10x injector rating means that you would be at 100% of the duty cycle of the injector at the 240 hp point. It's probably a better idea to size your injectors so that they aren't at 100% for any length of time. I would plan on using injectors that are at 85% of the max duty cycle.
Like Sappy says, BFSC is an educated guess. For gasoline powered engines BFSC is around .45 (very lean) to .60 (very rich). For actual operation .45-.5 is probably more realistic. During wide open throttle operations you want to be on the rich side, so on a turbo-charged engine .6 BFSC is a good conservative guess.
I know you don't want to hear about formulas but sometimes it's the best way to understand this stuff. You can use the following formulas to give you a ballpark idea what size injectors you should use and what HP you would be capable of.
If you dyno'd the engine and knew the exact horsepower output you could plug the number in and see exactly what your injector duty cycle is at that max HP. Since you don't know what the HP output of the engine will be you can switch the formula around to find out the HP the 36# injectors will give you at 85% duty cycle:
Max HP = 36#*6cyl*.85dutycycle/.6BFSC = 306 Max HP, a conservative estimate that puts you close to your 300HP goal without worrying about exceeding the 100% duty cycle of the injectors. Probably something GM figured when they supplied the 36# fuel injectors in the L67 at 8 PSI.
Last edited by FerrariFan; 07-20-2010 at 01:37 AM.
ROTFLMAO! i would trade you in a heart beat! im at 5000+ Ft Elevation. Either turbo will be fine. Im running a T04E "60" (T4) and i spool fine at elevation with cast manifolds, and crush bent 2.5" DP.
Shane "RedZMonte" 2004 Corvette Z06 Commemorative Edition-VIRGIN 1995 Monte Carlo Z34 14.38@101mph, 331hp/355tq
-Turbonetics T04E Super 60 Turbo, 2.5" Borla Catback, OBDII, 42.5# Injectors 2004 Subaru WRX STI -Lightly Modded (SOLD) 1994 Lumina Z34 -VIRGIN (SOLD) 1992 Lumina Z34-VIRGIN (RIP) 1992 L67 Lumina Z34 (SOLD) 1990 Turbo Grand Prix (SOLD)
What is that manifold off of? I know my beretta 3100 and minivan 3400 rears dump out the middle. I'm wondering bc if I remember right some manifolds are almost channeled towards the downpipe while yours looks like it would flow better and work well with wastegate mounting if it would clear my firewall....
Last edited by Daguse5853Z; 08-16-2010 at 03:57 AM.
I beleive that is is off of an early 3100 car. I can't say for sure. I baught it off Ebay, I paid more but figured that I would spend probably 2+ hours getting a rusted seized one off a junkyard engine. Worth the extra in my mind. I am planning to do a little smoothing work in the outlet area to promote better flow. As far as using a stock GM manifold for a turbo application, I think this one is the best option.
Originally Posted by Bridgetown
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