Malpassi VS Sard VS Nismo

[Skyrine-Dave]

yes, but my choice in injectors will definately be large enough. I dont want to know about band aid fixes as i am well aware of what happens.

I have the support systems all adequete, i just want to know about these fuel regs.

also just cause you have 700cc injectors... it'd be good to know at what PSI they support 700cc. Because at stock rail pressure (38psi) they might only be 400cc injectors.

so back on topic:

malpassi seems to fluctuate in rail pressure

sard is fkn expensive, yet quality

nismo.... is nismo quality :S

[mokompri]

i THINK they normally quote it at 3 bar (~45psi), but dont quote me, rather quote a spec sheet off there site and tell us all hehe

[Trust33]

Im gettin 550cc injectors, big bosch pump, and also an adjustable FPR to wind abit more out of my injectors if need be.

Where are you looking at getting your 550cc injectors from?

[4door_Sleeper]

Come on guys, stop posting all this "I think" and "a friend of a friend once told me that they knew someone who" crap. I wont even begin to extract the incorrect comments made in this thread and comment on the corrections. (but I would suggest you all ignore mokompri )

There is nothing wrong with rising rate regulators, but it is true some people use them to push the system too far. (but how many people run a standard turbo at 13-14 psi?)

If you are concerned about a regulator holding enough pressure - just add a pressure gauge and watch it for yourself. As for brand names, there are many many people who will claim one is better than the other, but the facts are that there are many high KW cars using all of the brands listed above, including top drag teams. (with no problems), but that there are bad regulators made by all companies due to poor quality control.

PS just as background info to help enlighten, a rising rate reg (which is standard on RBDET motors) stays open at idle and hence will not restrict flow and therefore keeps pressure low. As the boost increases the regulator closes, which reduces the flow and hence increases the pressure.

[Skyrine-Dave]

Thanks for the info 4 door sleeper

[krawler]

PS just as background info to help enlighten, a rising rate reg (which is standard on RBDET motors) stays open at idle and hence will not restrict flow and therefore keeps pressure low. As the boost increases the regulator closes, which reduces the flow and hence increases the pressure.

This was a misconception I had before I started repairing a dodgy fuel injection install in my KA Laser ... I thought the pressure regulator was BEFORE the fuel rail, like a traditional gas regulator (ie: CO2). Not that it was the problem with the fuel install (the surge tank was plumbed in wrong), but it was good to get it cleared up by a mechanic friend of mine.

Another slightly off topic question ... Doesnt a rising rate fuel regulator work in conjunction with a standard fuel regulator? The standard fuel regulator works at normal conditions and then the rising rate regulator restricts the flow even more once the standard fuel regulator runs out of "pinch" ?

[4door_Sleeper]

Doesnt a rising rate fuel regulator work in conjunction with a standard fuel regulator? The standard fuel regulator works at normal conditions and then the rising rate regulator restricts the flow even more once the standard fuel regulator runs out of "pinch" ?

It isnt uncommon to see the standard regulator used to control the base presure and an aftermarket reg (or other device) help with higher boost levels, however a quality regulator should be able to cope with both the higher boost and base pressures. This method of using 2 regulators is also useful if you havent got an aftermarket fuel computer as a single replacement reg may come on at a different rate and effect factory fuel settings.

[Sydneykid]

The main reason I have seen for 2 reg is it makes fitting the second reg easy. People just plumb it in the return hose. Otherwise they would have to fabricate or buy an adaptor for the fuel rail to plumb the new reg in.

Maybe it's just me, but I don't understand the logic for having 2 regs in series :confused: , the fuel pressure in the rail is governed by two things;

1. The pressure that the fuel pumps supplies. It doess't matter if I have a 60 psi regulator setting, if the fuel pump only supplies 50 psi, I will only ever get 50 psi.

2. The maximum relief setting on either of the two regulators, the other (lower setting) regulator does nothing to control the max fuel pressure.

The only reason for using 2 regs in series would be if the rising rate reg had a lower setting (at low or zero boost) than the standard reg. But that would mean I have chosen the wrong rate of rising rate regulator. :headspin:

I prefer to simply buy the right adj reg, that bolts directly onto the standard fuel rail. Nismo and Sard make them, amongst others.

