FiTech Dual Quad
I don't see much if anything on-line on the dual quad efi, let alone on a tunnel ram, so I thought I'd put this out there and see what happens. Of course, I can add to it when I learn something new, if there is interest. I also have a question on my spark plugs at the bottom.
383, aluminum heads, tunnel ram, efi.
I went from the tunnel ram with Holley 390s, to 600s, to a Performer RPM and a 750. I honestly preferred the way it ran with the tunnel ram.
I got the FiTech 30064, the Tanksinc tank, and passed on their pump, bought the FiTech pump, cut a 4 inch hole in the tank, capped the regulator, done. AN fittings right on it, o-ring gasket if it ever needs to come out. Put the Corvette fuel filter/regulator on the frame, and one teflon braided fuel line up to the engine.
Skip ahead to today, and I've been driving it regularly for a few months.
I increased the Crank Fuel setting for cold starts, it didn't get much better, so I increased the CRANK IAC, with little improvement. Turn the key on, wait for the pump to stop and the throttle body to click, it starts immediately by barely flicking the key when warm, and I mean barely, hold it longer than a second and it won't start as well. Cold starts require holding the pedal down slightly and it fires quickly. I'm thinking this is due to the tunnel ram. I tried turning the key on, off, on, a few times as it's supposed to shoot a small amount of fuel each time, kind of increasing the cranking fuel manually, but that did not help. I'll increase the Crank Fuel setting again and see what happens.
I installed a new throttle cable and made my own in-line linkage because for some reason a quality piece doesn't exist in the aftermarket. This helped immensely with finally getting the IAC set, which is now set perfectly and has remained stable since. The old linkage actually tweaked the one throttle body arm and put it out of alignment with the other.
I have been gradually increasing the Accel Pump and Fast Accel settings and the DFCO Return Fuel setting to get the AFR set.
Last week I adjusted again adding more fuel and it has responded well, best yet. I will probably increase again in a week or so, and back off if needed.
In the beginning I was misinterpreting what was happening when running through the gears, I thought it was dying on me too soon, then I realized it was getting up to speed faster than before and I needed to shift sooner.
The amount of air this thing is pulling in has increased greatly. You can hear the air rushing into it, in the exhaust, which is newer, I can now hear the slight leaks where the pipes are joined, to the point where I want to get it welded up. I have a scoop that I put on sometimes on top of the air cleaners and the AFR goes up.
Pulled the plugs today, just curious, but I'm not sure where they fall in the many online resources. They've been through a number of adjustments, so maybe I need to start with a fresh set.
Another thing, I put the highest octane in a few days ago, I have always used the lowest, it didn't run any better, in fact the only difference was it started to smell more like exhaust, not rich or gas, just exhaust. I finally filled it up today with the regular and it's back to normal.
Any thoughts on anything would be appreciated.
The plugs are RC12YC.
I don't see much if anything on-line on the dual quad efi, let alone on a tunnel ram, so I thought I'd put this out there and see what happens. Of course, I can add to it when I learn something new, if there is interest. I also have a question on my spark plugs at the bottom.
383, aluminum heads, tunnel ram, efi.
I went from the tunnel ram with Holley 390s, to 600s, to a Performer RPM and a 750. I honestly preferred the way it ran with the tunnel ram.
I got the FiTech 30064, the Tanksinc tank, and passed on their pump, bought the FiTech pump, cut a 4 inch hole in the tank, capped the regulator, done. AN fittings right on it, o-ring gasket if it ever needs to come out. Put the Corvette fuel filter/regulator on the frame, and one teflon braided fuel line up to the engine.
Skip ahead to today, and I've been driving it regularly for a few months.
I increased the Crank Fuel setting for cold starts, it didn't get much better, so I increased the CRANK IAC, with little improvement. Turn the key on, wait for the pump to stop and the throttle body to click, it starts immediately by barely flicking the key when warm, and I mean barely, hold it longer than a second and it won't start as well. Cold starts require holding the pedal down slightly and it fires quickly. I'm thinking this is due to the tunnel ram. I tried turning the key on, off, on, a few times as it's supposed to shoot a small amount of fuel each time, kind of increasing the cranking fuel manually, but that did not help. I'll increase the Crank Fuel setting again and see what happens.
I installed a new throttle cable and made my own in-line linkage because for some reason a quality piece doesn't exist in the aftermarket. This helped immensely with finally getting the IAC set, which is now set perfectly and has remained stable since. The old linkage actually tweaked the one throttle body arm and put it out of alignment with the other.
I have been gradually increasing the Accel Pump and Fast Accel settings and the DFCO Return Fuel setting to get the AFR set.
Last week I adjusted again adding more fuel and it has responded well, best yet. I will probably increase again in a week or so, and back off if needed.
In the beginning I was misinterpreting what was happening when running through the gears, I thought it was dying on me too soon, then I realized it was getting up to speed faster than before and I needed to shift sooner.
The amount of air this thing is pulling in has increased greatly. You can hear the air rushing into it, in the exhaust, which is newer, I can now hear the slight leaks where the pipes are joined, to the point where I want to get it welded up. I have a scoop that I put on sometimes on top of the air cleaners and the AFR goes up.
Pulled the plugs today, just curious, but I'm not sure where they fall in the many online resources. They've been through a number of adjustments, so maybe I need to start with a fresh set.
Another thing, I put the highest octane in a few days ago, I have always used the lowest, it didn't run any better, in fact the only difference was it started to smell more like exhaust, not rich or gas, just exhaust. I finally filled it up today with the regular and it's back to normal.
Any thoughts on anything would be appreciated.
The plugs are RC12YC.
