Miata Mailing List: February 1999, Message #113

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I recently had my '95 dyno'd at a local facility.  Before I tell you how I
pulled, I have JR Cold Air, headers, JR Hi Flow cat and JR sport muffler,
160 degree thermostat and 14 degrees timing.  I did 3 pulls and never got
past 109 HP at 6000 rpm.  Now, taking into account parasitic losses of
20-23%, that should equate to 134 HP at the flywheel.  A '99 pulled the
same rear wheel HP, except at a higher rpm.

My question is, has anyone else out there dyno'd a 1.8 motor with these
exact motor mods and achieved different results?  Should I be pulling
well into the 6000 rpm range?  Oh, by the way, I used both Spitfire and
Bosch Platinum+4 plugs and saw no difference in HP between the two. 
Other than some counseling I got to go back to standard NGK copper
core plugs, I don't plan any other changes to my motor.  The plugs that
were pulled looked like they had lean conditions during their life of 7000k
miles before they were pulled.  Although the flat edges of the plug by the
outer threads were sooty after the runs.  Any input would be
appreciated.  Please respond privately to meyerwg@tcg.com.

Bill Meyer