Why alter ecu mapping?

[68C]

I mentioned this topic in another thread re IAW15M K line, and realised I had wandered off topic, so am re-presenting it here.

 

Back to my point, in the 60's I recall tuning a bike meant getting the motor as close as possible to what the designer wanted - blueprinting. Build quality was often bad, for instance I believe Norton twin barrels were bored on the same machine that bored the singles having to be unbolted from the jig and repositioned to bore the second barrel - excellent way of keeping them truly parallel. Running your finger down the inlet tract of a 650 BSA soon reveals the imperfections. Basically we used files and sandpaper to tune a motor. We could increase power but often at the expense of flexibility. Into the 70's and 80's production quality had improved to the point that polshing intakes and balancing cranks led to little improvement, we were now trying to remove the dip in mid range performance caused by noise and emission regulations, enter the DynoJet kits, freer flowing (noisier)exhausts etc. Then came fuel injection.... So what are we trying to do now? Here I am speaking of stock machines, surely the build quality is adequate, are we still trying to remove mid range power dips due to legislation , don't these clever factory maps cure this?

 

Why are folk re-mapping their ecu.

 

I have a 2004 V11 LeMans Rosso Corsa, bog standard with a crossover pipe under the alternater ( actually I wish it was under it as it seems impossible to remove the cover without removing the exhaust) and the standard centre section/crossover.

[Trevini]

You answered your own question - it's about the legislation restricting emissions. The manufacturers could easily tune the engines for optimum power throughout their rev range, but their hands are tied, hence a market for power commanders and remapping ecu units.

 

Not a lot has changed from when you were tuning your old Nortons etc. It's just the technology is a little different.

 

Back in the day, if you fitted a free flow exhaust or high lift cam, you'd have to adjust the mixture by rejetting the carb(s) to provide optimum power (and most likely, prevent engine damage due to excessively weak mixture). The only thing that is different now is the way you adjust the mixture. Rather than change a mechanical object (jet), it's simply a case of altering the injector duration to provide a richer or weaker mixture as required. Much easier when you can do it via the electronics.

 

A lot of the tuning that is now needed is because of legislation controlling emissions and noise. As a result, many bikes (and cars) have less than optimal mixtures for power and torque at certain points in their rev range. Throw into the equation changing exhausts, air filters, cams and modifying heads and you'll certainly need to do something to correct it all. Build tolerances are much improved compared to older machines, hence one R1 being close to identical to another in terms of power and torque.

 

Take my V11 as an example. It has Mistral cans and crossover, a modified airbox, modified engine internals and a remapped ecu. Apart from the crossover, all this was done before my purchase, but changing from a std crossover to a Mistral made a huge difference to the engine power characteristics. It does run a little richer at the bottom end, has probably lost a couple of hp right at the top, but boy is it strong in the middle by comparison. It also needs to be remapped again to get the best from it, so a trip to the dyno is on the cards at some point. The last dyno print out showed 89bhp at the wheel with excellent power/torque throughout the rev range, particularly in the 3-6500 rpm range.

 

I don't think you'd be able to make massive gains on the engine to the top end power without major mods, but it's clearly possible to vastly improve the mid range without too much of a sacrifice at the top and extend the power over a wider band.

 

Hope this helps. Sorry for the lengthy post!

 

Trev

[gstallons]

All highway transportation that carries humans is governed by tailpipe emission laws. The optimum perdormance has nothing to do with O2, CO2,NOX, or any other exhaust gas. Meeting emissions governs all of this. Gas mileage and exhaust emissions is what manufacturers have to use as a target. What you do with your bike (unless you live in a very strict country) is your business.