bumped from p553 to correct it .....
Tommy Cookers wrote:tuned lehgth inlet systems appeared on motorcycles decades before their 'invention' by Mercedes-Benz as attributed in the Autozine reference
and Miller made twin-choke carbs (presumably for the 1920 183 straight eight), this used 4 of them, as did the 1923 122 straight 8s
upstream of each carb were 2 long rampipes with slashcut bellmouths, (though Miller valve timing was very conservative)
these rampipes are conspicuously long, to use the first (ie strongest) reflected pulse, and based on tests on local board tracks
the 122 then became supercharged, and tuned length in cars was stifled by the dominance of supercharging from the early 20s to 1951
Freddie Dixon used 6 carbs on his Riley, his tuned lengths seemed shorter ie used the second (ie slightly weaker) reflected pulse ?
a 1938 Norton race motorcycle was bought by UK National Physical Laboratory to investigate such 'free supercharging' (first pulse ?)
tuned length won everything in car WDC when that went to F2 rules in 1952 & 53 (Ascari in the Lampredi-designed 4 cyl Ferrari)
very few N/A engines had 1 inlet tract per cylinder (2 cylinders/carb typically gives a useful reflection pulse from the junction ?)
Offenhauser went 1 inlet tract/cylinder with fuel injection but often retained the original tract length (second pulse ?)
they also used long ram tubes, eg 16" to benefit high rpm at the expense of 4500 rpm, often longer in 'laydown' installations
tuned length was also being about enabling and implementing further extended valve timing
Mercedes-Benz did invent the continuously variable length system for the 1955 sportscar (WEC equivalent) - it was never raced ?
afaik, regarding 'free supercharging' ......
a tuned length induction system has the same proportionate benefit in current F1 as in N/A F1
because the pressure difference charging the cylinders rises as the induction pressure is boosted above atmospheric
but a tuned length exhaust system only adds a favourable pressure exhaust pulse proportionate to atmospheric presure
so the pressure difference scavenging the cylinders doesn't rise in proportion to the boosted induction pressure
btw
on my tv Clive Chapman (Lotus 88 owner) has just said he saw ground effect invented .....
in the wind tunnel the df generating bits sagged, so they were propped up along the edges with a cardboard strip
so forming a venturi, increasing the DF and reducing the drag
then 'they' (Peter Wright) made the strips flexible and called them skirts .......