Originally Posted by mrfred

AMS did all their testing on the bench without an Evo pump carrier. I'm sure that Walbro did the same.

Originally Posted by RSMike

We are looking to control the fuel pump with a solid state relay and a PWM signal from the ecu (Link/Vipec).

Is this a better way of doing it?
Will either this way or the standard resistor circuit bad for pump long term?

With using a SSR you can change the PWM signal to get the exact flow you want.

Cheers, Mike

Originally Posted by mrfred

Subies use a PWM signal to throttle the fuel pump, so apparently no problem for the fuel pump. You'll need to get the right SSR for the job. Most have fairly substantial resistance compared to the resistance of the fuel pump, and this will cause the pump to run below battery voltage even at 100% duty unless you intend to have a way to shunt the SSR above a certain load/boost. They also tend to run fairly hot, so it will need to be heat sinked. What frequency were you thinking of running?

Originally Posted by Gleason at STM

Sorry, Justin may have mis-spoke.

Both cars that we maxed out the rewired walbro 400 on last year ( a 2G DSM on E85 making 588whp on our dyno and an FP Red powered Evo on E85 that made 572whp ) both have our STM Fuel Pressure Regulator Return kits on them and NOT the stock FPR.



-Brian Gleason
www.stmtuned.com

Originally Posted by drb

Brian, did you need to drill out the siphon tube to get the flow required for these hp levels?

Originally Posted by evilevo2006

I have some questions if anyone knows. I bought two new E85 400 pumps to put into my double pumper. I am running a -8 feed / -6 return lines and a Fuel lab FPR. my question is

1. Do I need to do a rewire mod and if so how come?
2. Do I need to drill out the plastic tube thingy and if so how come?

Originally Posted by wizzo 8

1. No rewire needed.
2. You shouldn't have to drill the return tube.

Originally Posted by evilevo2006

OK thank you sir. i will leave it all alone. but would you mind explaining why some people rewire and drill out that part?

Originally Posted by wizzo 8

If you rewire the primary pump to battery voltage it will flow more. With these 2 pumps you shouldn't have any issues with fuel supply. If you are pushing over 1000 HP then yes rewire the primary pump. Drilling that suction tube is necessary only if you run out of gas when in fact you still have a 1/4 tank still on gauge. I wouldn't drill it until you find out you actually need to drill it.

Originally Posted by evilevo2006

I do not have that issue so no worries there. I thought what caused that was pump height?

One more thing. the red and black wire off the ''secondary'' pump. I have the red wire going to the + on the battery. The ground is just grounded. Would it be better to run that to the - terminal on the battery for best results?

Originally Posted by way2qik

600-650awhp is very respectable. Nothing wrong with that at all! Its just that once you start making over 750hp, you get into the territory where two Walbro 255s are just being pushed to their limits, especially on E85. The 400s are a nice step forward, but as fuel pressure increases the ability of those pumps to flow lots of fuel decreases as well. And it takes at least 80psi of fuel pressure to make 40lbs of boost (which is what it takes to make big power) if you have a base pressure of 40psi set on the regulator.