Injecter PW vs HP vs RPM

[TheMechanic]

Tell me if this is bad info
Maximum injector on time.
rpm dependent.
formula- 60000/rpm x 2 = max on time.
60 ms is 100% at 2000rpm
30 ms is 100% at 4000rpm
20 ms is 100% at 6000rpm
15 ms is 100% at 8000rpm
https://www.stealth316.com/2-calc-idc.htm <--- anyone have this as an excel sheet?

Street should be held to 80%
Short duration should be held to 90%
If you wanted to size an injector to a vehicle would you start with Horsepower as your base and lbs as your variable?
Lets say you have a relatively stock non E85 injector-ed vehicle. You put on headers, a modest to big cam, Cold Air intake, better exhaust, maybe larger TB.
What would you calculate the needed lb injector? Guess based on experience? Guess and a WOT while recording ms? Some spread sheet? A calculated range based on HP?
Thanks in advance.
Danny

[kevin87turbot]

You're on the right track.
It's pretty easy to calculate the proper injector size if you know the target hp and the BSFC.
Here's a link to Wallace Racing Calculator's site. It's pretty handy to get you in the ballpark.
http://wallaceracing.com/injector-sizing.php