Rising Rate Regulator

[Apex Man]

Anybody using a rising rate fuel pressure regulator?

Thanks

 

[Ted Jannetty]

Anybody using a rising rate fuel pressure regulator?

Thanks

Everyone with a turbo is or KABOOM!!!

Most any regulator that references manifold pressure will rise about 1:1

Ted.

 

[Boyko]

I am using one on a boosted efi 2-stroke, I knocked the stock fuel pressure down 25psi and have the regulator set up for 3:1 rate. On a EFI application you have to remove fuel from the factory curve at lower rpm. I herd the injectors on the apex do not like high fuel pressure, I think 65psi is the limit.

 

[Ted Jannetty]

I am using one on a boosted efi 2-stroke, I knocked the stock fuel pressure down 25psi and have the regulator set up for 3:1 rate. On a EFI application you have to remove fuel from the factory curve at lower rpm. I herd the injectors on the apex do not like high fuel pressure, I think 65psi is the limit.

You can get away with that on a 2 stroke because either you added bigger injectors or your extremely rich on the bottom to begin with.

The 4 strokes can not tolerate lower fuel pressure than stock then will go up with boost at a 1:1 ratio.

 

[HAMMER]

Not exactly sure how the stock system works but from a quick look at my Apex think I see a fuel pressure regulator that is reading vacuum. After the fuel rail and regulator I see a return line that goes back to the fuel tank. I’m assuming that that under vacuum it’s bleeding off fuel pressure to maintain Yamaha’s factory calculated fuel pressure specifications and as vacuum decreases it bypasses less fuel to maintain the factory calculated fuel pressure. Using an FMU to restrict this bypassing of fuel in relation to boost would increase fuel pressure and provide more fuel per injector cycle from the factory fuel system to a point. I haven’t really done any research or testing in this area. Hopefully one of the turbo gurus can properly explain how the factory Yamaha fuel system works, if the factory Yamaha system is designed to have zero bypass in zero vacuum conditions, and if an FMU like this is a feasible modification. I am also assuming the factory fuel pumps inlet/outlet/volume would be a limiting factor even with an FMU.

The Fuel Management Unit (Part 1 of 2)
http://www.superchargersonline.com/content.asp?ID=84

The Fuel Management Unit (Part 2 of 2)
http://www.superchargersonline.com/content.asp?ID=97

BEGi Adjustable Universal FMU
http://www.superchargersonline.com/prod ... r=BEG-2027

Good links and reading material:
http://www.mkiv.com/techarticles/fuel_p ... index.html

If the factory Yamaha system is designed to have zero bypass in zero vacuum conditions this may be an alternative solution. Again the factory fuel pumps inlet/outlet/volume and voltage operating range would be a limiting factor at some point.

MSD Fuel Pump Booster

Adding a turbo or supercharger to your engine is a great way to improve the power of your car. But you have to remember that when more air is being pushed into the engine, the need for additional fuel raises proportionally. Meeting these new fuel demands could mean larger injectors, or ECU programming, and both can be pricey. This new Fuel Pump Booster is the economical (and easy) answer for your engine’s new fuel demands.

The MSD Fuel Pump Booster will supply the electric fuel pump with increased voltage in relation to the manifold boost pressure. As boost pressure increases in the manifold, the MSD Booster will increase the voltage to the electric fuel pump. The amount of voltage is adjustable with a potentiometer from a range of an additional 1.5 volts (5 psia) to a maximum output of 22 volts (30 psia)

Fuel Pump Booster -- $304.60 -- PN 2350
NOTE: Not for use on Pulse Width Modulated EFI systems (no return line)

 

[Boyko]

I am using one on a boosted efi 2-stroke, I knocked the stock fuel pressure down 25psi and have the regulator set up for 3:1 rate. On a EFI application you have to remove fuel from the factory curve at lower rpm. I herd the injectors on the apex do not like high fuel pressure, I think 65psi is the limit.

You can get away with that on a 2 stroke because either you added bigger injectors or your extremely rich on the bottom to begin with.

The 4 strokes can not tolerate lower fuel pressure than stock then will go up with boost at a 1:1 ratio.

The sled I built a turbo system for run extremely lean from the factory (mandated emission standards) Adding bigger injectors will necessitate a entire remap of the fuel curve to get the tuning spot on. If you put a turbo on a efi set up and use the factory map you will have to pull fuel until the you get into boost, and then add a wack of fuel. This is due to the fact that your exhaust pressure will build up before your boost pressure comes up. Around 5 psi (depending on the turbo) in the exhaust before you even make 1 pound of boost.