10 replies to this topic

[Michael Müller]

The 1946-51 formula was 1.5 s/c against 4.5 atm., meaning a factor of 1:3. From 1954 to 1960 it was 0.75 s/c andd 2.5 atm., factor 1:3.33. Experience shows that the 1:3 factor was reasonable, whereas 1:3.33 was just “over the line”.
The 1966 formula had 1.5 s/c and 3.0 atm., so factor 1:2, so theoretical a 1.5 ltr s/c engine would have been competitive against a 3 litre atmospherical. What was the reason that nobody picked up this option? Or did the formula specify “superchargers” only to be exhaust-driven turbos?

[Frank de Jong]

The greatest difference in the early years compared to 1966 is the use of "standard" fuel compared to the impressive mixtures that were used earlier. With "pump" fuel, it was impossible to get the boost pressure high enough to get a decent power figure without destroying the engine, with supercharging or turbo alike.
BMW 2002 Turbo racing cars from 1969 only had about 280 HP from a full 2 litre engine, so on that moment a turbo engine was not very competitive. The exhaust-driven turbo only was usable and drivable after the adition of the wastegate. The wastegate on one side (pioneered by Porsche in 1972, if I am correct), and the mixture of legal "rocket" fuel like BMW had on the other side tipped the balance in favour of the turbo in the early 80´s.

[Michael Müller]

Frank, of course a turbo engine was not competitive in the 60s based on factor 1:2, details are all known. The advantage of alcohol fuel - at least partly - could also used in atmospherical engines by using rather high compression ratios (RON methanol = 130), but okay, you're right, the internal combustion cooling effect of alcohol allowed higher pressures.

Nevertheless I believe that there was a good chance for a (mechanical) supercharged 1.5 ltr engine to reach the 400-420 HP of the early 3 liter engines, and at least somebody should have tried in this direction. As this obviously didn't happen, could it be that the formula allowed only exhaust turbochargers? Btw, when the formula had been created of course nobody ever reckoned that turbos could beat the athmospherical engines, at that time the power plus was only approx. 25-30 %.

PS: The "standard" fuel was 101.5 RON, also not really bad!

[Roger Clark]

The 1966 formula certainly did not specify exhaust driven turbochargers. An additional problem with mechanically driven supercharggers would have been packaging. 400+ BHP would probably have required 2 or 3 stage supercharging and it would have been difficult to fit it into the cars of the time. unless of course somebody tried a centrifugal supercharger, but I can't think who would have done that.

i do remember, when the formula was announced Jack Brabham suggested that the likely configuration was 8-cylinders and suerchargers. I think he was thinking of supercharging the Climax V8.

I suspect that, apart from the technical reasons, all the engine suppliers had years of experience of unsupercharged engines and very little knowledge of blown ones.

[Michael Müller]

Considering that when the 3 ltr formula was announced all F1 engines had been 1.5 ltr, so the most logical step would have been to supercharge the existing machinery. However, I believe Roger is right, except for Ferrari and BRM there was no experience.

[Ray Bell]

...and Ferrari knew the fuel consumption flaws in the idea, BRM the headaches of it all!

As Roger says, the experience with naturally aspirated engines had taken them way ahead in usefulness compared to the known situation with blown engines.

I believe that turbochargers were so new and so sluggish (used almost exclusively on diesels at that time) that they weren't considered an option by the FIA.

I'm sure, however, anyone with a bit of supercharging experience could have wiped the board in those early years... and would have changed the course of history in so doing. I do agree, though, packaging would have been a problem, but much less so then than now, aerodynamics not being considered so vital at that time.

[Bernd]

BRM certainly got a lot of headaches after their choice of route for the 3L period!

[Roger Clark]

With the benefit of hindsight, a BRM P261 with mild supercharging could have been a very competitive proposition in 1966. forget about 400+ BHP, another 50 would have been enough.

[Bernd]

Yes I believe you are right Roger, Lotus were no where near the pace except for Clark brilliance on occasion. Brabham were still down on power with their Repco's at probably 330BHP or so. So I think a supercharged P261 with JYS and Hill at the wheel would have been very competitive.

[Ray Bell]

Now that is one car that would have been presented problems finding room for a pump!

But it would have flown, absolutely, though I'd reckon an extra 120hp would have been necessary.

[FLB]

And also remember the P261's were still quite competitive in their 2-liter interim form, as the Lotus 33's were.

There certainly was nothing wrong with the chassis. Nor the drivers.