[Subscribe to Daily Digest] |
If you can find out the output of a particular injector's rating, you can pretty much back-end into the "real" HP through mathematics. It does indeed recommend larger injectors if you're looking to boost the turbo.
Math goes like this:
Every injector has a specific output of fuel, called the Break Specific Fuel Consumption.
Max HP =[Injector Mass Flow Rate]x[Number of injectors]x[Duty Cycle]
------------------------------------------------------------
Break Specific Fuel Consumtion (BSFC)
For example, say a certain injector is rated at 280cc/Minute, this equals a MASS of fuel of about 27lbs./Hour.
A typical NA engine has a BSFC of .45 to .55 lbs./HP/hour. However a typical turbocharged engine has a BXFC of .5 to .6 lbs./HP/hour. Already you see that the injector is a higher rating.
The duty cycle for the average injector is at 85% usually. However at WOT the injector is at 100%. If the injector is running ALL the time at 100% (as some tuners may do) then they won't last verly long. For argument's sake we'll say they're at 85%.
So, for a NA engine:
Max HP = [27lbs/hour]x[4 injectors]x[0.85]
---------------------------------
.55 lbs/hp/hr.
Max HP = 184
Of course you need to know how much air is coming into the engine to then know the injector rating. The typical air/fuel ration is around 14/1(+/-). Since we're turbo charging, and each one of us is doing so anywhere beteen 5lbs of boost (an old 99 turbo) to 25lbs of boost (Jeff Cunningham) each of us needs their specific injectors. What I'm seeing for the most part are the FoMoCo Mustang injectors and 2.5 or 3.0 Bar FPR or even a RRFPR to deliver the fuel pressure in this BB. Seems about right.
So yes, it is beneficial for the most part, to upgrade your injectors, and in some specific cases, absolutely mandator, else you are going to cook your pistons!
'Nuff said. Have fun and happy Saabing!
Jim M.
No Site Registration is Required to Post - Site Membership is optional (Member Features List), but helps to keep the site online
for all Saabers. If the site helps you, please consider helping the site by becoming a member.
 |
 |
 |
 |
 |
