FPR questions - Page 2 - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Mikester · 09-16-2013, 08:15 AM

What ever happened to the K.I.S.S. concept?

Croustibat · 09-17-2013, 02:54 AM

Quote:

Originally Posted by max_POWER

[...]
What aftermarket FPR's do all you guys run? At what power level do you NEED to upgrade the FPR?
Thanks guys.

You wont need an aftermarket FPR, unless maybe hitting 500/600+ HP.

If you really want to upgrade your fuel system, get EV14 based fuel injectors.

Croustibat · 09-17-2013, 02:56 AM

Quote:

Originally Posted by UNISA JECS

Actually they are good for much higher fuel pressure like you say but the problem is when you install high volume fuel pumps on a Nissan vehicle that doesn't run a Fuel Pressure Control Module (i.e. like all Nissan 4 cylinders models) the stock FPR cannot bleed off enough fuel volume to keep the numbers at 43psi @ zero vaccumm.

Yeah, that is quite a lot of bullshit, but i have to admit i have read that alot on zilvia.

No matter how many times you guys repeat it, it still is bullshit.

Croustibat · 09-17-2013, 03:01 AM

Ah crap. 6 YO thread.

silnv · 09-17-2013, 07:27 AM

I just read through this old thread, and it raised a few questions for me.

1) Why is there no conclusive answer to this question? Those for the AFPR defended it to the death, and those for stock FPR. I feel like this should be able to be a cut and dry answer.

2)My SR'd coupe, with a Walbro 255 and stock the FPR runs higher fuel pressure than the factory pressure (causing it to run rich, but with a smooth idle). Is this do to "overrun"? Or is my stock FPR just wore out.

Edit: Just found this interesting information. It is DSM based, by a reputable DSM guy. Please give any information you may have to disprove his statements.

Quote:

I must say I'm rather disappointed, the amount of mis-information on this thread is just rediculous, some are coming from experience members.

1. 255 or 190 (to a lesser degree) will overrun stock fpr's, 1G or 2G. If you're running without an AFPR and you have a gauge to prove you have no overrun, something is wrong with your fuel system. I'll go ahead and say that most of you claiming no overrun doesn't own a fuel pressure gauge.

2. Much like you can't tune out venting a BOV with stock MAFs, you can't tune out FPR overrun. Why? Because the changes are NON-LINEAR and load based, anyone who claims they can tune it out, please provide detail information as to how, it would be the first.

3. No, higher fuel pressure will not make your injectors leak, there are people out there running 60 psi base pressure, the weak link when running higher pressure is the pump, not the injectors.

4. The smaller the injectors you have, the worse and the longer the duration of overrun.

5. An AFPR isn't just for dialing down base pressure and prevent overrun, it's a handy complimentry tuning tool when used properly.

6. The extra gas money you'll spend on overrun will pay for an AFPR in no time.

I'm not here to argue with you guys, these are facts, not opinions. The only reason this thread isn't closed, OP warned for asking a FAQ question and bunch of negative rep points handed out to some is because there are too many mis-information in here that needs to be addressed. Go ahead and ask follow up questions if you're unclear on my post, if you're going to dispute facts, make sure you bring facts of your own other than "I have been running one without any problems". The debate on this subject is long over, much like venting.

NoPistons! · 09-18-2013, 09:12 PM

My head hurts. Does anyone realize what the parts do before wanting to get them?

Croustibat · 09-19-2013, 03:33 AM

What i think is the funniest about all that FPR bullshit is it only happens to zilvians / US users.

It does not happens to people that have an SR20 or a CA18 under the hood as stock, like ... everywhere else in the world.

Strange, eh ? Check on any non US board and see for yourself. Try sxoc (england), it is quite a big board. Mostly run by boys who just want a slammed cars and not spend money on parts. Quite a lot like here actually.

As far as personal experience goes, i am running an SR20 stock FPR on my CA18 (because base pressure is 3bars instead of 2.5bars for the CA). Brand new genuine walbro 255LPH, brand new wiring to make sure it is fed properly, e85 fuel, 1000cc injectors.

I also use a nistune to make my own maps, and i tested fuel pressure when changing wiring and pump (actually that is what made me change these).

Never had a problem setting my fueling right. Pressure was and is spot on.

Which is the exact same thing that happens to everyone that owns an SR20, oem or tuned, around me with a stock FPR. So far i have NEVER seen, with my eyes, an SR20 FPR overrun by a walbro. And i have seen a few. So yes, I call that "internet bullshit that only happens on a continent that does not have an SR20DET in any car on their domestic market".

As far as the DSM authority argument, scientific methods says "prove your claims", not "tell detractors they need to prove you are wrong, and if they can tell them their tools are not working properly, because You Are God's Voice And Cannot Be Wrong". I dont know wether he is right or not, i dont know DSM engines, but i know he writes like a guru that ask for blind trust.

