Exhaust blown diffusers and FIA restrictions/ban

[atanatizante]

Before FP1 they were allowed max. 10% HOT blowing and max.10% COLD blowing, if I`m not wrong ...

So if 68% HOT blowing = 100% COLD blowing, and if RBR use only 45% COLD blowing, then if that`s true the situation is like that:
- RBR has lost 35% of COLD blowing or equal 23,8% HOT blowing (I don`t know it`s a direct proportion ...)
- Mercedes and Ferrari have lost 90% HOT blowing and that`s more than 3 times less !!!

End of championship and happy holiday chaps!

[myurr]

So many things going on here.

1. It is highly unfair that regulations change in the middle of the season for any reason except saftey. Especially when things were deemed legal for prior seasons.

2. Charlie has access to ALL teams data so even before he made the statement that only 10% would be allowed, he should have taken a look at what people were doing, and WHY they were doing it.

3. If you are using this overrun to solve reliability issues with your engine, that is a problem. A little overrun, no problem, but a 50% overrun, that is a design flaw and you are pushing your engine too much. Might be time to tune it back a little.

4. Why is Horner the one arguing for Renault engines? Shoudnt it be Renault complaining? That would be like STR arguing for Ferrari engines. Strange...unless it only affects Redbull....

1. Typically I'd agree with you but here teams are really stretching the rules. This is active aero, it is the computer doing things to the throttle on behalf of the driver to help balance the car, and it is the mechanical and chemical blowing of aero on the car - much like the Brabham fan car that was banned after its first race.

2. Agree, but equally the teams have known about this for many weeks so why wait until the morning of the first practice to raise an issue?

3. Using the overrun is nothing to do with reliability, nor is it 50%. It's 10% throttle and a little bit of fuel in 4 of the 8 cylinders and it's to control engine braking and the stresses that places on the drivetrain. Mercedes cars also pay a weight penalty to be able to do this, something Renault don't have if they're cold blowing.

4. Because there's no technical grounds for complaint, just the usual Horner whinging?

[ecapox]

Perhaps Renault doesnt own the team anymore?

True, i dont think they fully own the team anymore, but you havent heard a peeep out of LRGP or any of their principles. You'd assume that if it is true that Horner says the Renault engine needs overrun to cool it's valves, you think that you'd also be hearing from LRGP people as well.

[djos]

The thing is Renault engines have never had Hot-Blowing, apparently due to the type of exhaust valves they run and have always had cold blowing instead.

Some of you guys need to read what Scarbs has written on his blog which explains why you simply cant go from 18,000rpm full throttle to a max of 10% throttle on driver Accelerator pedal lift off - if you do this then you end up with a very unstable car that cant blip the throttle enuf to even change down gears without transmitting huge loads thru the engine and gearbox!

[TheRMVR]

Some of you guys need to read what Scarbs has written on his blog which explains why you simply cant go from 18,000rpm full throttle to a max of 10% throttle on driver Accelerator pedal lift off - if you do this then you end up with a very unstable car that cant blip the throttle enuf to even change down gears without transmitting huge loads thru the engine and gearbox!

It's not like they had to change it overnight. They have known this for a very long time. It's a lame excuse.

And for the people out there who question the decision to ban or limit it in the middle of the season. That's because of the protest of HRT.
FIA had to do something. They knew if HRT would go to the WMSC and protest all the cars because they are in fact illegal, the FIA and F1 would have a huge problem. It's not to limit RBR as Brawn explaned. It's because HRT agreed not to protest if FIA came up with rules to limit or ban it.

[Lorenzo_Bandini]

It's the end, nothing will change, it's 10%, Horner said to the BBC right now that they accepted it.

[djos]

Thats were you are wrong, the only thing that can technically be called illegal is using the exhaust gasses for "Active Aero" Gain, and even that ruling is so borderline it's not funny as diffuser blowing has been in F1 since the 80's.

Neither Cold-Blowing the valves or firing on the over-run has ever been illegal and this is yet another example of the idiots in the FIA messing with things that they dont understand!!!

[myurr]

Thats were you are wrong, the only thing that can technically be called illegal is using the exhaust gasses for "Active Aero" Gain, and even that ruling is so borderline it's not funny as diffuser blowing has been in F1 since the 80's.

Neither Cold-Blowing the valves or firing on the over-run has ever been illegal and this is yet another example of the idiots in the FIA messing with things that they dont understand!!!

Diffuser blowing isn't in dispute, it's the hot and cold blowing where the throttle is actively opened when the driver is off throttle that is in dispute and that has not been used in F1 since the 80's, it's new to the latest implementations.

Also Red Bull and their fans are constantly crowing that the flexing front wing is legal because it passes the FIAs tests - well the FIA just declared the hot and cold blowing of the diffuser to be illegal. FIA are always right in Red Bulls eyes when it comes to flexing aero...

[WhiteBlue]

The stringent ban on cold blowing doesn't make any sense. The FiA wants to avoid fuel wasting and the use of engines as aerodynamic devices.

