MX5 MK3 NC Turbo build guide for £2500 with step by step Videos

Technical Area Forced Induction & ITB
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I was looking to turbo my MX5 NC 3.5 and the only kit available in this country was about £5.5k. This amount was far too high for my budget and the relative cost of the car.

I set out with the goal of turbo’ing the car including tuning for £2500. I have added extras that others may not want or need and that has increased this figure. I have put a spreadsheet link below to all parts purchased including links.

Cost turned out to be £2578.27 and with extras £3061.70, pretty damn good!

The car is my only one and therefore I wasn’t looking for 400 bhp, but a nice amount of about 270bhp.

There isn’t that much information out there on turbo’ing the NC for the DIY home mechanic. I therefore decided that I would do a video series on each step so others could copy if they so wished.

A lot of earlier MX5’s use the Subaru TD04-13T, this is quite a small turbo, used for up to say 240bhp. Not all TD04’s are the same, there are many different types and sizes.

I went for a TD04-19T which was used in Saab’s, not only is it bigger, but I purchased the core of the turbo (CHRA) with upgraded bearings and billet turbine wheel. This turbo is meant to be good for 300 to 330bhp (if you run high boost). I have chosen this turbo due to costs compared to Garretts and many people go for too big a turbo and get slow spool. I wanted a turbo that in theory will spool quicker and be far more usable on the road.

Note I do have a stage 1 clutch already installed. 250 to 270 is about the max for a standard clutch, so I have been told.

I will also be using the standard ECU tuned by ECUTEK, this now has the function through Racerom to control an electronic boost controller by using the purge valve wiring. Therefore, there is no need for an expensive aftermarket ECU.

I have not been paid to do this and I’m not looking to make money from it (beer donations accepted). I have, however, had a small number of companies help me along the way and they are shown at the beginning of each video.

Please be kind with your comments, I have done a lot of research on each topic, but it is my first turbo build.

Facebook Page

Completely Driven - Mx5 NC Mk3.5 | Facebook

Turbo costs & links Spreadsheet

My Youtube channel is shown below, there is a playlist for all Turbo videos:

Completely Driven - YouTube

There are 16 parts to the build, a small number have been finished, but the others will be uploaded soon, all links are below:

Part 1 – Introduction, discussing parts used etc

Part 2 – Exhaust manifold construction

Part 3 – Exhaust downpipe construction

Part 4 – 3 Bar MAP sensor installation

Part 5 – Electronic Boost Controller installation

Part 6 – Intake piping and Intercooler installation

Part 7 – Oil feed & drain lines (includes drilling the block)

Part 8 – Water lines (Revised)

Part 9 – Building of the Turbo including clocking

Part 10 – Fuel Injector upgrade

Part 11 – Fuel Pump Upgrade

Part 12 – Spark Plug upgrade

Part 13 – Boost/Vacuum line overview

Part 14 – Boost and Oil pressure gauge installation

Part 15 - DIY Boost leak testing

Part 16 - Issues and fixes

Part 17 - Exhaust Manifold blow fix

Part 18 - Replacement Turbo Hot housing

If you have any questions or want to add to my beer fund (Paypal), then the email is completelydriven@hotmail.com

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Great thank you.
I will watch them all

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Saves me the effort - will watch and enjoy :grinning:

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Thanks

This is really interesting

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Another subscriber right here. Looking forward to watching.

:+1:

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I have now added the Part 1 - Intro, Part 5 - Electronic boost controller and Part 8 - Water Lines.

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Short little spark plug video added

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Part 6 - Intercooler and piping now up

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Part 7 - The oil feed and drain lines now up. This includes drilling the engine block!

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Part 14 - Boost and Oil pressure gauges installed including wiring, vac line and gauge pod.

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Part 9 now up, building up the turbo, attaching actuator, applying heat sheet to cam cover, bleeding the cooling system and first start.

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Part 13 - Vacuum Line overview now up

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I had my first session of tuning at the weekend. We could have got it done in a day but had issues with the Chinese MAP sensor that turned out not to work. We were able to get a Cosworth style 3 bar sensor and all started working and we were able to get the car tuned, but currently just based on the 7psi actuator spring.
The car feels amazing and so happy with it, boosts from about 2.5k and so little lag, its really nice to drive and super fast. Tuner thinks its about 240bhp currently.

I will be going back to so that we can program the electronic boost controller and see up to about 11psi and probably 270bhp give or take.

Very happy with how it has turned out, spend most of the day in it yesterday and just had a smile all the time,

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Part 10 Fuel injectors added

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Part 16 added - Issues and fixes

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Hi. So I know it started off at £2.5k has it realistically been that or how much in total, and does that include costs for tuning?

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Yes, in the top part of thread there is a link to the spreadsheet with all costs including tuning.

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Thanks

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I have gone through all the spreadsheet links and updated any that don’t work. I have also taken out a couple of parts that have been revised and replaced on spreadsheet (only small things).

I consider the exhaust heat wrap to be a required part, so swapped over from “Optional Extra”.

I have not updated any prices, if they have changed (you can always hunt for best price).

The current build cost including tuning is £2655.16

Leading UK kit is just under £5000 with no tuning included.

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Revised Part 8 added and new part 18.

As far as I know, no one has followed the guide, surprised as the car is so much fun.

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