Kc 1.5 or 2

06Amarillo · Oct 21, 2016

Do you have a lift pump or RR ? Also a quick question. My air dog should be fine without a rr shouldn't it ??

6.0 Tech · Oct 21, 2016

I would recommend a rr. It is cheap insurance on expensive injectors. Strictly's uel bowl derete is a very nice setup. The sinister kits fit like chit. Put one on a buddies truck, and was not happy with it at all. I put the strictly one on my truck and it fit a chit ton better.

06Amarillo · Oct 21, 2016

But it's the that the point of the air dog. It shouldn't drop below 55-60-psi. What ever the regulator spring is as long as there is enough volume to it.

6.0 Tech · Oct 21, 2016

Problem with the air dog for me was the use of the factory regulator. Pressure bounced quite a bit. After the rr pressure was steady till the pump died. Ive got a couple of months on the new 4g and its holding good so far.

06Amarillo · Oct 21, 2016

But with the air dog. And the blue spring kit your injectors shouldn't starve for fuel. The 165 would put out more volume than stock injectors can I assume ?

6.0 Tech · Oct 22, 2016

The factory fuel pressure regulator blows major donkey balls, even with a blue spring. Plus the fact that it regulates pressure prior to the injectors, means that the possibility of killing the rear most ones, especially #7 as it is last to get fuel, is pretty hi. A rr regulates pressure after all the drops the system will have to ensure that pressure is good prior to and after the injectors.

Inwayovermyhead · Oct 23, 2016

I compare a fuel injection system to an irrigation system since that's what I do for a living. When we "loop" the mainline, you get 2 advantages. You are in effect doubling the size of the feed pipe, and here's the important part, no matter where you tap into that line you will get the same volume.

No doubt the stock fuel lines and dead end fuel rails in the heads were designed to provide equal volume/pressure when new, but when you start considering age of system, worn injectors flowing different rates, poor filter and system maintenance, tuning that holds injector open longer, installing bigger injectors, etc..., it becomes more difficult to provide a consistent pressure environment.

As 6.0 Tech explained (and sorry for over simplifying your post), when you regulate before, your demand can potentially exceed your supply which would naturally and instantly drop pressure to injectors. Think of the poor performing stock regulator as a "restriction" that will only allow a pre determined amount of fuel through no matter how good your pump is. When you install an RR system, your pump flows directly to the injectors before it hits the regulator, basically moving the "restriction" after the injectors. Ironically, it is moving the regulator (restriction) after the injectors that allows you to build or HOLD as much pressure as you want, as long as your demand (injectors) doesn't exceed your supply (pump).

jeremiahmercier · Oct 23, 2016

Back to the vgt part, would either be much improved over my cast power max? My truck tows surprisingly well, towed our 14k fiver up and over the mountains this past week, power was good, and egt's were never even a concern. I'm actually very happy with the towing performance of this truck, sure a little more power would be nice, but overall very surprised. It took a lot to get me to this point with a 7.3, and now I'm doing it with with a mostly stock 6 liter, with a turbo and tunes. Most of the time I was at 2100rpm or higher, and never really went over 1000 degrees but once towing 7-8% grades in NC and TN. Like I said, a little more umph would be nice, especially up around 2400 rpm, but pretty satisfied

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Poglife · Oct 25, 2016

I have an air dog and blue spring but not a rr. Can't run my race tune bc my fuel pressure dives down so rr is next on the list bc the race tune feels awsome