Maybe someone else can explain the logic for me

[Bass Junky]

Sk

You Just Rock

[mokompri]

.... (but I would suggest you all ignore mokompri )....

gee thanx ! no need for comments like that, if ive made a mistake somewhere, im happy to be corrected, i put forward my opinion, what exactly have i said thats caused such a comment from you ? you werent too specific...

rising regs just arent my cup of tea, depending on how much boost your running if you have a 2:1 ratio rising reg, your going to see some pretty damn high pressure going through your injectors, ie 80psi+ ... if you think your injectors can handle that, then by all means go for life

but if what you want is safety, which is what hes looking for, then maybe you should reconsider

[GTR-Ben]

And when we talk about a "rising rate" regulator. They actually have a ratio as some have said... apposed to the factory ones as someone called rising rate, but are in a ratio of 1:1 with boost pressure.

A rising rate FPR will increase the fuel pressure more than a normal regulator as boost increases... which is a waste of time if you have a good fuel pump that can actually keep the fuel pressure and flow you need.

Spend your money on a decent fuel pump and injectors to supply fuel to the power you actually have. No point having 6x 1000cc injectors with your 400HP car.

Same thing goes for having 6x400c injectors in a car that has 600HP and pushing them to the limit..

A simple nismo reg will do the job for most cars, its the fuel pump and injectors that do the work here.

[4door_Sleeper]

gee thanx ! no need for comments like that, if ive made a mistake somewhere, im happy to be corrected, i put forward my opinion, what exactly have i said thats caused such a comment from you ? you werent too specific...

Sorry mokompri - dont take it personally (guess I shouldnt type after a few drinks) but there is nothing wrong with using a fuel pressure regulator within reason/ Just like boost pressure you can press them too far, but unless you change your turbo the standard injectors can be made to work well (and safely) with anything you throw at them.

And when we talk about a "rising rate" regulator. They actually have a ratio as some have said... apposed to the factory ones as someone called rising rate, but are in a ratio of 1:1 with boost pressure..

1:1 is still a ratio, as boost increases the pressure increases, so calling them a rising rateis correct. In a traditional EFI non turbo car the regulators job is to maintain a set pressure under under all conditions an as such isnt a rising rate regulator as the rail pressure remains constant.

A rising rate FPR will increase the fuel pressure more than a normal regulator as boost increases... which is a waste of time if you have a good fuel pump that can actually keep the fuel pressure and flow you need.

A $2000 fuel pump capable of 12,000psi will not increase the pressure in your fuel rail as the existing regulator will allow the fuel to flow through and hence maintain the pressure at the factory setting. The exception to this is if your pump is incapable of providing the flow required at the top end of your power curve, but if the turbo isnt upgraded (ie boost is kept below 13-14psi a standard pump in good condition will do the job. (but a GTR pump or better provides room to move as you change/upgrade the turbo in the future)

A simple nismo reg will do the job for most cars, its the fuel pump and injectors that do the work here.

Consider the complete package. A new pump is useless if the regulator is stuffed, and a new regulator is useless if the fuel pump is already struggling.

[rev210]

nothing wrong with the malpassi if it's given some shielding from heat, being sensible you try to mount it away from exhausts and things. I've heard a few mechanics bad mouth them because they put them too close to a strong heat source or the application had no room to thermally isolate it.

I'd be inclined to go the nismo unit because it's a bolt in. But, if you can get a very cheap malpassi then theres no reason to pass it up.

[mokompri]

no worries 4door, no offence taken, opinion noted, lots of people use fpr's and use them successfully, its just my way and opinion to keep stock pressure and just get bigger injectors, although i dont even have a skyline motor i have a sr20det nissan, most of the sr crowd go the bigger injector route

[4door_Sleeper]

Those with rb25DET have to fork out around $1200 for a set of (new) injectors (550cc) , its a lot more expensive than RB20 and RB26 motors. (there are also very few second hand large injectors available )

[GTR-Ben]

1:1 is still a ratio, as boost increases the pressure increases, so calling them a rising rateis correct. In a traditional EFI non turbo car the regulators job is to maintain a set pressure under under all conditions an as such isnt a rising rate regulator as the rail pressure remains constant.

