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Nautilus · 08-24-2020, 04:14 PM

Thank you, Sir

The experiments on Autospeed gave me the right info to solve a very annoying problem, which comes directly from VW design: the engine bay of the 1.8T is murderously hot.

The cooling system keeps the block in a bearable range of temperature and the oil cool enough to be touched by finger. But everything around the engine block is slowly cooked. Wire insulation hardens, hoses crack, factory intercooler barely cools. Small plastic fittings in the cooling system crack over time - they need to be changed at each timing belt change. And this happens even on stock engines, leave alone mods to raise horsepower in the 250 hp range.

Solutions:

Cooling system: full undertray from a 1.9TDI engine, from front splitter lip to the front side of the front axle subframe. With aluminum additions to the rear of the subframe. The decrease in static pressure below the sump and axle draws / pumps the air outside the engine bay, towards the exhaust tunnel.

Intercooler: 2 small undertrays at the sides of the engine bay, which protect the lower part of the intercooler from dust, dirt and hot pavement. Slits in the plastic fender liner, so the rotation of the wheel acts like a fan to suck air from behind the intercooler. All slits in the front bumper which do not lead to a radiator carefully closed, so all air is funneled in the intercooler or cooling radiator.

Intercooler itself had been replaced many years ago with a much bigger, almost cubic model from Boost Factory. They do no longer make them, but there are similar coolers on the market from Tyrolsport, Eurojet and other manufacturers.

Battery box: small duct from battery box to air filter box, so the engine draws plenty of air through the battery box.

Ducts and hoses: insulated coolant recovery tank and coolant hoses. Like a Prius, the coolant tank keeps coolant warm for many hours, and the pump draws directly from it upon engine start, so the block warms up in minutes, even in winter.

Also insulated fuel hoses and fuel rail, so the heat does not "boil" or "bubble" the fuel.

The improvements are visible in the fact radiator fans operate much less in moderate traffic.

Fact: fans operating alternately in high and low speed add about 0.1-0.2 liters/hour to fuel draw. With no fans, indicated idle fuel draw is 0.6-0.7 l/h, with fans in full speed 0.8-0.9 l/h

08-24-2020, 04:14 PM	#14 (permalink)
Nautilus EcoModding Lurker Join Date: Dec 2016 Location: Romania Posts: 45 Simba - '05 Seat Leon FR Thanks: 22 Thanked 29 Times in 17 Posts	Thank you, Sir The experiments on Autospeed gave me the right info to solve a very annoying problem, which comes directly from VW design: the engine bay of the 1.8T is murderously hot. The cooling system keeps the block in a bearable range of temperature and the oil cool enough to be touched by finger. But everything around the engine block is slowly cooked. Wire insulation hardens, hoses crack, factory intercooler barely cools. Small plastic fittings in the cooling system crack over time - they need to be changed at each timing belt change. And this happens even on stock engines, leave alone mods to raise horsepower in the 250 hp range. Solutions: Cooling system: full undertray from a 1.9TDI engine, from front splitter lip to the front side of the front axle subframe. With aluminum additions to the rear of the subframe. The decrease in static pressure below the sump and axle draws / pumps the air outside the engine bay, towards the exhaust tunnel. Intercooler: 2 small undertrays at the sides of the engine bay, which protect the lower part of the intercooler from dust, dirt and hot pavement. Slits in the plastic fender liner, so the rotation of the wheel acts like a fan to suck air from behind the intercooler. All slits in the front bumper which do not lead to a radiator carefully closed, so all air is funneled in the intercooler or cooling radiator. Intercooler itself had been replaced many years ago with a much bigger, almost cubic model from Boost Factory. They do no longer make them, but there are similar coolers on the market from Tyrolsport, Eurojet and other manufacturers. Battery box: small duct from battery box to air filter box, so the engine draws plenty of air through the battery box. Ducts and hoses: insulated coolant recovery tank and coolant hoses. Like a Prius, the coolant tank keeps coolant warm for many hours, and the pump draws directly from it upon engine start, so the block warms up in minutes, even in winter. Also insulated fuel hoses and fuel rail, so the heat does not "boil" or "bubble" the fuel. The improvements are visible in the fact radiator fans operate much less in moderate traffic. Fact: fans operating alternately in high and low speed add about 0.1-0.2 liters/hour to fuel draw. With no fans, indicated idle fuel draw is 0.6-0.7 l/h, with fans in full speed 0.8-0.9 l/h Last edited by Nautilus; 08-24-2020 at 04:24 PM..