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Re-Mapping Myths Busted

Sick of the marketing spin and outright BS? Here’s 7 of the biggest ECU re-mapping myths busted

The internet is a powerful tool. It lets ideas and information flow freely from those who know their s*%t to people who want to know theirs. It’s allowed us as a business to grow, not just in terms of reach, but the in-house knowledge we have from working with some of the biggest names in engine control systems. The downside is there’s no special license where you need to prove your credentials before passing on information. No fact-check to make sure some fly-by-night diesel tuning shop knows which end of a 4WD to put the engine before they start swaying people’s minds and talking them into costly ‘upgrades’ when there’s far better options out there. We figured it was high time we put right from wrong and start busting a lot of the myths floating around the interwebs from so called experts about ECU re-mapping and give you the straight-shooting, no-nonsense facts.

There’s a lot of BS that chips are safer than tunes, the reality is good kit is better than bad kit, no matter what system. Re-mapping is just the next level that gives us more control

Myth #1 – It’ll damage the ECU – ECU remapping has been around in petrol engines for near on 30 years now, but it’s only recently the ECUs in diesel 4WDs have been smart enough to tune them that way. The early ECUs in petrol engines were often incredibly rudimentary, meaning the people tuning them would have to crack them open, solder in patch leads and physically alter the ECU to get it to work, obviously not something you’d be keen on doing on a brand new 4WD. Modern ECUs are a lot more complicated but they’re also designed to be easily updated, just like a phone. In almost all 4WDs we’re simply able to plug into the diagnostics port, download the old program, make our changes then re-upload the new one. It does no more damage to your ECU than having the computer reset, just with a whole lot more usable power.


Myth #2 – Chips are safer than re-mapping – This is a common one lately but it’s been misrepresented. Re-mapping and chips both operate very differently. A chip alters the signals going to the ECU, tricking it into behaving the way the tuner wants it to. So if they want 3psi more boost, they’ll trick the ECU into thinking it’s running 3psi less than it actually is so it’ll ramp up to compensate. Re-mapping goes to the source and tells the ECU to bump up 3psi. With modern ECUs being so complicated that difference in pressure could mean the ECU will change multiple other parameters to suit, if it doesn’t know it’s doing it, it doesn’t know how to do it safely. A bad re-map is just as dangerous as a bad chip, but a good re-map is a lot better than a good chip.

The internet is a great source of info, but it’s hard to tell if the bloke you’re speaking to has years of diesel tuning experience or a degree in Google

Myth #3 – It can wreck your engine – ECUs are a lot smarter than many give them credit for. They’re not sitting idly on their hands watching as your engine rips itself to pieces. For every possible operation the engine will have, the ECU will have multiple maps to check against and act accordingly. We can bump one map up to slightly change boost pressure for normal operation, without changing the factory over-boost limits. We’ll read the existing maps to understand where things can be pushed and where they can’t and make sure we stay well within the factory limitations. If it reaches those factory limitations we leave in place it’ll still go into limp-mode, just like a stock one.


Myth #4 – The bigger the number the better the tune – Tuning a 4WD isn’t a race, there’s no ‘best’ tune we’re all aspiring to. The fact that one tune make 20hp more than another is basically pointless information. What matters is drivability. We can crank the wick right up on a tune till it’s making astronomical power figures and it’ll run down the dragstrip like a rocket. But it’ll drive like a bucket in every other situation. If you’re building a diesel drag car, or a family tourer we’ll do two completely different tuning levels to make the vehicle work how you want it to.

The days of physically altering the ECU are long over, with most models not even requiring the ECU be removed from the vehicle

Myth #5 – You need a dyno – A shops opinion on whether or not tuning on a dyno is necessary normally revolves around if they have a dyno. We have two, but they’re not always needed. With modern diesels the ECU controls every little detail of how the engine runs, to the point you can almost tune for a specific torque figure without ever seeing the vehicle the tune is going on. If the vehicle is reasonably late model, has been looked after and doesn’t have weird and wonderful power upgrades done to it the dyno is more verification of the adjustments, rather than a key step. It’s a tool we use constantly in the development of our tunes, but once we’re making predictable results it’s not required and can often be substituted with some on-road testing.


Myth #6 – It has to be done in-house – There’s a huge misconception that if the person removing the ECU isn’t the one doing the tune then the tune is just a generic map and dangerous for your engine. That couldn’t be further from the truth. When Apple sends an update out over the internet for your phone there’s no possibility of them accidentally installing Android. It doesn’t matter if the ECU we’re remapping is plugged into out hardware on the bench next to us, or if it’s thousands of kilometres away in one of our dealers and being done over the internet, the results are always the same.

Punching out big numbers on the dyno rarely transforms to a more drivable 4×4

Myth #7 – You’ll have no warranty – A huge concern for anyone with a new 4WD is voiding the factory warranty by fitting upgrades. The manufacturer will use any excuse to get out of paying warranty, including using your 4×4 as a 4×4. To stop this issue all the work we do at Roo is warranted, if something goes wrong because of a tune you’re still fully covered under warranty, even if the factory complains you’ve fitted an aftermarket floor mat.

Contact us now or call 1300 305 709 (Mon-Fri) and let us show you what we can do for your 4WD or contact one of our 60 nationwide dealers directly.