plugs & hp increases

[Tom Cloud]

>> > >Jeffrey: Another explaination for the HP increases you saw by changing
>> > >plugs (and I've heard this attributed to Bosch Platinum plugs in '92
>> > >and later 3 series BMWs) is that with that plug you're getting some
>> > >detonation and the knock sensor is dialing back the spark advance.
>> > >I've used Bosch Platinum plugs in my VW Jetta, it really liked them,
>> > >but it sounds like some cars don't like them for whatever reasons.
>> > >
>> >
>> Japanese cars don't like Bosch plugs. I spent days figuring out an
>> erratic idle problem which disappeared when I reverted to NGK.
>> My buddy was also having the same problem with the same cure.
>> I heard they work beautifully in German cars though.
>> 
>> gchan at compserv.senecac.on.ca
>Please explain how the nationality of the car affects plug type. Do they
>use different materials in the cylinder heads? This seems like saying
>"my Pinto runs good on Amoco, but my Vega likes Shell." What's the
>correlation?

if the platinums run hotter then, if the system were at it's
limit, it'd start to detonate or pre-ignite (can't get that
straight  8^)  ....  and combustion chamber design affects
things like that, so different types of engines could
conceivably not like platinum plugs ..... just a thought


Tom Cloud <cloud at peaches.ph.utexas.edu>