Toyota GR86, 86, FR-S and Subaru BRZ Forum & Owners Community - FT86CLUB - What Power Level for Upgraded Fuel Pump

- Engine, Exhaust, Transmission (https://www.ft86club.com/forums/forumdisplay.php?f=8)

- - What Power Level for Upgraded Fuel Pump - Pump Gas (https://www.ft86club.com/forums/showthread.php?t=139762)

What Power Level for Upgraded Fuel Pump - Pump Gas

As the title states, at what point were you forced to upgrade your fuel pump FOR PUMP GAS? I'm planning on 350-400whp on my rebuild and made about 330whp and 250wtq on 93 with 440cc injectors and stock pump on stock engine.
I'm lowering compression to 10:1 so I'm expecting that it'll take more fuel to get me there than before.

If you're going to comment, please don't give reason without evidence; I do not want to tamper with the stock fuel system if I can avoid it.
Let me know if you changed because of fuel pressure drop, or at the advisory of your tuner.
Please also include your octane rating and fuel injector size.

We will be dyno tuning the car so it's not like I'll run at risk and the tuner will wait for a datalog, we'll monitor rail pressure regardless.

Thank you in advance!

I made just shy of 400 whp on E85 with the stock fuel pump + 700cc injectors. E85 inherently requires a lot more fuel, so even with the compression drop I don't expect you to need an upgraded fuel pump running exclusively pump gas. If your tuner does notice insufficient fuel pressure in datalogs, it's a fairly quick process to install a fuel pump.

I'm not sure if 440cc injectors would continue to be sufficient given the increased fuel demand, but I don't know enough to be certain.

400hp on e85 sounds pretty far north of where tuners like you to replace your pump. I would certainly consider it. It's not hard

Sent from my ONEPLUS A5010 using Tapatalk

Bumping this to see if I can get more input. This will be specific to pump gas, no e85; somehow we don't have e85 in Vermont. I know, go figure.

I will obviously be upgrading my injectors, probably to ID1050X for their tunability

Quote:

Originally Posted by DarkPira7e (Post 3352805)

Well if the guy above made 400 on e85 then you should be fine on pump gas.

A new pump isn't exactly expensive.

Sent from my ONEPLUS A5010 using Tapatalk

Quote:

Originally Posted by Ashikabi (Post 3352867)

Well if the guy above made 400 on e85 then you should be fine on pump gas.

A new pump isn't exactly expensive.

Sent from my ONEPLUS A5010 using Tapatalk

It's not the expense, it's that I don't want to complicate something that has been working. I'll accept limiting my power before I replace the fuel pump. I'm just a stubborn ass

Quote:

Originally Posted by DarkPira7e (Post 3352869)

It's not the expense, it's that I don't want to complicate something that has been working. I'll accept limiting my power before I replace the fuel pump. I'm just a stubborn ass

So you're willing to modify anything else to make the power you desire but not the fuel pump?

Sent from my ONEPLUS A5010 using Tapatalk

Quote:

Originally Posted by Ashikabi (Post 3352870)

So you're willing to modify anything else to make the power you desire but not the fuel pump?

Sent from my ONEPLUS A5010 using Tapatalk

Not anything else. I won't replace my crash bar, I won't replace stock style struts with coilovers for clearance with larger wheels, I won't replace my throttle body or intake manifold, I won't remove my a/c components, I won't get slim fans. I'm sure there's more I'm not thinking of.

Aside getting a new engine block, (which is not something I'm doing because bi just wanted to) the only things I've changed are engine mounts, and the fuel injectors. Injectors are easily accessed and replaced within minutes, and mounts only cause noise.

I'm not disagreeing that I'm crazy. But I've replaced fuel pumps in several cars that had aftermarket pumps. I've had to disfigure in-tank pumps to accommodate the new pumps.
I just have had the worst times with aftermarket fuel systems and will avoid modifying -anything- I don't have to.

If I can only run 300whp, I'm happy with that. If I make it to 400, that's good too. The purpose of this inquiry was to help ungrey an area there there's not a lot of evidence with that's posted on this forum.

Is there such an issue with not replacing things that don't need to be replaced that aren't easily accessible? I'm replacing all of my pulleys with OEM replacements, I am replacing the serpentine belt, I am having my heads hot tanked and cleaned, I am replacing my plugs for the 3rd time in 500 miles, I am replacing all 4 OCVs. This build is about quality and longevity before power. But if we can document generally on pump gas where the stock fuel pump can't keep up, I'd like to capture that data.

My plan is as follows, whether I get responses or not-

If I run out of fuel, I'll document it here :)
If I don't run out of fuel, I'll document it here :)

I'm not trying to come across as argumentative; I just want you to have a thorough understanding of what my goal is and hopefully it'll help you see why I'm leaving the fuel pump alone. And to help others who may search "BRZ fuel pump limit" in Google, to have their answer quickly and passively.

Quote:

Originally Posted by DarkPira7e (Post 3352887)

Not anything else. I won't replace my crash bar, I won't replace stock style struts with coilovers for clearance with larger wheels, I won't replace my throttle body or intake manifold, I won't remove my a/c components, I won't get slim fans. I'm sure there's more I'm not thinking of.

Aside getting a new engine block, (which is not something I'm doing because bi just wanted to) the only things I've changed are engine mounts, and the fuel injectors. Injectors are easily accessed and replaced within minutes, and mounts only cause noise.

I'm not disagreeing that I'm crazy. But I've replaced fuel pumps in several cars that had aftermarket pumps. I've had to disfigure in-tank pumps to accommodate the new pumps.

I just have had the worst times with aftermarket fuel systems and will avoid modifying -anything- I don't have to.

If I can only run 300whp, I'm happy with that. If I make it to 400, that's good too. The purpose of this inquiry was to help ungrey an area there there's not a lot of evidence with that's posted on this forum.

Is there such an issue with not replacing things that don't need to be replaced that aren't easily accessible? I'm replacing all of my pulleys with OEM replacements, I am replacing the serpentine belt, I am having my heads hot tanked and cleaned, I am replacing my plugs for the 3rd time in 500 miles, I am replacing all 4 OCVs. This build is about quality and longevity before power. But if we can document generally on pump gas where the stock fuel pump can't keep up, I'd like to capture that data.

My plan is as follows, whether I get responses or not-

If I run out of fuel, I'll document it here :)

If I don't run out of fuel, I'll document it here :)

I'm not trying to come across as argumentative; I just want you to have a thorough understanding of what my goal is and hopefully it'll help you see why I'm leaving the fuel pump alone. And to help others who may search "BRZ fuel pump limit" in Google, to have their answer quickly and passively.

You know there are aftermarket pumps that fit the stock hanger right? I have a DW65C and it for just fine. There are higher flow ones too. Not difficult to replace either.

Good luck on your journey. I hope you find the information you're looking for

Sent from my ONEPLUS A5010 using Tapatalk

I only made 160whp on stock pump stock injectors.

Just do pump and injectors now. Peace of mind and you know you will have plenty of headroom.

Sent from my GM1915 using Tapatalk