convert lb/h or cc/m to ms/g ??

General Tuning Questions And Discussions
Post Reply
farmboynick
Posts: 14
Joined: Thu Feb 14, 2013 7:43 am
cars: vy ss ute
vy hsv r8 clubsport c4b
vr s pac ecotec

convert lb/h or cc/m to ms/g ??

Post by farmboynick »

could someone please help me with injector flow rate conversion, i need to convert lb per hour or cc per minute to miliseconds per gram
User avatar
darcy
Posts: 120
Joined: Fri May 22, 2009 10:28 am

Re: convert lb/h or cc/m to ms/g ??

Post by darcy »

1 lb/hr ~ 0.126grams/sec = 7936 ms/g ~ 10.76cc/min (assuming gasoline weighs 737kg/m3 per kingflow spreadsheet)
farmboynick
Posts: 14
Joined: Thu Feb 14, 2013 7:43 am
cars: vy ss ute
vy hsv r8 clubsport c4b
vr s pac ecotec

Re: convert lb/h or cc/m to ms/g ??

Post by farmboynick »

is there an easy way to change the injector size in the bin, e.g. changing from 220cc to 240cc without changing the tune as performance is not the goal?

also if for example if an injector runs 300cc at 3.0 bar does this make it 350cc at 3.5 bar

i know these are probably dumb noob questions but i need to learn the very basics and work too much to spend a lot of time toolin around with my projects
User avatar
antus
Site Admin
Posts: 9016
Joined: Sat Feb 28, 2009 8:34 pm
cars: TX Gemini 2L Twincam
TX Gemini SR20 18psi
Datsun 1200 Ute
Subaru Blitzen '06 EZ30 4th gen, 3.0R Spec B
Contact:

Re: convert lb/h or cc/m to ms/g ??

Post by antus »

You can adjust injrate by the % difference for cc changes. Eg 220 to 240 would be (220/240)*current injrate. (thats not much of a change though, you'd probably want to go a fair bit larger injectors to make the change worth while and for headroom).
Have you read the FAQ? For lots of information and links to significant threads see here: http://pcmhacking.net/forums/viewtopic.php?f=7&t=1396
User avatar
Holden202T
Posts: 10394
Joined: Sat Feb 28, 2009 9:05 pm
Location: Tenambit, NSW
Contact:

Re: convert lb/h or cc/m to ms/g ??

Post by Holden202T »

i guess it depends on the reason behind the change, if its purely because you have a brand new (or cleaned) set of 240cc's and they are replacing old dodgy 220cc's then its fair enough, but if like antus says your going for more capacity etc then you probably really need to go bigger to make it worth the effort.

that said 10% change in injector size can be the difference between big enough or not :)
farmboynick
Posts: 14
Joined: Thu Feb 14, 2013 7:43 am
cars: vy ss ute
vy hsv r8 clubsport c4b
vr s pac ecotec

Re: convert lb/h or cc/m to ms/g ??

Post by farmboynick »

if an injector runs 300cc at 3.0 bar does this make it 350cc at 3.5 bar
User avatar
VL400
Posts: 4991
Joined: Sun Mar 01, 2009 2:54 pm
cars: VL Calais and Toyota Landcruiser. Plus some toys :)
Location: Perth, WA
Contact:

Re: convert lb/h or cc/m to ms/g ??

Post by VL400 »

No it will much less of a change, this spreadsheet does the calc .. https://pcmhacking.net/forums/viewtopi ... 675#p21675

But if you want to manually calc it, use.. New Flow Rate = Current Flow rate * sqrt(NewPressure/CurrentPressure)
Post Reply