I know how to scale them with stock psi, but what do you do when someone is running a higher psi system for boost?
Scaling injectors with new fuel pressure?
I know how to scale them with stock psi, but what do you do when someone is running a higher psi system for boost?
are you sure that right...it cant even get it to match my stock injector table
You still use the spreadsheet to set the IFR, and then when you tune the 2 bar VE, the upper VE will take care of the fact that the IFR covers vacuum only (not boost).Originally Posted by minytrker
If you want to be accurate, you can install a MAP-referenced pressure regulator (the regulator's pressure is adjusted by MAP vacuum/boost);
a MAP-referenced regulator keeps the pressure difference across an injector constant regardless of MAP vacuum/boost (it does this by adding MAP to the regulated absolute pressure, so MAP pressure is present on both ends of the injector and so subtracts itself out).
To calculate IFR for MAP-referenced regulator (flatline IFR table):
Flowrate = SQRT((P+BARO) / Rated_Pressure) x Rated_Flowrate
where pressure measured at rail with engine running is P+MAP, and from P+MAP subtract MAP and add BARO to get P+BARO.
Othwerwise, this is what the spreadsheet computes for an unreferenced regulator (sloped IFR table):
Flowrate = SQRT((P+BARO-MAP) / Rated_Pressure) x Rated_Flowrate
where pressure measured at rail with engine running is P, and BARO-MAP is manifold vacuum.
Last edited by joecar; May 18th, 2006 at 06:59 PM.
What are your numbers (rated flow, rated pressure, and rail pressure is 58psi)...?
let me guess, was the car tuned by a 'professional' before?
and by that i mean did they tweak your IFR to get a quick'n'dirty dyno tune?
nope i was going off my stock z06 injector table
you sure you're doing it in right units? i've verified the few stock bin's against the number i get out of the spreadsheet and they all check out just fine.
miny - how far off are the numbers? IIRC, they won't be exact due to the way the PCM stores them.
Post your numbers and an image of your IFR table.
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