https://superchargersonline.com/wp-content/uploads/2020/03/4809643.pdfI have a 2001 w/ built engine and Paxton. It was built using a VEC along with the traditional Paxton fuel setup (i.e., 2 external pumps and the FMU).
I'm having some drivability issues so going to re-tune without the VEC, so figured now is a good time to upgrade the fuel setup to RSI's double hanger kit. Questions:
1 - What fuel pressure do I want to set the regulator at?
2 - When I set the fuel pressure, do I want the vacuum/boost port connected to the manifold, open to atmosphere, or does not matter?
3 - Can I connect the vacuum/boost port to any connection after the throttle body, or are there specific ones I do/don't want to use?
Sorry for dumb questions, I usually only build n/a engines so learning how boosted vehicles are setup (compounded by the fuuun of figuring out what the last owner did to the car)
You can modify the stock basket to hold two pumps. Saves you a bunch of money. Had both my supercharged Gen 1 and supercharged Gen 3 done like thatI have a 2001 w/ built engine and Paxton. It was built using a VEC along with the traditional Paxton fuel setup (i.e., 2 external pumps and the FMU).
I'm having some drivability issues so going to re-tune without the VEC, so figured now is a good time to upgrade the fuel setup to RSI's double hanger kit. Questions:
1 - What fuel pressure do I want to set the regulator at?
2 - When I set the fuel pressure, do I want the vacuum/boost port connected to the manifold, open to atmosphere, or does not matter?
3 - Can I connect the vacuum/boost port to any connection after the throttle body, or are there specific ones I do/don't want to use?
Sorry for dumb questions, I usually only build n/a engines so learning how boosted vehicles are setup (compounded by the fuuun of figuring out what the last owner did to the car)
I've been reading about fuel pressures and it seems everybody genreally agrees to be 55-60 psi at idle on a paxton setup.https://superchargersonline.com/wp-content/uploads/2020/03/4809643.pdf
1 = 55-60 but depends on injectors/fuel line size/WOT, etc
2 = manifold. you need it boost referenced
3 = search on the forum. You connect tap into manifold around the MAP or use the ports by the thermostat but that depends on what you want to do.
Yes, that is what I meant, thank youFor #2, I believe you are asking should the reference line be connected or disconnected when setting fuel pressure. You generally want the reference line disconnected for that activity if the vehicle is running, as manifold vacuum will skew the reading. If you gone to a return system and have the ability to run the pump with the engine off, you can do it with the reference line connected.
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Already bought the RSI setup ... it's supposed to be complete complete (all items, including pre-built lines)Dan Lesser can build you a killer fuel system that will drop in the hole with a minumum of work outside the tank.
I don't know how everyone else feels but I would definitely ditch the FMUHey there!!
I have a question first. Are you keeping the FMU? and if not, are you installing larger injectors?
Just to save time, the purpose of the pumps and FMU was to raise the fuel pressure to very high levels under boost to make the stock injectors flow enough.
The stock injectors are really only good for ABOUT 550 hp.
If you ditch the FMU, you will need bigger injectors.
As an added note, doubling fuel pressure does not double flow. Doubling fuel pressure increases flow by about 40%
To answer your questions:
1) it doesn't matter within reason. The point here is to work with available fuel injector "data", which most manufacturers only supply for 43.5 psi and 58 psi. This is not crazy critical, most good tooners can work around these things. So the typical fuel pressure is therefore 43.5 psi ("3 bar"), and 58 psi ("4 bar"). The other caveat is that you have enough fuel flow for your engine.
2) When setting fuel pressure, the vacuum port on the regulator is open to atmosphere. Once set, you can connect it to the intake manifold, usually the plenum.
3) You usually want a dedicated port for the fuel pressure regulator, although again, not super critical, but it has to be a secure connection. The heat under those manifolds is hard on vacuum lines, so they can degrade quickly, and that would be bad. You could consider an AN style line with teflon hose or hard line, but that's usually overkill for street cars.
