Fuel Pressure regulator, what do you guys recommend?

[TERRA Operative]

I'm looking at installing a rising-rate FPR into my AE101 4AGZE. It's currently at 140-150Hp at the wheels with bigger throttle body etc, with more power to come. (Lots of head work etc).

What FPR do you guys recommend? I have a Turbosmart adapter, so I can remote mount the thing if need be.
Oh, a fuel pressure gauge fitting on the FPR (or one already fitted) would be nice too.

Thanks.

[al167]

i use a malpasi 2:1 rising rate fuel pressure reg.(for every 1 psi of boost you get 2psi fuel pressure increase) you can get it in 1:1 also
it works fine and has been in the car for 4 years. its about $150 and has a fuel pressure guage port. the ports are 1/8 npt
there are heaps of brands to choose from, the main difference between them is the:

flow: if you are running twin pumps you would go for a higher flow model with 1/2 npt or so ports so that at idle your fuel pressure will still be 40 psi by letting the high volume of unused fuel back to tank

fuel types: some can run methanol/ ethanol

good luck

[TERRA Operative]

Yea, I'm tossing up between Sard, Malpassi and Turbosmart. It'll probably come down to what I can get for trade price though.....

Just wondering what people use on the 4A engines and their results.


What's the go with selecting 1:1 or 2:1 ratios etc?

[Cuzzo]

using a malpassi on the 4agte.

it works thats all i can see.. not a tuner so havent played with it.

I guess the main reason for it is to give extra pressure to the injectors...

[IN 05 NT]

im using sard, seems to be the one that everyone recomended to me.

[Hibba]

We use sard ones on pretty much everything at work. We've had to many problems with pressure fluctuations on Malpassi reg's and the diaphragms leaking

[TERRA Operative]

I was leaning toward the Sard unit. Think I might go that way.

What's the go with rising rate, 2:1, 1:1 etc etc?

[Norbie]

Stay away from Malpassi, I've heard from way too many people that they're hopeless, ie pressure fluctuates seemingly at random. Sard is good, I have one and it's rock solid at all times.

1:1 = linear rate FPR, same as factory - this adjusts fuel pressure to match manifold pressure.

2:1 = rising rate FPR, this increases fuel pressure at twice the rate of manifold pressure.

[thechuckster]

rising rate FPR's make tuning quite difficult - you want the computer to control with what amount fuel gets to the engine.

If you start increasing fuel pressure in a non-linear relationship to manifold pressure, you loose fuelling resolution when on boost.

Instead of tracking manifold pressure in a 1:1 relationship (like a factory or SARD or Aeromotive unit would), a RRFPR increases pressure at a higher proportion as indicated by the ration so for every 1psi of boost, a 1:2 RRFPR would increase fuel pressure by 2psi - the downside of this is that at 15psi of boost, the rail is now being held up 30psi ABOVE the static pressure of 38psi, e.g. a total of 68psi.

And most fuel pumps don't like heading into stratospheric levels of pressure - and they also start to flow less fuel.

You have to remember that with the engine off and the manifold pressure the same as atmospheric pressure (14.7 psi above absolute vacuum), the fuel rail is already at 38-40psi depending on regulator or adjustment. When the engine is not on boost, that pressure is reduced accordingly, and in boost it increases.

Also, 4AGZE injectors should flow 365cc/min - and should make roughly 235-240bhp @ flywheel if run up to 80-85% duty cycle. That would at around the factory static pressure.

fwiw: I use a 2nd-hand SARD that used to be in this 1JZ drag car - it's a 1:1 rate regulator. It was much easier to tune than a Malpassi RRFPR that also had poor/variable flow rates, My limited experience with the Malpassi was that they're good for turbo carbi's (low pressure, high flow) but shit for EFI.

[TERRA Operative]

Excellent info, rep will be dished out to all.

Looks like a Sard 1:1 Adjustable FPR for me then.

[Draven]

yeps, Sard are the goods
depending on uegency, Nengun are probably cheaper than trade price in Aus (that's where I got mine from)

[Cuzzo]

Well i had my rolla on the dyno last night and the malpassi was bouncing like a rev limiter.

Quite gay.

What prices for the sard 1:1 unit?

[TERRA Operative]

Well, nengun appear to have a special on the Sard units at the moment. They have two to choose from, a street version (I assume) and a 'Type-RJ' version. Links below.

http://www.nengun.com/sard/fuel-regulator-8mm-nipple
http://www.nengun.com/sard/fuel-regulator-type-rj

Any recommendations as to which one? I think the first link will suit my needs, but what are the benefits of the Type-RJ unit?
I plan to run a max of 15psi, so there won't a huge amount of boost pressure there.

[Draven]

I got the typre RJ (altho it wasn't called taht when I bought it) - but after doing some research that was completely unneccesary, unless you've got a completely nuts setup

[Norbie]

Yeah I got the Type RJ one as well, but as above I think it's overkill for my needs (approx 500rwhp). The smaller/cheaper one should be adequate for practically any streeter.