Question regarding ECU re-map (Not the usual where to!!)

[Mike M]

Been wondering, if a car leaves a factory with a factory ECU programme for performance, consumption, emissions etc how comes if you get an ECU re-map you (allegedly) gain performance, increase red line point by a couple of hundred revs, fuel consumption and the car generally appears to be smoother yet still complies to emissions. Why dont the manufacturers install an optimum programme from day 1? What dont I get??

Ive had a re-map years ago so thats not the point, more the curiosity of how can you get performance gains yet still have fuel gains!! (Driving style pending!)

Apologies for posting twice. 1st one did not appear then when I re-submitted a new one, my 1st one appeared!!! not sure how to delete a post!!

 

[szklarek]

I think one of the issues is that the ECU program that it has when it leaves the factory is a 'generic' one intended to work fine on all cars - ie to cope with manufacturing tolerances and also err on the side of safety (not stress the engine too much). Remaps should be specific to the particular car and therefore be optimal for that vehicle.

Regards
Anton

 

[D Ward]

Its more to do with covering all eventualities, allowing car to run on inferior fuels, higher altitudes, the car not being maintain correctly or as specified etc etc.

Which is where a remap gains extra power, take fueling, the chip tuner can take out the part of the program which allows the car to run on inferior fuel or fine tune it, hence more power.
Hence the reason a decent chip tuner will advise you to only use high octane fuel, keep the car well serviced etc once they have remaped it
The dme will still protect the engine if you do use lower grade fuel etc, but not to the same degree the factory program maps would have

 

[clyde]

While I agree with all that Anton and Darren say, the other aspect to consider is of course the longevity of the engine.

The factory mapping will be well within the known parameters of the engine as it will have been bench tested and run on the road in all kinds of environments for many thousands of miles. In this state of tune the engine will do what good Porsche engines do and easily see inexcess of 150,000 (at least 993 engines) without major work being required pretty much regardless of how it's driven on the road.

A re-mapped engine will be much less tolerant of abuse as the higher revs, faster spinning engine, etc put a greater strain on the engine. This is fine if it's a week-end toy and/or not abused too much but if you like the extra power and use it most of the time then I would suggest your engine re-build will come sooner rather than later. This is why Scooby engines for example tend to fail at (in Porsche terms) low mileages.

 

[Mike M]

Thanks all, that joins the gaps for me.

Maurice, again thanks for the reply, I got the car tuned by Wayne at Chipwizard so I'm confident of his abilities. I had it done hoping for the gains admittedly but primeraly for the smoother drive. I was suffering from throbbing at slow speeds (No pun intended!) and Wayne was advised as a solution by my service garage, RLR. The gains were nominal as it was running pretty well to start with ( I think it had already had a tune of some degree) During the tune he noticed the power dropping at the top of the curve due to some flappy thing sticking, which he mended. However the car ran a lot smoother at slow speeds and totally eliminated the throbbing kangaroo effect in slow traffic. A much nicer drive so result