this summer I have been on a mission to get the most out of my ct26 / 440cc setup. I want to run around 18psi.
440cc injectors should support this power level ~ 300-330 WHP. here is the setup I am working with
rebuilt 7mgte / ARP studs with felpro HG
stock low mile ct26
3" DDP / 3" test pipe and exhaust
2.5" hard pipes and fmic
Maft pro piggy back running speed density (so car has MAP/intake temp sensor and NO AFM)
walbro 255 pump
with the above setup I was running out of fuel (fuel cut) around 12 PSI. this was after leaning out to 11.5 :1
not close to where I wanted to be.
that walbro needed 2 more items to wake it up
1. bigger wiring / new relay (it was dropping 2v with stock wiring). if your going to run high pressure with a walbro (or others I suspect), you need to drive your pump with as much voltage as you can.
2. adjustable fuel pressure regulator.
after I added those items and jacked the rail pressure up to 50 psi.....way more fuel is there to work with. my maft-pro lets me data log, here is a comparison of before and after the above 2 mods (snapshot data @ around 4500 rpm)
worth pointing out this mod allowed me go 11% leaner on my piggy back, effectively moving fuel cut up many PSI.
the install :
1. regulator mounted by battery (overflow moved)
2. stock regulator removed, used a 12mm banjo to-6an fitting on the rail. I had a spare 12mmx1.25 banjo bolt, the blue fitting didn't include that, but was sized for 12mm honda rails/banjo's.
3. AUX fuse box installed by brake booster. this box has 3 relays : 1- wideband 02 2- maft-pro and guage lights 3-(yellow hd siemens) new fuel pump relay
*time will tell if this yellow 40a relay will hold up. it is activated by the stock ECU pin (grounds out coil and turns pump on) so my pump shuts off if the engine stalls / does not run when key is in ON position.
4. new monster cable (red) from relay to trunk. new large chassis ground. deans style connector (no way I was doing all this and leaving a 30 year old oem connector in there).
5. how I got the wiring through the access panel ...taller weatherstripping (vs cutting a hole / grommet)
all in all I am pleased with this upgrade. the pump screams now (yes, its even louder haha) ...and runs .05 volts below battery voltage. I will keep reporting back on this post if/when I find fuel cut.