I have been interested in supercharging for some time, but would like to see
some definative information regarding performance improvement before going
ahead.
I went so far as to contact the owner of "Mad Max" regarding the source of
his kit, and found it to be a Vintage Induction unit. He was not sure that
he was getting the performance he wanted, and was considering going to
webers etc. I have visited Ray Hall's turbo site, and the automotive
calculations by Bowling, and have arrived at the conclusion (unscientific
and unproven) that the possible limitations to supercharging are the limited
flow by the 2" SU, the restriction of the unmodified intake manifold and the
limited volume of the attached plenum. There are other factors, including
the head and cam lift, which can also be addressed. It would look like the
expected power increase of 35-40 hp is reasonable based on what I have seen,
but the engine would require approximately 350-400 cfm into the supercharger
to realize a true 10 psi boost at 5500 rpm. I think the actual flow of the
2" SU is probably around 200-250 CFM. Is that accurate? I would encourage
the less mathematically challenged to 'cipher away and provide more accurate
calculations. I have read that the supercharger will "take what it needs",
but I don't believe that to be true, as there is only atmospheric pressure
pushing the air into the supercharger inlet. A 2" throttle body, without the
restriction of a venturi would probably flow the required CFM, but requires
fuel injection, an additional expense.
I admire the V-8 conversions, and have seen several, including one where a
fabricator will supply a complete frame etc. Unfortunately, I am stubborn
enough to prefer that the car stay entirely Triumph, and would only stetch
to the use of a Rover aluminum V-8, which are fairly rare.
Dennis
'73 TR6
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