I am not quite sure of what is in the spare tire well, I believe it may be a cooler of some sort.



As far as the KSP setup, they run the GTR fuel pump (240 lph) into the catch can and the 2 Bosch pumps (280 lph each) feed the engine. The reason they go this route is that the bosch pumps flow more than the GTR pump, but they are external pumps, whereas the GT-R pump is internal. In order not to have to run a fuel cell in the car they run this.

So does anyone know how much power the Walbro 255lph HP is good for?







Also, something I didnt understand is that people said you need a fuel pump bigger than a walbro if youre using 4x1000cc injectors...

Well...Thats 4 liters per minute, which comes out to 240 liters per hour. If the walbro pushes 255 liters per hour, why do you need a different pump for those injectors?













P.S. Ive read on few places online that the Walbro 255lph HP is good for 90psi and 550hp...Any truth to this?

The Walbro is rated at 255lph @ 45 psi of fuel. Now bumping that to 90psi is not a good thing. One of the guys asked why there pump got louder when they installed the engine management system. This is because most Engine management systems require you to run a relay to the pump instead of the factory computer controlling the pump. Well in the factory ECU's the ground is controlled by the ECU for the fuel pump and will not go into a high flow rate until the ECU commands it to, by giving the pump a relay and a full ground you are at max output of the pump at all times hence the pump being louder.



I personally would not mind having a pump rated a lot higher than the rated output of the injectors for the circulation value. For each person it is different. I prefer overkill rather than what might get me by in a pinch.

or you can just get a sump like i have no more fuel slosh https://www.nopistons.com/forums/pub...#>/biggrin.png

pixs https://www.nopistons.com/forums/pub...IR#>/smile.png ?

that cooler in the spare tire well most likley is the differential oil cooler. a neat trick for going FAST. MCR in japan uses that on the skylines they build.

how would it cool if it's in the tire well?

it just gets the heat out of the diff

Great post so far. It has answered many of my questions. I am in need of a new fuel pump since the factory likes to lean me out before 15 psi https://www.nopistons.com/forums/pub...O_DIR#>/11.gif .



So Camel, are you saying that if you bypass the ECU's ground to the pump and instead ground the pump to the chasiss, you can trick the pump in to pumping more fuel or just full pumping all the time??



I've seen those little fuel pump rewire kits, do they just replace the ground wire then or what??

Does anyone know how much power the pump is good for?..

Is the 550hp number right?