Shopping: Real Estate |  Costumes  |  Guitars
This Issue Archived Articles Blog About Us Contact Us

Engine Management for Turbo Conversions - Part Two

Adding a turbocharger to your engine? These are your spare-no-expense engine management options...

By Michael Knowling

Click on pics to view larger images

At a glance...

  • Final of two-part series
  • Cost-no-object approaches to engine management when adding a turbocharger
  • Programmable management, custom ECU reprogramming, bigger injectors and more
Email a friend     Print article

If you’re adding a turbocharger to a naturally aspirated engine you will inevitably have some concerns regarding engine management. In the first part of this series (see Engine Management for Turbo Conversions - Part One ) we examined ways to sneak through with zero or minimal changes to the engine management system. Now it’s time to look at more expensive solutions that, arguably, provide a better result...

Approaches to Engine Management

Click for larger image

According to Lachlan Riddel, the head of ChipTorque, the most all-round attractive way to optimize engine management with a bolt-on turbocharger is a custom ECU reprogram. Using dedicated programming software, the tuner is able to tailor fuel and ignition maps to provide the best balance of power, reliability and fuel economy. You can also control a host of other functions including the closed-loop switch-over point, intake air temperature correction and knock retard. It’s these functions which really make this approach attractive. In most instances, the management can be recalibrated to work with a turbo-compatible MAP sensor (which is rated at 2 Bar absolute or higher), a bigger airflow meter and bigger injectors. All this while retaining factory cold-start qualities, air conditioning compensation and failsafe strategies... Perfect for a street car.

Mr Riddel says a custom remap to suit a turbo fitment typically costs around AUD$1900 including any necessary MAP sensor swaps. A popular vehicle where there’s lots of existing tuning information available – such as a Holden Commodore – costs a few hundred dollars less.

The most expensive option is an aftermarket programmable management system.

Click for larger image

An aftermarket system gives total tuning flexibility – you can change the type of ignition system, upgrade injectors, add extra injectors, customize fuel and ignition timing and associated correction factors (such as inlet air temperature). This approach is arguably the most sophisticated solution to your management woes – but it’s important to recognize the drawbacks...

“The biggest issue with most programmable management systems is the lack of closed-loop fuel control and knock sensing,” Mr Riddel says.

“This makes it difficult to meet emission standards and to compensate for the variations in fuel.

“And, in later model cars, there’s also the problem of working with electronic controlled automatic transmissions and other car systems.”

Click for larger image

Depending on the vehicle, switching to aftermarket programmable management may mean that you lose the factory trip computer, stability control, electronic throttle control and more. However, as seen in this Nizpro modified Ford XR6 Turbo, it is possible to use a stand-alone programmable management system in a piggy-back configuration with the standard management system. In this arrangement, everything remains under the control of the factory management except for the injectors and ignition which are controlled by the programmable ECU. Inevitably, though, you will lose some functionality – for example, it’s impossible maintain proper operation of the trip computer.

Expect a tuned aftermarket management system to set you back at least AUD$2000, depending largely on the brand of management system and the extent of tuning. Some installations may run closer to AUD$4000.

Fuel System

Once you’ve fitted a turbocharger and commenced tuning, it’s likely you’ll need some extra fuel delivery.

In the first part of this series we discussed modifications to the fuel tank return line, adding an aftermarket fuel pressure regulator and increasing the voltage supplied to the fuel pump. Each of these approaches can perform well, but a more elegant result can be achieved if you’re prepared to spend some extra...

Click for larger image

Ideally, the engine should be fitted with injectors that are rated for your target power output. This might seem simple but, of course, there’s more to it. According to Mr Riddel, an injector that’s rated at X pounds of fuel per hour is not necessarily the same as another injector with the same rating.

“If you took a Mazda 13B Turbo injector and a new Siemens injector of the same rating, I know which I’d prefer,” he says.

Apparently, most of the latest high-grade injectors offer far better fuel injection linearity. In other words, doubling injector duty cycle will virtually double the fuel flow whereas lower grade injectors often have a non-linear fuel delivery. This makes tuning more difficult and you’re more likely to end up with small glitches in the tune.

Click for larger image

Bigger injectors can be used without any changes to the rest of the fuel system but often they should be fitted in conjunction with an upgrade fuel pump. This is necessary where, when the bigger injectors are fitted, the fuel pump can’t maintain adequate pressure at full noise. An upgrade pump typically costs a few hundred dollars and helps ensure there is no drop-off in pressure as the injectors near maximum flow. In some instances, you can use two fuel pumps in parallel or in series to achieve the necessary fuel flow – this depends largely on your desired power output.

Combined, a set of bigger and injectors and an upgrade fuel pump might set you back well over AUD$1000.

If all this sounds too expensive, refer back to Part One of this series...


ChipTorque +61 7 5596 4204

Nizpro +61 3 9761 1522

Did you enjoy this article?

Please consider supporting AutoSpeed with a small contribution. More Info...

Share this Article: 

More of our most popular articles.
Is it time for a new direction in car modification?

Special Features - 13 May, 2008

Where to From Here?

Unique and cheap modification to keep the car longer in lean cruise

DIY Tech Features - 7 April, 2008

Giving the Insight a Good Driver

Planning, earthworks and site access - beginning the home workshop build

DIY Tech Features - 19 August, 2008

Building a Home Workshop, Part 2

A new low cost data logger

DIY Tech Features - 30 June, 2009

Five Channel USB Data Logger, Part 1

Mixing a dose of LPG with diesel to improve power and economy

Technical Features - 12 March, 2008

Diesel LPG - an Amazing Breakthrough

Getting a home workshop to the lock-up stage

DIY Tech Features - 2 September, 2008

Building a Home Workshop, Part 4

The aerodynamic development of Mercedes large sedans from the 1950s to the 1990s

Technical Features - 6 May, 2014

Aero Timeline

Sand casting metals in aluminium

Technical Features - 18 November, 2008

Metal Casting, Part 1

Refining a light-weight pneumatic / hydraulic suspension system

DIY Tech Features - 13 July, 2010

Chalky, Part 9

Building electronic kits

DIY Tech Features - 10 February, 2009

How to Electronically Modify Your Car, Part 9

Copyright © 1996-2020 Web Publications Pty Limited. All Rights ReservedRSS|Privacy policy|Advertise
Consulting Services: Magento Experts|Technologies : Magento Extensions|ReadytoShip