Megan Racing FPR Rising Rate?

[2plus4plus0eq6]

Hey guys,

Ive got a megan racing FPR that I bought a real long time ago. I was thinking of putting it on my sr20. I am sure this has been covered before, but I couldn't really find any sold threads. I am curious to know if the people who have this FPR installed on their SR can confirm that its actually raises 1:1 because the manufacture websites clearly states its not rising rate and that it is a predetermined setting.

From my understanding, someone who has a fuel pressure gauge in view of the driver seat will be able to see if its rising rate. Fuel pressure should rise when boost rises which means there has to be load on the engine so reviving the engine within the engine bay should not increase pressure right? You have to be driving it. Correct me if I am wrong.

I know some of you are probably thinking to not even take the chance and just get an aeromotive.

[dorkidori_s13]

get either an Aeromotive or Tomei Type S. Make sure to get a liquid filled gauge with both (if youre not running an external gauge). Most companies out there copy Tomei style FPRs and use cheaper parts for the internal spring and diaphragms. i personally prefer Aeromotives -6 rising FPR as ive used them in my last 2 builds with zero issues in consistency.

also, if youre running a walbro or any high pressure fuel pump, an adjustable FPR will give you the ability to drop you fuel pressure back down to around 40psi instead of the 55+psi that walbros push the stock FPR up to (too much fuel pressure is bad as it will cause the injector to get stuck open instead of allowing it to pulsate)

[2plus4plus0eq6]

Originally Posted by dorkidori_s13

get either an Aeromotive or Tomei Type S. Make sure to get a liquid filled gauge with both (if youre not running an external gauge). Most companies out there copy Tomei style FPRs and use cheaper parts for the internal spring and diaphragms. i personally prefer Aeromotives -6 rising FPR as ive used them in my last 2 builds with zero issues in consistency.

also, if youre running a walbro or any high pressure fuel pump, an adjustable FPR will give you the ability to drop you fuel pressure back down to around 40psi instead of the 55+psi that walbros push the stock FPR up to (too much fuel pressure is bad as it will cause the injector to get stuck open instead of allowing it to pulsate)

Thanks for the reply. I currently have a walbro. I didn't know walbros would push the stock pressure up that high. I figured the stock FPR would have limited that?

The megan one I have now is adjustable. I have been having some issues where I idle rich and cruise lean. From what I have been reading, the FPR could be the culprit. I am going to switch out my fuel filter today, but I also wanted to see what my fuel pressure was doing so thats why I was thinking off installing a FPR. Then I can see what my fuel pump is pushing out.

[jr_ss]

Get rid of the Megan as suggested prior and upgrade to a quality one. SARD, Tomei, aeromotive, etc are all good regulators. A gauge is a must as well. 0-100psi should be acceptable.

You don't need to install a regulator to see what PSI you have. An inline gauge would suffice and it can be installed on the fuel feed line to the rail. You can rent/borrow from the auto parts store for this.

[2plus4plus0eq6]

Originally Posted by jr_ss

Get rid of the Megan as suggested prior and upgrade to a quality one. SARD, Tomei, aeromotive, etc are all good regulators. A gauge is a must as well. 0-100psi should be acceptable.

I would love to have a guage on the FPR as well as one inside the car. Do they both need to be liquid filled and whats the reasoning behind the liquid fill?

Thanks

[bboyclo]

used to have that and it's crap, switched over to isis one it's pretty good for what it is. enjuku sells a whole kit with it too. but if you want to spend more $ then do as what was mentioned above

[dorkidori_s13]

Originally Posted by 2plus4plus0eq6

I have been having some issues where I idle rich and cruise lean.

clean your MAF and check for boost leaks. if youre leaning out at open throttle, it means your pulling air in BEFORE the turbo (post MAF). if youre running rich, it means you have a boost leak. shitty screw type clamps and thin couplers usually cause this. invest in quality t-bolt clamps and thicker couplers.

oh also, one MAJOR bit of advice. never never NEVER run your car below a quarter of a tank with a walbro. you will burn the pump out. intank pumps rely on fuel to keep them cool. walbros are notorious for burning out after a while when they get hot! took me 3 pumps in my first 240 around 10-12 years ago to figure this out. the average life span of a walbro if kept in good shape is about 3-5 years.

Originally Posted by bboyclo

used to have that and it's crap, switched over to isis one it's pretty good for what it is. enjuku sells a whole kit with it too. but if you want to spend more $ then do as what was mentioned above

isis is the same quality as megan boss... both are economy brand parts.

[2plus4plus0eq6]

Originally Posted by dorkidori_s13

clean your MAF and check for boost leaks. if youre leaning out at open throttle, it means your pulling air in BEFORE the turbo (post MAF). if youre running rich, it means you have a boost leak. shitty screw type clamps and thin couplers usually cause this. invest in quality t-bolt clamps and thicker couplers.

oh also, one MAJOR bit of advice. never never NEVER run your car below a quarter of a tank with a walbro. you will burn the pump out. intank pumps rely on fuel to keep them cool. walbros are notorious for burning out after a while when they get hot! took me 3 pumps in my first 240 around 10-12 years ago to figure this out. the average life span of a walbro if kept in good shape is about 3-5 years.


isis is the same quality as megan boss... both are economy brand parts.

