Fuel Vortech Supercharger injectors

Dontknowchit · Mar 13, 2025

My new base model vortech v3 supercharger kit should be here by the end of the month at 5-6psi I had planned to go with a 3 staged plan.

Stage 1 was upgraded pump to a walboro 255 and install the kit as-is with the FMU.

Stage 2 was upgraded injectors, upgraded maf, install AFR gauge, and ditch the fmu.

Stage 3 was terminator x, sensors, adjustable fpr, no maf, and a smaller pulley.

Target of 400hp at wheels or crank, no more than 10lbs boost max.

I got a good deal on 30lb injectors and a matching maf earlier than expected.

Question is can I make this a 2 stage plan now and just not use the fmu and install the new injectors and maf with the kit? Will the stock computer be fine with 30lb'ers and a maf and just 5-6lbs boost? I will not yet have a AFR monitor on the car, this is why I'm concerned.

Noobz347 · Mar 13, 2025

gkomo · Mar 13, 2025

We got the same plan, except I only have stage 1 and 2. Although my stage 2 is also with the addition of my TFS heads and an engine rebuild of some kind.

Mines also with my Novi 1220SL. Gonna start the S/C install this year sometime… just completed my walboro 255lph pump install.

Dontknowchit · Mar 13, 2025

Noobz347 said:
No

So I'll still go lean with 30lb injectors at 5-6psi without the fmu? Is that what you are saying?

Dontknowchit · Mar 13, 2025

gkomo said:
We got the same plan, except I only have stage 1 and 2. Although my stage 2 is also with the addition of my TFS heads and an engine rebuild of some kind.

Mines also with my Novi 1220SL. Gonna start the S/C install this year sometime… just completed my walboro 255lph pump install.

You also running stock ecu?

gkomo · Mar 13, 2025

Dontknowchit said:
You also running stock ecu?

That’s the plan. I don’t see myself doing some standalone management system. Probably quarterhorse down the road but plan on stock for a while.

Noobz347 · Mar 13, 2025

Dontknowchit said:
So I'll still go lean with 30lb injectors at 5-6psi without the fmu? Is that what you are saying?

At minimum, you would need to be able to monitor your AFR.

A "calibrated mass air meter" is not what many think that it is. All it can do is skew mass air readings in order to "fool" a stock computer to spray an approximation of fuel with a larger injector. Of course, the same MAF on two different induction setups is going to change.

This puts you into a situation where the car will be lean at some power setting and fat at others. All it takes is one good lean "Pop" to send the entire combo straight to hell.

You have a system that currently works, correct? If so, keep what you got until you are ready to tune. Don't be in a hurry to start tossing parts at it.

AeroCoupe · Mar 13, 2025

One option is to install the 30 lb/hr injectors and sell the MAF. Install a 1998-2000 GT MAF and get a tune with a chip.

Dontknowchit · Mar 13, 2025

Noobz347 said:
At minimum, you would need to be able to monitor your AFR.

A "calibrated mass air meter" is not what many think that it is. All it can do is skew mass air readings in order to "fool" a stock computer to spray an approximation of fuel with a larger injector. Of course, the same MAF on two different induction setups is going to change.

This puts you into a situation where the car will be lean at some power setting and fat at others. All it takes is one good lean "Pop" to send the entire combo straight to hell.

You have a system that currently works, correct? If so, keep what you got until you are ready to tune. Don't be in a hurry to start tossing parts at it.

So then are you saying the vortech kit, as sits is also to be avoided before a AFR is installed?

Dontknowchit · Mar 13, 2025

AeroCoupe said:
One option is to install the 30 lb/hr injectors and sell the MAF. Install a 1998-2000 GT MAF and get a tune with a chip.

My end goal is a terminator x or a megasquirt, so I'm not sure I'd be ok spending on a tune till I had that investment made. At that point the maf goes away.

AeroCoupe · Mar 13, 2025

Then stack the parts and wait until you have everything. Do it once and do it right.

Dontknowchit · Mar 13, 2025

I was searching on the vortech site to find any recommendations, I found this chart on the calibration discs page. I figured I'd post it here in case this came up again:

Looks without any active fuel management from a more advanced computer, they intend for you to use a FMU the whole time.

