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Discussion Starter #1
My Spider has a high output motor with 45DCOE's and an AR plenum and airbox with a UNI foam filter. RJ has modified the plenum to match it to the 45 Webers. The filter is almost new with just 1000 miles on it and it has not been oiled. I had it on a dyno yesterday and I removed the canister and filter so that the plenum was open. The engine made an extra 7 HP. The hood was open and a squirrel cage fan was ventilating the radiator. I told Jim Steck and he was not surprised.
I plan to repeat the test on Al Mitchell's dyno in a few weeks time. It may cause me to reconsider my intake system.
 

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Discussion Starter #3
I did not try it with the can but without a filter. I will do that next time.
 

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Discussion Starter #7
I don't know. AFR was not recorded but I would not expect it to change. Webers add fuel according to air flow.
 

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I had a few Dyno sessions recently on my warm 1300. With sock filters on GTA trumpets it was 7hp down. With RamAir twin sock low height filters it was 4hp down.
With the RamAir twin sock tall filters it was at 125bhp.
With no filters just the GTA trumpets it was 3hp up........... but I’m not even going to entertain running it with no filters on a freshly built engine.
 

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I had a few Dyno sessions recently on my warm 1300. With sock filters on GTA trumpets it was 7hp down. With RamAir twin sock low height filters it was 4hp down.
With the RamAir twin sock tall filters it was at 125bhp.
With no filters just the GTA trumpets it was 3hp up........... but I’m not even going to entertain running it with no filters on a freshly built engine.
My 2 cents if you running on a contemporary race circuit more then some 2 layers of cheesecloth is about all you need on a hopped up ride. Those oil soaked filters choke the engine..
 

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Discussion Starter #10
A LONG time ago when I raced motorcycles we used a leg of pantyhose inside a coil of wire but those motors were rebuilt every season.
 

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Discussion Starter #12
I would imagine it was like racing on a beach..
It was. There was a British Sand Racing Championship, a bit like long track over here. Lots of fun power sliding around turns, throwing up rooster tails of sand.
 
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