Do I really NEED an Air Dog or Raptor?

[Broncman]

Ok, what do these motors really need for about 250-300hp. I am ready to get my fuel system going and have the old Lo Pressure LP vs. Carter electric vs AirDog etc thing going on in my brain.

First off, Do I need another filter in the system? I do want to go away from the diaphram because I never want to rupture one. I have heard of the longevity issues with Carter and Hollley pumps so that leaves me with Air Dog/Raptor or a simple Low pressure Lift Pump and spend my money on something else??

I have looked at remote filter setups and piece parting it together but end up near the same price as an Air Dog if I include a remote filter setup plus a new pump. Or is the stock filter setup good enough and then just add a new pump

Gosh these decisions are enought to drive you crazy!

[Tacoclaw]

My truck put down 268 horse on the dyno with a LPLP and stock non-IC'd sticks on the fuel side. It's never acted like it was hurting for fuel since I did the LPLP. I do intend to run 3/8 or 1/2" lines and 2 remote filterheads, while bypassing the stock fuel filter one of these days.

If I had to do it all over again, I would have probably gone with a regulated 2nd gen piston pump.



It is a personal choice since I don't like to have any more electric stuff on my truck than I have to. If you don't mind running electric stuff, and are pretty sure you are gonna cap your HP around 300, then I'm sure there are cheaper electric options out there. I would recommend more filtering however. There's nothing wrong with the stock filter, but if you've got the means more filtering couldn't hurt.

As long as it can get fuel through, I don't think there's such a thing as too much filtering.

[Broncman]

Thanks. Did the factory trucks have a primary electric pump in the tank that feeds the diaphragm pump?

[Diesel Dawg]

no they did not. You could probably get to 300hp with a low pressure piston lift pump.

[Redneckintraining]

could always run a light duty piston lift pump.its the piston lift pump for a 4bt so pressure is within reason..

[amartin_72]

Well, the IP has a vane pump which is pretty powerfull especially at high RPM. there is also constant leakage through the pump no matter what via return. So you need to account for all of these factors. You dont want to let the vane pump in the IP overtake your supply setup. My setup never budges from 70psi rail 15psi pump. I have a new 3/8 suction tube going into a 10 micron hydraulic filter head, then into a walbro 392. Then 5/8 line to fender well which contains relief valve. The relief valve is a simple ball and spring venting to tank. This maintians 70psi to my 2 micron stanadyne FM100 and holley dead head regulator, and anything over 70 goes back to tank via its own return line. Then the holley dead head takes the 70 psi and blocks off flow and only allows 13psi outlet pressure . Pump can consume all it wants if demand increases, ball in relief seats, and all fuel goes into IP. if you let off the throttle, the relief opens protecting the electric pump and cooling it.

If you go this route, put a needle valve near your relief, and make sure your relief ball seals good! it will suck air from the return if not !

[cmann250]

The thing with the low pressure piston lift pump is that it is like a $300 dollar lift pump (if we're thinking of the same thing). I checked into it what my stock lift pump took a dump. Or there is the high pressure piston lift pump intended for the P7100 12v's that's $120 plus a regulator, if you want to stay mechanical

[Broncman]

Well, the IP has a vane pump which is pretty powerfull especially at high RPM. there is also constant leakage through the pump no matter what via return. So you need to account for all of these factors. You dont want to let the vane pump in the IP overtake your supply setup. My setup never budges from 70psi rail 15psi pump. I have a new 3/8 suction tube going into a 10 micron hydraulic filter head, then into a walbro 392. Then 5/8 line to fender well which contains relief valve. The relief valve is a simple ball and spring venting to tank. This maintians 70psi to my 2 micron stanadyne FM100 and holley dead head regulator, and anything over 70 goes back to tank via its own return line. Then the holley dead head takes the 70 psi and blocks off flow and only allows 13psi outlet pressure . Pump can consume all it wants if demand increases, ball in relief seats, and all fuel goes into IP. if you let off the throttle, the relief opens protecting the electric pump and cooling it.

If you go this route, put a needle valve near your relief, and make sure your relief ball seals good! it will suck air from the return if not !

Which pressure relief valve are you using? Which Holley regulator are you using? I might go this route...

[Remps]

I'm using a Taylor relief valve with 1" inlet/outlet/return similar to this: http://taylorvalve.com/Products/Safety-Relief-Valves/Direct-Spring-Operated/8200/8300-Series-Safety-Relief-Valves/8200/8300-Safety-Relief-Valve.html

[Broncman]

Thanks. Which holley regulator?

[Broncman]

Does the carter 4601 need abypass style regulator or can it be deadheaded?

[Smokin359]

Im running a Vulcan Performance DrawStraw II, 1/2" tube with 3/8" fittings and line. Factory return line.

I belive the pump is what Edelbrock calls thier "quiet flow series".. 120gph, also has a 30 micron stainless mesh filter before the pump and the factory filter before the IP.

So far no problems, and this pump was on my dads 98.5 VP44 truck for a few years before i got ahold of it.