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Asking to investigate if a original Cooper s twin air box (hs2,s ) is good in respect of getting the best air flow needed?
Twin air box is on 1275 with a 11 stud 12g940 big valve head which looks like head was skimmed sometime in past. Twin hs2s has maniflow intake with rc40 exhaust. Is Cooper s twin air box good for airflow rates or bit restrictive for full power potential from carbs.?
Thanks

outright power then throw it .. otherwise do you want to put up with all that intake noise on road use ?

That's a fair point for a few extra horses.

The airbox is a complete waste of time. On the rolling road, with no filters the power dropped 6 HP, with the fileters in it dropped another 4.
Pancake filters are the better option, or ram pipes with sock filters,

Doesn't surprise me Cooper s twin filter box restricts full potential. They look good and sound OK. Has anyone had any experience with the MED hs2 twin stub stack ?

The best air filters ever scientifically tested by BMC/BL and Unipart were, by a long way, Coopers.

And the most effiicient use of those Coopers air filters were in the usual filter box BUT, the small air intake removed and a series of 1" or so dia holes trepanned all the way around the side of the box for 360 degree intake of air. The difference in warm-up time with calibrated bi-metal valves fitted was negligible. Much more to it than that of course.

And remember that the only way you can have unrestricted air flow into an engine, contrary to some manufacturers 'unrestricted-flow' claims is with oil bath intake filters such as used by tanks for example. Air duction...... one of my favourite subjects

I've got bell mouths fitted, I find the accompanying induction noises very pleasing and satisfying after all, in my opinion noise is synonymous with speed/performance. In addition I appreciate a positive and nice tone on an exhaust note, However I do frown on these over loud popping and banging noises emitted by the cars of boy racers that can be heard on the by-pass in earshot of my garage.

Thanks for all the replies. I like idea of keeping original Cooper metal air box liking how it looks and sounds. Can't see myself cutting or drilling holes in it yet but i might do later. Would shortening cooper box air pipe so it wasn't so close to exhaust make a difference? Definitely interested to see what changes in performance can be had by trying different air filter. Going to try a MED twin hs2 stub stack IGT filter maybe it can add bit more horses.