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Aftermarket FPR vs OEM STI FPR


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So I bought a DWR1000 FPR, but when I installed it my fuel pressure gauge constantly fluctuates within like a 2+- range. But when I have the sti fpr installed the fp gauge has a solid constant reading..... not sure what to think of this? I am currently exchanging the dwr1000 for another one to see if its a fluke or standard thing. All I can think of is the dwr needs something else, but I am wondering how the oem does a better job being like a 3rd of the size of the aftermarket and half the price?
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Theres a device... can't remember the exact name atm, something to do with pulses or dampening.... not sure what its called. But I seen a setup where there was a device right before the aftermarket fpr to stop such a thing. I think I pulled all the oem stuff of my setup that would regulate the flow.

 

Good to know I just wasted my time on this return lol.

Edited by Tehnation
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fuel dampeners

 

The stock '05 LGT has three of them, one by the FPR and one on each rail.

I've replaced all mine with Radium dampeners and my FPR was STi, is not Radium as well.

I see small fluctuations in the fuel pressure (<1psi), doesn't appear to do any harm in any way.

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Are you running aftermarket fuel rails and lines? Do you have any drivability issues with either FPR?

 

I've been plagued by the low rpm, stumble, whatever you want to call it since the car was new. Stock, Infamous Tuned (Opensource) and dyno tuned currently, it still happens. It's annoying when I'm off throttle then back on, in first gear - generally around 1500-2500rpms. Makes it look like I can't drive manual with the bucking. Sorry for going off topic.

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Yea, I am getting a stumble/hesitation/jerking between 2-3k. I am running a modified fuel rail made form the top feed lgt fuel rail and my 05 oem fuel rail. Its basically straight through no dampeners.

 

That's unfortunate Tehnation, I had these issues with the stock tune and the stock fueling system. Now I'm on aftermarket rails, lines and FPR. I also don't have any dampeners. The fuel lines are ran in a parallel system.

 

I'd love to see who else has these issues or who may have some insight / feedback on where to start looking for clues / solutions. I'm thinking it may not be tune related since I've had this with the stock / base tune and two tuned maps. Maybe it's a mechanical issue with fuel delivery.

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That's unfortunate Tehnation, I had these issues with the stock tune and the stock fueling system. Now I'm on aftermarket rails, lines and FPR. I also don't have any dampeners. The fuel lines are ran in a parallel system.

 

 

 

I'd love to see who else has these issues or who may have some insight / feedback on where to start looking for clues / solutions. I'm thinking it may not be tune related since I've had this with the stock / base tune and two tuned maps. Maybe it's a mechanical issue with fuel delivery.

I have mild case of this , bone stock and also with stage one AP tune.

 

New set up will be ID rails in parallel ,1050 ID injectors, separate return line for each rail from the back side to Radium FPR

 

Pressure side will be stock line into Radium inline damper then out then a y that splits to the front of each rail

 

Radium said obviously their rails with the ports for their own rail mounted dampers was best, but the inline with their fpr should be fine. They do make a fpr with built in damper also.

 

Some research I have done suggested having separate lines into the fpr is going to help with pulses as well.

 

Only time will tell and I'm also curious to see the difference in e85 and pump gas in this department

 

Sent from my Pixel 3a using Tapatalk

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I have mild case of this , bone stock and also with stage one AP tune.

 

New set up will be ID rails in parallel ,1050 ID injectors, separate return line for each rail from the back side to Radium FPR

 

Pressure side will be stock line into Radium inline damper then out then a y that splits to the front of each rail

 

Radium said obviously their rails with the ports for their own rail mounted dampers was best, but the inline with their fpr should be fine. They do make a fpr with built in damper also.

 

Some research I have done suggested having separate lines into the fpr is going to help with pulses as well.

 

Only time will tell and I'm also curious to see the difference in e85 and pump gas in this department

 

Sent from my Pixel 3a using Tapatalk

 

 

Ah, thanks for your insight.

 

I have a fuel filter installed right before it splits off to each fuel rail. The return from the rails merge to a single line back to my Aeromotive FPR. I run both E85 and pump gas on my tune, mainly E85 but I experience the same regardless of fuel.

 

I would consider an inline dampener. If I find the time, I would do some testing to see if one or two dampeners would make any significant improvement. Essentially if I could add one, it would be right after the fuel filter before it splits off to the rails. For two, I would add one before each rail. That would be the most amount of work, since I'd have to shorten my lines and add additional AN fittings. But looking at Radium's trick FPR-D, Fuel Pressure Regulator-Damper I may be able to directly swap the Aeromotive FPR with this unit. But now the dampener will be after the fuel rails, so I'm not sure if that is another variable to look into.

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