Revisted: Twin-Charging — Good Idea or Unnecessary Complication?

Tuned In

*** We’ll be taking a break over the Christmas/New Year period and will be back in action mid-January.

That means that although there won’t be any new episodes for a few weeks, we’ll be taking another look at some of our favourite conversations from 2024. ***

Anyone with even a passing interest in Time Attack has likely heard of Norris Designs, a UK-based tuning company probably best known for its insane north-south oriented, twin-charged, short-wheel base Evo IX time attack monster. On this episode of Tuned In, we sit down with founder Simon Norris to get some insight into this brain-melting build, plus much, much more.
Use “NORRIS100” to get $100 off our HPA Tuning Starter Package: https://hpcdmy.co/starterb
Like many of us, Simon Norris began his love affair with cars and motors early in life, pulling apart engines on the kitchen table as a child. While there was a slight detour after leaving school to study engineering, it wasn’t long before Simon spied a new opportunity in the burgeoning JDM aftermarket tuning scene just as he was cutting his teeth working in a Nissan dealership in the mid-nineties. So, after seeing how others were starting to mess with tuning ECUs, Simon decided he could do better, and promptly opened Norris Designs way back in 1998.
Nearly three decades later, Norris Designs is one of the biggest names in the UK tuning scene. In this conversation, we first kick into the business side of Simon’s life, finding some great insight into what works and what doesn’t when it comes to building a company in the motorsport industry.
We next get into tuning in general, where Simon discusses different ECU options, dyno styles, and the many factors that can cause discrepancies between individual dyno runs. From there it’s on to the real meat and potatoes of this episode — Simon’s incredible Mitsubishi Evo IX.
With its north-south-orientated billet supercharged AND turbocharged 4G63, the AWD Evo is an engineering masterpiece that absolutely tears up any race circuit it’s unleashed upon. Simon does his best to answer the many questions we have about this car in an attempt to get to the bottom of what makes this shortened and roof-chopped weapon tick, and why Simon made the choices he has with this build.
Follow Norris Designs here:

IG: @norris_designs
FB: Norris Designs
YT: Norrisdesigns
WWW: norrisdesigns.com
Don’t forget, you can use “NORRIS100” to get $100 off our HPA Tuning Starter Package: https://hpcdmy.co/starterb
Time Stamps:
3:41 How did you get into cars?
8:25 Did you have much industry experience before starting your business?
12:39 What sparked the interest in JDM cars?
16:18 How did Norris Designs grow?
25:56 Overview of Norris Designs today
31:12 What does your day-to-day look like at Norris Designs?
38:36 What vehicles are you specialising in?
42:54 How did you learn to tune?
52:44 Are you relying on knock control and close loop fuel control?
57:35 Did you start with an engine dyno or rolling road?
1:01:17 Do you have fixtures and harnesses for quick and easy engine dyno setups?
1:02:27 How accurate is the engine dyno?
1:10:23 Repeatability issues with rolling road
1:14:16 ECU of choice?
1:20:20 What is a short wheelbase Evo 9?
1:24:33 Engine package
1:34:45 Billet blocks for street applications?
1:38:41 Twin charge setup
1:44:24 Transmission
1:50:39 What’s next in the development of the car?
1:52:33 Lap time difference with new aero package