Is this nesasary - Toyota Nation Forum : Toyota Car and Truck Forums

almc2242 · 01-12-2005, 04:14 PM

I was wondering if the 3SFE engine needs a Fuel Rail. Since I'm changing fuel injectors from stock to 23250-46050 360cc for a turbo charge setup. BTW, this is for a 5SFE engine. Will it fit my 3SFE?

white90dx · 01-12-2005, 04:44 PM

No need for an upgraded few fuel rail unless you are going WAY over the stock power levels. Don't worry about it.

-Charlie

almc2242 · 01-12-2005, 06:54 PM

What about a Pressure regulator?

userlain · 01-12-2005, 09:35 PM

What does a Fuel Rail do?

Toysrme · 01-12-2005, 09:43 PM

It's a hollow piece of metal the fuel send hose plugs in to.
There are cut-out's along it's legnth for injectors to plug into. Generally the FPR will thread into the fuel rail opposite the fuel send, or after the last injector if their are multiple rails.

It's basically how injectors get fuel and stay mounted. The bottom of the injectors push into the manifold/head, the top is held in the same way via the fuel rail.

almc2242 · 01-13-2005, 01:34 PM

Will this add power, or more fuel? Like, lets say it will keep a large amount of gas to the injectors? I guess your answers are not clear. Come Back!

TekPhobia · 01-13-2005, 02:18 PM

What's your reasoning for adding more fuel = more power? More fuel + no increase in air = no power. You'll be hard pressed to max out the flow of the stock fuel rail for any injector you use.

But no, it won't add more fuel, the injectors will still be opening at the same duty cycle with the same amount of pressure.

-Tim

88 LE · 01-13-2005, 02:30 PM

Quote:

Originally Posted by almc2242

Will this add power, or more fuel?

Neither.

If you have a engine that creates a crazy amount of power, the stock fuel rail can become a restriction.

Basicly you need a certain size fuel rail for a certain amount of flow. If its to small it becomes a restriction.

In your case you don't have to worry about it. Your only going to 360cc injectors.

Just plug in the bigger injectors. I suggest that you get new o-rings for the injectors.

Quote:

What about a Pressure regulator?

The stock fuel rail has a fpr (fuel pressure regulator) on it.

You can buy a aftermarket adjustable one, but you have to modify your fuel rail to use it.

aosmith · 01-13-2005, 03:09 PM

can you mod the stock pressure regulator (ie clip the spring)...less risky than drilling into a fuel rail

TekPhobia · 01-13-2005, 04:41 PM

I suppose, but why? More fuel pressure = less flow. Unless you're boosting, leave the fuel pressure at its steady 38psi.

-Tim

almc2242 · 01-13-2005, 05:51 PM

I guess I have to apply the following

"Keep it Simple stupid"

automatic · 01-13-2005, 06:19 PM

You can use the FPR to tune with, have my stock unit boosted a little bit to prevent a lean condition at wide open throttle, shifts just under the fuel cut, is faster now.
The problem with upping the fuel pressure is that you can only go one way, richer, and when you've made it too rich you have to get another regulator, or lean the mixture some other way.
I used a large drift and a small ball/peen hammer to tap on the back of the regulator until it ran the way I wanted.I made adjustments while using the stock air filter with no ducting before the filter, then when I'd gone just a little too far on the mixture, I installed a foam sock(motorcycle)type air filter, and now it's just right.
The lower rpms will self tune again using feedback from the O2 sensor.

white90dx · 01-13-2005, 11:15 PM

Quote:

Originally Posted by TekPhobia

I suppose, but why? More fuel pressure = less flow. Unless you're boosting, leave the fuel pressure at its steady 38psi.

-Tim

This is incorrect... More fuel pressure = more fuel flow. Of course, in this case, he doesn't want more fuel unless he's boosting.

-Charlie

TekPhobia · 01-13-2005, 11:19 PM

Quote:

Originally Posted by white90dx

This is incorrect... More fuel pressure = more fuel flow. Of course, in this case, he doesn't want more fuel unless he's boosting.

-Charlie

No, it's correct. Fuel pumps are positive displacement pumps. More pressure = less flow (gph or lph).

-Tim

white90dx · 01-13-2005, 11:26 PM

Quote:

Originally Posted by TekPhobia

No, it's correct. Fuel pumps are positive displacement pumps. More pressure = less flow (gph or lph).

-Tim

More fuel pressure will lower the maximum amount of fuel the fuel pump can flow. That's not the issue here. If there is headroom (and there will be if he goes with a Walbro pump), there will still be extra flow past the regulator.

Extra fuel pressure at the injectors will flow more fuel for a given injector pulse time, which is my point.

-Charlie