Fuel System Help Regarding FMU?
I just purchased a KB 2.1 L Blowzilla kit for my 1994 Mustang Cobra. The car has the following mods:
331
GT-40 alum Heads
E-303 Cam
Full Exhaust No-Cats
73 mm MA
65 mm TB
255 lph Walbro in tank
Stock Computer & 24lb injectors
After the install with the included FMU the car ran well but obviously really rich. Checked th KB paperwork and found the FMU was 12:1 and they advised against using any thing but the stock 110 lph pump. Which made no sense since every other brand of super charger says to get a bigger pump and includes a 10:1 FMU for cars with 24lb injectors. After thinking about the combo I became concerned with the fuel pressure causing static injectors at the 5-7 lbs boost the car sees.
I called KB and they were less then helpful telling me the kits are for stock cars only and would not even sell me a 10:1 FMU. Which did not make me happy since they changed the pulleys on my kit for the added displacement knowing the car was not bone stock. At some point I will move up to 42lb injectors, bigger MA and a tune. BUt I like driveability and cant afford to do it right now.
By my calculations a 10:1 FMU should be fine with 24lb injectors, 255 lph in tank pump on an engine seeing 6-7 lbs boost. My math says that would be 60 PSI from the FMU and half the normal pressure at 19 (Set at 38). :confused: Giving me 79 lbs of pressure on the injectors.
Can anyone tell me if my math is right and that would be in the safe zone to get a dyno and air/fuel pull in? The car only made around 275 HP to the wheels prior to the install so I figure it's probably seeing around 350-370 to the wheels with the KB and proper air/fuel. :confused:
Thanks In Advance
Fox-4-Cobra