Link Computers -by Mike Coory

Introduction

For The 300ZX the LINK ECU comes in two types, one that replaces the existing ECU and uses factory sensors (300ZX LINK) and one that requires rewiring all the sensors and is a separate unit replacing the standard ECU (LINK PLUS). All require tuning and this is the key to get them running properly and you should do a road tune then fine tune on a dyno. Also like the JWT chip you need to increase boost to get power, you can buy Subaru boost solenoids or probably use an aftermarket boost controller.

Basic facts

Link ElectroSystems Limited is a New Zealand based company making replacement ECU for a variety of vehicles. For the Z32 there are two options; one the 300ZX link and the other is the Link plus

300ZX Link

This is a replacement board that fits in your existing computer box it has a serial cable connection that will either go to a Link controller or a laptop for programming. My link is not programmable via a laptop though I have heard the new 300ZXLINK will be. The controller is NZ$400 and simple to use. You can monitor via laptop just not adjust settings via laptop (refer below to link+ which you can monitor and adjust via laptop).

This can handle all the standard functions of the Nissan ECU and uses all factory sensors other than the air flow meter (AFM). The AFM is replaced with a manifold air pressure (MAP) sensor. However you can still use the existing airflow meter by running the link in intercept mode where it receives AFM reading and converts it to a MAP reading. Not much point as the AFM just reduces airflow and on the Z32 is rumored to be unreliable.

The MAP sensor is just a tube from the manifold to the side of the LINK.

Link Plus

This is a separate standalone ECU using custom sensors, it has all the functions of the 300ZX link but additional functions such as shift light control, water sprayer controls, air conditioning control and data logging.

This setup is more for race than road use or for those delving into the high HP areas. I installed the 300Zx link so my comments relate to that.

My mechanic is running the link plus in his race car and its working fine, allows finer tuning and also tuning via laptop.

The problem with the LINK plus is that you have to wire it in, all sensors have to be wired in as opposed to the 300ZX link which uses the factory wiring loom.

Link vs JWT

The main difference between the link and JWT is the ability to change engine parameters (such as fuel and ignition) at different rev and boost levels.

While the JWT software is good it is a standard setup that does not take into account the specifics of your car and requires a chip upgrade and downtime when you make any change. The link system lets you change the amount of fuel, spark timing for 96 different settings. For example if you note at 4000 rpm with 1.2bar boost it seems to be running lean, get you controller, call up zone 335 and increase fuel delivery by a few percent, problem solved. Click here to see some opinions on this.

Add new cams, no new chip needed just a couple of hours of tuning time to take into account the new settings.

As i have been slowly modifing my car over the past three years there have been three seperate upgrades and three dyno readings. The last two where all done via link, so when I put in the new injectors we just had to return.

What can the link control

The link can control fuel (injector timing and pulse rate), ignition timing, wastegate, TPS and set boost targets at various RPM levels, cam timing, cold start, knock control, oxygen sensor readings and many others.

How does the Link control boost
The 300ZX link comes with two boost control solenoids (Subaru ones) that allow the computer to control the boost before sending to the wastegates. These are in addition to the cost of the link but are provided.

Tuning

To make the link run properly get a good programmer, actually programming the link is simple (i.e. call up a zone, press up or done to increase fuel or timing) but knowing what needs to be done is the key. A link set up incorrectly will result in a poor running engine (if it survives at all). As you have almost complete control it is imperative that it is done properly.

The link comes with a base map (i.e. settings that the factory believe is close to what you want) this base is then adjusted for your vehicle requirements and modifications. This base map is not perfect (some say not even close) but is usually good enough to get it running.

Most tuning can be done on the road similar to the methods used in tuning boost jets but with much more control. Fine tuning requires dyno work and my last dyno run resulted in 300RWKW with 555injectors, dual pop, 3 in exhaust and almost standard turbos.

Emissions

In New Zealand we do not have the stringent emission controls that the US have and whether after fitting a link you will meet emissions controls is hard to say. However as you have so much control I see no reason why it cannot be done. I note my car does not produce as much unburned fuel and the pipes run a nice grey instead of the black when the JWT chip was running. All the emission control stuff has been removed from my car, i.e. all cats and cold start recirculation etc so can't really comment.

Injectors

As the link can increase the pulse rate of the injectors you can get more fuel out of the standard injectors without an upgrade. JWT says that the max out of the standard injectors is 14 psi, but I was running 15.5psi with pulse rates of less than 90% with no problems. This is definitely the max available, I have heard of someone getting 20psi with standard injectors but I would not recommend it. Now I have 555 injectors and are running 18.5 psi at 60% duty cycle.

Cost

The link systems cost NZ$1500 (about US$500), boost solenoids NZ$400 each and tuning (to be advised). Also did blow off valves as the turbos were stalling $NZ500 each and dual intake (to be advised). The blow off valves are bled into the dual intake to reduce noise and reuse the air. All up looking around NZ$5000 (US$2150). (old conversion rates)

PDF Files (right click, save as to download, click to read from here):
 Link Manual Link Plus Manual Link for Windows