Blog Zbod
Podium Finisher
I posted in the archived 2013 Singapore thread about speculation from Giancarlo Minardi regarding the odd exhaust note Vettel's car was heard making during that race, insinuating it might be some form of traction control. (ROOTERSPORT, OTOH, are claiming it could be torque control). At the time it was more baseless rumour than anything (after all, Minardi's old F1 team since has become Toro Rosso, so Mateschitz is as much as sleeping with Minardi's old lover) but the story since has grown legs, so I thought I should create a new bespoke thread in the Technical forum.
What Red Bull are doing allegedly isn't traction control but rather a very clever exhaust blowing of the rear diffuser. The story goes that the TR (5.6.1) allow for a delay of a maximum of 50 ms after throttle application before fuel must must be introduced. And as a holdover from the blown diffuser days, the Renault engines still feature a cylinder deactivation scheme, which they claim is essential to cooling, but which also is reported to boost fuel economy. Some sources -- like Auto Motor und Sport -- believe Red Bull somehow are merging the cylinder deactivation with the 50 ms delay to create more or more energetic exhaust gasses which, thanks to the Coandă exhausts, produces all the greater downforce.
Vettel already has taunted us, claiming we'd never figure it out, but I have concocted one scenario that might work (which might bear absolutely no relation to reality). When the driver applies throttle, what if for that 50 ms, fuel only is increased to the deactivated bank of cylinders, and the ignition timing to those cylinders simultaneously is drastically retarded? There would be no significant rise in power delivered to the crank, but there would be an extra shot of gasses spewed out the exhaust ports. At 10,000 rpms, 50 ms is enough for about 17 ignition cycles from the bank of four deactivated cylinders. I doubt they ever get that low in the revs, even through the Lowe's hairpin at Monaco, but even just 17 combustion cycles comes to near as makes no difference five litres of hot, burning, expanding fuel-air mix, coursing through the exhaust, into the manufactured slipstream and across the rear diffuser.
This would increase the Coandă-generated downforce before the car changes speed in response to the change in accelerator position, which means the downforce would arrive before the added torque at the wheels. It would be a novel solution because cars ordinarily are dependent on increased speed for increased downforce. The extra downforce would reduce the tendency to wheelspin under throttle, allowing power to be applied all the sooner on corner exit. Just like traction control. And the 50 ms delay is minute enough the driver should have no difficulty adjusting the timing of his accelerator pedal applications.
Anyway, another clue was reported at Singapore. In free practices, Vettel's car was seen with FlowViz only on one side and Webber's car was seen with it only on the opposite side. Which gave rise to speculation that this new system might somehow be being "focused" on one side of the car or the other, presumably the side inboard to the corner, as body roll tends to lift and "unseal" that side of the rear diffuser. Which fueled further speculation about how they controlled which side of the car was receiving the additional Coandă.
F1 Analisi Tecnica claim to have been told by Franco Nugnes (Spanish driver currently in the Porsche Cup series) that the system is not automatic but is manually activated by the driver, who selects which side of the car is to receive the extra downforce. They claim it is good for 0.1-0.2 seconds per lap.
Which reminds me of the story a couple of weeks ago stating Lotus had abandoned their passive double-DRS, claiming it only was good for 0.2-0.4 seconds per lap, which was too little to close the gap to the Red Bulls. Red Bull, OTOH, do not seem too proud to accept lap time increases in even smaller denominations.
Niki Lauda has remarked that the FIA reviewed the Red Bull system during developmental testing, and initially ruled against it, but RBR modded it to satisfy the FIA's concerns. Which is why Charlie Whiting et al have been so unequivocal in stating the system is within the regulations.
The oddest aspect of all this is that the 2012 exhaust overrun-driven EBD was banned because it constituted a moveable aerodynamic device (undoubtedly the most tortured interpretation of the TR I ever have come across). Material differences? The old system blew extra exhaust gas beneath the rear diffuser on throttle lift. RBR's new system (if speculations are accurate) blows extra exhaust gas across the top of the rear diffuser on throttle application. So I am baffled the latter has been ruled legal when the former was not.
What Red Bull are doing allegedly isn't traction control but rather a very clever exhaust blowing of the rear diffuser. The story goes that the TR (5.6.1) allow for a delay of a maximum of 50 ms after throttle application before fuel must must be introduced. And as a holdover from the blown diffuser days, the Renault engines still feature a cylinder deactivation scheme, which they claim is essential to cooling, but which also is reported to boost fuel economy. Some sources -- like Auto Motor und Sport -- believe Red Bull somehow are merging the cylinder deactivation with the 50 ms delay to create more or more energetic exhaust gasses which, thanks to the Coandă exhausts, produces all the greater downforce.
Vettel already has taunted us, claiming we'd never figure it out, but I have concocted one scenario that might work (which might bear absolutely no relation to reality). When the driver applies throttle, what if for that 50 ms, fuel only is increased to the deactivated bank of cylinders, and the ignition timing to those cylinders simultaneously is drastically retarded? There would be no significant rise in power delivered to the crank, but there would be an extra shot of gasses spewed out the exhaust ports. At 10,000 rpms, 50 ms is enough for about 17 ignition cycles from the bank of four deactivated cylinders. I doubt they ever get that low in the revs, even through the Lowe's hairpin at Monaco, but even just 17 combustion cycles comes to near as makes no difference five litres of hot, burning, expanding fuel-air mix, coursing through the exhaust, into the manufactured slipstream and across the rear diffuser.
This would increase the Coandă-generated downforce before the car changes speed in response to the change in accelerator position, which means the downforce would arrive before the added torque at the wheels. It would be a novel solution because cars ordinarily are dependent on increased speed for increased downforce. The extra downforce would reduce the tendency to wheelspin under throttle, allowing power to be applied all the sooner on corner exit. Just like traction control. And the 50 ms delay is minute enough the driver should have no difficulty adjusting the timing of his accelerator pedal applications.
Anyway, another clue was reported at Singapore. In free practices, Vettel's car was seen with FlowViz only on one side and Webber's car was seen with it only on the opposite side. Which gave rise to speculation that this new system might somehow be being "focused" on one side of the car or the other, presumably the side inboard to the corner, as body roll tends to lift and "unseal" that side of the rear diffuser. Which fueled further speculation about how they controlled which side of the car was receiving the additional Coandă.
F1 Analisi Tecnica claim to have been told by Franco Nugnes (Spanish driver currently in the Porsche Cup series) that the system is not automatic but is manually activated by the driver, who selects which side of the car is to receive the extra downforce. They claim it is good for 0.1-0.2 seconds per lap.
Which reminds me of the story a couple of weeks ago stating Lotus had abandoned their passive double-DRS, claiming it only was good for 0.2-0.4 seconds per lap, which was too little to close the gap to the Red Bulls. Red Bull, OTOH, do not seem too proud to accept lap time increases in even smaller denominations.
Niki Lauda has remarked that the FIA reviewed the Red Bull system during developmental testing, and initially ruled against it, but RBR modded it to satisfy the FIA's concerns. Which is why Charlie Whiting et al have been so unequivocal in stating the system is within the regulations.
The oddest aspect of all this is that the 2012 exhaust overrun-driven EBD was banned because it constituted a moveable aerodynamic device (undoubtedly the most tortured interpretation of the TR I ever have come across). Material differences? The old system blew extra exhaust gas beneath the rear diffuser on throttle lift. RBR's new system (if speculations are accurate) blows extra exhaust gas across the top of the rear diffuser on throttle application. So I am baffled the latter has been ruled legal when the former was not.