map sensor cheating?

[fdsjakl890]

(08-18-2025 05:49 PM)decryphe Wrote:  If you want to keep running the stock ECU, a piggyback that converts the sensor signal according to some custom map would be the way to go. If you're into electronics, you could try doing this with some form of Arduino or other small microcontroller. Personally, I'd go for anything that can run Rust, as I don't like C on embedded, such as https://www.waveshare.com/rp2040-zero.htm and either breadboard or design a little PCB to do the voltage conversions and some voltage spike protection on all pins.

If that's not an option, you'll have to jump to an aftermarket ECU now.

I could imagine there's also some form of analog circuitry that you could use to adjust the sensor output signal, maybe some form of pull-up resistor could help, depending on the polarity of the signal. I'd have to oscilloscope that sensor to know.

But to me, it's quite interesting that it could be quite simple to slap ITBs on mine without swapping the ECU... I'm surprised it runs at all. What does the setup look like?

i was thinking of a microcontroller but i would have to learn how to code and do electronics stuff. im kind of spooked of all the electronic stuff because i really dont want to fry my ecu or anything if i mess up.

i did some research how i could do it all analog. lets say my signal is 3-5v. i would need a 3v reference to substract my current idle signal voltage and then amplify the signal voltage x2(?) so the output would be 0-5v with the same vacuum range. and voltage regulator so it doesnt go above 5v. and it could be made adjustable with potentiometers for simple tuning. atleast thats how i think it would work... im not an electrician but if its just soldering components i think this is something i could manage.. just dont know how

my itbs are just slapped on with an adapter i got on ebay. i just had to shorten the water outlet a bit since it was hitting the tps and had to leave the tvis plate on because the adapter was wayy too short. i did take the tvis valves off.

but it really does run great at full throttle

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(08-18-2025 05:53 PM)banpei Wrote:  The issue is that the vacuum on the MAP system is very different from the vacuum on ITBs. For the MAP system, there is a single sensor, as it's a single throttle body. By T-ing the four vacuum lines on the manifold, you will get a very different vacuum than on the single throttle body. This is apparent in both low-end and top-end. Usually, this isn't a huge issue to remap with an aftermarket ECU, but on a stock ECU this is a problem. Some people (like Robokill) use a stock ECU with a different map (e.g. using a custom EPROM), but this is not something you can obtain freely.

About the 02 sensor: some European ECUs did get a cat, so they also have an O2 sensor. However, if your ECU doesn't have a cat, it will not do anything with the O2 signal.

Edit: You could try to go for a Speeduino (which is not a piggyback), but keep in mind that you would have to create your own tune that matches your ITB setup. Even if there is a 4AGE map available for the Speeduino, it probably would be different from your setup, as it could differ in manifold or ITBs used. Most of the cost for aftermarket ECUs isn't in the ECU itself, but in creating the right map.

yeah the vacuum is wayy different. i have the vacuum connections t-d together right now but maybe i should try what kind of effect adding a vacuum block or some kind of vacuum canister would have. or maybe bigger vacuum inlets?? would be way easier if there was a 0-5v map sensor with adjustable tension to adjust for the lower vacuum but i dont think those exist

i thought the o2 sensor goes in the manifold so cat doesnt effect it? but i guess that doesnt matter if the map ecu doesnt have the internals for the o2 sensor.

im sure theres a lazy and cheap way to fix it
or ill just have to swap the ecu and bike around until its done