I'm running the K&N 3" thick air filters that Moss sells, and the
performance difference over the stock air filter assembly is noticeable.
Also, when I was running a stock exhaust system the open element air
cleaners really added an additional new powerful sound when accelerating.
However, after adding a Monza system, I can't hear a thing coming from the
engine compartment (or that 747 landing on top of me either!). Also, the
performance of my car definitely varies with ambient temperature. I think
an air intake setup like Richard Good sells with the cold air intake coming
from the front radiator shroud might be ideal.
About transmission & overdrive oil - when we are discussing oil
viscosity, we have to remember that engine oil and gear oil are oranges and
apples! Engine oil viscosity is measured at a much higher temperature than
gear oil, so the two scales are not interchangeable. Someone must have the
actual data, but in my experience, 80w/90 gear oil is not that much
difference in viscosity than SAE 40 engine oil. I believe that SAE 50
engine oil has more viscosity at room temperature than 80w/90 gear oil. So,
actually when we are comparing running gear oil to engine oil in our
transmission, the difference in oil viscosity is not as much as it seems. I
believe that the main difference between the two is in the additives (gear
oil doesn't have to cope with the high temperatures and by-products of
combustion, but it does have to deal with the shearing action of
differential gears). When I used to own Austin-Healeys, because engine oil
was recommended by Healey, I ran SAE 30 non-detergent Valvoline engine oil
in my gearbox and A-type overdrives. I found that SAE 40 made shifting too
stiff. I'm presently running 80w/90 in my TR6 box, but I bought some GM
manual transmission fluid that is 75 weight gear oil that I was going to try
to see if it would improve the cold shifting of the TR. (I haven't tried it
yet!)
Automatic transmission fluid is a very highly engineered product. Even
the slushbox manufacturers can't agree on fluid specs, so there several
varieties. Yes, some manual transmissions and some 4-wheel drive transfer
cases actually specify ATF, but as it has a viscosity of about SAE 10 engine
oil, I would be a little afraid to try it in gearboxes not designed for it.
It might adequately lubricate the bearings and provide enough pressure to
engage the overdrive, but I fear the synchronizer action wouldn't be normal.
(IMHO)
Rex Townsend
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