IFR Scaling; 28.8 lb/hr to 42 lb/hr;??
#1
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IFR Scaling; 28.8 lb/hr to 42 lb/hr;??
I am going from a H/C 346 to a LS2 402 and from 28.8 lb/hr stock 98 injectors to Lucas 42 lb/hr injectors.
I will start with my existing tune but obviously will need to scale the IFR initially.
I don't believe it is a 42/28.8 factor but something less. Does anyone have the formula or a guess at initial scale.
Perry
I will start with my existing tune but obviously will need to scale the IFR initially.
I don't believe it is a 42/28.8 factor but something less. Does anyone have the formula or a guess at initial scale.
Perry
#2
TECH Senior Member
the equation is square root of (new pressure / rated pressure )
For our purposes since 1 bar, 2 bar, etc... are even increments we can use 4 bar = 4, 3 bar = 3
4/3 = 1.333... square root is 1.155 (square root is the same as bringing the value to the 1/2 power)
then multiply by the injector size rated at rated pressure (since aftermarket injectors are almost always rated at 3 bar and LS1s run at 4 bar)
so 42lb 3 bar is 42*above value is 48.5 lb/hr on our cars
then you take the percent difference between them (since our 28lb injectors are rated 4 bar)
48.5/28.8 = 1.684
so the 42lb injectors at 3 bar are 168.4% larger than stock in this case
so 168.4 is a good starting scalar
For our purposes since 1 bar, 2 bar, etc... are even increments we can use 4 bar = 4, 3 bar = 3
4/3 = 1.333... square root is 1.155 (square root is the same as bringing the value to the 1/2 power)
then multiply by the injector size rated at rated pressure (since aftermarket injectors are almost always rated at 3 bar and LS1s run at 4 bar)
so 42lb 3 bar is 42*above value is 48.5 lb/hr on our cars
then you take the percent difference between them (since our 28lb injectors are rated 4 bar)
48.5/28.8 = 1.684
so the 42lb injectors at 3 bar are 168.4% larger than stock in this case
so 168.4 is a good starting scalar