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To maximize airbox volume we wanted to use a flat element air filter. Due to some space constraints in area, as well as off-the-shelf filter elements and their associated airflow limitations, we needed TWO air filter boxes. So we ordered those up while Ryan started building a plenum at the throttle body.
This box above will attach to the 102mm throttle body and create a certain amount of plenum volume for the engine to draw from. Air will enter through each of the 3" oval openings from the two air boxes. The constraints of the hood and engine placement limited the intakes to these 3" oval sizes.
The 4" opening to the throttle body has a formed bell mouth and the box itself sits up under the dash. Ryan will make another fire proof enclosure to completely surround this and seal the engine compartment away from the passenger cabin/dash area (see below/left)
Twin air filter boxes were built, one for each side of the engine bay. They are somewhat mirror images but they do have some differences side to side, which are underneath.
These air filter boxes mount to the chassis and then 3" tube and 3" silicone hose couplers route the "cold air" to the throttle body plenum box. Two K&N filters fit snugly into the tops of these air boxes and we will add some additional structure and seals that touch the bottom of the hood soon. These will mate up with two big holes we will cut in the hood to feed these filters.
A couple of dozen hours went into the firewall clearancing, layout, plenum box fab and two air box fab work, but it should be more than able to supply this air to engine. This is being fed by a high pressure zone at the base of the windshield, which will help "at speed". And it all will help the Optima Design & Engineering scoring, too. Again, this is really being done to open up the front of the engine bay for hood ducting, to improve downforce on the splitter (soon) and improve cooling on the main radiator.
INTERIOR PANELS + STEERING WHEEL
Up to this point we haven't shown much of the interior or our plans to make it safe yet pleasing to the eye. Gotta pass muster for D&E - they really punish gutted race cars in Optima, unless some real attempts at "an alternative interior" are made. Initially we just had roll up windows and custom door panels, but the rest was pretty Spartan. All business, no frills, and somewhat ugly. Time to spruce it up in there...
This interior was largely gutted when we found it, along with the air bags. The stock HVAC is also too heavy for a build like this, but we did add a compact heater core and blower motor unit that we've used on a number of race cars (just like on the tube frame 69 Camaro build). This 7 pound unit from Summit Racing is cost effective, compact, and much lighter than the OEM parts. This box was mounted under the dash on the passenger side and the outlets will be plumbed to the defroster vents soon. No air conditioning is going to be added - too heavy, and there is no place to drive an AC compressor with a 4 stage dry sump pump in the way.
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