Hi Mike,
Your choice of fuel pressure regulator is a solid one. Personally I have used the SX performance fuel pressure regulator but both yours and mine I have seen consistently hold the base fuel pressure, even at high flow rates. What is the bad choice is the malpassi (malcrappy) I have personally seen and also had others report of shifting base pressure with the malcrappy and I know of one turbo rotary engine that blew on the dyno when it ran lean under WOT because the malcrappy wrecked the fuel flow.
Personally I would have run a twin feed parallel fuel rail system to better combat pulsation and to ensure the injectors are fed a solid diet of fuel and pressure. This is just my opinion and personal preference
- from an engineering point of view there is devices you can install to control this in a single feed system so if its a problem we can talk about that later on.
Im not a great fan of external swirl pots but nonetheless my Mazda has one, using a low pressure lift pump and then a high pressure pump. I believe that custom fuel tanks are needed anyway because in high output applications your going to need large pickups, large feed and return lines etcetc. An internal swirl pot also means you can whack in a big intank pump.....One of the things that craps me about my Mazda is the phreakin bee hive that drives me mad that is my bosch motorsport "044" external pump. Ive still got problems with restrictive pickup, feed and return lines in the stock tank anyway.....
When it comes to pumps, 99% of the pumps on the market flow stuff all at higher pressures. This isnt so much a problem with NA engines as it is with force fed ones but nonetheless theres still alot of pressure loss in the lines anyway. Be sure your fuel system will flow the numbers at the pressures youll be running.
Im a big beliver in only one high pressure pump because the last thing you want is 2 or more pumps, where 1 fails and you dont notice during cruise but at wot you run the motor lean and pop it before realising whats gone wrong. Walbro and Supra in tank pumps flow up to around 5 litres a minute, but external ones like the bosch 044 and the SX performance can in some circumstances flow more.
With your surge tank, I highly recommend having the return feed back to the tank and not the surge tank. This is because otherwise it will be a closed loop and youll heat the fuel up.....This will lower the detonation threshold of your engine tune, the pumps will be noiser and other general problems with it.
I consider closed loop style fuel coolers to be a horror band aid solution to the problem of heating fuel between the swirl tank and the pressure reg closed loop.
Dash 8 is a good size but I prefer the double lip type of AN fittings onto the hosing not the single nipple type.
cheers