There is a good reason for cold blowing without exhaust blown diffusor as practised by Renault in 2009. You avoid throttling losses if you keep the throttle in a more open position without injecting the corresponding amount of fuel into the ports. It is actually better to do that than injecting fuel like Mercedes does.

So I think the compromise must be a uniform strategy that is the same for all and will apply for all teams from this weekend on.

[myurr]

The stringent ban on cold blowing doesn't make any sense. The FiA wants to avoid fuel wasting and the use of engines as aerodynamic devices.

There is a good reason for cold blowing without exhaust blown diffusor as practised by Renault in 2009. You avoid throttling losses if you keep the throttle in a more open position without injecting the corresponding amount of fuel into the ports. It is actually better to do that than injecting fuel like Mercedes does.

So I think the compromise must be a uniform strategy that is the same for all and will apply for all teams from this weekend on.

That is why the teams have gotten away with it for so long. They're still allowed to cold blow, but the teams were taking it to the extreme where it no longer had anything to do with the engine and was only for aero purposes. It is disingenuous to claim that the teams are cold blowing to the extent that they do for any reason other than the aero benefits it gives, which is why the FIA believe that it could be illegal and are clamping down on it.

[WhiteBlue]

It is disingenuous to claim that the teams are cold blowing to the extent that they do for any reason other than the aero benefits it gives, which is why the FIA believe that it could be illegal and are clamping down on it.

That makes no sense if Red Bull have run the Renault engine in 2009 with 50% throttle and no fuel injection as they claim. The objective obviously is saving fuel and avoiding the low pressure in the crank housing. It is better than the Mercedes strategy to waste 10% fuel for the same purpose.

The FiA have pushed the wrong rule strategy IMO by focussing only on throttle instead of looking also at the fuel injectors.

[Pierce89]

Thats were you are wrong, the only thing that can technically be called illegal is using the exhaust gasses for "Active Aero" Gain, and even that ruling is so borderline it's not funny as diffuser blowing has been in F1 since the 80's.

Neither Cold-Blowing the valves or firing on the over-run has ever been illegal and this is yet another example of the idiots in the FIA messing with things that they dont understand!!!

Diffuser blowing isn't in dispute, it's the hot and cold blowing where the throttle is actively opened when the driver is off throttle that is in dispute and that has not been used in F1 since the 80's, it's new to the latest implementations.

Also Red Bull and their fans are constantly crowing that the flexing front wing is legal because it passes the FIAs tests - well the FIA just declared the hot and cold blowing of the diffuser to be illegal. FIA are always right in Red Bulls eyes when it comes to flexing aero...

You're wrong about it being out of use since the 80's. Merc provided 2009 data showing they used fuel on the overrun.

[Pierce89]

4. Why is Horner the one arguing for Renault engines? Shoudnt it be Renault complaining? That would be like STR arguing for Ferrari engines. Strange...unless it only affects Redbull....

Perhaps Renault doesnt own the team anymore?

His point is that Red Bull don't do engines and if was truly an engine reliability issue Renault would do the arguing for their own engine rather than Red Bull. The fact that it's RED BULL complaining rather than their engine manufacturer, leads me to believe the engine doesn't really require 50% throttle on the overrun to survive.

[WhiteBlue]

The fact that it's RED BULL complaining rather than their engine manufacturer, leads me to believe the engine doesn't really require 50% throttle on the overrun to survive.

That is immaterial to the issue IMO. Red Bull only want to do what they were allowed to do before blown diffusors were introduced. Additionally their method is more fuel efficient than the Merc way of burning fuel for the same purpose. They should not be disadvantaged. If the question arises Merc should be allowed to make adjustments that would enable them to use the same amount of air for cooling purposes that Red Bull uses with the Renault engine.

[Nickel]

Before FP1 they were allowed max. 10% HOT blowing and max.10% COLD blowing, if I`m not wrong ...

So if 68% HOT blowing = 100% COLD blowing, and if RBR use only 45% COLD blowing, then if that`s true the situation is like that:
- RBR has lost 35% of COLD blowing or equal 23,8% HOT blowing (I don`t know it`s a direct proportion ...)
- Mercedes and Ferrari have lost 90% HOT blowing and that`s more than 3 times less !!!

End of championship and happy holiday chaps!

I think you may be getting your numbers confused. It has been estimated that hot blown is worth around a second over no blow, and that cold blown is worth around 4 tenths. The only time I've heard the number 68% bandied about in this discussion is related to the renault butterfly valves, and it is regarding the fact that with the renault, apparently a 45 or 50% throttle oppening somehow equates to a 68% opening. Merceded have not lost 90% hot blowing. They are allowed to hot blow 4 out of 8 cylinders, which by my understanding, is not equal to 10% throttle.

During quali Martin Brundle and DC raised a valid point the Ferrari have been strangely quiet about all these concesions to different manufacturers...