I will be getting rid of the whole setup (external pumps, FMU, etc.) and going w/ RSI's double hanger complete kit, so has new pumps, injectors, rails, etc.Hey there!!
I have a question first. Are you keeping the FMU? and if not, are you installing larger injectors?
Just to save time, the purpose of the pumps and FMU was to raise the fuel pressure to very high levels under boost to make the stock injectors flow enough.
The stock injectors are really only good for ABOUT 550 hp.
If you ditch the FMU, you will need bigger injectors.
As an added note, doubling fuel pressure does not double flow. Doubling fuel pressure increases flow by about 40%
To answer your questions:
1) it doesn't matter within reason. The point here is to work with available fuel injector "data", which most manufacturers only supply for 43.5 psi and 58 psi. This is not crazy critical, most good tooners can work around these things. So the typical fuel pressure is therefore 43.5 psi ("3 bar"), and 58 psi ("4 bar"). The other caveat is that you have enough fuel flow for your engine.
2) When setting fuel pressure, the vacuum port on the regulator is open to atmosphere. Once set, you can connect it to the intake manifold, usually the plenum.
3) You usually want a dedicated port for the fuel pressure regulator, although again, not super critical, but it has to be a secure connection. The heat under those manifolds is hard on vacuum lines, so they can degrade quickly, and that would be bad. You could consider an AN style line with teflon hose or hard line, but that's usually overkill for street cars.
The floats themselves were my biggest issue. But I haven't had to run a carb in 20+ years lol. Thank God for computers!Old carbs hate ethanol because the float needles are coated with 'wax' and the ethanol stripes the 'wax' off in addition to all the other 'rubber' seals, etc.
I actually had the shop just modify my stock fuel pump hangar to accommodate two pumps versus spending so much money on just a double hanger kit. I switched to top feed injectors and rails and I'm going to be running E85 with a flex fuel sensor so I can bounce back and forth between pump gas. I also have an Alky Control kit and am spraying straight VP M1 on top. I went with an Emtron stand alone ECU. Going to have knock sensors and traction control. I switched to a 3" pulley and should be somewhere around 10lbs of boost. Depending on what it puts down on a dyno (Gen 1) I may end up dropping pulley sizes to push more towards 14lbs of boost.I will be getting rid of the whole setup (external pumps, FMU, etc.) and going w/ RSI's double hanger complete kit, so has new pumps, injectors, rails, etc.
Nice! Emtron is a bad ass setup. You should do a DBW throttle body with it, and setup for it to run TMF (throttle mass flow).I actually had the shop just modify my stock fuel pump hangar to accommodate two pumps versus spending so much money on just a double hanger kit. I switched to top feed injectors and rails and I'm going to be running E85 with a flex fuel sensor so I can bounce back and forth between pump gas. I also have an Alky Control kit and am spraying straight VP M1 on top. I went with an Emtron stand alone ECU. Going to have knock sensors and traction control. I switched to a 3" pulley and should be somewhere around 10lbs of boost. Depending on what it puts down on a dyno (Gen 1) I may end up dropping pulley sizes to push more towards 14lbs of boost.
Yeah the Tuner was saying he likes using the Emtrons more than Motec which kind of shocked me. I originally was trying to do a Gen 3 intake swap and was going to switch to one throttle body but it became a fabricating nightmare because of the paxton and alternator so I said screw it, Plan B.Nice! Emtron is a bad ass setup. You should do a DBW throttle body with it, and setup for it to run TMF (throttle mass flow).
You could just run 2 DBW throttle bodies.Yeah the Tuner was saying he likes using the Emtrons more than Motec which kind of shocked me. I originally was trying to do a Gen 3 intake swap and was going to switch to one throttle body but it became a fabricating nightmare because of the paxton and alternator so I said screw it, Plan B.
Haha, right? I have no idea where it came from, been kicking around the shop for years. It houses my in cylinder preasure goodies from TFX lol.Don't trust a Canadian who steals grey grocery baskets. The store even wrote 'PLEASE' on the basket and he still took it out of the store. Damn rude Canadian.
