FIA to clamp down on exhaust blown diffusers

Should result in interesting balance changes to address the instability that will come now when off throttle. As DRZ pointed out, I do wonder if RBR will be forced to reduce their rake angle now that their 'extended' diffuser will be much less efficient. Having said that, watching Vettel in particular he seems to be able to utilise DRS in qualifying much earlier than rival teams out of corners, which suggests RBR's down force when at full throttle is better than everyone else too.

Apparently Mercedes could be running a new Renault style side exit exhaust this weekend with restyled side pods. Not sure whether this will have a lesser effect or perhaps even exaggerated effect off throttle.

Lots of new bits for everyone this weekend, will be interesting.
 
Shimmy said:
Should result in interesting balance changes to address the instability that will come now when off throttle. As DRZ pointed out, I do wonder if RBR will be forced to reduce their rake angle now that their 'extended' diffuser will be much less efficient. Having said that, watching Vettel in particular he seems to be able to utilise DRS in qualifying much earlier than rival teams out of corners, which suggests RBR's down force when at full throttle is better than everyone else too.

Apparently Mercedes could be running a new Renault style side exit exhaust this weekend with restyled side pods. Not sure whether this will have a lesser effect or perhaps even exaggerated effect off throttle.

Lots of new bits for everyone this weekend, will be interesting.
Click to expand...

I suspect that they extract far more downforce than the other teams just from the front of the car and they way they can manipulate the air around the tea tray because of the rake angle forcing the front to be nearer the ground.

My understanding of the way the FIA have done this is that basically, because the throttle pedal does not fully close (and the retarded timing allows the engine to run at pretty much full power on the over-run), during braking it is manipulating air flow at the back of the car and thus is deemed to be a moveable aerodynamic device.

I have already dreamt up a possible way around this, depending on the wording of the Technical Directive responsible, they might be able to have a second inlet to the engine, controllable by an f-duct style flow from the main inlet (just think how easy it would be for them to use a fluidic switch now they have mastered the f-duct conceptually) which allows air to flow in from a secondary inlet. You wouldn't even need any form of air monitoring as you could probably model the airflow enough to get your map close enough to the right zone and then let a knock sensor do the rest of the work...
 
DRZ said:
What IS interesting with regards to RBR is that the knock-on effect of this is that they might not be able to run such an extreme rake angle, raising the wing up to where it "should be" in the spirit of the regs rather than where it is by projecting the reference plane below the floor. The theory is that the RBR exhaust minimises the vortex generated by the rear wheels , effectively "sealing" the sides - much like the Renault is believed to use the exhaust energy to form a skirt around the sides of the car. The upshot of that is the diffuser can remain efficient whilst being relatively high - something none of the other teams' diffusers can do. They will have to reduce the rake angle to bring the diffuser down to restore the efficiency if they want to keep the car balanced, which means they will sacrifice the more efficient aerodynamic flows they are able to run by running at such an extreme rake angle.

Bear in mind that there could be as much as "800bhp" worth of energy coming out of the exhaust pipe when the engine is on full power - this is a HUGE net loss of energy from the diffuser when under braking!!
Click to expand...

Hmm didn't even think of that. Hopefully Scarb will have some further info on how this will effect them.

Few messages on his Twitter about it - http://twitter.com/#!/scarbsf1
 
Last edited:
Wait, so this has been going on for this season and the last and has only just been noticed by the FIA?

Will be really interesting to see how this affects RBR and any of the other teams - I agree with DRZ, that is a HUGE loss of energy. Who knows where this will leave the teams.
 
CaptainRAVE said:
Wait, so this has been going on for this season and the last and has only just been noticed by the FIA?
Click to expand...

I don't think its quite as simple as that. It is probably more of a case that the engines are being too much for aero use rather than just driving the wheels, which the FIA have decided to clamp down on (with the help of a few teams no doubt).
 
CaptainRAVE said:
Wait, so this has been going on for this season and the last and has only just been noticed by the FIA?

Will be really interesting to see how this affects RBR and any of the other teams - I agree with DRZ, that is a HUGE loss of energy. Who knows where this will leave the teams.
Click to expand...

I just read somewhere (one of the F1 fan forums) that McLaren *might* have gone to the FIA with their revised RBR-style map and said "is this OK?" to which the FIA went ape and issued this Technical Directive.


TaKeN said:
Wouldn't your idea cause the engine to run hot though DRZ?
Click to expand...

No, at least no hotter than they do at the moment - they do exactly this but by just controlling how much the butterfly closes when the throttle pedal is released. Basically, previous to this ruling they could have been running with it never being less than 70% closed and using the trick mapping to keep the engine spinning at full power, by running it leaner and hotter. They could get away with this by virtue of the fact that at a lot of the circuits they are running at wide open throttle for 60-70% of the lap.
 
Last edited:
CaptainRAVE said:
So McLaren don't have this system then? The next race will be fascinating. Reminiscent of the mass damper system of the Renault.
Click to expand...

They all did to some extent - they all figured out roughly what RBR were doing towards the latter part of 2010 when all of the cars started to sound mighty strange when lifting off.