Mikester · 09-19-2013, 08:12 AM

Well, I would add that when you INCREASE fuel pressure, flow from any electric fuel pump (including any Walbro 190/255) will DECREASE... There are some great graphs here that illustrate this point. That being the case, if that 'guru' is saying that dialing down fuel pressure 'to prevent overrun' is a common practice; then he is exactly WRONG because less pressure in the system translates into higher volume of fuel being fed to the rail by the pump.

I 100% agree with Croustibat- there is NO NEED for an AFPR for a stock to mildly-modded & tuned SR, CA, RB etc. All it does is add a potential free radical to the equation... another thing to keep an eye on. Hence the KISS concept- If it ain't broke, don't fix it. Lived in Japan for 6yrs... Guess what? All the American & Japanese car guys there know that an AFPR is not necessary in most cases... Those very same guys push 400+hp daily/track-mobiles to the limit every chance they get... ON STOCK FPR'S!!!

09-16-2013, 08:15 AM	#31
Mikester Nissanaholic! Join Date: Jun 2007 Location: Kathleen, GA Age: 50 Posts: 1,938 Trader Rating: (0) Feedback Score: 0 reviews	What ever happened to the K.I.S.S. concept? __________________

09-18-2013, 09:12 PM	#36
NoPistons! Zilvia Junkie Join Date: Jan 2009 Location: Carolina Posts: 548 Trader Rating: (1) Feedback Score: 1 reviews	My head hurts. Does anyone realize what the parts do before wanting to get them? __________________ Just another broke ass drifter

09-19-2013, 08:12 AM	#38
Mikester Nissanaholic! Join Date: Jun 2007 Location: Kathleen, GA Age: 50 Posts: 1,938 Trader Rating: (0) Feedback Score: 0 reviews	Well, I would add that when you INCREASE fuel pressure, flow from any electric fuel pump (including any Walbro 190/255) will DECREASE... There are some great graphs here that illustrate this point. That being the case, if that 'guru' is saying that dialing down fuel pressure 'to prevent overrun' is a common practice; then he is exactly WRONG because less pressure in the system translates into higher volume of fuel being fed to the rail by the pump. I 100% agree with Croustibat- there is NO NEED for an AFPR for a stock to mildly-modded & tuned SR, CA, RB etc. All it does is add a potential free radical to the equation... another thing to keep an eye on. Hence the KISS concept- If it ain't broke, don't fix it. Lived in Japan for 6yrs... Guess what? All the American & Japanese car guys there know that an AFPR is not necessary in most cases... Those very same guys push 400+hp daily/track-mobiles to the limit every chance they get... ON STOCK FPR'S!!! __________________

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09-17-2013, 03:01 AM	#34
Croustibat Nissanaholic! Join Date: Aug 2011 Location: France - Toulouse Age: 41 Posts: 1,851 Trader Rating: (0) Feedback Score: 0 reviews	Ah crap. 6 YO thread.

09-19-2013, 03:33 AM	#37
Croustibat Nissanaholic! Join Date: Aug 2011 Location: France - Toulouse Age: 41 Posts: 1,851 Trader Rating: (0) Feedback Score: 0 reviews	What i think is the funniest about all that FPR bullshit is it only happens to zilvians / US users. It does not happens to people that have an SR20 or a CA18 under the hood as stock, like ... everywhere else in the world. Strange, eh ? Check on any non US board and see for yourself. Try sxoc (england), it is quite a big board. Mostly run by boys who just want a slammed cars and not spend money on parts. Quite a lot like here actually. As far as personal experience goes, i am running an SR20 stock FPR on my CA18 (because base pressure is 3bars instead of 2.5bars for the CA). Brand new genuine walbro 255LPH, brand new wiring to make sure it is fed properly, e85 fuel, 1000cc injectors. I also use a nistune to make my own maps, and i tested fuel pressure when changing wiring and pump (actually that is what made me change these). Never had a problem setting my fueling right. Pressure was and is spot on. Which is the exact same thing that happens to everyone that owns an SR20, oem or tuned, around me with a stock FPR. So far i have NEVER seen, with my eyes, an SR20 FPR overrun by a walbro. And i have seen a few. So yes, I call that "internet bullshit that only happens on a continent that does not have an SR20DET in any car on their domestic market". As far as the DSM authority argument, scientific methods says "prove your claims", not "tell detractors they need to prove you are wrong, and if they can tell them their tools are not working properly, because You Are God's Voice And Cannot Be Wrong". I dont know wether he is right or not, i dont know DSM engines, but i know he writes like a guru that ask for blind trust.