Boost referenced FPR for M90?

[Mattmannz]

I am nearly finished acumulating all the bits and pieces that I need to get an M90 on my 1UZ Soarer.

The plan is to run 6psi on stock fuelling and ECU. I have access to a dyno and will be installing an Innovate wideband sensor and gauge for when I do the first power run.

Depending on who you talk to and listen to, a boost referenced fuel pressure regulator is necessary.

I want to have everything available so that when I go to put it together and do a power run I don't want to encounter any problems.

Anyone here have experience that they can share?

Cheers
Matt.

 

[JustenGT8]

Yes it is required and guess what....that's exactly what the stock FPR is no need to upgrade until making stupid power.

 

[Mattmannz]

Thanks Justin. I thought the stock regulator was only vacuum referenced - I thought there was a difference between vacuum and boost aware units?

Cheers
Matt.

 

[stevechumo]

For a reliable system, you must have the rising rate FMU, the preferred ratio is 12:1 and a high flow high pressure fuel pump. This setup is good for up to 9 psi of boost, but the safety is 8 psi and lower.

 

[Peewee]

Bullshit. Excuse the language but RRFPR are the devils equipment.

For a reliable system you need an aftermarket ecu and injectors that can easily deliver the right fuel.


For a 6psi setup there is nothing wrong with using the stock FPR and maybe an S-AFC to tweak the fuel in the upper end if needed.

 

[stevechumo]

Bullshit. Excuse the language but RRFPR are the devils equipment.

For a reliable system you need an aftermarket ecu and injectors that can easily deliver the right fuel.


For a 6psi setup there is nothing wrong with using the stock FPR and maybe an S-AFC to tweak the fuel in the upper end if needed.

That's ok. onder: I'm an open minded person. Could you explain why it's BS?

I've been running this fuel system with no problem whatsoever. I'm actually running 9 psi now. It's just not now, I ran this system on other cars with great successes. I say again "Great Success". I also see many of turbo and supercharge systems use this type of fuel enrichment. They're also smog legal. I know its disadvantage but within its limit, it's a great advantage. I've been monitoring the A/F ratio with the wideband gauge and it's just perfect. The car responds to boost just like stock. Note: I still keep the stock FPR with the RRFMU.

From what I read, the SAFC is actually a devil. It's hard to be tuned, but doable. The stock ECU will relearn after awhile and put everything back to stock. The other disadvantage that I read is this SAFC will cause the stock ECU to advance the timing. These 2 things will create a disaster when your car is under boost. The next thing is the SAFC is used to trim down the fuel injector pulses. It's mostly used when the big injectors are used, but not to increase the injector pulses to flow more. I believe the stock injectors are already set at 80% of their duty cycle, so if you increase the pulses, they might get stuck either closed or opened. Other people might have good experience with the SAFC, but I've had a bad experience with it in the past.

There're other alternatives to enrich the fuel, but I wouldn't go with the SAFC.

 

[1uzvl]

My understanding is that its a bandaid for small injectors by increasing fuel pressure to get more fuel to flow through them.The increased pressure will get more fuel through at the same injector pulse width.

The problem here is that increased pressure does also mean there has to be a restriction to get that pressure,ultimatly meaning less flow.

sounds condraticting doesnt it.

 

[stevechumo]

For example, if you compare between 2 same water hoses pumping the water out with the same pumping force. The 1st one with regular pressure will pump out whatever the pressure that comes from the source. The 2nd one that is pinched a little bit, but with greater pressure, will pump out farther and stronger than the 1st one. The concept is very similar to the fuel injectors without the FMU and with the FMU. The FMU will squirt more fuel out faster than regular FPR and it will provide enough fuel when needed.

 

[Mattmannz]

Thanks for the replies.

Stevechumo, how do you run your setup? You mention you keep the stock regulator but still use a rising rate regulator?

The way I understand it is that just increasing the base pressure will richen the mixture up across the board by effectively increasing the amount of fuel passed through the injector with the same open time. This isn't the required outcome though as with no boost there will be no additional fuel requirements so at low load situations it might run rich.

A boost referenced regulator should increase the pressure when boost rises to effectively increase the pressure only under load when enrichment is likely to be required.