This season I think in terms of EBD efficiency RBR were at the top, with McLaren and Ferrari on pretty much level pegging - I think Ferrari unlocked something in the last race which gave them a bit better pace. I think McLaren's failure with the pyrosic "octopus" exhaust which hurt them so much during winter testing means that they were so late to the 2011 EBD party that they might just get away with this. FP1 will be absolutely fascinating!

How much damage will this have done to the Renault FEE/EBF system? Nobody in the public domain seems to really understand their solution so it is hard to pick out anything on how this might affect them. It would be a real shame if it really damaged their season IMO, although I have a personal suspicion that their system is all about maintaining downforce when driving OUT of a slower speed corner rather than the RBR approach of maintaining downforce on the way IN/through the longer sweeping corners.
 
Duke said:
Where did this come from?



http://www.autosport.com/news/report.php/id/91475


I'm guessing the teams can change the engines to stop doing this quite quickly, is it done by electronics? Or it could cause some very quick shipping of new parts?
Click to expand...

This will purely be a change in the engine mapping. At the moment when the driver lifts off he can switch to a map which holds the throttle open and retards the ignition.

NathanE said:
It was only recently McLaren indicated they were aware of it. Sort of suggests that not all teams are doing it TBH.
Click to expand...

McLaren were running over run exhaust blowing last season, as were most of the other teams, to maintain the flow through slots into the outer diffuser. RBR were certainly there first though.
 
I am going to suggest we may see some spins due to this.

When McLaren were first trying the blown diffuser at Silverstone last year they had a major problem with a sudden an large reduction in rear end downforce on lifting the throttle. Anyone who watched Friday practice at Becketts will have seen the McLarens off the road a LOT as they lost rear grip.

This sudden change in engine mapping with no time to develop the exhausts could mean all the teams using the system are thrown back to how McLaren were at the begining. Expect to see some twitching and possibly some spins as drivers lift off in high speed corners.
 
Skeeter said:
Lol.

I bet the major teams complained about the sudden loss of rear grip.

TBH, I can see their point. The engine map is just one part of a whole rear end design. Changing just one bit can make handling rather unpredictable.
Click to expand...

Yup, you'd think the all-powerful FIA would thoroughly research such things before reaching a decision. I mean, surely... right? Errr...
 
So by the time it goes to the TWG and decisions are made, it will basically stay this season and be gone in 2012 no doubt.
 
Last edited:
People (and media) are getting confused by what has been banned.

EBD isn't banned. EBD is responsible for the vast majority of the awesome overrun noise you now hear on the F1 cars when braking, down shifting and slow corners.

What has been banned is the seemingly Renault-only (maybe Mercedes too, but definitely not McLaren) engine mappings which play with the throttle opening against fuel mixture and ignition retardation. Basically the ECU is mapped to always try to keep the widest possible throttle opening.

This allows the EBD to function better during partial throttle events than it would without the special mapping.

Bear in mind this special mapping is ONLY used in Q3 qualifying. I suppose they might also use it to pump in the odd fast lap during a race when needed - but we don't know that for sure. It damages the engine due to heat, so they will definitely be using it sparingly. So again, the awesome EBD overrun noise we hear all through practice, qually and the race is not going anywhere.
 
Last edited:
NathanE said:
People (and media) are getting confused by what has been banned.

EBD isn't banned. EBD is responsible for the vast majority of the awesome overrun noise you now hear on the F1 cars when braking, down shifting and slow corners.

What has been banned is the seemingly Renault-only (maybe Mercedes too, but definitely not McLaren) engine mappings which play with the throttle opening against fuel mixture and ignition retardation. Basically the ECU is mapped to always try to keep the widest possible throttle opening.

This allows the EBD to function better during partial throttle events than it would without the special mapping.

Bear in mind this special mapping is ONLY used in Q3 qualifying. I suppose they might also use it to pump in the odd fast lap during a race when needed - but we don't know that for sure. It damages the engine due to heat, so they will definitely be using it sparingly. So again, the awesome EBD overrun noise we hear all through practice, qually and the race is not going anywhere.
Click to expand...

Given that the "awesome overrun noises" are exactly what this ban would have affected, I think you are wide of the mark.

They don't only run the special mapping in Q3, they run it all of the time (which is why the engines sound different on over-run) but in quali spec they run at much higher power than when in race trim. It is very important, particularly for RBR, to maintain large amounts of energy in the diffuser area because of the balance of the car.

In 2010, MW was able to manipulate the pedals to keep the engine revving higher whilst under braking and this translated to him being around 0.2s faster than SV, fairly consistently. RBR changed the engine mapping to make this engine manipulation the same on both cars and SV suddenly jumped to be about 0.3s faster than MW...

I think you are confusing the general EBD concept (which is simply that the exhaust energy is used to make the diffuser more efficient) with the RBR-led concept of maintaining that exhaust energy even when the engine isn't being used to accelerate the car.
 
I complained about this last season, but I'm surprised they took so long to make a reg change about it.

I wonder how they can police it?
 
You must log in or register to reply here.
Back
Top Bottom