Reply To J-Spec Engine Question

I have some knowledge on this subject becuase my best friend has a 93 MX6 (Mazda's version of the Probe) and his brother has a 92 240 SXSE. Anyway they are both comtimplating the J-Spec engine swap. They J-Spec engine have better air flow, better vavle timing, ususally a stronger crank for higher revs. The high grade octane level in Japan is 110 and this engines usually run on that grade. I know a guy personally that swapped a stock Probe engine for the J-spec one and ran 93 octane. He dynoed at 162 with everything stock beside the engine. Then a few months later he ran 100 octane for a few weeks and dynoed at 175. So go figure but everyone I know that talks about the J-Spec engine swap debates the fuel question.

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89' 5.0 GT Convertible Mustang and a 69' Mustang Mach 1 Fastback. If you want to know the rest, buy the rights.
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