Before I jump in and buy a Walbro 255 fuel pump I am curious as to what you guys think. Mildly hopped up 5.0 maybe 350 or 350 at the flywheel, probably 6K or so top end. Is the 255 overkill? Rhetorical question. I don't want something too large such that it recirculates fuel and overheats it. I'd also just as soon have something made here in the USA. I've been told that the stock Miata pump is sufficient for milder builds but the car no longer has that pump installed. It has some god awful loud and obnoxious sounding thing that I can't wait to get rid of. I do however want something that allows for growth. -Brad

 

I'm using a BBK-1607 high volume -in tank fuel pump. 255 LPH. Works well for me. Not had any issues. I keep the fuel pressure adjusted to around 35 psi, but I'm running 30lb injectors. If you have 40's I'm sure it would keep up. Walbro is a great product and I'm sure you won't go wrong with it. I snuck in a fuel pump shutoff switch hidden to keep it from ever being stolen. I forgot it was off a couple of times. Starts OK, runs for about 3 seconds until the residual pressure bleeds off, then dies. Then it's....Dugh!!!

 

Hi,
As a side note the NB miata has the fuel pressure regulator inside the tank. If you are pulling the pump to upgrade for a 5.0L conversion then will you need to remove the regulator from the fuel pump assembly. the Ford 5.0L has its own regulator at the engine in the injector fuel rail. So us e the 5.0L regulator and then run the return line back to the tank like in a std ford fox setup.

The miata pump is OK up to a point (around that 300-350hp) mark. But as its already 20 year old pump it would be wise to replace it anyway even if you are not pushing it higher than 350hp.The walbro pumps are excellent and will provide 255lph for a true 500hp capability.

The only little gripe I have with teh W\albro is it is a little noisy. The Miata pump was essentially silent, whereas this pump is definitely audible...not in a bad way..just audible.