[Tech Issue] Off throttle diffusers banned from Silverstone >

[Marbot]

The FIA have informed the teams that from Silverstone onwards, off throttle diffusers will be banned. Furthermore, from 2012 onwards, the exhaust can only exit the car in an area that will not allow the exhaust gases to work on the diffuser at all.

http://www.autosport.com/news/report.php/id/92236

[browney]

Well, it's lucky none of the teams spent tens of millions of dollars designing a car that complied with the rules at the start of the season and thus have plenty of money to develop a car half way through.... :S ?

To me this is a crazy move, the double decker diffuser was much further into the grey area. Many teams thought the DDD was illegal, as opposed to just Williams (serial complainers about things not going there way) and HRT this time. If using a fluid to change the aero set-up of a car constitutes a movable aerodynamic device, than the F-duct should also have been banned half way through the season last year.

I also see nothing wrong with using exhaust gasses this way. Maybe using down force from this instead of needing clean air flow on to the wings could even help cars follow each other a bit better?

[Marbot]

Originally Posted by browney

I also see nothing wrong with using exhaust gasses this way. Maybe using down force from this instead of needing clean air flow on to the wings could even help cars follow each other a bit better?

Maybe if they only used downforce from the diffuser, that would make the whole thing more road relevant in some way? Probably not. And I hate the noise they make!

More info:

"Whiting believes this is illegal because it is using the moving parts of the engine to influence aerodynamics and therefore, in his opinion, contravenes a long-standing rule banning moveable aerodynamic devices."

I can only agree with that. Just wonder why they allowed it, even in small measures, in the first place.

http://news.bbc.co.uk/sport1/hi/form...e/13739621.stm

[Rachel Richards]

I wonder if just once: the rule-book could stay the same all season?

F1 is simply a joke, with a chequered history of mid season changes, and optional (not mandatory) technology.

The sooner it gets bought out the better

[browney]

It is really stretching the definition to call this a moving aerodynamic device. That rule was designed to stop wings that move. This, at best, only contravenes the 'spirit' of the rules - if there is such a thing. I still don't know why using the exhaust gasses like this is such a problem for the FIA? It certainly shouldn't be banned mid season, when it is legal according to the rules at the start of the season.

None of the aero on the F1 cars is road relevant, at least this was an interesting and different piece of aero that the average person can understand. Who cares about little changes to winglets or end plates and how are they more relevant? It also influences strategy because using it, uses more fuel.

I really think this is a mistake by the FIA, and is probably just an attempt to bring the top cars back to the field (ie. red bull, who seem to have this working well).

[Marbot]

Originally Posted by Rachel Richards

I wonder if just once: the rule-book could stay the same all season?

No. This is F1.

Originally Posted by Rachel Richards

F1 is simply a joke, with a chequered history of mid season changes, and optional (not mandatory) technology.

That's always going to be the rub with a non-spec series. Even Red Bull only have a 2/3rds KERS.

Originally Posted by Rachel Richards

The sooner it gets bought out the better

Not really sure what difference F1 getting "bought out" will make, if the FIA are still overseeing the regulations? It is their series!

[Marbot]

Originally Posted by browney

It is really stretching the definition to call this a moving aerodynamic device.

The teams are basically using the piston as a compressor to increase downforce. I think that it can easily be argued that the piston is a moving object. This will now be limited to 10% of maximum fuelling, by the ECU. Which should be enough to cover any of the teams fears of damage to exhaust valves by not having additional fuel, off-throttle, to cool them down. It's not as if blown diffusers are anything new.

[phoenix]

Originally Posted by Marbot

Maybe if they only used downforce from the diffuser, that would make the whole thing more road relevant in some way? Probably not. And I hate the noise they make!

More info:

"Whiting believes this is illegal because it is using the moving parts of the engine to influence aerodynamics and therefore, in his opinion, contravenes a long-standing rule banning moveable aerodynamic devices."

I can only agree with that. Just wonder why they allowed it, even in small measures, in the first place.

http://news.bbc.co.uk/sport1/hi/form...e/13739621.stm

The exhaust gasses have for a long time been used by the designers to help aero - whether it is 'driving' the underside of the rear wing or 'driving' the diffuser. Even if this happens only on throttle rather than on and off throttle, the same argument holds that the internals of the engine are behaving as 'moveable aerodynamic devices'. So the only solutions would be to have the tail pipe finishing in a place where the exhaust has no aero effect - and it's hard to imagine where that might physically be - or to ban moving parts in engines....

