I personally would like to place another paper filter element in parallel to my stock one to reduce pressure drop across the filter. But my main motivation is the fact I have an 85 Cali car and the filters for that cost $$$ . Another filter in parallel would extend the life of the stock one and reduce over all operating costs for me.

As for power gains produced by using a K&N filter I'm not very optimistic.

A simple test to see what the maximum possible difference would be for people is to time a few 0 to 60 runs with a clean stock filter and then remove the filter and do some more timing runs.

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green 85 300SD 200K miles "Das Schlepper Frog" With a OM603 TBO360 turbo ( To be intercooled someday )( Kalifornistani emissons )
white 79 300SD 200K'ish miles "Farfegnugen" (RIP - cracked crank)
desert storm primer 63 T-bird "The Undead" (long term hibernation)

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