20 replies to this topic

[Phil Rainford]

http://www.classican...to_le_mans.html

Damon to take the place of his father?

PAR

[arttidesco]

http://www.classican...to_le_mans.html

Damon to take the place of his father?

PAR

[johnthebridge]

http://www.classican...to_le_mans.html

Damon to take the place of his father?

PAR

After nearly 40 years, I still have the sound of an MS650 in my head! Brands pits, and this thing fired up next to us. Oh boy. Tell me a better noise..........

[sabrejet]

After nearly 40 years, I still have the sound of an MS650 in my head! Brands pits, and this thing fired up next to us. Oh boy. Tell me a better noise..........

Mazda 787B.

[MCS]

Mazda 787B.

Vile - well we are all different.

Edited by MCS, 18 February 2012 - 08:52.

[RTH]

Mazda 787B.

No , I was there that Mazda made a chainsaw sound melodic , the exhaust noise on all those rotaries was unpleasantly painful.

[AAGR]

Regarding the Mazda's gorgeous engine noise, my dear departed friend Keith Duckworth once commented that '...if it's making all that f*****g' noise, think of how much power is being wasted by not getting to the flywheel ....?'

An ever practical engineer, was Keith ....

AAGR

[sabrejet]

Regarding the Mazda's gorgeous engine noise, my dear departed friend Keith Duckworth once commented that '...if it's making all that f*****g' noise, think of how much power is being wasted by not getting to the flywheel ....?'

An ever practical engineer, was Keith ....

AAGR

Noisy enough to win at Le Mans eh?

[BRG]

Regarding the Mazda's gorgeous engine noise, my dear departed friend Keith Duckworth once commented that '...if it's making all that f*****g' noise, think of how much power is being wasted by not getting to the flywheel ....?'

An ever practical engineer, was Keith ....

AAGR

Absolutely so, but it also begs the question of how many chevaux were galloping away down the Matra's exhaust pipes? I recall that, at times, you could hear them changing down for Mulsanne corner from several miles away at the start line.

[AAGR]

Absolutely so, but it also begs the question of how many chevaux were galloping away down the Matra's exhaust pipes? I recall that, at times, you could hear them changing down for Mulsanne corner from several miles away at the start line.

Which was exactly Keith Duckworth's point....

AAGR

[arttidesco]

Noisy enough to win at Le Mans eh?

IIRC only when the opposition were saddled with somewhere between 100 - 150 kg dead weight more than the Mazda to make up for all the horsepower it was loosing down the exhaust pipe ;)

[DOHC]

Absolutely so, but it also begs the question of how many chevaux were galloping away down the Matra's exhaust pipes?

And the surprising answer is: less than one. That's still a helluva lot of noise -- even the acoustic noise of a turbojet engine roaring at full power is a mere 1-10 kW (and can be heard from afar, just like the Matra engine).

Acoustic losses are completely negligible. The real loss is in heat. My guess for the Matra would be 350 kW mechanical output, 750 kW heat losses, 1 kW acoustic losses (that's less than 0.1%).

So I'm afraid Keith Duckworth either had it wrong or was just joking. My bet is on the latter.


Just as a side note: how much power does it take to blow a trumpet? It's quite loud, and yet the energy comes from the lips alone. Even a big band fortissimo is just 10-30 W. And that is loud.

Edited by DOHC, 18 February 2012 - 18:28.

[AAGR]

So I'm afraid Keith Duckworth either had it wrong or was just joking. My bet is on the latter.

Keith personally getting it wrong on engine design ? It was never known ....

AAGR

[DOHC]

Not on engine design, but thinking that exhaust noise equates to lost mechanical power, an idea which is patently false. But again, he might have been joking.

[sabrejet]

Not on engine design, but thinking that exhaust noise equates to lost mechanical power, an idea which is patently false. But again, he might have been joking.

Agreed: the DFV isn't exactly the quietest of engines either.

[Jagracer]

Mazda 787B.

I was at Le Mans in 1971 & the Matra Team were in the pits next to us & yes it was a lovely sound but certainly not when you were so close to it & ear defenders weren't around much in those days

If you want a little story regarding Graham Hill who was driving the Matra that year, there was 8 of us in the same eatery & we were trying to get the waitress to understand that we wanted 8 Beers & she just looked blank at us just as Graham was walking past us & asked what the problem was we told him we wanted 8 beers to which he replied "that'll be 9 then with mine" to which looked at the waitress & said loud & clear "Neuf F####ng Bier souv o play" (excuse my french spelling) to which she replied We monsiour & off she went & came back with 9 beers, Graham just smiled & said "see it's simple" & sat down with us with his beer

Ah those were the days Phil Bradford

[DOHC]

Amazing!

[Bill Wagenblatt]

My favorite Matra sound was Spa 1000km 1974. I was working my way along the train tracks that ran parallel to the Masta straight this was across the valley from Les Combs but when the Matra started the downhill run from there to Burneville its canvas tearing scream was clearly identifiable. The sound would drop as the car worked its way around Burneville, but approaching Malmedy the pitch would increase. As the cars came on to the Masta straight the scream just grew if you didn’t turn your head as the car past your ears were going to hurt. For me decades later still one of my most memorable racing moments.

Bill

[LittleChris]

Lovely description Bill,

Being a bit picky though, wasn't the Malmedy chicane in place for all car races during 1974 hence maybe the sound dropping was as the cars rounded this chicane rather than Burnenville ?

[Bill Wagenblatt]

Chris,

Yes in 74 the Malmedy chicane was used, the sound would change more due to the road being behind hills or buildinds blocking. When they round Les Comes there is a long valley with little to block the sound waves, as they go through Burneville and work towards Malmedy there were buildings and hills that muffled the sound. Once they left Malmedy there were fewer buildings and yes, acceleration from the chicane.

Bill

[LittleChris]

Thanks for the explanation Bill,

Wife, daughter & I camped for three days down near the old Stavelot corner last July and I did several runs of what remains of the old circuit .

There are some photos I took ( on the only day it didn't rain ) on this thread - post 117 .

http://forums.autosp...=spa definitive