If you have the filter contained in a metal housing and run a tube from it up to the front of the car, as in the first picture I shared, it should work like the factory cold air intake. Actually, if the air filter is in front of the turbo and far enough from the engine, the air shouldn't be all that much warmer, especially if the car is moving and outside air is flowing into the engine compartment.

But, I'd be careful about a setup which places the air filter over the turbo or exhaust, though that's how the factory setup was, other than it having a tube which draws in cold air from the front of the car.

The W116 is difficult when it comes to fabricating a custom air intake, as the battery is located at the front of the engine compartment, and the cold air intake is located behind the headlight--and if you convert to Euro headlights, it seals off the air intake, choking the engine of air unless you disconnect the plastic tube and let it float over it so it sucks in air from under the hood.

__________________
Stop paying for animal enslavement, cruelty, and slaughter. Save your health and the planet. Go vegan! I did 18 years ago. https://challenge22.com/

DON'T MESS WITH MY MERCEDES!


1967 W110 Universal Wagon, Euro, Turbo Diesel, Tail Fins, 4 Speed Manual Column Shift, A/C
1980 W116 300SD Turbo Diesel, DB479 Walnut Brown, Sunroof, Highly Optioned, 350,000+ Miles