You won't get the power or driveability of a custom tune but an out-of-the-box ATI setup is perfectly safe and just as reliable.

 

I agree that is is just as safe. It relies on the stock parameters for engine control and force feeds fuel by putting the fuel pressure regulator under the control of a FMU that spikes the pressure under boost. So as long as you stay out of boost you remain under the full control of the PCM. That means your truck is as slow as it was stock till the FMU sees boost. What concerns me is that if the FMU fails ,and apparently they do, you can go instantly lean and it will destroy your engine. If you get a tune it cannot go instantly lean because the PCM is in full control of the fuel delivery.

JMC

 

5.4 3v
Vortech S-trim with aftercooler pushing 12lbs
Upgraded pump
39# injectors
True dual through a magnaflow muffler
Tuned with a Diablo by HPP Racing

450rwhp/450rwtq de-tuned.

Over 30k miles on this setup.

 

True JMC Very True!

 

What about timing? Are you allowing the truck to pull it? If so, how much can it safely pull?

 

What kind of fuel pump did you use when you upgraded? Did it fit in the stock location or did you have to modify anything?

Thanks
Jack

 

wow dude thats awesome 12psi on stock truck.

i hit 12psi on mine on the dyno and said no way.... im going to replace my wastegate with a tial i just bought to ditch the ****ty ebay one.

and the new tial has a .6 bar spring in it. w00t

then im getting tuned by PSI motorsports next week i hope.

its got a base tune on it, i drove it from one shop that was 20 miles away from my house back home.. everything seemd okay, i stayed way out of boost.

the psi motorsports place is 40 miles :-( i hope its safe to drive it there. as long as i stay out of boost i would hope so.

 

$20,000 engines get destroyed when $250 fuel pumps fail also...nothing a PCM can do about it.



There are no absolutes in this game.

 

running around 10 psi at shift points. I have had this set up for about 2 years now. Not a daily driver though. anyone who has a simalar set up feel free to check in with me and tell me more upgrades or things i can do diffrently. This is my first toy and i have done everything so far myself..

 

Except - an FMU is absolutely controlled by vacuum - I'll pass.

 

Most high-end fuel pressure regulators are boost/vacuum referenced. There's nothing stating that electronically controlled devices are more or less reliable than a mechanical analog.


Oh...and not all FMU's are controlled by vacuum, so that isn't an absolute either.

 

How are the FMUs that come with the Superchargers controlled?

JMC

 

Depends on the kit. Most use a manifold pressure reference and some use a programmable unit that ramps up voltage to the fuel pump. The electronic units are much more expensive but do not force the fuel system to increase pressure at a purely linear rate (e.g. 10/12:1 mechanical rising rate FMU's that add 10 - 12 psi fuel pressure for every 1 psi of boost). Really helps in high powered applications that use only primary fuel injectors or returnless fuel systems. Really hard to make a car idle well with 83# injectors and 1% duty cycle with low pressure at the rail.

 

I was originally told it was out of a saleen s7, apprently it's also the same pump as a ford GT. It was put in the factory place of the original.

When I said 30k on this setup, i mean 30k since the blower install. I have 60K+miles now total on the truck.

 

I was told that the GT fuel pump has a 310 lph output.

Lee