I have a 2000 f-150 5.4 with an ati system on it with a 2 core intercooler. I just put on a 3.5 inch pully. It was suposed to give me 12psi but I see 10psi. I know the factory injectors, mass air, exhaust, etc. are holding me back. How much boost can ati fmu compensate for? and should I try a 3.3 pully. How far can I go with out spending lots?

Thanks,

Jonathan

 

dont forget you'll lose about 2 pounds of boost in the summer heat. just wait till colder weather. mine ranges from around 10 in the summer to its full 14 or 15 in the winter........

 

Would you be kind enough to describe the modifications to your truck in greater detail.

Thanks,

Jonathan

 

sure.

its a 97 4.6L with auto transmission. non-PI heads. stock internals and tranny except for transgo shift kit. i have the P-1sc with the "12#" pulley from ATI. you can order it with the smaller pulley directly from ATI which is what i did. I have a larger K&N air filter, I never even put on the one which came with the kit. I have the 3 core intercooler, which is a TON better than the standard 2 core. i also added 42# injectors (green tops) and a 90mm Lightning Maf sensor at the same time. a diablo flip chip with my custom tune makes this all work. i also have a fuel pressure guage, boost/vac guage/ and air/fuel monitor inside the cab. my exaust is shorty headers, no catalytic converters, H pipe, dual magnaflow mufflers with turndowns.

as i said before, i lose a couple pounds of boost at least in the summer because of the hot weather. it usually hits around 14-15 when i run it in the winter.

my best times with 28 tall slicks are 13.32@101 and 13.44@99

good luck and if you need anything else just ask.
~mac

 

That sounds like some future modification I may like to make to mine. Are you still used the factory fuel pump with the booster pump. I supose the ati fmu is still keeping up. What size pully in inches are you using. The pully I had on mine was a 3.7 and it gave me 8psi in this hot weather and 10psi in cool weather. The 3.5 is giving me 2 more pounds now. I could see it giving me 12psi in cool weather. The motor is stock everything but a dioblo chip only for trans shifts and speed limiter delete, 4.10 gears, helwig rear anti-role bar, helwig helper springs and the Ati. I is a 2000 F-150 5.4 4x4 super cab. I used it for pulling a 24ft inclosed car trailer. I was thinking of going to a 3.3 inch pully to get some more power down lower. It may be better to do some of the things you have done fist.

Thanks,

Jonathan

 

i really dont know what size it is. but i think its 3.5, i've never really looked into it since it puts out truthfully more boost than i really wanted. but of course i'm not gonna back off. i dont run the FMU. once you upgrade injectors you dont need an FMU. fmu's suck anyways and i would NEVER use one.

yes i have the stock in tank pump and ati supplied inline pump. works fine. you said you didnt have a tune and you are running around 10 or 12 pounds of boost. THAT"S DANGEROUS. if you want to keep your truck running, dont run that much boost without a good tune.......

 

I just put the pully on couple of days ago. I am going to see what it is doing on a dyno dynamics dyon soon and I have been staying out of it with the one exeption. The dyno facility here in Calhoun is called Dyno4mance. I will include their web site. http://www.dynoformance.com/index.php

Thanks,

Jonathan