A $2000 fuel pump capable of 12,000psi will not increase the pressure in your fuel rail as the existing regulator will allow the fuel to flow through and hence maintain the pressure at the factory setting. The exception to this is if your pump is incapable of providing the flow required at the top end of your power curve, but if the turbo isnt upgraded (ie boost is kept below 13-14psi a standard pump in good condition will do the job. (but a GTR pump or better provides room to move as you change/upgrade the turbo in the future)

Consider the complete package. A new pump is useless if the regulator is stuffed, and a new regulator is useless if the fuel pump is already struggling.

I think you missed my point. When I (and others) talk about a Rising Rate FPR., I am talking about one with a ratio other than 1:1 like any stock FPR on a turbo car... Yes a non turbo car has a non rising rate reg..

From that point I said there is no point getting a "rising rate FPR" (meaning with a ratio other than 1:1) as you should have the right fuel pump and injectors to meet the engines needs.. not pushing them past 100%.

So from there.. Buy a good pump, and a good 1:1 FPR like the Nismo should do the job.

I have quite often just plumbed and extra pump in the tank for a backup, and bolted on a fpr to control the pressure.

I have tried most brands including the malapassi, nismo, aem.. they all did there job.

A Rising Rate with a ratio increase is a cheap way to push the system though if you don't want to fork out for right injectors etc.

Saying that we have pushed a GTR with stock fuel system to mid 11's, this car had a Malapassi FPR..

:headspin:

[GTR-Ben]

Sorry mokompri - dont take it personally (guess I shouldnt type after a few drinks) but there is nothing wrong with using a fuel pressure regulator within reason/ Just like boost pressure you can press them too far, but unless you change your turbo the standard injectors can be made to work well (and safely) with anything you throw at them.

1:1 is still a ratio, as boost increases the pressure increases, so calling them a rising rateis correct. In a traditional EFI non turbo car the regulators job is to maintain a set pressure under under all conditions an as such isnt a rising rate regulator as the rail pressure remains constant.

A $2000 fuel pump capable of 12,000psi will not increase the pressure in your fuel rail as the existing regulator will allow the fuel to flow through and hence maintain the pressure at the factory setting. The exception to this is if your pump is incapable of providing the flow required at the top end of your power curve, but if the turbo isnt upgraded (ie boost is kept below 13-14psi a standard pump in good condition will do the job. (but a GTR pump or better provides room to move as you change/upgrade the turbo in the future)

Consider the complete package. A new pump is useless if the regulator is stuffed, and a new regulator is useless if the fuel pump is already struggling.

Yep we shouldn't post after a few drinks...

But you didn't get my point.

I (as well as others) would call a rising rate FPR one that has a ratio other than 1:1 like any stock FPR on a turbo car. Yes a non turbo car has a non rising rate reg.

Malapassi are refered to as rising rate with the ratio other than 1:1, where if you buy the Nismo stock replacement it wont be.

From there I said it is a waste of time using a "rising rate FPR" (meaning one with a ratio other than 1:1...!) when you should have the right fuel pump and injectors to supply the fuel instead of pushing the whole system. They are a good cheap alternative.. if you don't want to go the whole way and buy bigger injectors etc.

Saying that I have pushed a stock GTR with stock fuel system into mid 11's, that car ran a Malapassi FPR.

On that note... do the job right.

Get a good pump or as I have done, plump another one into the system to keep the flow up.

Get a good 1:1 Reg like the nismo unit.. and have the right size injectors for the power you are making.

got me 4 door?

[9krpm]

 

Another slightly off topic question ... Doesnt a rising rate fuel regulator work in conjunction with a standard fuel regulator? The standard fuel regulator works at normal conditions and then the rising rate regulator restricts the flow even more once the standard fuel regulator runs out of "pinch" ?

don't get confuse between a fpr and a fmu like vortech

the fmu piggy back the stock fpr and act like a adjustable fpr