When turbo'ing my 3SFE engine, what if I use a 2:1 rising rate fuel pressure regulator to help correct fueling for the increased air flow.
With a 2:1 RRFPR, the inline fuel pressure will increase by twice as much as std as boost increases and the regulator sees boost pressure. So, effectively, the 32psi odd will increase to 64 psi odd at 1 bar as the increase is linear.

The standard fuel pressure is around 43 psi (0 boost, 0 vacuum). So, if you boost at 10 psi with a 2:1 rising rate fuel regulator, the new fuel pressure will be 43 + (2 x 10 psi) = 63 psi. 63 psi is big. You will need a big fuel pump to be able to flow the needed fuel at that pressure.

Look at "Wolfkatz" fuel pump pressure tests on MR2OC.com for more info.

It's doable, but you will be limited in boost by your fuel pump and injectors.

Hope to help

Sam

This post has been edited by pitcelica: Feb 18, 2010 - 10:13 AM

I was going to run actuator boost about 0.7 bar, not more. Annd use a Walbro fuel pump.

If you have big enough injectors to support the new power gains, along with a higher rate fuel pump, a FPR is not necessary. And just out of personal experience, RRFPRs are J-U-N-K with a capital "J"!!!!!!! I've seen rocks that have more potential at being useful than one of those things. If you want to be able to control your fuel pressure, bite the bullet and but an actual adjustable fuel pressure regulator. But like I said, with the correct injectors, and a better fuel pump, an FPR is not necessary.

in my early 7th gen celica turbo kits i used an FMU. it was more like a rising rate. so it was not always 2:1 it was rising. we then used a split second to pull back on the fuel in boost. it worked well.