# FYI: Carter P4070 & DCOE's, talked to Carter tech, false info online



## Boost_Retard (Oct 10, 2005)

i have been trying to get my 2.0L 8V on 40 DCOEs running correctly over the past 2 days, and i have had some problems that i have since solved. i just wanted to share my findings..
if one was to jump online and search a fuel pump for side drafts i am almost sure they would stumble across the Carter P4070, and there would be some info saying that the pump was never intended for a regulator and should not be regulated, and that it puts out 4PSI at 70GPH, and that it will work out of the box for your DCOE's (this is what i found anyhow, and i did allot of homework before purchase)
anyhow, my results were nothing like they were claimed to be, so i called carter twice to sort things out. 
turns out the P4070 puts out 5.3PSI and is a positive displacement pump, it can put out more than 5.3 PSI depending on voltage (i have found) its also rated at 73GPH, and carter says the part number (P4070) has nothing to do with the specs of the pump, its just a part number.
i then called overseas auto wich is a local weber parts dealer and talked to them about some of their side draft race setups, and what fuel PSI has worked best for them, they claim 2.5 PSI to be exactly whats needed, i will know first hand how 2.5PSI works out later today, i am just waiting for my filter king regulator to show up, this is the regulator they recommended, and altho it does not come with a gauge they said they have tested them and 99% of the time they are spot on at 2.5 PSI pre set from the factory and that a gauge is not needed because of that.
i hope this regulator is all that its claimed to be because its the only regulator (other than the low PSI holley, not a big fan of holley) that i have found that can be turned down to such a low PSI but still keep up with the GPH. the next option at over twice the cost is the mallory bypass 3+ PSI regulator.
now about the bypass... Carter says that the P4070 should be used with a bypass system to extend pump life and keep fuel temps down, makes sence to me. if your looking to buy a low PSI bypass type regulator the only one i found was the mallory, and possibly and areomotive, but both were rated for 3PSI and up, wich supposedly is .5PSI on the high side 
after looking around some more i found out that anyone can run a bypass setup on any regulator and all that is needed is to run a Y off your output (this is what i was told, i will try both the input and output later tonight) then run your 5/16" or similar fuel line to your DCOEs, and then to run another 5/16" or similar fuel line back to your tank, but to install a main jet inline to choke it down, i am going to try one of the sliding fishing weights i have, kinda football shape with a small orfice and fits snug into the fuel line.
this setup, with the carter p4070 and the filter king regulator should get the job done, the holley 1-4 would work also but again you would need to build your own bypass setup
i should also add that when i did some calculating with an overshot HP# of 150 at 2.0L my fuel demands were in the 25GPH range, FAR less than what the carter pump puts out.
i will have more facts later today when i get all the new parts installed and see how it runs, but i just felt like i should post the info i have found because its a piss off to take a bunch of online "advice" only to find out that its way off and now your fancy braided lines are all cut and plumbed but then need to be chopped up and changed again.
if your using this pump (its a good pump, just overkill) do yourself a favour and buy a good regulator and set it up in a bypass system, save yourself the trouble of having to do everything twice.
or maybe your one of the lucky people that just slapped the pump in and it ran like a top! me.. not so much


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## woodrowstar (Jun 17, 2005)

wow.... you are so late to the rodeo.


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## B4S (Apr 16, 2003)

*FV-QR*

I've always stressed that the carter needs a regulator, so this is a good bit of proof http://****************.com/smile/emthup.gif.
I use a Facet 40105 solid-state pump, that's rated at 2.5-4psi. I don't use a regulator, but the gauge is steady at 3.5 most of the time.


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## 75injectedSB (Feb 6, 2006)

*Re: FV-QR (B4S)*

Putting the reg in my daily this weekend. The carter is a great pump, but its meant for v8 cars that require way more fuel than we will ever need.


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## MkIIRoc (Feb 20, 2005)

*Re: FV-QR (75injectedSB)*

Yeah, I've read about that pump quite a bit, everywhere recomending it (including this forums FAQ).
But it's advertised as 4-6psi...
http://www.jegs.com/p/Carter/748050/10002/-1
Never made much sense to me. Like a carter rep was hiding out in forums, haha.
I use the holley red with holley 1-4 psi regulator set at 2.5psi. Feeds my race engine fine, and has survived 16.8 volts going into for the past year.
I'm now switching to the edelbrock 1791. Factory set 6.5psi, adjustable output pressure, alcohol compatible, and can feed 600hp.


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## joezeeuw (Feb 23, 2003)

*Re: FV-QR (MkIIRoc)*

It's weird. I've built two carbutated side draft cars. The first I ran the 4070 unregulated and had no issues. The second was having pressure spikes all over the place. I'm running the Mallory regulator now and things are better. http://****************.com/smile/emthup.gif


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## Boost_Retard (Oct 10, 2005)

Hey thanks for that quality post woodrowstar, just the kinda info we need here.
anyhow, the filter king regulator solved all my problems, i never got around to testing what it was pre set at but once i installed it and test fired the motor all problems were solved..i was able to put in an extra 2° of initial timing and now the motor idles like a stocker but rips to life at the blip of the throttle. seems that 36mm vents work OK in 40DCOE's


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## woodrowstar (Jun 17, 2005)

You're welcome, Boo.


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## Justin 123 (Apr 11, 2005)

*FV-QR*

I had the exact same issue. Read all over that the 4070 didn't need a regulator and all that, so I set up as such and had WAY too much fuel. Bought a cheapo regulator and haven't had a fueling issue since.


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