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Aeromotive FPR - be careful

How did you put it on the stock rail

I made my fuel rail, and the back end is too close to the firewall, and the front is too close to the plenum and plug wires. I mounted the FPR to the firewall at the booster:

140Details-0133.jpg
 
Interesting

I was running a slightly different version of the Aeromotive FPR on my 142 with the original B20E engine.

https://www.aeromotiveinc.com/product/universal-bypass-regulator/

My take is that the primary difference is that this regulator has an optional spring which allows lower operating pressures.

Like others, I noticed that on shut down the regulator would allow loss of fuel pressure very quickly. The bigger problem I encountered was irregularities in fuel pressure, particularly spikes in fuel pressure and a lot of noise from the FPR. In particular the FPR seemed to have a lot of valve chatter anytime the FPR was by-passing lots of fuel. When driving, if you lifted the gas pedal quickly the FPR would howl - being mounted on the firewall made for a great sounding board and lots of noise.

By experimentation, I discovered that this Aeromotive FPR is acutely sensitive to back pressure on the fuel return line and it has a problem managing pressures at low flow (high by-pass) rates. I improved operation slightly by making sure that all the bends on the discharge were very large radius >15cm. Aeromotive's technical support suggested that the problem was that the return line was too small. In their technical documents the minimum recommended return line is 3/8" and the stock return line on the 142 E is 5/16". I ultimately solved the problem by using an FPR for a Nissan 280 ZX. Non adjustable, does not look as trick; but, provides consistent reliable operation.

As an observation. If your regulator is chattering it will cause accelerated wear on the control orifice and other problems. Depending on how you have the FPR mounted you may not notice the valve chatter. Also, if you have large fuel return lines you may not encounter the back pressure problem.
 
So, I've had this Aeromotive FPR on my 142 since I did the engine swap. It's about 6 months old, I'd say.

It never help line pressure after the pumps primed, and the needle on the gauge always fluctuated up to 7-8 psi. I was getting my TLAO chips dialed in with my light blue (390cc?) injectors, but I couldn't escape a nasty lean condition under boost toward 5k rpm. Increased fuel pressure to 58 psi, and the FPR would BARELY get there. It should be capable of 30-70psi base pressure, so I took it apart to see what was up.

Sure enough, the hole that the ball valve should seal against was worn unevenly. They apparently just drill a hole, after the base is already anodized, and don't put a radius or chamfer on it. I used a counter sink bit and milled a chamfer on the seat by hand, carefully.

I'm glad I saw this before installing mine. So what do we think, would a 60 degree taper countersink be better than a 45 degree for this?
 
I'm glad I saw this before installing mine. So what do we think, would a 60 degree taper countersink be better than a 45 degree for this?

In a perfect world, I assume a matched radius would be best. I used a 45, and it's marginal. 60 would give it more room to settle in, I assume.
 
my Aeromotive FPR never holds any pressure when the car is off. Always thought that was kind of odd.

Yeah, I'm calling BS on their claim that it's better for performance. This is what their FAQ says about it:

6.) I?ve installed my new Aeromotive bypass regulator. Fuel pressure seems to adjust fine and holds great when the engine is running, but when I shut the engine off, pressure drops quickly to zero. Shouldn?t the pressure hold like it did with a stock regulator?
No, Aeromotive EFI bypass regulators may not seal perfectly when the pump is off. They are engineered for the highest possible performance when the engine is running. OEM regulators must hold pressure for 30-minutes after shut-down to pass EPA emissions standards. At Aeromotive we know our customers priority is to have the best possible flow and pressure control when the engine is running and we don?t compromise this standard to force the regulator to seal when the engine is off. If extended crank or hard-start becomes a concern, first allow the pump to run and prime as long as possible after turning the key to the run position, then start cranking the engine, just before the pump shuts off. If the priming cycle is too short to allow the engine to start easily with this approach, extend the priming cycle in the ECU if programmable, or ad a timer board or momentary button to the fuel pump run circuit.
 
To be fair, an OEM regulator is usually a small needle or tapered metering orifice that seals quite well since it's small and has a considerable amount of surface area to seal against. Great for holding pressure when the pump isn't running, but horrible for bypass flow. This works great for OEM applications and fuel systems with low overall flow and delivery volume.

The ball and seat style like commonly found on aftermarket regulators aren't so great for holding pressure when the pump is off because the sealing area is considerably less, in exchange for a greater return orifice size.

