Field Report: What do 2-stoke Detroit diesels and this LS V8 have in common?
About this episode
Exploring a unique LS V8 build in a Nissan S13, this episode features Mitch from Pull Spec Engines discussing the unconventional use of a roots blower. The conversation dives into the challenges of tuning, fuel delivery, and the engineering behind the setup, including the choice of a Haltech Nexus R5 ECU and the intricacies of managing EGTs. With insights on the engine's architecture, including a shorter stroke for reliability and the use of LS1 heads, listeners gain a deeper understanding of this innovative combination and its performance capabilities.
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
Lancia Lambda
"...r. It's not quite the same as individual cylinder lambda, but in terms of fuel trimming it's long been a r..."
Request an Explanation
Heard something you'd like explained? We'll add it to this episode.
Sign in to request explanations for terms you heard.
Want to learn more?
Browse our glossary for plain-English explanations of automotive terms, jargon, and concepts.
Help improve this episode
See something that's not quite right? Our annotations are AI-generated and can sometimes miss the mark. Click the flag icon on any annotation to suggest a correction.