Saturday, January 28, 2012

Wastegate-blown diffusers

Whilst the FIA have made extensive efforts to prohibit the use of exhaust-blown diffusers in Formula 1 from 2012 onwards, there appears to be no such proscription on the use of compressed air from the inlet manifold of an engine. Formula 1's engine formula changes to a 1.6 litre turbo-charged V6 in 2014, and the turbine in such an engine is constantly generating compressed air. The inlet manifold of a turbo engine has a blow-off valve, specifically designed to release pressure when the driver lifts off the throttle or the throttle is closed. Thus, the blow-off valve could be vented down to the sides of the diffuser, providing vital extra downforce when a driver comes off the throttle turning into a corner.

In terms of the legality of such a system, there is already a clear precedent. As pointed out in Giorgio Piola's Formula 1 Technical Analysis 2010/2011, the very first exhaust-blown diffuser, the Renault RE40 of 1983, had several outlets blowing each lateral channel of the diffuser; in Piola's diagram (p15), three came from the exhaust, but one came from the turbo wastegate, (in fact, in pictures featured on Craig Scarborough's site, there are only two outlets from the exhaust, and one from the wastegate).

Piola points out that the legality of the system was protested by Brabham at the 1983 Detroit Grand Prix, but the protest was rejected both in situ, and at a subsequent tribunal on 26th July. Hence, whilst the FIA might be able to regulate the position of the exhaust outlets, and the off-throttle pumping effect of the engine, the turbo wastegate could conceivably be used as an independent blowing device in 2014.


Barry said...

Better tell the FIA now and have them ban it now instead halfway the season

drayfx said...

Turbo wastegates and blow off valves are two totally different devices and are usually confused. blow off valves are mounted on the pressure intake side and the purpose of the valve is to vent off pressure when the throttle is shut. It just dumps the air in to the atmosphere or you can dump the air back into the turbine intake. To dump the air into the diffuser would not do much I don't think as its just dumps it in just 1-2 secs. Where as a wastegate is mounted on the exhaust side and the valve controls the amount of exhaust going into the turbine thus regulating boost pressure. Max venting of the exhaust via the wastegate is achieved when the max boost is reached. So the vent of the exhaust through the wastegate can aid down force in channel to the diffuser. This system is most advantages in medium to long corners where the engine can produce enough of boost to allow the wastegate to open and create some added downforce.

Gordon McCabe said...

Yep, you're spot-on.

And if the 2014 regulations involved exhaust-driven turbines, then whilst the regulations would have to change to encompass the fact that you'd have an exhaust pipe and a wastegate pipe, one presumes that neither would be permitted to blow the diffuser.

drayfx said...

Knowing the FIA, they will over look this and Newey will find a way to make full use of it. Hahaha. Then the whole "Redbull illegal" or "Rebull to dominant" saga will start again for the "new" cars.