re: cams for GTV/10548 cams

[Dana Loomis <dloomis@xxxxxxxxxxxxxx>]

Bob Brady wrote:
>So far, after installing 10548 cams (the euro 2l) in my '74 gtv, the 
>improvements have been much less dramatic...
>Finally, I haven't dialed in the SPICA to work best with these cams.  >The
mixture is basically where it was with the stock units.

My experience has been that the "48" cams do provide a subjectively
substantial increase in performance, with the greatest gains occurring
between 3000 and 5000 RPM.  To get the maximum benefit from the cams,
however, it is not only necessary to time them correctly, but to  increase
fuel flow at higher RPM to take advantage of the improvements in breathing.
 Changing the idle mixture won't necessarily do the job.  On early SPICA
cars, moving the ambient temperature-adjusting lever on the FI pump from N
to F helps some and doesn't cost a penny.  The best solution, however, is a
high-performance SPICA pump calibrated to your cams.  

Two other changes that really help US-spec cars from early in the
emission-control era are to replace the stock distributor with one with a
faster advance curve (and advance the base timing as Bob described) and to
replace the fan with an electric one.

Dana Loomis
'72 2000 GT Veloce 

It can be really hard to tell how well a modification is working without
timed testing on a closed course or a dynamometer.  

------------------------------