I think this FIA argument is as nonsensical as their argument against the rather clever mass damper that Renault came up with. I think the FIA have been looking for a way to ban the off-throttle blown diffusers for their own reasons and have come up with this as the closest regulation that will support their ambition if the interpretation is stretched to the limit, but I think it is an entirely farcical use of the regulation.

[REALIST]

Originally Posted by Marbot

The teams are basically using the piston as a compressor to increase downforce. I think that it can easily be argued that the piston is a moving object. This will now be limited to 10% of maximum fuelling, by the ECU. Which should be enough to cover any of the teams fears of damage to exhaust valves by not having additional fuel, off-throttle, to cool them down. It's not as if blown diffusers are anything new.

But several of the teams, if not all, are actually injecting fuel straight into the exhaust to keep the hot gases flowing off throttle.

How is that a moving part?

[phoenix]

Originally Posted by Marbot

The teams are basically using the piston as a compressor to increase downforce. I think that it can easily be argued that the piston is a moving object. This will now be limited to 10% of maximum fuelling, by the ECU. Which should be enough to cover any of the teams fears of damage to exhaust valves by not having additional fuel, off-throttle, to cool them down. It's not as if blown diffusers are anything new.

Technically you are quite wrong. The expansion of the incoming air which provides the driving force for the diffusers on the overrun comes from burning fuel in the exhaust manifold, not in the cylinder, so the piston is not producing the 'blowing' force at all.

[browney]

I wish the Charlie would say why they are so against this practice (after all the exhaust gas isn't any more a moving part than last year, when they were also using it). Is it about pollution/green image or is it about evening up the field?

[fourWheelDrift]

Originally Posted by phoenix

Technically you are quite wrong. The expansion of the incoming air which provides the driving force for the diffusers on the overrun comes from burning fuel in the exhaust manifold, not in the cylinder, so the piston is not producing the 'blowing' force at all.

If it is going to get this pedantic the moving parts could equally well be in the fuel injection system or be the throttle butterflys. At the end of the day you are not going to get the exhaust gases flowing under the car without using the throttle butterflies, fuel injection, pistons and valves to get it there, presumably the air is going through the engine? you can't burn fuel without air.

I actually think there is merit in the FIA's position (and I don't often agree with them) because in principle there has been an unwritten acknowledgement that even though the exhaust does affect the aerodynamics of the car as a side effect of what goes on inside it the purpose of the engine is to provide traction and aerodynamically the engine is a passive lump which can reasonably be considered one single part. However once the teams deliberately change what is going on *inside* the engine to change the aerodynamics the idea of the engine (for aerodynamic purposes) as a black box, which we means we don't consider what goes on inside it, is gone so applying the rules about no moving aerodynamic devices to it makes sense.

Viewed in this way it's not the FIA moving the goalposts, rather it's the teams opening up the black box of the engine and making it do things that are designed to change the aerodynamics of the car, thus opening the door to applying the rules about aerodynamic parts to the engine.

[Marbot]

Originally Posted by REALIST

But several of the teams, if not all, are actually injecting fuel straight into the exhaust to keep the hot gases flowing off throttle.

How is that a moving part?

They are injecting fuel into the cylinder as normal as is required under the regulations. They are simply retarding the ignition so that the engine does not produce power when that fuel is ignited. It is then pushed out of the exhaust pipe by the action of the pistons, whether or not it is ignited in the cylinder or the exhaust pipe.

[Spritle]

From ESPN:

"FIA president Jean Todt said last week he is resolute because sophisticated 'hot' exhaust blowing is a "needless waste of fuel".

In other fuel saving changes announced by Todt, teams will be walking to all European venues and the safety car will be replaced with a bicycle...

[JeremySmith]

Originally Posted by Marbot

Maybe if they only used downforce from the diffuser, that would make the whole thing more road relevant in some way? Probably not. And I hate the noise they make!

More info:

"Whiting believes this is illegal because it is using the moving parts of the engine to influence aerodynamics and therefore, in his opinion, contravenes a long-standing rule banning moveable aerodynamic devices."

I can only agree with that. Just wonder why they allowed it, even in small measures, in the first place.

http://news.bbc.co.uk/sport1/hi/form...e/13739621.stm

But the aerodynamic device in this case is stationary, it does not move...

[ScotsBrutesFan]

Originally Posted by Marbot

More info:

"Whiting believes this is illegal because it is using the moving parts of the engine to influence aerodynamics and therefore, in his opinion, contravenes a long-standing rule banning moveable aerodynamic devices."

