Rising Rate Fuel Regulator on a 1UZ?

[Celsiorous]

Hi,

Just wondering if it is possible to setup a FMU on a 1UZ and if so whether anyone has done it?
Would it be worthwhile with headers, catback exhaust setup and a coldair box?

Cheers

 

[Peewee]

Ummm, are you turbo or not?

RRFPR are only to be used on cars with NA computers running turbo's, and a cheap piggyback (if one at all).

Under no other circumstances are they good.

 

[Celsiorous]

My Celsior is NA, i dont know much about FMU's but I know of several people running them on NA 4 cylinders. I was just thinking that after some intake and exhaust mods it may want/need more fuel. Is the reason FMU's are not applicable becuase the oxygen sensors etc will tell the ECU that there is too much fuel and change the injector load?

 

[Peewee]

If FMU mean Fuel Management Unit, or a fancy word for a piggyback fuel computer, then yes, that will help.

However a Rising rate Fuel Pressure Regulator is unwanted.

 

[Celsiorous]

Sorry mate by FMU I mean Rising Rate Fuel Regulator, I dont know why people call them that but thats what I have always heard people refer to them as.

 

[Peewee]

Must be a brand name.

But, its useless.
In order to raise the full pressure, it needs boost.
No boost means it does nothing.

A standard fuel pressure regulator has a 1:1 regulator in it.
Therefore for every psi of boost, it raises the fuel pressure one psi.
ie, standard fuel pressure at 0psi boost is 42psi. At 5psi boost it will be 47psi.

With a RRFPR you have a ratio of 1.5:1 or 2:1 (it can be set)
Therefore with 5psi of boost you will increase the fuel pressure by 1.5x5 or 2x5psi.
5psi boost on a 2:1 regulator is 10psi increase, or 52psi total.

Without boost there is NO increase in fuel pressure.

Now, if the FMU is an ADJUSTABLE fuel pressure regulator, then you can adjust the fuel pressure to what you want with a screw.

This however is not needed on a Toyota as they run fairly rich from factory.
After you do all the mods, get a dyno done and have a look at the air/fuel ratio output.

Unless its going above 13:1 (say 13.5 or greater) under full throttle then leave.

 

[Celsiorous]

ahhhh I see, thanks for all the information peewee

 

[Peewee]

This is the important bit of this whole page

After you do all the mods, get a dyno done and have a look at the air/fuel ratio output.

Unless its going above 13:1 (say 13.5 or greater) under full throttle then leave it as is.

 

[Lextreme II]

Like the above moderators had stated its useless in NA application. U can read more about FMU. http://www.lextreme.com/FMU.htm

 

[SCV8]

For N/A , the stock regulator is probably fine; it works on the same principle as the aftermarket ones, can be adjusted to go richer(but not leaner) by raising the fuel pressure, but you won't likely need it unless you have additional ignition timing, headwork as I have done.