I was wondering if there is a chart somewhere that gives a general rough idea on what injector size is good up to a certain HP range.

Search being down sucks

 

Id like to know also ... or if some one just want to tell me im looking for 400-425 whp. im going to use bosch injectors but what size????

 

750 should be fine

 

I've seen the chart, but dont know where it is. Hope that helps

 

nm, found one

http://www.rceng.com/technical.aspx#...tor_Worksheet_

 

You beat me to it, the BSFC should be aroung .5 for our cars and I would use 48PSI for your fuel pressure at 0 PSIG.

 

id725 or id1000 /thread

 

BSFC 0.5 for N/A and ~0.60 if you are going to turbocharge

Also, keep in mind this is for "crank" HP. So HP results should be multiplied by ~0.85 (~15% drivetrain loss) to guesstimate HP at the wheels as read by most dynos. The RC Eng inj calculator is a pretty good tool for sizing up injectors. You can also get a "one size larger" as most EMS units can handle large capacity injectors well for cold starts and idling.

 

If you want to look at it this way then yes a 0.6 x .85 = 0.51.

This is why I suggested 0.50, based on reasearch when I was sizing my fuel system this will still give you pleanty of injector while using a 85% duty cycle. I actually used a VE table that was calculated from real power curves to back calculate.

The last peice of advice I can throw in is to but the largest injector you can buy even if it is much larger than you need and still maintain a good idle. The ID1000's seem to be the best bang for the buck and still yeild a great idle. Once you go larger than 1000 cc's then you will need more than a Walbro 255lph anyway.

 

http://www.injectordynamics.com/hors...alculator.html