After I bought up my current common rail diesel (CRD) Nissan Patrol in 2008, one of the first modifications that I planned was the installation of a diesel chip. Diesel chips are piggy back Electronic Control Units (ECU) that can be programmed to override some functions of the factory ECU and improve engine power, torque and fuel economy. I’ve had experience with ECUs from my previous Di Patrols, which improved overall performance and fuel economy to some degree, so there was no reason why the same would not apply to the new CRD. The Di Patrol ECU only altered fuel delivery, so they weren’t overly sophisticated and sometimes introduced their own problems, and the CRD diesel ECUs were no different, as they too only adjusted fuel delivery. But then a new ECU came out offering much more and I was asked to do a test and review, which was something that I couldn’t refuse.
The ‘new’ diesel chip or ECU in question was the Chip It from Chip Tuning. The Chip It comes from the same company that I wrote about earlier regarding the electronic throttle controller and has been fully developed in Australia, including the software, which I understand was written by an ex-Mercedes systems engineer who had migrated to Australia. The ECU review that I did back in late-2011 took 39 pages and required several months of driving over all manner of conditions to provide a thorough understanding of how it worked and how it performed. To be honest, I was somewhat dubious about the claims of the Chip It but, at the end of the day, it really came up trumps. So after all these years, I thought I’d post a story about the Chip It and how its fared since those days back in 2011. I still have it and it still keeps performing as well as the day I installed it, actually better, but first a bit of history.
The Chip It that I received was one of the very first of their ECUs and provided control over both fuel and boost (air), which is critical for proper tuning. Simply increasing the fuel quantity is not ideal, as too much fuel increases combustion temperatures, as well as the production of NOx, the former which can be catastrophic for a diesel engine. High exhaust gas temperature (EGT) is an indicator that combustion temperatures are high because too much fuel is being fed to the engine and a further indicator is a diesel that blows too much smoke. A well tuned diesel should never blow smoke, except briefly and only lightly when the throttle is initially applied under load. Diesel engines work in the opposite way to petrol engines in that they don’t like too rich a mixture and can run at air/fuel ratios of 100 – 150:1 at light loads and typically a maximum of around 17:1 at full engine load. This is where the Chip It comes to the fore, as it allows you to adjust both fuel and boost to balance the air/fuel ratio so that you get optimum results across the entire engine load range. The newer versions have improved in many ways and now also allow control of injection timing for ‘fine tuning’ the fuel delivery.
My evaluation of the Chip It took many months of driving the same routes over and over again in conditions that were as close as possible to each other in terms of weather each day. I checked the weather reports every time before a test run, also recording images of the forecasts for each day that the testing occurred, so that I could be confident that I was being as fair and meticulous as possible. This driving involved hills, suburban roads and long stretches of open road each time, and I clocked at least 100km each test. As things progressed, I was pleasantly surprised with the improvements in both performance and fuel economy with the Chip It.
But after all of this testing, I’d reached a point where I knew that I was being limited by the basic tuning software that only allowed pre-set tunes to be installed (even though there was quite a selection). Having decades of experience with petrol engine tuning and getting into the aftermarket fuel injection scene when it started to develop in Australia, I knew that more could be achieved with this chip, especially after having done just that with systems like the early Wolf 3D in petrol engines. So I approached Chip It and they decided to supply me with the full tuner software that allowed me to precisely adjust the fuel and boost in increments across the engine load range. Every single engine that comes off a factory assembly line is as different as every baby that is born, no two are exactly alike or equally tuned. So while ‘canned’ tunes can provide engine improvements, nothing beats individual tuning of an engine and nothing beats actual on-road tuning.
After I received the tuning software, I started a second series of testing, pretty much repeating what I’d done previously, but this time modifying the ‘best’ tune to see what I could get by ‘personalising’ the tune. The results were immediately obvious and once I got a feel for the changes, from both the actual data readings of EGTs, boost and fuel economy, as well as my own seat of the pants feel, I knew I was getting somewhere. It didn’t take long to improve the results quite significantly and, after I moved to Mirboo North, I continued the testing and adjusting in our hilly terrain until I’d achieved as close to an optimum result as possible. By that I mean I now have excellent power, torque and great fuel economy, achieving 13lt/100km around our local hills (and no smoke) and on the highways I get around 10lt/100km, not bad for a 3t 4WD. And towing a 2t trailer full of wood on those same hills was not a chore at all.
So back to more or less the present. Last year I was asked for help from another CRD Patrol owner with a Chip It, as they weren’t fully satisfied with the results they were getting from the standard tunes (different engine from birth again). So we started a tuning exercise remotely (the owner lives in Western Victoria) and by sending tunes via email and getting the owner to drive and record data for me, it allowed me to make adjustments and perfect the tune for their Patrol. The owner then did some exhaust modifications and we repeated the testing. The owner is now over the moon with the way it performs and even others think that it’s a different vehicle.That’s one of the beauties of the Chip It, you can do tuning remotely, the owner will be able to apply those tuning adjustments themselves and immediately see the results, then provide feedback for further adjustments as necessary. No other aftermarket ECU (that I know of) allows such an option.
I keep reading about the latest technology where diesel engines are having the factory ECUs reprogrammed, something that’s been available for years for petrol engines, but things don’t always seem to work out. Owners are sending in their ECUs, having them reprogrammed with a generic tune and then finding that the outcomes aren’t quite what they expected or problems arise. The reality is that canned tunes can be hit or miss and the only way to get it right is to individually tune the engine on a dyno or by on-road, real-time, adjustment. So owners are left with solutions that may or may not work satisfactorily. I’m not suggesting ECU reprogramming doesn’t work, but you need to understand and/or accept the limitations of canned tunes. Anyway, I certainly look forward to years more enjoyment from my Chip It and Patrol.
Update 1. The other day I heard back from the Patrol owner for whom I’d made the tune and his Patrol is running fine. He’s went up to the Cape last year and is going back again in a few months. It’s good to hear success stories from time to time and not always bad news.