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Old October 16th 05, 04:17 PM
Leon van Dommelen
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Default Basic Horsepower Upgrades

"Mal Osborne" > wrote:

>Does this mean you need to use higher octane fuel to avoid pinging? With
>older pre-EFI cars I have always tuned timing to just below where I star to
>hear pinging. It is amazing how much variation there can be from one batch
>of fuel to the next, but generally I could get more advance and a little
>more grunt with premium fuel. Of course this increases running costs.


More advance requires indeed higher octane. However, there is some dyno
data around somewhere for an M1 Miata that going from 14 to 18 actually
reduces maximum horsepower again, though there is still and improvement
at lower rpm. People find that 18 degrees BTDC definitely requires
premium fuel, 14 might. A good detergent fuel may help, since it can
reduce carbon deposits that promote knock.

Leon

>"Lanny Chambers" > wrote in message
...
>> In article .com>,
>> "ritchiekidd" > wrote:
>>
>>> I'd like to know if anyone has suggestions about how to increase the
>>> horsepower via minor/inexpensive changes, such as exhaust or air
>>> filters?

>>
>> Except for advancing the timing to 14BTDC (1990-97 cars only), there are
>> no inexpensive mods that make a noticeable difference.

>

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Leon van Dommelen Bozo, the White 96 Sebring Miata .)
http://www.dommelen.net/miata
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