load part in the way that current aero/suspension fittings are.

 

[legatoblues]

Its also not something that would change with greater mechanical grip either, as once aero grip comes into play its the dominant factor by a low way (and you are not going to get modern aero levels of grip out of tyres alone).

Great post. This part specifically is something I'm rather interested in.

We know that downforce is important at high speed, mechanical grip at low speed.

Hypothetical situation here: take a car that has downforce of X and mechanical grip of Y and send it through a high speed corner. If we keep the aero the same but increase or decrease the mechanical grip (is it possible to do this without effecting drag?), how does this change the performance of the car?

I guess what it is that I'm most unsure about is the relationship between mechanical grip and aero grip. If we increase or decrease the two at the same rate, is this better than changing one and leaving the other the same? Or are they effectively two separate entities that do their own thing when needed?

(And as for the Can-Am rear and the Evo TA car, that was just a visual comparison between high grip and high downforce....nothing too serious about it!)

 

[VNAF Ace]

Less turbulence is also generated when most of the aero grip is generated using the underbody of the car (i.e. ground effect). Ground effect has been used in IndyCar design since the 1960s while it has unfortunately been banned in F1 since the 1980s which resulted in dramatic differences in the quality of racing between the two open wheel racing series. Thankfully, the new 2018 universal IndyCar aerokit will generate most of its aero grip via its underbody which will greatly improve the quality of racing.

 

[TenEightyOne]

Hypothetical situation here: take a car that has downforce of X and mechanical grip of Y and send it through a high speed corner. If we keep the aero the same but increase or decrease the mechanical grip (is it possible to do this without effecting drag?), how does this change the performance of the car?

Less grip = slower, more grip = faster, it's the lateral G tolerance that you need to keep. The only part of a car that provides any grip is the tyres, i.e. the mechanical aspects of the car. Centripetal force tries to push the car wide, mechanical grip stops it doing so. Adding vertical load with aerodynamics pushes the car into the ground harder increasing the resistance to the centripetal force.

The offset of that in higher-speed corners is that you generate greater aerodynamic downforce by increasing the angle of attack of the aerodynamic pieces - that means you increase the frontal area of the car making it slower through the static air.

 

[TheElbows]

Is it wrong I got a little "hnnngggghh" when I clicked on the first pic in the thread?

 

[TheBook]

Is it wrong I got a little "hnnngggghh" when I clicked on the first pic in the thread?

If it's wrong, then I don't want to be right.

 

[LeGeNd-1]

Personally I would like the sucker fan approach for F1 (ala Brabham BT46/Chaparral 2J/Red Bull X1). Remove all body aero (or keep them to a minimum) and rely on full underbody downforce and huge tyres. Ground effects was banned in the past because of the dangers of suddenly losing all downforce on bumpy circuits, but on modern circuits which are much smoother and with the fan always running I think the risk can be mitigated. The only problem is the fan throwing rocks/debris to the trailing car behind, but some kind of metal sieve covering the fan should prevent the bigger stuff getting thrown behind.

 

[Tired Tyres]

Single element flatplane wings like they used to run on the old Hockenheim track.

Lose all the winglets on the body of the car and the diffuser.

Run hard tyres none stop, medium tyres with one stop or soft tyres with two stops. No compulsion to run different tyres, just tactical decisions by the teams.

Plenty of power from the engine.

 

[TheCracker]

Personally I would like the sucker fan approach for F1 (ala Brabham BT46/Chaparral 2J/Red Bull X1). Remove all body aero (or keep them to a minimum) and rely on full underbody downforce and huge tyres. Ground effects was banned in the past because of the dangers of suddenly losing all downforce on bumpy circuits, but on modern circuits which are much smoother and with the fan always running I think the risk can be mitigated. The only problem is the fan throwing rocks/debris to the trailing car behind, but some kind of metal sieve covering the fan should prevent the bigger stuff getting thrown behind.

Modern circuits can still be bumpy and the curbs that all circuits have and all drivers use would be enough to quickly change the aero balance of any car riding them.

 

[mustafur]

A Perfect example of an F1 car that sacrificed Aero grip for Mechanical Grip:

Extra Rubber on the road Helped the grip in slow sections but ruined the Aero flow off the wheels with extra Turbulence.

 

[TheCracker]

A Perfect example of an F1 car that sacrificed Aero grip for Mechanical Grip:

Extra Rubber on the road Helped the grip in slow sections but ruined the Aero flow off the wheels with extra Turbulence.

It was a concept born out a need for better aerodynamics though. The lower front wheels 'hid' behind the front wing (which at the time had a limit on the maximum height and width) and smoothed the airflow to the rear wing.

 

[EDK]

Modern circuits can still be bumpy and the curbs that all circuits have and all drivers use would be enough to quickly change the aero balance of any car riding them.

COTA started to have a lot of problems with bumps over the past couple of years. I understand it started with a lot of heavy rainfall, which made the ground under the track less stable. They have been working to rectify it, but I think it's something they will always be chasing.

http://www.f1fanatic.co.uk/2016/10/20/cota-removes-bump-which-put-williams-cars-out/

http://www.motoamerica.com/goodbye-braking-bumps-garrett-gerloff-talks-cota-track-mods

There are also the city tracks to think about, Monaco and Singapore are always going to be bumpy.

 

[twitcher]

COTA started to have a lot of problems with bumps over the past couple of years. I understand it started with a lot of heavy rainfall, which made the ground under the track less stable. They have been working to rectify it, but I think it's something they will always be chasing.

http://www.f1fanatic.co.uk/2016/10/20/cota-removes-bump-which-put-williams-cars-out/

http://www.motoamerica.com/goodbye-braking-bumps-garrett-gerloff-talks-cota-track-mods

There are also the city tracks to think about, Monaco and Singapore are always going to be bumpy.

Montreal too. It's on a man made island in the middle of a massive river, in a place that gets very cold in the winter and therefore the roads surfaces suffer from frost heaving. If that's not a recipe for bumps, I don't know what is

 

[LeGeNd-1]

Modern circuits can still be bumpy and the curbs that all circuits have and all drivers use would be enough to quickly change the aero balance of any car riding them.

Fair enough. I always thought the extra suction of the fans will outweigh small changes in ride height due to minor bumps. It's not like pure ground effects with skirts where once you're off, you're gone. If you pair it with active suspension it will be even more effective and safe.

A Perfect example of an F1 car that sacrificed Aero grip for Mechanical Grip:
Extra Rubber on the road Helped the grip in slow sections but ruined the Aero flow off the wheels with extra Turbulence.

IIRC the extra grip is outweighed by the increased complexity (poorer reliability) and increased unsprung mass (making steering more difficult and suspension movements harder to control).