I'm not quite sure I've ever seen an aftermarket regulator that holds pressure for a significant amount of time after the pump is shut off.

Not saying that the construction on yours isn't poor, because it's Aeromotive and they don't make super high quality stuff to begin with. But, I don't think it's rational to expect them to hold pressure for a long time after turning the pump off either.

Thinking about it, the only thing Aeromotive I've personally have dealt with in the past twenty years that's been worth its own weight are the Stealth A340 pumps. Their A1000 pumps are complete garbage, and sort of set the tone of the crap quality they produce.

My own preference is the super cheap (well, back when they were $89) Mallory 29389. Of the 30 I've installed, none of them came back for any sort of failure, the oldest one being in my rustang for the past 15 years. Average pressure decay is around 20 seconds after turning the pump off. Something that's about average for an aftermarket ball and seat regulator.

Aside from proper operation, I wouldn't expect an aftermarket high flow regulator to hold pressure after the engine is shut off. That's the primary concern Aeromotive is addressing in their FAQ.
 
To be fair, an OEM regulator is usually a small needle or tapered metering orifice that seals quite well since it's small and has a considerable amount of surface area to seal against. Great for holding pressure when the pump isn't running, but horrible for bypass flow. This works great for OEM applications and fuel systems with low overall flow and delivery volume.

The ball and seat style like commonly found on aftermarket regulators aren't so great for holding pressure when the pump is off because the sealing area is considerably less, in exchange for a greater return orifice size.

I'm not quite sure I've ever seen an aftermarket regulator that holds pressure for a significant amount of time after the pump is shut off.

Not saying that the construction on yours isn't poor, because it's Aeromotive and they don't make super high quality stuff to begin with. But, I don't think it's rational to expect them to hold pressure for a long time after turning the pump off either.

Thinking about it, the only thing Aeromotive I've personally have dealt with in the past twenty years that's been worth its own weight are the Stealth A340 pumps. Their A1000 pumps are complete garbage, and sort of set the tone of the crap quality they produce.

My own preference is the super cheap (well, back when they were $89) Mallory 29389. Of the 30 I've installed, none of them came back for any sort of failure, the oldest one being in my rustang for the past 15 years. Average pressure decay is around 20 seconds after turning the pump off. Something that's about average for an aftermarket ball and seat regulator.

Aside from proper operation, I wouldn't expect an aftermarket high flow regulator to hold pressure after the engine is shut off. That's the primary concern Aeromotive is addressing in their FAQ.
 
"high flow" regulator... all marketing.

A stock 850 3 bar regulator is fine with a 340lph pump, in fact, even a 3/16 hole will flow at least 206lph and possibly way more.
 
A stock 850 3 bar regulator is fine with a 340lph pump, in fact, even a 3/16 hole will flow at least 206lph and possibly way more.

I have not found this to be true, because as you pointed out, an orifice that can’t flow beyond pump capacity will increase pressure until the pump volume drops, or the orifice can sustain flow. Every 3 bar Volvo regulator I’ve had on the bench with an A340 pump would rise to 50-52 psi at low demand (idle and cruising) and would not fall into the rated pressure of the regulator until more considerable demands. The higher rated flow of fuel pump, the worse this gets.
 
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Just wanted to update this, as I've heard from Aeromotive. The guy better explained why the orifice is of a different design compared to the stock style regulators, like gross polluter said. He also told me that if the seat on the ball valve wears, it's because the ball is being allowed to touch or chatter against the seat, indicated cavitated or insufficient fuel supply.

He said that a fuel system delivering enough fuel will keep the ball from touching the seat at all, except when the car's off of course. All of this makes sense to me and explains all my issues. I'm going to take back some of my angst towards Aeromotive.
 
I use Accufabs bolt on adustable fuel pressure regulator for a Buick Grand National turbo. It's a direct bolt on bosch replacement. Just bolt it on adjust and go. Works like a champ. I can't believe nobody figured this out.
20171127_223754.png
 
I use Accufabs bolt on adustable fuel pressure regulator for a Buick Grand National turbo. It's a direct bolt on bosch replacement. Just bolt it on adjust and go. Works like a champ. I can't believe nobody figured this out.
20171127_223754.png

I use the Kirban version of this regulator, i think people have replaced their fuel rail and require a stand alone regulator like what's being discussed
 
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