iluvmysh

i'll be running 10psi MAX (if that) on my stock 99 gsr, t3 thunderbird turbo, fmic, vafc, 440 or 390 injectors.

here it says i don't need a higher flowing fuel pump
https://www.homemadeturbo.com/forum/...threadid=14497

others said i should......

should i or shouldn't i?

TurboEF9

For 10psi, you'll need the 440ccs.

..you do not need a different fuel pump for 10psi.

juli0_bustamante

wow i did not know this...i have the 390's am i still good if i run 10psi or would i need a walbro>>>

TurboEF9

Fuel flow is not your issue with the AFC hack. It's a combination of the injector flow differential and the voltage range of the MAP sensor vs the max PSI and fuel flow needed to reliabily support the cfm.

Chris Harris

In english :P, it depends on the duty cycle and your AFRs.

IF, your MAX duty cycle is below 90% (preferrably %85), at whatever fuel pressure you are running (typically between 41-48psi on a Honda), then you are good if acheiving typically safe AFRs.

A lot of it has to do with how much power you are making.

Do a search on GOOGLE for "Brake Specific Fuel Consumption" or BFSC, you will get a lot of enlightening results that go into more detail with equations and all.

TurboEF9

With the AFC hack being the focus, I wouldn't even get that technical with it..

..basically, it's simple math. (I'll try in English. ) Too low cc of injector, and you won't be able to scale them back far enough to achieve higher (10psi) boost levels without leaning out. On the plus side, this helps people who really don't understand the details of the AFC hack and why/how it works because they'll be covered for higher boost levels if they just initially use the 440/450 injectors.

..if you'd like me to show the math again, I will, but I detailed this information in several other posts.