My question is still whether one is required or not. The stock regulator is not adjustable so if I am going to get an aftermarket setup it would seem the boost referenced unit would be the one to go for.

I don't know how much additional pressure and volume capability the stock fuel pump has. I do know that without a wire in piggyback or full ecu replacement there aren't many options for fuel management - at low boost perhaps it's not needed.

I will find out when I dyno the car with the Innovate installed. Phase 2 is ecu, fmic, M112 and hopefully some decent numbers.

Keep the info coming.

Matt.

 

[stevechumo]

The rising rate fuel pressure regulator or called FMU only raises the fuel pressure under boost. If you don't boost, it doesn't work. If you boost and as the boost increases, it'll increase the pressure in "LINEAR" to the boost. It's actually a piggy back fuel pressure regulartor. It connects to the stock pressure regulator on the return line. Here's the diagram.

 

[Mattmannz]

Thanks Steve.

So running the RR reg after the stock reg will increase the pressure in the rail through the stock reg which still thinks it's at whatever specific pressure.

Is your RR reg adjustable? Have you dyno'd and run a wideband sensor?

Cheers
Matt.

 

[Jake Breyck]

Im with the Bullshit croud on this one..

the reason is the unreliable tune that it couses.

yes you can get more fuel though the same pulse time with a raising rate regulator, but its not accurate, you are way more accurate having static fuel pressure, and the computer changes the injector pulse to accomadate the proper fuel, this is a very accurate way of metering out fuel, doing it this way will net you more power reliably this is ofcorse with properly sized injectors so your not running an insane duty cycle to get the proper fuel.


so yes with some boost, and a raiseing rate regulator your butt dyno will feel more power and the wideband wont protest. seeming to be a win. but its not the best system.

hope this made sence.

also running the stock reg then a rasing rate regulator is just dirty. dont be getto! if you have to run an remote regulator toss out the stock one and run a line from the rail to the remote reg. its so much cleaner.

 

[Mattmannz]

The key here is that I am not doing any other fuel management, stock ecu, stock injetors, stock pump.

I understand that a RR reg might not be perfect but I am not looking for perfection, just whether it's needed a it's one of a few limited options.

Cheers
Matt.

 

[JustenGT8]

Hmmm if you aren't running any other fuel control then as 'ugly' as a rising rate reg is then it is probably needed......i can't believe people still do this but that's a whole other issue

Only way to be sure though is to check the AFs and preferably on a dyno as a bit safer than street testing. You'll see pretty quickly if you are heading lean.

Steve's setup is a good indication though that a rising rate reg will be needed to cope with the extra fuel demands.

 

[Mattmannz]

Thanks Justen.

I don't know if anyone has actually done a dyno run and checked AFR's with some boost. From the readings I have done there is a lot of fat in the stock fuel curve, perhaps there is not enough.

Anyone have a brand of RR reg and any settings that can be shared?

Cheers
Matt.

 

[ed_ma61]

not malpassi

 

[cribbj]

I have a hotshot $200 TWM regulator on my Supra, and I used a $120 Aeromotive on my 1UZ. The TWM was not stable at all initially and wouldn't hold pressure, etc., but settled down after the first week.

The Aeromotive was rock solid out of the box and hasn't given a moment of trouble, but it hasn't seen underhood temps yet.

These are both linear regulators, BTW, and will adjust fuel pressure in proportion to manifold pressure.

 

[stevechumo]

If anyone of you are against this type of fuel enrichment, you may contact www.vortechsuperchargers.com and ask for the info. This company is a reputable company and they have great products.

Remember, this fuel enrichment is only good for low boost. It's a budget setup. However, any FI kit out there using this setup isn't cheap at all.

 

[Jake Breyck]

Every reputable company that survives are a business for more then a week does things the cheap way, otherwise there kits would be insanely expensive and people wont feel inclined to plop there credit card down to jegs for a kit

its totally a cost/vs profit thing there. those are kits, which are just that a kit, designed to be bought on a whim and installed by people who don't even change there own oil.

have you ever looked at greddys turbo kits for hondas? oh my lord.

 

[stevechumo]

Oh my goodness! I still don't understand why you folks don't like this setup...LOL. Anyway, the opinion is part of science and part of personal preference.