2002/Black/SS

iTrader: (3)

the ati fmu connects after the stock regulator in the tank around where the line connects to the fuel rail. so how does it do anything?

i have a turbo and 2 intank pumps with a stock eveything else fuel system and i found an ati fmu for sale. will this work on my car? will it help control the fuel system better??

Lonnies Performance

iTrader: (16)

It will only work with a front mounted regulator or you must block the stock return line near the fuel filter & run a new return line from the under hood mounted FMU back to the regulator in the tank. This is not the preferred way to do things on an LS1. If you need twin pumps, you are in the HP range that fueling is critical & shortcuts will quickly lead to broken engine parts.

I suggest you spend money on lines , regulator & injectors to properly feed the engine.

2002/Black/SS

iTrader: (3)

so when do people ever use the FMU?

lethal93ta

FMUs are and easy way out for most stock guys, you can keep the stock size injectors and basicly double them, there not very reliable tho, I heard of to many of them going out and the engine runs lean. then kiss all the $$$ in parts you spent goodbye. I ran one on my stock LT1 with 24 lb injectors I was running 90 lbs of fuel pressure under boost so I doubled the fuel pressure to the injectors on an LT1 car so I basicly had 48 lb injectors. it worked but the new set up Im ditching the FMU and going to a real set up.

Nasty N8

iTrader: (33)

The ATI FMU was for the LT1 cars not the LS1 cars. Do your self a favor and do it right as Lonnie said.

Nate

Lonnies Performance

iTrader: (16)

The early very LS1 kits came with FMU's & worked as I stated, but it is less than the ideal way to do things.


For the record, increasing fuel pressure will increase flow at the square root of the pressure increase.

For example 45psi pressure stock upped to 90psi is as follows:
Sqrt (90/45)* injector flow of 24# = 34# injectors
You would need 4 times the fuel pressure to double the flow.


This is why 60# injectors rated at 43psi flow approx. 70# at 58psi.

Frost

iTrader: (45)

FMUs are dinosaurs and tuning solutions brought their end