whizzybang

Hi all,

Attached is my msq.

My setup : Microsquirt V2, 50mm ITB's, no airbox, 1x ID 2000 per rotor, 36-1 trigger wheel, 4 IGN-1A coils firing wasted COP. On premix unleaded ron 98. Base pressure : 3.1bar.
100% alpha-n.

All of this in an NA miata.

I managed to get a roughly good map, made 250hp at 8500 and decided to go to a track day.

However, two major problems :

1. The racetrack was higher in altitude than my home town where i made my tune. When i got to the track, tune was way off. I had to turn the fuel pressure down to 2 bar since i didn't want to re do a full tune instead of driving.

Do you know how i can make the MS compensate for altitude ? I plan to make an airbox to help but i doubt this will be enough.

2. Accel enrich : this is a nightmare. Either it goes full rich, or full lean but nothing in between. I can't seem to find the ballpark where i need to be in terms of added PW duration.

Maybe i missed something big but i have been trying for so long i don't see anything fishy anymore.

Thank you for your help.

Max

Shainiac

iTrader: (7)

I believe there is an option to have it do barometric correction where it takes the initial barometric reading whenever the key is cycled. This doesn't do you much good if you're changing altitude, but if you get to the high altitude track and cycle the key, it should help. I'm also not sure how this effects Alpha-N tuning. You could always fudge you Req Fuel value to compensate rather than change base fuel pressure.

whizzybang

Thank you for your answer mate.
Cycling the MS is good if you are at a fixed altitude.
But if i go up a big hill, it won't compensate so in the end it won't be good anyway.

If somebody has an answer for a good all around tune, that is non dependant on altitude or temperature.

What about accel enrichments ? Anybody ?

Shainiac

iTrader: (7)

Another option would be to upgrade to a dual-map system.
I ran this map with my MS3X and it ran great. My altitude only varies from sea level to ~300m, but I never noticed a difference. It has live Baro and a 4-bar (overkill for NA, but it'll work).
I don't know if you can designate the stock MAP sensor to do baro since you're not doing speed-density anyways. but the dual-map would work.

whizzybang

With microsquirt there isn't any built in map sensor. I can only plug the 3bar GM i got.
But i will have to choose between baro and MAP. If i want to use it as a MAP, i must use the blended ITB mode which i am still not comfortable with. I defo need to learn how it works.

But again, it won't solve the problem. You are right saying that the best option is baro + MAP but I don't plan on changing ECU as of yet.

I am quite confident the airbox will do some good as it acts as an air tank for the engine with a fairly constant velocity inside thus fairly constant pressure thus faily constant quantity of air swallowed by engine. Altitude won't matter as much hopefully.

Thanks for the input man.

Shainiac

iTrader: (7)

Oops, I thought you have a MS2. Doesn't the Micro have 2 spare analog inputs? I'm guessing you could throw a spare 1bar map sensor on one of these and assign it to Baro.