Generic Remap vs Custom Remap
Within the aftermarket ECU “remapping”, “chipping”, “tuning” etc world there’s an enormous difference between a properly optimised ECU calibration and what most companies offer.
The vast majority of firms offering this service are just selling you a modified ECU calibration file which has been done by another firm on somebody else’s car, or by guesswork! They download the standard file from your ECU, send it to wherever they buy it from who then modifies it and sends it back to your vendor who then uploads it to your ECU. The actual time that your vendor spends on the car is the several minutes that it takes to download and upload the ECU file, and the profit is the difference in the price between what he pays for the file and what he sells it to you for. The vendor’s profit is quite high because of his minimal input. However, the risks to you are high because in most cases no testing is carried out to establish whether the multiple facets of the tuning have been optimised or indeed whether it is even safe!
The only way to ensure that each car has the maximum engine performance and safety is to iteratively make adjustments on the dyno with full data logging and detonation detection, which normally takes between 4 and 8 hours to do properly.
The performance graph above shows what we typically expect to see in terms of the differences between a generic remap vs custom remap. This is a 2008 Subaru Impreza that had been using a generic remap for quite a while. The driver had been quite happy with it but wanted to see whether we could make it any better. The initial power run we did was aborted at the top end of the RPM range because the engine was detonating (which is harmful!).
After optimising the air/fuel ration (AFR), ignition timing and camshaft timing (with no change to the turbocharger boost pressure), the results were an impressive increase in power and torque as you can see.
A few days later the owner left the following feedback on our Facebook page “just to say..great job guys.. low down it has got just so much more pull and right up to the redline…and a few flames with big big bangs…LOL just what i wanted.. ohh yea.. Launch Control is brilliant. soon be clutch time ..thanks guys … be in touch”