That must be a really custom operating system......Originally Posted by blindsquirrel
That must be a really custom operating system......
What is the internal regulator's set point on those pump modules, if you know? If there is one, that is. Looks like there is from pics online.
I *think* it's around 60 PSI. My injectors flow almost as much fuel at 50 PSI as 60 PSI so that's where I set the flow rate in my tune and controller. My s/c doesn't make more than around 8 PSI of boost so even under boost the pumps stay under that 60 PSI module regulator set point.
Just curious because: 1. the way the VaporWorx documentation explains it, their system can only reduce pressure from whatever the regulated point is; and 2. VaporWorx offers a 85psi pod regulator thing for stock pump modules. Meaning at 100% pump duty cycle the system pressure is whatever the mechanical regulator caps it at, all they're doing is reducing DC% from there to lower pressure. Interesting concept for sure, as long as it works like they say and it's set up right.
So i've thought about in the past how to use those two DW300 pumps without having to send the ficm out to get beefed up. Could you take the two pumps and run one off of the normal pwm and have the other set up on the hobb's switch, with the boost reference regulator and return line?
I never did like the idea of tapping the tank and having a soft fuel line running under the car. But if that is how the pros do it...
edit: i realize you have to have a return line tapped in but it seems different to run a tap a small return line vs a large feed line at the bottom.
Last edited by Capt Chewy; 05-09-2023 at 08:29 PM. Reason: edit
You will need to figure out how to get the fuel back into the tank as the stock fuel hat does not have a return line. However, if the regulator output is the same pressure as your commanded WOT pressure is it should be ok, maybe need to monitor and tweak a little , but it should be ok.
i saw your post and was replying. i didnt see your first post before mine. that is an interesting way to set it up.
I recently installed a KPM twin pump setup into a 2015 Camaro SS and used VaporWorx controller to control the second pump. It works great. The KPM module does not have the check valve or regulator the stock module has When I spoke to Carl at VaporWorx, he told me the regulator is really only for protection of over pressure. The injectors do not like to open over 90-100 psi. I wanted to have an external fuel filter and I like the check valve for quicker starts, so I had to install the regulator to basically bypass the check valve if an over pressure condition is present. However the pressure while running is dependent on the pressure sensor and what it's programmed to run at. Hopefully I said that correctly.
I was trying to edit my post and somehow ended up deleting it🤦🏻*♂️, trouble using my phone vs a computer.
That'd be 90-100psi pressure Delta. The injectors don't care about PSIG or PSIA, they only see the difference between inlet & outlet.
From what I understood what Carl told me... without the regulator, the fuel pressure can exceed what the injectors will operate in. So if you drive the car and left it sit and say the outside temp or engine bay heat allow the fuel pressure to increase, without the regulator, the result will be a hard or no start condition. So if you run a check valve on a returnless setup, the regulator is what prevents this. Now some pumps will operate well above 60psi and some systems can utilize more than 60psi, so the 85psi is a great alternative. However, if understood him correctly, the regulator has no real effect on controlling the pumps.
What I mean is, 100psi in the rail is just fine... if you are at 40psi boost. Injectors will work just fine there as they are only seeing a 60psi Delta.
Check valves plus heat soak is an altogether different flavor of potential clusterfk...
I've had this happen before on a few hotrod swaps. Fuel is checked forward with no way to bleed off too much pressure and fuel boils on a hot shut down.. fuel rail pressure gauge will wrap around and car will not start until you bleed off pressure.
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I used the 85psi regulator from VaporWorx and installed it in a housing made by Radium Engineering. It's just allowing the check valve to be bypassed when over pressure happens. My check valve is integrated into the Fuel Lab fuel filter, so its not at the pump module. Haven't had a issue, so I think it's working as designed. It's nice having the check valve so I don't have to wait for the system to prime every start. Some cars I've had to set the prime to 4 seconds just so I don't have to key on twice just to start cold.
...or just use a regulator and pump properly designed for EFI systems. A lot of the aftermarket companies are trying to claim that their regulators lead down at key-off for some performance-enhancing reason that they are somehow never able to explain. A real EFI regulator should seal and hold pressure when the pump is off, if it doesn't it's just a carbureted regulator somebody stuck a big fat spring in to jack up the pressure.
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