Fuel upgrades, when and what?

[diss7]

I've searched and searched and can't find a definite answer on this.

Lets just focus on pump fuel.

At what point is the stock fuel system in sufficient? It appears to be 260-270whp?

Then you get a better pump, or port injectors? And then what does that get you to?

I'm trying to work out what I need for 300whp, so say fueling for 340whp to have some redundancy there.

I don't want to buy parts I don't need. But equally, I really don't want to get on the dyno and find out I need something.

Ta.

[ecko04]

You're going to get so many varying answers here and it's nearly impossible to compare one setup vs another.

What I'd do is ask your tuner. They all have different experience, differing styles and have preferences.

Some tuners try to tune off port injectors only (big no-no) so they'll inevitably run out of fuel or max the duty cycle far sooner than those who tune for both DI & PI.

The rule of thumb I follow, if it ain't broke, don't fix it.

I wouldn't touch the fuel pump unless you have to.

The factory pump, depending on tuning style, is good in excess of your stated goal. It's also one less variable that your tuner will be concerned with if there's a fueling issue (i.e. is it installed properly? Did he cut the housing for the pressure regulator? Did he use 1, 2 or 3 o-rings? Is the pump defective?).

Not to mention fuel pump installation on this platform requires quite a bit of permanent fuel canister modification. If done wrong, you can see your fuel pressure fall off a cliff and start leaning out. If done right, a fuel pump alone shouldn't require a tune.

Injectors will require scaling and thus require a tune. Since the JDL system doesn't come with a basemap, I don't think, make sure you discuss this with your tuner. The car will run like shit until the scaling is done.

[jamesm]

just get a drop-in pump and some injectors, doesn't matter what size at that level. smaller injectors are usually easier to tune, but that's not even universal.

the stuff is relatively cheap compared to whatever you're installing that makes you require them, so no reason not to just get it out of the way and be done with it. it's always best to have a bit of overhead when it comes to these things.

and if you're tuner is disabling the di, you need to find a new tuner . it's one of the best things about this car, and a huge benefit all around. disabling it is only out of laziness or an inability to calibrate things properly, there is no upside to disabling it, and many downsides.

[lexusb3]

550s and a denzo pump and call it a day!

[Ironsquid]

To answer this the OP must understand the reason why the stock fuel system has limits or rather why you need more than this limit at some undefined power level.

Simply put we use "excess" fuel, meaning more than we need for combustion, to instantly supercool the air charge in the exhaust gases to lower chamber heat and thus pressure. You "could" achieve this with water vapor without the need for extra fuel. It just happens to be easier to use excess fuel to do it. Some other methods include methanol injection for the same reason only to greater effect.

So technically speaking you cant really put a dyno number on the stock fuel system. :p

For the common person though 270-300 is about the limitation wherr injector duty cycle reaches the max.

Of course I could always be wrong and silly.

[King Tut]

Ultimately it depends on how much your tuner wants to lean on the DI system. There have been cars that have made 300 whp on the factory pump and injectors.

[jamesm]

true there are ways to extend the limitations of the stock system by bumping up di pressure targets (from 20mpa <~2900psi> to 22-23mpa <~3200-3300psi>) but it's not a very wise move. or maybe it is, who knows? but that's the point, we have no idea what long term effect that has on the mechanical fuel pump.

the safe bet is to just buy a set of injectors and a pump. they're cheap.

[ptuning]

You absolutely, positively, without a shadow of a doubt, DO NOT need to bother with an upgraded fuel pump if you simply upgrade the port injectors and are running on 93 pump gas. There is no amount of power that anyone's turbo system can put out on 93 pump gas that would require more than a set of upgraded port injectors.

Drop in a set of FIC 770cc or DW 700cc injectors and you'll be fine. If your tuner knows what he is doing, he'll set up the right amount of DI/PI as well as a few other parameters in the ROM to allow for the best tune without running out of fuel.

This "need" for an upgraded fuel pump on pump gas probably came from early tuners attempting to run pure PI with their tunes, which is simply crazy. You'll want to keep DI running under boost too, if you like to keep your engine together.

During dyno testing of our turbo system, we've made it to 320whp on our Dyno Dynamics dyno on 93 pump and 400whp on WMI injection using FIC 770cc injectors and an unopened stock fuel assembly/pump. Also, the 50/50 WMI mix did not contribute to 75whp worth of fuel either. I would guess that it would be possible to achieve upwards of 375whp with the stock fuel pump on race gas.

Hope this info helps save people 2-3 hours of labor, fuel on their clothes, and a hundred and something dollars.

- Toan

[jamesm]

Originally Posted by ptuning

You absolutely, positively, without a shadow of a doubt, DO NOT need to bother with an upgraded fuel pump if you simply upgrade the port injectors and are running on 93 pump gas. There is no amount of power that anyone's turbo system can put out on 93 pump gas that would require more than a set of upgraded port injectors.

Drop in a set of FIC 770cc or DW 700cc injectors and you'll be fine. If your tuner knows what he is doing, he'll set up the right amount of DI/PI as well as a few other parameters in the ROM to allow for the best tune without running out of fuel.

This "need" for an upgraded fuel pump on pump gas probably came from early tuners attempting to run pure PI with their tunes, which is simply crazy. You'll want to keep DI running under boost too, if you like to keep your engine together.

During dyno testing of our turbo system, we've made it to 320whp on our Dyno Dynamics dyno on 93 pump and 400whp on WMI injection using FIC 770cc injectors and an unopened stock fuel assembly/pump. Also, the 50/50 WMI mix did not contribute to 75whp worth of fuel either. I would guess that it would be possible to achieve upwards of 375whp with the stock fuel pump on race gas.

Hope this info helps save people 2-3 hours of labor, fuel on their clothes, and a hundred and something dollars.

- Toan

i wish i would've known that when i bought the POS dw pump. there has been much debate over how far the stock pump can go... nice to hear it from a reputable source that the limits are high enough that most won't have to bother with it.

[diss7]

Originally Posted by ptuning

You absolutely, positively, without a shadow of a doubt, DO NOT need to bother with an upgraded fuel pump if you simply upgrade the port injectors and are running on 93 pump gas. There is no amount of power that anyone's turbo system can put out on 93 pump gas that would require more than a set of upgraded port injectors.

Drop in a set of FIC 770cc or DW 700cc injectors and you'll be fine. If your tuner knows what he is doing, he'll set up the right amount of DI/PI as well as a few other parameters in the ROM to allow for the best tune without running out of fuel.

This "need" for an upgraded fuel pump on pump gas probably came from early tuners attempting to run pure PI with their tunes, which is simply crazy. You'll want to keep DI running under boost too, if you like to keep your engine together.

During dyno testing of our turbo system, we've made it to 320whp on our Dyno Dynamics dyno on 93 pump and 400whp on WMI injection using FIC 770cc injectors and an unopened stock fuel assembly/pump. Also, the 50/50 WMI mix did not contribute to 75whp worth of fuel either. I would guess that it would be possible to achieve upwards of 375whp with the stock fuel pump on race gas.

Hope this info helps save people 2-3 hours of labor, fuel on their clothes, and a hundred and something dollars.

- Toan

That's what I was hoping to hear.

Thanks.