tpi fuel system

[dusterbd13]

so im doing a tpi swap in a muscle car. I have found that the LS1 fuel pump module from a fourth gen has the proper 58 psi for my ls1 injectors im using. I already have to create a custom PROM, so I know some things will have to be changed in the code. the fourth gen module also will adapt to my tank pretty easily.

so, is there any reason that I shouldn't use a fixed 58 psi fuel pressure for this setup, with a returnless fuel system and 5/16 feed line? normally the TPI has a return style system, and a vacuum referenced fuel pressure regulator. single feed will be much cleaner, cheaper, and easier to implement, and the module mounted regulator is again for cleanliness and simplicity.

so, can I? should I? and yes, this is going on a big headed, solid roller cammed, stroked small block. (mopar actually, using TPI 7727 computer, sensors, distributer, and harness from a 92 tpi corvette. single plane intake, 4bbl throttle body, high flow rails, 97 ls1 injectors. motor made 425 at the wheels at 6500 rpm with a victor junior and 850 holley, off the bottle)

[fastacton]

I can only comment on the feed line. I'd recommend going with a 3/8" line at a minimum.

[JP86SS]

The 92' style TPI code in the 727 or 730, 749 ECMs expect to have the fuel pressure controlled via the vacuum reference.
This keeps the commanded fuel output linear over the different manifold vacuum conditions.

Later designs using non-referenced pressure control (as you are using) has compensation in the PCM code to make the correction.
Using the non-referenced will cause problems but how severe is unknown.
It's an unneeded risk IMO, but "should" only become a problem at "cruise" type driving during load transitions.
WOT will not be a problem when tuning it.