Currently have a 1jz sitting in my 180 it has a holset hx35,avcr ,intercooler,3"exhaust, walbro 255 and will be getting emanage ultimate ,800cc injectors, question is how far can i push with a walbro 255 hopin for 450+ maybe even near 500bhp would it be enough?
Wouldn't go past 450. You want one of these: Walbro 450 lph Competition In Tank Fuel Pump Kit from Driftworks.com We've used it to 565HP, no problem. Greg rates them.
I was going to recommend the Walbro 450lph too.. Great little pumps.. Ps, Bosch 044 only flows 300lph @ 14.4v.. They also warm a tank of fuel in about 15mins.. (Warm fuel isn't a good thing)
I had walbro 255lph, HX40Pro, 2bar boost and 850cc injectors, 4 cylinders. Had no problems with it. You have 6 cylinders, so I don't know anymore.
People have pushed re-wired 255s to over 600bhp. Fuel warming is purely due to too much flow, type of pump has little/nowt to do with it.
So you think i should chance it? Have the walbro in the tank already, but if people reckon i need a bigger pump il get one,
Probably means hard wired to receive a proper 12v supply rather than the 9v odd that most oem cars get through old Wiring etc. In fairness does make a massive difference but personally I'd go with a bosch over a walbro any day of the week, comparing the 2 side by side the walbros look like kids toys and there's plenty of stories of genuine ones shitting themselves all day long
I'd have expected him to say hard wired in that case. Walbro pumps are quality, we sell LOTS and have never had one fail.
Hard wire it with a direct relayed 12v supply and see how it goes. If you need to upgrade, get a Bosch 044, a proper one not at knock off.
By re-wiring I assume he means beefing up the guage of the wire that feeds the fuel pump. And similarly for the earth. You get a huge amount of voltage drop on 12v systems over even small distances using narrow gauge cable. The beefier the cabling, the less voltage drop. Bigger is always better on 12v systems. Calcs like this one are handy for choosing cabling size Handy Hints – REDARC Electronics
And the other option is to give it more than 12V. I'm feeding 22V to the standard pump on the E55 AMG Turbo.
The thing with the bosch is that its flow doesnt tail off anywhere nearly as much as the fuel pressure increases. Compare the flow vs pressure graphs, quite suprising. All the rated figures are at free flow, doesnt tell you what happens as you bump up the fuel pressure.