Pros / Cons of running a RRFPR

[Nebraska_e28]

I'm running megasquirt on a stock b34 motor with 42lbs injectors. Boost is currently set at 10psi (from what I recall). Eventually I'll be in the 12-15 (maybe 20) psi range. What are the pros/cons of going with a RRFPR? I'll be changing my intake manifold setup & the stock FPR may not fit easily.

TIA!

[Duke]

I'll be in the 12-15 (maybe 20) psi

POP goes the HG!

[T_C_D]

I'm running megasquirt on a stock b34 motor with 42lbs injectors. Boost is currently set at 10psi (from what I recall). Eventually I'll be in the 12-15 (maybe 20) psi range. What are the pros/cons of going with a RRFPR? I'll be changing my intake manifold setup & the stock FPR may not fit easily.

TIA!

I bought a standalone regulator and set my fuel pressure to 4.0bar. They are inexpensive. You don't need a RRFPR like a BEGI.

[turbodan]

Pros include better fuel atomization and enabling smaller injectors to support a wider range of operating conditions. The latter becomes advantageous when you're trying to support high power levels while maintaining driveability. Huge injectors can require very short pulsewidths in the sub-2 millisecond range under high vacuum conditions. Injectors don't meter fuel as effectively and are harder to control at such short pulsewidths. By using an RRFPR you can keep smaller injectors that are better suited to running off boost and jack up the flow rate when you need it.

Not much on the cons side of the chart. Adds another component that can fail but is generally very reliable.

[Nebraska_e28]

It sounds like sticking with a standard adjustable fpr will obtain desired results. This should also make for 1 less varibale when tuning.

On a similar note, can I get away with $30 ebay unit for an adjustable fpr or do I need to invest $100+ in an AEM or Aeromotive in order to secure longevity?

[Shadow]

http://www.holley.com/512-503-5.asp

I'm a big fan of bolt on stuff.

http://www.accufabracing.com/index.php? ... 3&Itemid=7

http://www.gn1performance.com/proddetai ... letFuelReg

[turbodan]

I like the stock regulator because they're reliable and consistent. Aftermarket adjustable regulators are often lacking in those regards.

If you're not going to run a rising rate I dont see the point to using an adjustable regulator. Might as well run the stock 3 bar and size your injectors to suit the engine. The rising rate is only useful because it only increases fuel pressure under boost. I don't see the benefit to an adjustable FPR.

[Nebraska_e28]

I like the stock regulator because they're reliable and consistent. Aftermarket adjustable regulators are often lacking in those regards.

If you're not going to run a rising rate I dont see the point to using an adjustable regulator. Might as well run the stock 3 bar and size your injectors to suit the engine. The rising rate is only useful because it only increases fuel pressure under boost. I don't see the benefit to an adjustable FPR.

My inital reason for going with a remote mount FPR was (didnt necessarily have to be a rrfpr) was to make it a tad easier to run my fuel rail under a slightly modded e12 intake mani that I'm installing. I have 42# injectors & figured having the ability to run a fpr with slilghtly higher psi would be a good thing. Worth the time & investment?

http://www.holley.com/512-503-5.asp

I'm a big fan of bolt on stuff.

http://www.accufabracing.com/index.php? ... 3&Itemid=7

http://www.gn1performance.com/proddetai ... letFuelReg

Good to know, thanks!

[jim325]

I have an accufab afpr for sale. Its brand new, never used. They go for about $140 depending on who you go through. Mines cheaper :p

It fits an m30b34 manifold. I don't know much about e12's or setting it up remote mounted.

[Patrick McHugh]

I have a BEGI RRFPR i'd sell you, PM me if you're interested.

[Shadow]

I don't see the benefit to an adjustable FPR.

ok ok... now WHAT IF.
You're at 98% duty cycle
and you can't justify spending
almost 300bux for bigger injectors,
so you raise fuel pressure
to like 50psi at idle and continue to run low boost in a safer
duty?

orrrrr your injectors are so large and hard to control at idle
fuel pressure at a 25psi makes it possible???

I'm just throwing stuff out there.

[Patrick McHugh]

I don't see the benefit to an adjustable FPR.

ok ok... now WHAT IF.
You're at 98% duty cycle
and you can't justify spending
almost 300bux for bigger injectors,
so you raise fuel pressure
to like 50psi at idle and continue to run low boost in a safer
duty?

orrrrr your injectors are so large and hard to control at idle
fuel pressure at a 25psi makes it possible???

I'm just throwing stuff out there.

For the first one i'd suspect that the spray pattern would be affected. I had problems with this even at idle with the FP turned up on smaller injectors.