Thanks for the tips. I was just reading the FSM about the MAF. I am going to diagnose my MAF, change my fuel filter and see if that does anything so I can at least rule that out. I just changed my CTS the other day and noticed my mileage got way better. I am running rich at like 9.5 at idle when cold and about 11 idle when warm. partial throttle raises AFR to sometimes 18. WOT seems to bring my AFR down to 14.7-15. From what I have been reading, some say a rich idle and lean throttle is a symptom of a shitty FPR, but really how often does the stock FPR go bad? I am just worried about putting the shitty megan one on right now. I'll try the little things first then tackle the bigger things after

[zurud]

my stock fpr run fine with walbro. My Supra and 240 run with walbro and stock fpr. I tried Aeromotive once . The fuel pressure is the same on both cars with Aeromotive and stock. So I took the Aeromotive off. I can sell you my Aeromotive if you want tobuy it. Personally I have never seen car with higher volume pump mess up with stock fpr. I think megan quality is worst than what Nissan can offer.

[2plus4plus0eq6]

I am getting like 25 hg on vaccum and I am boosting fine. Has anyone even heard of the stock FPR failing? does it ever happen? how can the stock FPR be diagnosed? I am really tight on cash at the moment so I cant run out and buy a proper FPR and I don't necessarily want to rely on my megan one right now plus that might not be the problem.

If it is true that a walbro increases the fuel pressure of the stock fpr, wouldn't that be kinda good in my situation since I am leaning out on throttle? I increased my boost to a about 14-15 anyways so the extra fuel would be good.

I'll have to read some more.

[Croustibat]

Originally Posted by 2plus4plus0eq6

I know some of you are probably thinking to not even take the chance and just get an aeromotive.

That.

Or just keep your oem FPR.

The walbro that overruns the stock sr20 regulator seems to only happen in america, so i'd say it is more a rumor than anything else.

[2plus4plus0eq6]

Originally Posted by Croustibat

That.

Or just keep your oem FPR.

The walbro that overruns the stock sr20 regulator seems to only happen in america, so i'd say it is more a rumor than anything else.

I honestly don't know if you're being sarcastic or not about the OEM fpr lol

[jr_ss]

The problem when running the OEM regulator vs an adjustable one, is people often do a laundry list of upgrades and over look the regulator. It's not that it can't keep up with the Walbro, but when you have a bunch of money wrapped up into your motor, don't you think it's a wise idea to have a means to adjust and monitor what your actual fuel pressure is?

The liquid in the gauge helps with overall accuracy and keeps the needle from vibrating erratically.

[dorkidori_s13]

Originally Posted by zurud

my stock fpr run fine with walbro. My Supra and 240 run with walbro and stock fpr. I tried Aeromotive once . The fuel pressure is the same on both cars with Aeromotive and stock. So I took the Aeromotive off. I can sell you my Aeromotive if you want tobuy it. Personally I have never seen car with higher volume pump mess up with stock fpr. I think megan quality is worst than what Nissan can offer.

perhaps you shouldve adjusted the aeromotive FPR from 55-60psi back down to 38-42 where it should be on your 240sx? hence the "adjustable" part of the fuel pressure regulator... and im guessing you never poked your head in the engine bay and checked the gauge on your FPR after installing it correctly with your Walbro fuel pump? a high pressure fuel raises fuel pressure due to the increased force at which it pumps more fuel into the motor... im pretty sure you missed something.

Originally Posted by Croustibat

That.

Or just keep your oem FPR.

The walbro that overruns the stock sr20 regulator seems to only happen in america, so i'd say it is more a rumor than anything else.

i highly doubt by some miraculous twist of physics defying fate that the increased pressure created by a walbro fuel pump run in France with a CA18det powered S13 is going to be drastically different than an SR20det powered 240sx given theyre both the same car... just saying

[2plus4plus0eq6]

Thanks for the advice guys. I think I will just have to save and wait and get a decent fpr. Don't wanna risk anything. I'll probably get a gauge for the inside as well. Both liquid filled.

Thanks

[Croustibat]

Originally Posted by jr_ss

The problem when running the OEM regulator vs an adjustable one, is people often do a laundry list of upgrades and over look the regulator. It's not that it can't keep up with the Walbro, but when you have a bunch of money wrapped up into your motor, don't you think it's a wise idea to have a means to adjust and monitor what your actual fuel pressure is?

The liquid in the gauge helps with overall accuracy and keeps the needle from vibrating erratically.

You don't need an adjustable FPR to have a fuel pressure gauge. Anyway, too many gauges are a problem; i'd rather use an AFR gauge, and if it goes lean i then tee a fuel pressure gauge after the filter to check, then remove it.

Originally Posted by dorkidori_s13

i highly doubt by some miraculous twist of physics defying fate that the increased pressure created by a walbro fuel pump run in France with a CA18det powered S13 is going to be drastically different than an SR20det powered 240sx given theyre both the same car... just saying

My point exactly. In France we only have CA18DET and SR20DET.
Same goes for all Europe, and frankly i have never witnessed nor heard (IRL) of any case of overrun OEM FPR by a walbro in 10 years. I am running an SR20DET OEM FPR on my CA18DET (CA is 2.5bars, SR is 3bars), have always run walbros or clones, and so does everyone around. They don't change their FPRs unless they aim at 400/500+ HP, and this is more a question of line diameter than pressure regulation. No pressure problem, ever.

I discovered this problem on zilvia. I think it just is a rumor, launched by an influent member here that happened to get a bad FPR and reached wrong conclusions. Since then, everyone kept repeating without ever checking.

Now it might be real, i don't rule it out completely. But i have never seen it. Maybe the import process or the fuel you use kills the FPR, i don't know.

But then, there is Occam's razor ...

[KAT-PWR]

I've been running an oem fpr since i switched from 550s to 850cc injectors, walbro the whole time. No issues.