The McLaren F1 had two secret downforce fans. Who knew?

Gordon Murray has set the internet ablaze in recent days, revealing his latest creation the T.50 to the world – a 488kW, 986kg, manual, atmo V12 rocketship.

As part of the press reveal, Murray has been doing extended walkaround videos, talking about his new car’s technical details.

One, hosted by Harry Metcalfe, former owner of Evo and all-round good chap, for his Harry’s Garage channel caught our attention.

The floral-shirted Murray proceeds to drop all manner of technical bombshells about the new car, but it was something he said about a previous creation, the iconic McLaren F1, that really had us reaching for the rewind.

Old Harry saunters round to the back of the car and considers its standout external design feature – a giant downforce-magnifying fan.

"The fan, which we've not seen on a road car," says the usually very well informed Metcalfe, referring to the unit on the back of the T.50 designed to improve the effectiveness of its diffuser.

"The F1 had two. It had the same ground effect, but in a tiny area." countered Murray.

10

Huh? That is a nugget of information that has flown under the radar.

Turns out the truth has been hiding in plain site, with the technology referenced in Driving Ambition, the definitive history of the F1’s development, written by Doug Nye, Ron Dennis, and Murray himself. Page 84, to be exact.

"What the F1 did was, I had two reflex diffusers, very steep, that the air would not normally follow. But only so wide," Murray continued, indicating a width of maybe 20cm or so.

"It had two 140mm fans, sucking the air out of them and when you switched them on we got five percent downforce and a two percent reduction in drag.

"But we had so little time in the wind tunnel because it was the Formula 1 tunnel we were borrowing, effectively.

"I logged it in the memory and I thought 'If ever I do another supercar, I'd like to do that over the whole floor of the car – the diffuser floor – and that's what we've done."

The T.50’s fan looks more like Murray’s iconic Brabham BT46B 'Fan Car' design, due to packaging restrictions preventing it being hidden under the engine cover.

"The Brabham was a crude device," said Murray. "It was a vacuum cleaner, basically."

So there you go. The original F1 – a car many thought to be a bit of an aerodynamic disaster area – had some very clever tricks buried beneath its bodywork. And the T.50 takes those ideas and really runs with them.