Wondering how to get more out of your 4×4 diesel? Discover the key differences between power modules, ECU tunes, and diesel chips here.
If you own a diesel engine overseen by an electronic control unit (ECU), then we have good news for you. There is significantly more power available reliably without having to do much work and without having to auction one of your kidneys off on the dark web.
When a vehicle manufacturer releases a new engine, there are a billion lines of code relating to fuel maps. This code oversees fuel delivery, turbo boost, injector pulse, injector duration, and a bunch of other things. Essentially, these maps dictate how much fuel and boost are delivered to the combustion chambers and how much resultant power is put out.
Now, the manufacturers have to be careful with their mapping as different countries have a lot of variation in things like fuel quality, so they can’t throw in an aggressive map and hope for the best because it’d take a bat to their reliability. Nor can they develop different maps for different parts of the globe, as it wouldn’t be cost-effective. So they shoot for the middle and put out safely repeatable figures. These figures might not be that impressive but they will allow the engine to run well from the Middle East to the Yarra Valley to Reykjavik.
But back to that good news. With a little work and a few bucks, you can turn your diesel into something a lot more driveable, capable, and enjoyable to own without affecting its reliability with a chip, power module, or ECU tune.
But which one to go for?
Getting more power from any diesel
Without getting too deep into it, let’s take a brief look at how to get more horsies and Newtons from your oil burner. Basically, fuel = power. The more fuel you pump into the cylinder before it gets lit on fire, the bigger the explosion, the more force the piston turns the crankshaft with, and the faster you go. Of course, you need the right amount of air to mix with this fuel dose, which is where turbo boost pressure comes in. The more boost pressure, the more air in the cylinder, the more fuel you can pump in to keep that magical flammable air-fuel ratio bang-on.
So more fuel combined with more air equates to more power. Cool?
However, as you might have guessed, it’s nowhere near as simple as we’re making it sound. More fuel also = more heat. More power can also have negative impacts on things like clutches (LC70 owners, we’re looking in your direction) or CV shafts. If you have more available under the right boot, then the rule is that you’re probs going to use it. This means your fuel consumption can rise.
The problem now becomes maintaining reliability and fuel use. Knowing where and how to tweak fuel maps is paramount. A little too much in one area and not enough in another is a surefire recipe for a cooked engine.
Luckily, there are some big brains working on the aftermarket tuning scene, and these days, pretty much all of the guesswork has been taken out of the equation. So, let’s get into the three main methods of making your diesel engine sing.
Plug-n-play chips
What it does
Like it says on the wrapper, these roughly-matchbox-sized chips plug into the fuel system and boom! More power is now available. While these are the cheapest form of level-up, they’re also the simplest. They basically alter one or two parameters on the fuel map, upping something like injector rail pressure (so more fuel is delivered when the injector opens) or something similar.
The cool
Good ones can make power reliably and effectively. They’re also relatively cheap compared to ECU tuning or power modules. Plus, they’re by far the easiest to install, usually taking a few minutes or less.
The lame
The line between good and bad units can be difficult to find. Bad ones will deliver maximum fuel and maximum power all the time, which is a great slogan for an energy drink, but is absolute garbage for a diesel engine and will essentially be a wrecking ball at anything other than full throttle. Be VERY wary before heading down this path, friendo.
ECU tuning
What it does
No chip, no module, and no physical changes are made with an ECU tune. The vehicle’s ECU is plugged into a laptop, a new mapping file is transferred over, and just like that, your rig now has ~20% more mumbo. Done correctly, this can alter all of the required parameters of your base tune file and get you a comprehensive improvement right across the torque curve, without any ramifications. But, and it’s a big one, there are tuners, and there are “tuners’.
The cool
More power, more torque, better fuel economy. A good tune will be written onto the ECU and then tested on a dyno to ensure it’s doing what it’s meant to. If you take your rig to a tuner who knows what they’re doing, there’s literally no downside.
The lame
Finding a good tuner. Lots of folks these days have discovered how to plug their laptops into ECUs and click “upload file.” While that means they’re not too shabby on a keyboard, it doesn’t mean they know what makes a diesel engine work. Stories of tunes that have windowed blocks, burnt-out fuel pumps and engines running hotter than Sydney Sweeney asking you to be her sidepiece are common. Bad tunes will set off error codes, throw check engine lights and basically have you asking yourself why God hates you. Also, if you’re still getting your rig dealer serviced, they’ll likely wipe the tune when they install ECU updates.
Long story medium: do some research online about the tuner you’re looking at. Make sure they know your vehicle, make sure they use a dyno to check their files and make sure they don’t look like they’ve never spun a spanner before in their life and ensure they haven’t just bought the file off eBay.
Power modules
What it does
Power modules are the next evolution from plug-and-play chips. They’re more comprehensive, they work better, and they don’t affect reliability. Unlike ECU tunes, they retain the advantage of being completely reversible by simply unplugging them from the harness.
The big player in this segment is the Steinbauer Power Module, which has been around for ages now and is well-proven to be functional and as reliable as gravity. The module works by increasing injector duration (the length of time the injector stays open during each power cycle, so more fuel is delivered), which is arguably the safest method of tweaking things as rail pressure is not touched and the fuel system’s components are not unduly stressed.
The cool
20% more power and torque across the rev range (just as a side note, anyone claiming much more than, say, a 25% increase from a chip/tune/module alone is probably talking smack) and an enviable reputation for reliability and results. Emissions and exhaust gas temperatures are unaffected, and Steinbauer has one of the largest application lists worldwide, so there’s almost certainly a module for your vehicle. Each one is mapped to the individual vehicle as well, so it’s not a one-size-fits-all sitch either.
You can find `em for yourself on the Diesel Care website if you enjoy hassle-free power and torque.
The lame
Not too much, to be honest. We guess that they do take a little more installing than a chip, given they’re wired directly to the individual injectors, but it’s fairly doable by a handy DIYer, or there are plenty of installers dotted around the country to help out if required.
One last thing
We’d like to think it goes without saying, but our lawyers are such hand-wringers that we have to throw this bit in. If your vehicle is leaking oil, has coolant that looks like baby poo, hasn’t been serviced in the last three years or is blowing more smoke like a Rastafarian at knock-off time, then no chip, tune or power module should be on your to-buy list. Get your engine running sweetly with some fresh fluids, filters and anything else it needs before pursuing more go power, you animal.
