Ducati Scrambler Forum banner

1 - 7 of 7 Posts

·
Registered
Joined
·
100 Posts
Discussion Starter #1
Hi all,

there is anyone that knows the code of the air temperature sensor, please?
I know it is Magneti Marelli, but I need the code, to find the data sheet, cause I'd like to mod this sensor to increase slightly the gas percentage.

Thanks a lot in advance.
Egidio
 

Attachments

·
Registered
Joined
·
100 Posts
Discussion Starter #3
I think you're right. It's the same as the ones used on Moto Guzzi bikes and Fiat cars.

Thanks a lot, Derek!!!
 

·
Registered
Joined
·
100 Posts
Discussion Starter #4
So, I palyed with the data and I supposed to increase the stechiometric rate to +5%, to tame the ON/OFF issue and the hiccup at low speed.
To get this result, it could be sufficient to put another NTC with the same features as the stock one in series to the stock one, in the same position, modifying the stock one (Magneti Marelli ATS05).
Here is a file with the data.
What do you think about?
 

Attachments

·
Registered
Joined
·
32 Posts
thats good Egidio! If I interpret your graph correctly, for example, @25C the ECU should see total R corresponding to 10C and enrich the a/f mixture accordingly? It would be good to know, what is the relationship between temperature and a/f ratio? Alternatively might consider moving the temperature sensor to a location less affected by engine heat, possibly in front of the air box. Noticed the gauge temp reads several degrees warm than the true local temp. I assume this is because the gauge is using the same air box sensor nestled between the cylinders? This is my first fuel injected bike and think Ducati has done a great job, really have no complaints. Richer is better seems to be the consensus.
 

·
Registered
Joined
·
100 Posts
Discussion Starter #6
We know that the ideal stoichiometric ratio is 14.7 parts of air to 1 of gasoline, but we also know that the engines deliver peak performance at around 13.5/1.
So, if (it is not always the case) the standard carburation is the ideal one at all engine rpm, we should produce a first approximation increasing the stoichiometric ratio by about 7-8%.
Another useful information is that the air density increases with decreasing temperature, by about 3-4% per 10 °C and then to obtain a + 7-8% we can simply simulate a temperature about 20 °C lower than the real one. We could start with a lower increment (+5-6%) to reach the best ratio for our specific engine step by step.
I don't know if the best choice is to connect another stock NTC in series with the stock one. Maybe it could be a better solution to find a new NTC with a higher "beta" value (>= 4200K). I found a very good explanation of this topic here in Italian (you can use google translator).
I'm finding a stock sensor to do some nondestructive experiments :joyous:
 
1 - 7 of 7 Posts
Top