The adjustable front wing last season and the flip up rear wing this season are surely then by definition moveable aerodynamic devices.

Or how about when drivers were seen to cant their heads to one side to allow more air into the airbox, surely the driver when was a moveable aerodevice.

Hypocrisy rules in the FIA yet again

[Marbot]

Originally Posted by JeremySmith

But the aerodynamic device in this case is stationary, it does not move...

The pistons are moving the flow of the exhaust gases as they do in any other car fitted with an i.c. engine.

Originally Posted by ScotsBrutesFan

The adjustable front wing last season and the flip up rear wing this season are surely then by definition moveable aerodynamic devices.

Or how about when drivers were seen to cant their heads to one side to allow more air into the airbox, surely the driver when was a moveable aerodevice.

Hypocrisy rules in the FIA yet again

The adjustable front wing and DRS were/are 'legal' aerodynamic devices according to the regulations at the time. An adjustable front wing would most certainly be illegal this season.

In all probability, a driver moving his head to one side isn't likely to do a lot for the aero characteristics of an F1 car. But it might help the engine produce more power. His head is acting as a throttle plate, and therefore has nothing to do with aero. If a drivers head is so big that he needs to move it to one side in order to allow more air to get into the airbox, then surely hiring a driver with a smaller head or a shorter body would be of some benefit?

[JeremySmith]

Originally Posted by Marbot

The pistons are moving the flow of the exhaust gases as they do in any other car fitted with an i.c. engine.

Yes but the diffuser which is the aerodynamic part of the car is a fixed stationary piece of kit..

[phoenix]

Originally Posted by Marbot

The pistons are moving the flow of the exhaust gases as they do in any other car fitted with an i.c. engine.

On any i.c. petrol engine the piston 'pumps' about 2% of the total exhaust gas volume - the rest evacuates the cylinder under the force of it's own expansion due to the pressure differential between cylinder and ambient.

However, persuing your argument, the piston does the same on throttle - so it would still be a moving aerodynamic device.....

[Marbot]

Originally Posted by JeremySmith

Yes but the diffuser which is the aerodynamic part of the car is a fixed stationary piece of kit..

Define: "aerodynamic part of the car"

Currently, a button controls the rear wing flap. Is the button aerodynamic?

[Marbot]

Originally Posted by phoenix

On any i.c. petrol engine the piston 'pumps' about 2% of the total exhaust gas volume - the rest evacuates the cylinder under the force of it's own expansion due to the pressure differential between cylinder and ambient.

The expansion of the gases pushes the piston down on the power stroke. The exhaust stroke then pushes out the now uncompressed burnt gases. Whatever, the resultant flow of gas was initiated by the piston.

Originally Posted by phoenix

However, persuing your argument, the piston does the same on throttle - so it would still be a moving aerodynamic device.....

Which is my only argument against the FIA, in that it should never have been allowed to get even that far.

[phoenix]

Originally Posted by Marbot

The expansion of the gases pushes the piston down on the compression stroke. The exhaust stroke then pushes out the now uncompressed burnt gases. Whatever, the resultant flow of gas was initiated by the piston.



Which is my only argument against the FIA, in that it should never have been allowed to get even that far.

Well, if that's what you believe, this is not the place for the discussion, but you are wrong.

However, as I said above, if the piston is a moveable aerodynamic device then it should be banned on throttle as well as off throttle.

[JeremySmith]

Originally Posted by Marbot

Define: "aerodynamic part of the car"

Currently, a button controls the rear wing flap. Is the button aerodynamic?

No the button is a control device for allowing the movable flap to move..

Parts of the car that are created to aid aerodynamics,such as fixed diffusers that do not move.. Engine covers that do not move, wings that do not move, with the exception of the DRS...

[Marbot]

Originally Posted by phoenix

Well, if that's what you believe, this is not the place for the discussion, but you are wrong.

Ok. But I think that you'll find that is why they are called 'blown' diffusers and not 'sucked' diffusers.

Originally Posted by phoenix

However, as I said above, if the piston is a moveable aerodynamic device then it should be banned on throttle as well as off throttle.

Agreed. Which it will be for 2012.

[phoenix]

Originally Posted by Marbot

Ok. But I think that you'll find that is why they are called 'blown' diffusers and not 'sucked' diffusers.

OK - you are the font of all knowledge and the pistons pump the diffuser.......... (But I guess you never studied or understood thermodynamics.)

Originally Posted by Marbot

Agreed. Which it will be for 2012.

So - moving pistons are banned from 2012? How will the cars be powered?