Sneak Peek: Killer B Motorsport’s KILRB1

by Khiem Dinh

Those who race a Subaru know the name Killer B Motorsport. They likely have a number of Killer B parts on their car such as the engine saving Killer B oil pickup which replaces the failure prone OEM component. Aside from their oil related products, Killer B is well-known for their unique and highest performing Holy Header too. KILRB1 is the car all those parts were developed on and if you hurry, it can be yours.

The car is currently up on Ebay with the auction set to expire on July 22^nd. There are so many go-fast, high-power, and reliability parts on this car- it’s ridiculous! As it was the development car for Killer B, it basically has every Killer B Motorsport part on it. We’re going to give you a little sneak peek of what some lucky buyer will get.

KILRB1 has this unique low-mount turbo kit which utilizes the modified Holy Header.

The Holy Header has a number of very important design features with material selection being the first using 321SS instead of 304SS. By using mandrel bent tubes, Killer B minimizes the number of weld joints which improves reliability. The merge collector is a cast piece, instead of fabricated, allowing for optimized design of the flow paths to maximize power. The wastegate placement is at a good angle to the flow to allow precise wastegate flow control. The Tial turbine housing is Swain Tech ceramic coated for thermal management and improved performance. Notice that with the low mounting location of the turbine, the downpipe coming off the turbine housing is nearly a straight horizontal pipe reducing back pressure. The downpipe transitions from round to oval to maintain flow area while maintaining ground clearance.

The turbo sits very low, and the exhaust dumps out behind the front tires resulting in very low back pressure. The header is also Swain Tech coated. Of course, KILRB1 has the high performance oil pan. A Mocal heavy duty scavenge pump is required for the oil drain due to the turbo being so low.

Due to the location of the turbo, a 4” intake tube wouldn’t fit on the compressor housing to the Garrett GTX3582R. So, Killer B machined up this custom adapter to go down to a smaller intake tube.

This is the adapter bolted to the modified compressor housing. Notice that the inlet is larger than the wheel inducer and does not restrict flow at all. The design of the adapter is actually very similar to what is used on big diesel turbos like those used on the Ford Powerstroke and Chevy DMax, where the ported shroud geometry is covered from incoming airflow. A slot is kept between the inlet adapter and wheel inducer to allow recirculated airflow from the ported shroud to go back to the inducer of the compressor wheel, which allows the ported shroud to keep on functioning and prevent compressor surge.

The modified compressor housing with the custom reduced diameter inlet is also shorter than stock.