Do modern bikes need re mapping ?

An interesting conversation has cropped up within my circle of pals...

Do modern FI / ECU controlled bikes need re mapping if fitting different and less restrictive exhaust pipes?

Now, me being old skool says of course they do, modern engines run weak anyway and fitting a free flowing exhaust and cat delete etc is gonna make that worse.

Ah, but, say the modern boys, what are all those o2 sensors etc for if they’re not for the ECU to keep the mixture correct?

Which does seem like a valid point.

My old skool layman’s thinking is that whilst they’re right, the ECU will still be ‘correcting’ the mixture to run lean, it’ll still be trying to meet emissions regs etc and may have various ‘cheats’ programmed in there for flats spots at given revs etc, etc. Hence re mapping is required to return mixtures closer to whats required for performance and undo the various programmed in cheats etc.

Does anyone on here actually know owt about this ?

I have a 2016 Triumph Thruxton 1200S that I brought new in 2018 (old stock) after the first month of ownership I contacted Peter at Meerkat Exhaust (which is only 100 miles away from my place) to replace the cat with his well made x-pipe and he also opened up my stock mufflers for free flowing and he replaced the baffles with his own made baffles to the same design of the old Conti exhaust baffles of the 70s, after the first ride the ECU adapted to the new x-pipe and opened mufflers, today there are now new tunes for the ECU but my bike runs quite well and will run to full rev limits without any problems, so yes the ECU will adapt to the x-pipe and open pipes, my bike is still quiet but open it up it revs and sounds great, so much better than when it was all stock and a few more HP and very happy with the increase in get up and go.

Ashley

My late, lamented '07 ZX-14 sported a Power Commander w/slip-ons map for fueling adjustments, Scorpion Ti Slip-ons, an ATRE to remove the timing retard in lower gears, a Muzzy adjustable ignition wheel with 4 degrees advance and a BMC air filter. It ran like a striped ape. I'm sure a stock ZX-14 has plenty of stonk. Mine had a bit more. Winding out in first, the front would come up just like my old H1 500 3-cylinder 2-smoke.

The question was; did it NEED all that? No, but it sure was more fun. My KTM has a decat midpipe and low-speed fueling dongles (O2 sensor eliminators). Without the dongles, they run very lean at low speeds, making parking-lot manuevers sketchy and it ran pretty rough up until 4K rpm. Now I have an extra usable 500 rpm at the bottom and only lost 1.8 mpg. Lots of folks opt for the Rottweiler Airbox, Power Commander and full exhaust system for that little bit of extra power that can be extracted without considerable mechanical modification. At my age, I really don't need all that. The ECU is somewhat adaptive to changes.

Thanks guys, the summary seems to be that the ECUs are adaptive to change the days, but changing pipes without mapping intervention will result in lean running and possibly sacrifice some smoothness of running and some power.

Sounds about right to me.

My question would be - how has the new map been developed ? Many guys are capable of tuning their bikes to a stand-still. And experts are often not.
When you road race, you are usually faster if you do not lift the front wheel as you accelerate. Modern bikes are a balanced package - power, suspension and weight distribution. What are you trying to achieve by modifying ? If you need to do that, you probably also need a track bike.

You need to be very careful when you modify road bikes. It is very easy to become a full-blown addict. Personally I don't like making policemen so happy.

On my 2016 Thruxton 1200S the ECU was locked and couldn't be remap but the standard map had a built in 10% range for adapting to different pipes, after fitting the Meerkat x-pipe and opened up stock mufflers the bike ran really rough and very lean on the first run after, but after the first 20 minutes and shutting the bike down, the next ride the ECU had made its own adjustments and the bike ran perfect after that first run, that was 3 years ago now and 20k clocked up, my bike runs perfect from low revs to rev limiter at 7,500 RPMs and is very smooth throughout the rev range, the mufflers are showing a good colour (not lean), but after a few years on the market there are now smart people who have designed and made new maps for the locked ECUs on these later models.
My 1200 Thruxton is now my main bike for doing everything from riding around the suburbs, city riding, highway riding to high speed runs up in the tight twisties up in the ranges it gets up to ton and over pretty quickly without any problems at all, no hesation at all and with traction control turned off will pull outs standing wheelies with easy if I want to, going from first to second the front wheel comes up without trying if I take off quickly, my motor is all stock but the Thruxton's do have a lighter crank than the Bonnie motors from the factory and in sports mode it does get up and go, I no need to go any faster.
There are now new high performance cams coming on the market for these bikes as well a supercharger kit for them but I am happy with what I have got, no need for more HP but I love to try one with the SC kit installed.

Ashley

Fast Eddie said:

Ah, but, say the modern boys, what are all those o2 sensors etc for if they’re not for the ECU to keep the mixture correct?

Click to expand...

But correct mixture for emissions tests, not for rideability or best performance.

The map contains a target mixture which is not always the mixture the rider wants or feels they should have. Remapping sets new mixture targets which will be more to a riders wants and these are usually on the richer side and aim for more power.

kommando said:

But correct mixture for emissions tests, not for rideability or best performance.

The map contains a target mixture which is not always the mixture the rider wants or feels they should have. Remapping sets new mixture targets which will be more to a riders wants and these are usually on the richer side and aim for more power.

Click to expand...

That’s what I had concluded. Thanks for the confirmation.

Richer should not mean faster. If the mixture was so lean that richer means faster, then the original set-up was probably doing damage with combustion temperatures which were too high.

When you make a change to your bike and pay somebody to do it, it is easy to convince yourself it is better. Especially if they use a computer.

Nigel
'
Ah, but, say the modern boys, what are all those o2 sensors etc for if they’re not for the ECU to keep the mixture correct?

Which does seem like a valid point.'

O2 sensors are probably reverse calibrated from a motor which performed well on a dyno. They probably do not often set the optimum oxygen content in the exhaust for motors using different fuels and different compression ratios.
I cannot imagine any engineer trying to calculate the perfect O2 content in exhaust gases from the chemical composition of the fuel. Even accurately measuring the O2 content would be a problem.
If the O2 sensor sets the tuning starting point for the mixture, that is probably all they achieve. The rest might be up to the dyno and small changes to the maps and mixture.
Better control is good. But we should not believe bullshit.

Just to be clear Al, we’re not talking about improving the fuelling on an otherwise stock machine. We‘re talking about whether or not it’s necessary to alter things when a modern machine has things changed like exhausts, cats, air filters, ALL of which are designed for optimal emissions and not performance.

Having said that, many modern bikes, especially big singles and twins, are known to run poorly at low rpms, even out of the crate, as they are set up so lean in order to pass modern emissions.

Anyway... my questions has already been answered. The answer was yes !

is that 'yes' to the proposition that re-mapping is necessary ? If I was racing a modern bike, I'd take a different approach to riding one on public roads. But I think the bikes which are slower in races are usually only slower because the rider is slower. If your bike is fast enough to be in the lead bunch, you leave it alone and just ride it quick. A faster bike costs more money.
All public roads have speed limits and police.