NefMoto

Hi All

I'm looking to try and work out what is used for the reference cylinder displacement when calculating load etc. Main reason is for asking is a 2.0 engine rebored or stroked out to a larger size worth writing home about.

I've searched so far but have been unsucessful.

Any pointers for dealing with changed displacement?

MLMAX - do a search :)

Thanks but that is maximum possible air flow for load calculation, which would be adjusted on boosted cars for example.

I'm on about the actual calculation of load

i.e

Load = Mass ingested over Mass Standard. From what I understand mass standard is displacement in cc multiplied by 0.00122521 g[cc]

http://s4wiki.com/wiki/Load

I am trying to workout where the ECU would get the displacement cc from

So far I've found posts relating to KUMSRL and KISRM but I'm not 100% sure on how these would relate to engine load.

KISRM converts rlroh_w to ps_w and KFURL converts ps_w into rl_w.

I believe you should scale KISRM to get ps_w in line with boost pressure(I dont remember the variable name off my head) and thus getting rl_w back in line. I could be wrong but that is how I would approach it.

KUMSRL converts kg/hr of air into load per rpm

It is inversely proportional to displacement.

Seems KRKTE uses displacement in its calculationt too.

KUMSIRL=Vh/2578, where Vh is cylinder volume in Litre

KRKTE = Vh*50.2624/Qstat, where Qstat is Injector static flow in gm/min.

Wrong

KUMSIRL in directly proportional to displacement.

Certainly seeming alot more difficult than a standalone ecu which just asks for engine displacement and number of cylinders  :D

HMM. I rechecked this. As far as I can tell, KUMSRL (not KUMISRL) is, in fact, inversely proportional to displacement. I don't actually know what KUMISRL is.

Here you go. You were right, KUMSRL is proportional to displacement:

(((.001072 (kg / hr)) / (1.27500 (kg / (m^3)))) / (0.5 * (1 / min))) * 100 = 2.80261438 liters

Not sure why 2.8 though, and not 2.7

Am i using the wrong density for air?

In any case, I think ABCD definitely has it right.

displacement/2578 will get you in the ballpark.

Hi nyet,

I cud not get what have you calculated here. Pls elaborate.

density of air = 1.293 gm/L at 273K

(((.001072 (kg / hr)) / (1.29300 (kg / (m^3)))) / (0.5 * (1 / min))) * 100 (http://www.google.com/search?q=%28%28%28.001072+%28kg+%2F+hr%29%29+%2F+%281.29300+%28kg+%2F+%28m^3%29%29%29%29+%2F+%280.5+*+%281+%2F+min%29%29%29+*+100)

Let google do the conversions for you :)

the .5rpm (1/min) is for 4 stroke (1 cyl filling = 2 cycles)

100 is for conversion to %

Hi nyet,

Thanks for the google calculation.

I want to know how did u get value of .001072 (kg / hr) for MAF.

Nice work guys will do some further pondering about it tonight.  ;D

That isn't MAF. That is 2.7t stock KUMSRL

Here you go :

((( (kg / hr /l)) / (1.29300 (kg / (m^3)))) / (0.5 * (1 / min))) * 100 (https://www.google.com/search?q=%28%28%28+%28kg+%2F+hr+%2Fl%29%29+%2F+%281.29300+%28kg+%2F+%28m^3%29%29%29%29+%2F+%280.5+*+%281+%2F+min%29%29%29+*+100) = 2578

I am dealing with my 1.8t converted from 1,781liter to 1,984liter (tfsi crank)

I changed KUMSRL and KISRM which was easy but i do not understand what todo with KFURL.

Hi,

is it necessary to change the KFZW/2 because of displacement?

There are potentially a lot of reasons to alter timing.... displacement isn't the only one....