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Discussion Starter · #1 ·
First of all are most people running the 9 psi kit or the 6 psi one.
I know the 9psi kit comes with a bigger MAF and injectors but is it the same blower with a different size pulley. What I'm think is I will get the 6 psi one then upgrade later to the bigger injectors and MAF ect ect. Also how is it the 6psi blower can run with a stock MAF and not peg it thus running the engine too lean? Thanks
 

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Scott,

Call AED and ask for Scott. That is the best source for the MOST ACCURATE info.

How does the 6-psi kit work? Well their 6-psi kits come with a SFPR (fmu) and a 190 lph fuel pump. The injectors are stock as is the MAF. The MAF will get pegged, there is no doubt about that. The way it works is, the fmu is a 5:1 gain rate and when boost is present, the return line to the gas tank is pinched closed. The fuel pressure then increases at the rail and to the injectors. So for every 1 psi of boost you'll get 5 psi of fuel pressure. If you have 40 psi of fuel pressure at WOT when stock and you have an AED kit with the stock pulley (6-psi or so) that means you have 70 psi of fuel pressure at WOT. That means the 19's flow like 28's (not exactly, but you get the idea). You have enough fuel to cover your needs, but the MAF isn't telling the EEC to add more fuel since you pegged 5 Volts around 4,500 rpm.

By comparison, you need approx 13-14 lb./hr. of fuel at each injector at WOT for a stock '94-'97 4.6L T-Bird to maintain a 12.5:1 A/F ratio. For an AED kit with 6-psi of boost, you need approx 24-26 lb./hr. of fuel at each injector at WOT to maintain a 12.0:1 A/F ratio. So if you move to the smaller pulley you will not have enough fuel injector and MAF to feed the engine. You must eliminate the fmu or drivability will suffer when messing with the fmu gain rates and larger injectors. You have to get inside the EEC-V via a tune or a chip.

The system works and many like using fmu's. I used it for a while, but there is nothing like eliminating it and going with a L-MAF, larger injectors and a GOOD tune on a dyno by someone who knows their stuff.

Most people are running the stock pulley with the AED kit. The ones who tried the smaller pulley lost their engines. I did myself, the piston ring land broke on the #2 cylinder. That was with a good tune, by the way. 2 years with the stock pulley and 6 months with the smaller pulley.

The only guy I know who is running and running hard with the smaller blower pulley and the stock 1995 long block, is EECDOC. I'm running a '00 GT engine right now and the smaller blower pulley on the AED kit. So far so good and it's been a year now. It's only a matter of time though before the stock pistons give up, but I'm prepared.

So if you want to run 9 psi of boost as you call it, be warned, the engine's life will be shorter than if you run the stock pulley. The cylinder pressure is just to great for the weak hyperpathetic pistons. Some will argue that the key is in the tune. I disagree, it helps to have a great tune, but things aren't designed to take boost on the 4.6L. That's why the '03 Cobra has forged pistons, forged rods, a forged crankshaft, a cast iron block, head studs, a knock sensor and an ACT sensor.

I hope this helps,

A-Train
 

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Discussion Starter · #3 ·
WOW, many thanks. That was great info. I think the 6 psi blower with the stock stuff sounds like the way to go. I'll call Scott soon.
 
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