Long story short, doing a procharger setup so purchased a 340 and vette filter/regulator kit from a vendor. Been a HORRIBLE experience. apparently these filters are a 5/16th feed and 3/8 return. Vendor didnt know? So ive got a hacked to hell fuel system that was deadheading the pump. Can ANYONE point me in the direction of a simple static fuel pressure regulator I can use somewhere near where the factory T block and fuel filter went? I already have just re ran 6 AN fuel feed line but im really concerned necking down to a 5/16th port for this filter. The entire experience has left me with a sour taste. Paid a premium for a mediocre setup for simple ease of installation, yet here I am with a hacked up fuel stock system and running braided line anyway. I dont need to go boost ref or anything only going to run 6-7PSI with methanol.. Any ideas?

 

You need to do some research to understand fuel pressure and the fuel volume requirement when running a boosted application VS NA (naturally aspirated).

Because more air is forced into the engine in a boosted state compared to a naturally aspirated engine, the engine needs more fuel when it is in a boosted state.

You have a Procharger so your fuel system requires a different fuel pressure regulator since your fuel system is no longer considered NA. To provide more fuel and fuel pressure to the engine when boosted you need to replace the static fuel pressure regulator with a fuel pressure regulator that is boost referenced (explained in the links below). The boost referenced FPR adds more fuel and pressure as needed when making boost.

You will need a Hobbs switch if you are runninging dual pumps. The Hobbs switch will turn on the second pump based on boost (positive intake pressure in the intake manifold as the Procharger head unit starts to build boost turning the pressure state in the manifold from a vacuum state to a pressurize state anywhere from zero to 15- 20 psi). It's the positive pressure in the intake that signals the FPR (fuel pressure regulator) to mechanically increase pressure and fuel volume.

A static fuel pressure regulator like the stock intank regulator or the Corvette fuel filter regulator does NOT increase or decrease fuel pressure and volume. Pressure remains static at approximately 58 psi. This is explained in detail in the links below.

Here are some links to get you started.

http://injectordynamics.com/articles...ure-explained/

https://aeromotiveinc.com/wp-content/uploads/2014/12/TB_202_EFI_FPR_Vac_Boost_01.pdf

https://www.fuelab.com/blog/11-boost-reference-fuel-pressure-regulators/49

You also need to verify that your tuner changed tables in the tune as a result of switching from NA to a boosted fuel system. The first and most obvious table to change is the IFR table. With a boosted fuel system the table is changed from a curved table to a flat line table (all values in the IFR table are the same based the value given to you from the vendor determined by the size of the injector). If the values are different in the IFR table and follow a curve then you need to talk to your tuner, fix the tables and retune.

Now: there are still some on this forum that will tell you that you can use a Corvette filter in a boosted application because they tell you that they adjust values in the tune to account for the additional fuel and pressure required with boost. That's the way it was done 15 - 20 years ago. My last tuner still believes that and argued that this is the way he has been tuning for the last 20 years.

Read the link again. Yes I suppose you can decide to try to use the Corvette filter, get an adapter that downsizes the push lock quick connector from -6an down to 5/16 inch so you can connect the -6an return line to the 5/16 inch return outlet on the filter. Racentronix sells them.

But if you plan to run - say 10 lbs of boost - you actually need 68 psi of rail pressure as boost pressure in the intake maximizes at 10 psi. The Corvette filter will only give you 58 psi. A mechanical FPR in contrast will adjust fuel pressure and volume on a 1:1 ratio as boost goes from zero to 10 psi or more.

There is a scientific rule to know also. As fuel pressure increases, fuel volume decreases. The Corvette filter does NOT allow an increase in pressure or volume when your application starts to make boost.

 

I’m not too worried about that just yet. I have 60lb injectors and a 340 pump. I do my own tuning and will be injecting 10gph of methanol at pretty much 2PSI ramp in.… I do agree however, boost ref is better. But It’s not in the cards for my needs right now I don’t think. I plan I will easily tune around the small diffferential pressure difference of max of 6 or 7 PSI…right now I’m hoping to only make about 3 or 4 PSI to get my car situated and repopulate my VE table with the methanol kit and later downsize the pulley for my desired PSI. Also, I’m only planning for 550ish wheel(stock block)..but I’m desperately concerned about a 5/16th feed port on this filter not being good enough and if I have issues I’d like to know what I can do…just trying to see if anyone else has went this route and if it’s possible to use a boost ref regulator and just capping the vacuum feed and setting it to say a static 58PSI?..Once the block turns inside out I’ll likely redo the fuel system with 8AN…Note if I wasn’t injecting supplemental fuel Id absolutely be running a boost reffed deal..I’ll have to do some reading on them, thanks for the links! Seems the A1000 is popular round here..decisions decisions

 

I remember something about the Corvette filter deal vs I want to say a S10 2.2 flex fuel filter. So the fead/return lines were opposite of each other in both size and function. (Been 10 years since I messed with them so verify)
I don't know if you're just over it and not looking to spend any more money on it or where your at.

 

Thanks for the response. Yea. Atm I have a 6 an feed into a 5/16th quick connect and a 6 an return connected into the factory 5/16th return line half way up the tank. At the moment it looks like I’m about 70% duty cycle commanding 11.0 AFR while on meth so I guess it’s fine. I’m not really sure what to do to make it better. I tried like hell to connect my factory feed line on the return side of the fuel pump( that would Atleast give me 3/8” return. But just couldn’t do it comfortably. If I get bored enough all I’d have to do is use a 45 connector on AN line and just run it down the gas tank again. But as of right now it’s working.