The S15 was originally purchased in 2017. It was a mostly stock vehicle with simple mods such as a worn bride seat, HKS Silent power cat back, Greddy Intake, HKS coilovers and Yokohama Connoisseur wheels. Modifications came soon after purchase. Starting with an in-house made custom stainless downpipes. Followed by a Greddy front mount intercooler, Walbro 255lph fuel pump, Haltech ECU, ID injectors and custom tune. With more power things began to break. SR20. Rocker arms. After the first one broke it was a simple rocker replacement with rocker arm stoppers. Shortly after, another one broke but the rocker arm stopper made the situation worse. More damage to the head, and debris was scattered throughout. Taking more time to research and rebuild, aided in learning about the dual guide rocker arm conversion. Doing this single mod has allowed the SR to this day not to throw or break a rocker arm. A loose flywheel was the demise of one of the SR engines and transmissions. Since time and budget were tight at the time a naturally aspirated SR20 was swapped into the car with all of the turbo modifications bolted on in addition to the introduction of E85. The higher compression made tremendous power on the first dyno pull and net 360whp. Knowing the connecting rods would not take the abuse the power was pulled down to a “modest” 340whp. The car would undergo 8 track days between Roebling Road Raceway, Atlanta Motorsports Park and Carolina Motorsports Park. Then at an event at Roebling road a connecting rod let go, going down the straight away. Thankfully no vehicle damage, or personnel damage. Again not fully doing research about the naturally aspirated motor was the demise of another good engine. This time was going to be the “final OEM+ form”. This next motor was a built bottom end including Eagle Rods and Wiesco 9.5 CR pistons and new OEM oil pump. The cylinder head included a port and polish, supertech springs/retainers as well as their stainless intake and inconel exhaust valves. This combination made 315whp on the dyno staying at a modest 16psi of boost. One event at Roebling Road, one event at Carolina Motorsports Park and one event at Virginia International Raceway would be all this motor would see. Upon inspection we discovered an oiling problem across all bearings excluding rods 3 and 4. The jury is still out for debate as to what exactly was the cause and why 2 pistons were unharmed. Now we have come down to the last iteration of the SR that this vehicle will see. With parts availability being scarce, aftermarket suppliers being slow to support/ respond the only other option is to swap the S15. As to what’s in store who knows.. maybe Coyote, LS, K?
