Not that he needs it but I will vouch for Andrews knowledge and ability to remote tune.. and his patience with EFI challenged people like myself.

I see the Vaporworx materials say that no post-pump filter is needed, but Holley prescribes a 10 micron filter post pump, anyone feel it’s necessary? I don’t want to add the restriction if the pump module’s filter is sufficient…

I have a 10 micron inline filter on mine with Carls Vaporworx controller. Carl did recommend the filter being as far back towards the tank as practical, but he didn't have a problem with me running one. I've always had them, and been in the 900-950 rwhp range without issue.

Same I have a 10micron in-line close to the tank. No issues at all beyond making sure compatible with e85.

Same as the above guys...I have a 10 micron filter as well with my Vaporworx too.

Perfect! Thanks for the input gents!

A bit of clarification.......

When using an OEM fuel module like the Gen5 SS, ZL1, CTS-V, etc., no inline filter is needed or recommended.

Most all modern OEM fuel modules have pre and post pump filters. There are no inline filters present in most modern chassis. The Gen3 Coyote GT500 is an exception.

The problem with using an inline filter is that some have an internal check valve. At key-off, heat soak will cause the fuel pressure in the line to go up. If there is a check valve in the filter there is no pressure release mechanism. That's what the 85psi pressure regulator/safety valve in the fuel module is for, heat soak pressure release. Once the line pressure goes over about 100psi the injectors will not work. Just a few weeks ago a customer had this exact problem and was measuring 190psi in the fuel line, hence leaving him stranded since the car would not start. If this happens the simplest way to get the car started is to release a bit of pressure through the fuel rail diagnostics port/Schrader valve. But, many aftermarket fuel rails lack this feature. I recommend to everyone to install one in an easily accessible location since it will also tell you if there is no fuel pressure.

There is no drawback to putting a filter in, but it's redundant. I've not run an inline filter in the Camaro since starting VaporWorx back in 2010.

For other pump types, where essentially the pumps are hung on a stick inside of the tank (Aeromotive, Tanks Inc., etc.) an inline fine element filter is mandatory. However, if a pressure regulator is plumbed upstream of the filter, the same heat soak overpressure condition will occur if a check valve is inside the filter body.

Carl, if we do have an in-line filter after a GM (CTS-V2) pump, should your vaporworx fuel pressure sensor be before or after that filter?

From a practical standpoint, it won't matter since the external filter will never become enough of a restriction to create a pressure delta.

For stand-alone pumps it's best to have the sensor just downstream of the filter as long as the filter is in the back of the car near the pump.
If the sensor is too close to the engine it will pick up the injector pulses and chase them, creating an unstable idle fuel pressure. In some cases, even with the sensor in the back, a Radium pressure damper is needed. This is most common in throttle body type injection systems where fewer, quite large, injectors are used.

Glad to hear you are back on this project. Holler if you ever need any help or an extra hand with anything...I'm right around the corner.