1261 replies to this topic

[Ardmore]

Stops big rocks being sucked in the top. Probably high enough to not upset the standoff from the throat,

As someone who does not feed engines rocks I would use a K&N or Unifilter and bugger the originality.

That is a weird looking intake though.

 

This shot shows the air box on the car.

 

[alansart]

Novel use for a tea strainer. Seen on a Classic F3 car's air box  at Brands Hatch.

 

 

It was quite common at the time for the old fashioned teas strainer to be used as a filter on F3 restrictors.

Simon Hadfield had to search for when when he rebuilt Rupert Keegans F3 March.

F3 March 743, Mallory Park 20.4.2011 by Alan Raine, on Flickr

Ironically the air restrictor was the original one that was raced in period and apparently was found to be illegal!!

[Duc-Man]

Novel use for a tea strainer. Seen on a Classic F3 car's air box  at Brands Hatch.

 

 

I've seen the same thing on a F-3 back in '92 runing in the german championship.

[Ardmore]

 

On a 1929 Buick

Edited by Ardmore, 13 December 2019 - 07:24.

[Ardmore]

[elansprint72]

Stops big rocks being sucked in the top. Probably high enough to not upset the standoff from the throat,

As someone who does not feed engines rocks I would use a K&N or Unifilter and bugger the originality.

That is a weird looking intake though.

At the Le Mans Classic a few years ago I saw a bloke in one of the entertainment bands wearing a pair of goggles made out of two of those exact-same tea strainers!

[Simon Hadfield]

It was quite common at the time for the old fashioned teas strainer to be used as a filter on F3 restrictors.

Simon Hadfield had to search for when when he rebuilt Rupert Keegans F3 March.

F3 March 743, Mallory Park 20.4.2011 by Alan Raine, on Flickr

Ironically the air restrictor was the original one that was raced in period and apparently was found to be illegal! 

Only just seen this and that’s not quite right.  I did buy the car from Rupert but it was less engine and most of the gearbox - and seatbelts, instruments, etc, all of which went to keep the Hawke and  Chevron running he said - so I bought a Toyota engine which came without the airbox.  Stuart Rolt rebuilt the engine and found, from another competitor, a complete airbox/restrictor assembly. The simple truth is that neither Stuart or I ever checked the restrictor bore as it was assumed to be correct.  We obviously both know who the airbox came from and to preserve their dignity we have kept that to ourselves....

Back to the post I’m utterly sure that when Alan Docking ran the car for Rupert it was scrupulously correct and legal.  

[Simon Hadfield]

I've seen the same thing on a F-3 back in '92 runing in the german championship.

Back to back tested on my own and customers cars, and validated both in car and via the V-box Sport there is absolutely no discernible difference with or without.  As the nose of the airbox is where the front wheels flick stuff up on lock it seems sensible to run them.....

Internally the airbox is substantially more complex than you would think, its not just the restrictor orifice at the front of a tube.......

[2F-001]

The talk of airboxes and their complex internals on F3s reminds me of the 1984 controversy at the end of the Euro F3 series.

I don’t know if I’m remembering all of the details correctly, but the story as I recall it, concerned the Coloni entry for Ivan Capelli (who won the series). Johnny Dumfries (who won the British series that year) was in with a chance of the Euro title too, but had an “off” in a late-in-the-series round.

Capelli’s airbox was thought to be illegal (and I think had been ‘dissected’, revealing something possibly untoward/clever/sneaky inside) and was retained by the FIA (or possibly the local sporting authority)  for further study or as evidence or whatever. Whilst in their custody, the suspect item unaccountably disappeared… and there were no further actions or sanctions.

Dumfries lost points that might have secured him the title having his 'off' whilst chasing an ‘illegal’ car; without that extra pace, he wouldn’t have had to push so hard to stay in touch. I don’t doubt that similar things have happened before, and I don’t know if the legality of the car in the preceding rounds was questioned.

Does anyone else recall this, or have a different take on the episode? Or can show us what actually goes on inside such an airbox - or what Coloni might have done to theirs?

[Simon Hadfield]

The detachable front piece that contains the restricting orifice is a properly shaped venturi with an intake and very long expansion part behind.  This ends somewhere around the second intake trumpet but the fabricated box part is there to equalise the pressure into all four.  This front part is a beautifully machined magnesium casting on Novamotor engines. 

If there was any nonsense going on then I presume it was something in the box part - see also the period 1600 F3 airbox shenanigans!   

Edited by Simon Hadfield, 04 January 2020 - 12:40.

[Duc-Man]

We had this "airbox arguement" on here before around 2013.

All kind of theories were coming up but funny enough nobody was able to post a photo of all this secret stuff inside.

Coincidence helped me out a bit. At the Nürburgring OGP 2013 was a mechanic cleaning the bodywork parts of the Amon F-1 car.

Things might have changed later on but in the 1970s there was only air inside the airboxes.

 

[elansprint72]

 

King of cool...  

Edited by elansprint72, 15 February 2020 - 20:31.