The natural follow up question is that if 30lb injectors can support ~350hp in a n/a application is there an additional "differential" you have to add to that for a boosted application? Like once I have all the necessary supporting parts, will I still need to upsize? I may just flip what I bought and get a AFR guage instead to be safe. I thought I had gathered all the info I needed before I made a purchase but I was clearly missing some important bits. If these injectors won't work final state, and they are not needed in the base kit, I might as well sell them and get the AFR guage.

gkomo · Mar 13, 2025

Is your engine otherwise stock now?

Dontknowchit · Mar 14, 2025

gkomo said:
Is your engine otherwise stock now?

ish, yes. Stock heads/cam/bottom end. Has the edelbrock performer intake and a 75mm TB to a CAI. Has the lincoln maf swap (still for 19lbs)

AeroCoupe · Mar 14, 2025

So in a boosted application rough numbers are as follows:

350hp = 33 lb/hr
400hp = 38 lb/hr
450hp = 42 lb/hr
500hp = 47 lb/hr

This is calculated at 80% injector duty and with gasoline.

Support tools | FuelTech Fuel Injector Calculator

FuelTech offers a Fuel Injector Calculator to assist racers and builders select the proper fuel injector sizing. Picking the proper fuel injector size is critical for performance and tuning control. All FuelTech engine management systems are capable of driving stock injectors to massive 850...

www.fueltech.net

I ran 42 lb/hr injectors on a NA 306 making 350+ fwhp with zero issues and currently use them on a 331 making 460+ fwhp so yes you can run bigger than you need to set up for future need.

from6to8 · Mar 8, 2026

AeroCoupe said:
So in a boosted application rough numbers are as follows:

350hp = 33 lb/hr
400hp = 38 lb/hr
450hp = 42 lb/hr
500hp = 47 lb/hr

This is calculated at 80% injector duty and with gasoline.

Support tools | FuelTech Fuel Injector Calculator

FuelTech offers a Fuel Injector Calculator to assist racers and builders select the proper fuel injector sizing. Picking the proper fuel injector size is critical for performance and tuning control. All FuelTech engine management systems are capable of driving stock injectors to massive 850...

www.fueltech.net

I ran 42 lb/hr injectors on a NA 306 making 350+ fwhp with zero issues and currently use them on a 331 making 460+ fwhp so yes you can run bigger than you need to set up for future need.

what fp do you have again on the 331? I'm going to go back to our talks in a thread about your fp and injectors and being at a certain duty cycle. I just updated my 94 Cobra project thread by the way on a question about my fp after a chip adjustment....

AeroCoupe · Mar 8, 2026

The tuner turned mine up to 46 psi. This was a combination of dirty injectors and not enough fuel system. Will turn it back down to 39 psi when I get the MSPnP installed.

from6to8 · Mar 8, 2026

AeroCoupe said:
The tuner turned mine up to 46 psi. This was a combination of dirty injectors and not enough fuel system. Will turn it back down to 39 psi when I get the MSPnP installed.

i meant what fuel pump? i know on your 306 or 331 you said something about being maxed out on injector or pump or something. So turning down your fp won't affect the tune?

from6to8 · Mar 8, 2026

oh i see you're not going to turn it down until you get the msp&p which I'm assuming is a megasquirt ecu?

check out my update to my 94 Cobra thread and reply when u get time. Thanks

AeroCoupe · Mar 8, 2026

Just did. I’m running a 255 lph Walbro.

Fuel Vortech Supercharger injectors

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Stangnet Facilities Maint Tech... Er... Janitor

now i can hopefully expect to receive the shaft

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now i can hopefully expect to receive the shaft

Stangnet Facilities Maint Tech... Er... Janitor

lube between the nut and the face. I know my lubes

Active Member

Active Member

lube between the nut and the face. I know my lubes

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now i can hopefully expect to receive the shaft

Active Member

lube between the nut and the face. I know my lubes

There's suction so I used that end O_O

lube between the nut and the face. I know my lubes

There's suction so I used that end O_O

There's suction so I used that end O_O

lube between the nut and the face. I know my lubes

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