Also keep in mind that as the engine heats up, the aluminum intake
manifold will expand (get longer). I'm not sure which one would have
the greatest effect, but the two phenomenon combined can affect idle,
if there's not enough slack in the cable.
Victor is 100%, you need some slack, but your linkage should open the
throttles completely.
Another thing people often miss if you are looking for that last
little bit of performance is matching butterfly positions at wide
open throttle (WOT).
Getting the linkages balanced at idle is a good first step, but is no
guarantee that the butterflies will still be matched at WOT. They'll
be pretty close, but if you're racing, and want that extra bit of
performance, it's worth tinkering a bit with the linkage.
Chris Coker
On Jul 18, 2006, at 9:13 PM, Victor Laury wrote:
> The cable does not shrink it expands. But the cable housing expands
> more, so the cable gets tighter and the idle speeds up. The housing
> is a
> spiral wound flat steel strap, that if straightened out, would be very
> long indeed (maybe 10 feet or more). Because of that mass, the outcome
> of the coefficient of expansion is greater than the cable (it changes
> more in length that the cable will per each degree change).
>
> Your cable should have slack, but it should be short enough to open
> the
> throttles completely.
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