About this episode
Let's be honest, power is easy to make these days. Anyone with a modest budget can build a 1000hp dyno queen, but what about high-output engines that are expected to last for more than just a few full-power dyno pulls? Use ‘PODCAST75’ for $75 off your first HPA course here: https://hpcdmy.co/hpa-tuned-in Mixing a unique roots style blower (aka supercharger) with 8-into-1 headers for wow factor, Mitch Pullen of Pullen Spec Engines hasn't glossed over the essential parts to ensure this LS-based build will last. Improving rod angle, slowing piston speed, and choosing a stout valvetrain option over pure peak HP figures are all part of this, along with running a dual DBW throttle fuel-injected setup with 16 injectors over the carburettors you'd typically see on a setup like this. Why roots-type blowers are considered so inefficient compared to other supercharging and turbocharging options is discussed, along with individual cylinder trimming and running rich 0.80 lambda of E85 fuel to help cool combustion charges for 8 PSI of boost, making an easy 800hp during the Garrett International Drifting Cup at World Time Attack Challenge. TIME STAMPS: 0:00 - Blown S13 0:30 - Why The LS 0:54 - Roots Blower 1:38 - Haltech NEXUS R5 1:55 - PDM & Can 2:26 - 16 Injectors 2:58 - Primary Injectors 3:05 - Fuel Cooling & Lubrication 3:12 - Trimming Injectors 3:20 - Liquid Intercooling 3:55 - Why A Roots Blower Is Considered Inefficient 4:24 - Boost Pressure 4:58 - Pre Supercharger Fuelling 5:28 - Ethanol Fuelled 5:35 - Fuel Mixture & Cylinder Trims 6:12 - EGT-Based Fuel Trims 7:45 - EGT Temperatureres 8:03 - Transient Throttle Tuning 8:32 - Acceleration Enrichment 9:23 - Short-Term Fuel Trims 10:47 - LS Engine Specs 11:14 - Why Short Stroke? 11:49 - LS Rod To Stroke Ratio 12:43 - Dart Block 13:30 - Power Level & 8,800 RPM 13:55 - Cylinder Head 14:30 - Rectangle Vs Cathedral Port