By a fluke i was looking thru Mar 02 street machine and found this bit of info in the dirty stuff column...
He has a 4 cyl NA race motor running between 5000-9500 RPM and i quote-
'Our cam drive is a duplex chain on indexing sprockets, so that the valve timing can be easily changed to impove bottom end torque or top end grunt. Advance the cam timing by 10 to 15 degrees and you pick up on mid-range acceleration. Retard by the same amount and peak developed horsepower increases.'
I think a 30 degree range in a street motor would be a little savage, but smaller changes would have a similar effect, you'd think.
IMHO i love a revy motor with a highish (6000) power peak. my car currently has a heap more mid-range grunt, and its just not as fun. esp when you go to overtake and the motors dead past 5000... I should prob add that i also have a fair gob of torque at low rpm, so its pretty easy to cruise round in to.
Wed, 18 February 2004 02:30
