Project-T Parts: Part 2 - Compensating Equipment

Alright! So the turbo and computer is sorted, considering the Yin and Yang, I'll need compensating equipment!

The turbo will increase manifold pressure and in turn I'll need sufficient fuel to balance the forced air. In many new turbo builds, a brand new fuel pump and injectors are usually required to deliver the additional fuelling needs.

Further online reading has suggested that the existing fuel pump and injectors should be sufficient for low boost applications, but I want to ensure it by at least upgrading the injectors.

While doing my online research I came across the Micro Image forums and found the following information about the stock 1NZFE injectors:

P/N: 23250-21040
Flow: 200cc/min @ 43.5 psi (100% duty cycle)

Further reading suggested that the 1ZZFE or even the 2AZFE motor injectors would provide an easy replacement of the stock injectors. I decided to go with the 2AZFE injectors which provided approximately 370cc while the 1ZZFE provided approximately 255cc. This allowed a little more head room for future upgrades.

2AZFE Injector specs:
P/N: 232090H030 / 232090H060 / 2325028080
Flow: 370cc/min @ 43.5psi (100% duty cycle)

Cool! What else? Air, fuel... Spark! I'm currently using the stock plugs. Although I could simply re-gap (adjust) them to account for the additional pressure and fuel, I thought it would be a good idea to upgrade! My first thought... Iridiums!

For now I'll go with the NGK Iridium IX(R) Spark Plugs (BKR5EIX). But depending on how tuning goes, I may have to use a step colder plugs (heat rating) due to the increased heat produced by forced induction. The heat rating is defined by the number in the NGK part number, e.g. BKR6EIX is the next step colder plug etc.

via NGK

Stock, these guys are gapped to 0.032". Although quite suitable for normal applications, for turbo applications that gap is too large. Why?

The bigger the gap, the larger the spark, the more potential for air/fuel combustion. Although it may sound good, once you pressurise the air and at higher Revolutions Per Minute (RPM), miss-fires can happen (not to mention super hot exhaust gases). On the otherhand, too narrow and the spark may be too small to ignite the mix. Therefore you'll need to experiment and re-gap the plugs as necessary to get a balanced result.

Oh, let's back track bit...! What is this gap you ask? It's the gap between the central electrode and earth electrode.

To gap spark plugs you can simply bend the earth electrode closer to the central electrode or pull it away. Use a feeler gauge to determine the correct gap size.. Not everyone has super eye-sight that an see 0.032".

In the end I've settled at a gap of 0.028", which will probably change depending on tuning.

So the engine fundamentals are all compensated; air, fuel and spark.. The next thing would be cooling.

Luckily the Echo already has an aluminium radiator and the turbo kit already contains an intercooler to cool the intake charge. One thing that I will do however is to flush the engine coolant and replace it with some fresh stuff to ensure everything is well.... Cool.

As you can see, although you may have everything you need for forced induction (or any upgrade for that matter), you'll usually need compensating factors or equipment to balance the modification.

Tuning harmony!