Pages: [1] 2
Author Topic: Engine Displacement  (Read 17253 times)
Rabbid
Full Member
***

Karma: +0/-0
Offline Offline

Posts: 55


« on: November 24, 2012, 12:41:04 PM »

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?

Logged
Rick
Hero Member
*****

Karma: +63/-4
Offline Offline

Posts: 704


« Reply #1 on: November 24, 2012, 12:59:27 PM »

MLMAX - do a search Smiley
Logged
Rabbid
Full Member
***

Karma: +0/-0
Offline Offline

Posts: 55


« Reply #2 on: November 24, 2012, 01:21:48 PM »

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

Logged
Rabbid
Full Member
***

Karma: +0/-0
Offline Offline

Posts: 55


« Reply #3 on: November 24, 2012, 01:23:34 PM »

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.
Logged
Bische
Sr. Member
****

Karma: +25/-4
Offline Offline

Posts: 397



WWW
« Reply #4 on: November 25, 2012, 11:31:42 PM »

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.
Logged
nyet
Administrator
Hero Member
*****

Karma: +608/-168
Offline Offline

Posts: 12270


WWW
« Reply #5 on: November 25, 2012, 11:52:51 PM »

KUMSRL converts kg/hr of air into load per rpm

It is inversely proportional to displacement.
Logged

ME7.1 tuning guide
ECUx Plot
ME7Sum checksum
Trim heatmap tool

Please do not ask me for tunes. I'm here to help people make their own.

Do not PM me technical questions! Please, ask all questions on the forums! Doing so will ensure the next person with the same issue gets the opportunity to learn from your ex
Rabbid
Full Member
***

Karma: +0/-0
Offline Offline

Posts: 55


« Reply #6 on: November 28, 2012, 02:16:28 AM »

Seems KRKTE uses displacement in its calculationt too.
Logged
ABCD
Full Member
***

Karma: +4/-0
Offline Offline

Posts: 78



« Reply #7 on: November 28, 2012, 02:51:21 AM »

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

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

Karma: +4/-0
Offline Offline

Posts: 78



« Reply #8 on: November 28, 2012, 02:52:25 AM »

Quote
It is inversely proportional to displacement.

Wrong

KUMSIRL in directly proportional to displacement.
« Last Edit: November 28, 2012, 11:23:41 AM by nyet » Logged
Rabbid
Full Member
***

Karma: +0/-0
Offline Offline

Posts: 55


« Reply #9 on: November 28, 2012, 07:09:04 AM »

Certainly seeming alot more difficult than a standalone ecu which just asks for engine displacement and number of cylinders  Cheesy
Logged
nyet
Administrator
Hero Member
*****

Karma: +608/-168
Offline Offline

Posts: 12270


WWW
« Reply #10 on: November 28, 2012, 11:33:20 AM »

Wrong

KUMSIRL in directly proportional to displacement.


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.
Logged

ME7.1 tuning guide
ECUx Plot
ME7Sum checksum
Trim heatmap tool

Please do not ask me for tunes. I'm here to help people make their own.

Do not PM me technical questions! Please, ask all questions on the forums! Doing so will ensure the next person with the same issue gets the opportunity to learn from your ex
nyet
Administrator
Hero Member
*****

Karma: +608/-168
Offline Offline

Posts: 12270


WWW
« Reply #11 on: November 28, 2012, 11:40:56 AM »

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?
Logged

ME7.1 tuning guide
ECUx Plot
ME7Sum checksum
Trim heatmap tool

Please do not ask me for tunes. I'm here to help people make their own.

Do not PM me technical questions! Please, ask all questions on the forums! Doing so will ensure the next person with the same issue gets the opportunity to learn from your ex
nyet
Administrator
Hero Member
*****

Karma: +608/-168
Offline Offline

Posts: 12270


WWW
« Reply #12 on: November 28, 2012, 12:05:47 PM »

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

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

displacement/2578 will get you in the ballpark.
Logged

ME7.1 tuning guide
ECUx Plot
ME7Sum checksum
Trim heatmap tool

Please do not ask me for tunes. I'm here to help people make their own.

Do not PM me technical questions! Please, ask all questions on the forums! Doing so will ensure the next person with the same issue gets the opportunity to learn from your ex
ABCD
Full Member
***

Karma: +4/-0
Offline Offline

Posts: 78



« Reply #13 on: November 28, 2012, 11:55:26 PM »

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?


Hi nyet,

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

density of air = 1.293 gm/L at 273K
Logged
nyet
Administrator
Hero Member
*****

Karma: +608/-168
Offline Offline

Posts: 12270


WWW
« Reply #14 on: November 29, 2012, 12:07:45 AM »

(((.001072 (kg / hr)) / (1.29300 (kg / (m^3)))) / (0.5 * (1 / min))) * 100

Let google do the conversions for you Smiley

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

100 is for conversion to %
Logged

ME7.1 tuning guide
ECUx Plot
ME7Sum checksum
Trim heatmap tool

Please do not ask me for tunes. I'm here to help people make their own.

Do not PM me technical questions! Please, ask all questions on the forums! Doing so will ensure the next person with the same issue gets the opportunity to learn from your ex
Pages: [1] 2
  Print  
 
Jump to:  

Powered by SMF 1.1.21 | SMF © 2015, Simple Machines Page created in 0.04 seconds with 16 queries. (Pretty URLs adds 0s, 0q)