Tuned Length

Apparently some of the owners of the 'newer' MGs feel I am
'OK' at what I know but I am unwilling to 'change' or learn
'new things'or even, 'move with the times'.......so, this one is for
you Bob!

Over a number of test sessions we have noticed the K+N filter
for the 'K-series' seems to lose some bhp at peak power. Following
some hallucinogenic tea ( have you seen our tea urn!?) it was
hypothesized that the tuned induction length was wrong with
the K+N fitment.
We searched for a suitable extension....and....(is it obvious?) we
bought a two metre length of drainpipe. The interesting
contraption, somewhat reminiscent of an Alpine Flugelhorn,
can be seen in these photos.

In standard form the engine produced 88 bhp at the wheels.
With the K+N filter the max bhp was 83.
Both tests showed 75bhp at the wheels at 7000rpm.

With the Flugelhorn added, the bhp increased to 86 at the wheels
....BUT...air filter/induction systems are also designed to reduce
intake noise! Not so with our 'Flugelhorn', at 3000 rpm a
standing wave was set up in the pipe (very loud flappy sound) and
at 6000rpm ( second harmonic/first overtone?) the whole unit
reverberated to what can only be described as a squadron of
bi-planes taking off!
The pipe was reduced in length and bhp tested until the

pipe shortened to nothing and the power dropped back to 83.

The moral of this tale is.......car engineers do know what they
are doing afterall....and they keep the car nice and quiet too!