KyleF

How are you guys testing fuel pressure at higher RPMs? Ongoing tuning and tweaking, I am wondering about my fuel pressure under load over 3K RPMs.

I know I can get rich/lean from the computer, but I am interested in it for more than just that. I would like to know how much my fuel pressure goes up with boost.

Kingtal0n

In LS applications
It is fairly simple to install a typical 0-5v pressure sensor
and connect to the ECU using an un-used wire (such as EGR Input)

In other applications. I Would think something similar, a pressure sensor and computer with which to log the data.
If you don't have anyway to log w/ computer there are myriad ways around this. For example DATAQ sells a small serial device which allows logging over time, and i think they send free samples of their stuff. Or maybe its $5.

Anyways. I bet for less than $20 you could set something up, if you found the right pressure sensor.

The old fashioned way to do this is to buy a fuel pressure gauge and try to watch it as you approach redline.
Not a bad thing on a dynometer where the vehicle isn't moving and you have extra eyes.

As an aside. It is highly recommended to log oil pressure this way (using a sensor and computer) because oil pressure will often drop when you are 'not looking at the gauge' such as during hard accel/braking or cornering.

Orr89RocZ

iTrader: (20)

What is your setup and ecm?

on stock tpi ecms that dont have any pressure inputs, i used mechanical gauges and watched them on dyno or tapped to windshield lol. Crude but works

If the regulator is good and has the capability to handle fuel capacity then it should rise with boost to whatever ratio you use, like most are 1:1. Seen some 2:1

if you use an fmu the rise will be higher.

You could get a 0-100 psi sensor and run the signal wire to a volt meter as well and watch that

Kingtal0n

these guys DataQ
https://www.dataq.com/data-acquisition/starter-kits/

have starter kits which come with everything to log a signal,
their cheapest starter kit you can log up 4 sensors at 20khz(way too fast, unneeded speed)

KyleF

Well guys, I don't have a dyno. This will have to be done on the road... but what I do have is a son with an extra set of eyes. So I got that covered.

My gauge's hose isn't long enough to reach the windshield. that was my first thought.

All the computer stuff would probably work, but dang that seems to be excessive. Might have to go that route eventually. I need to get some log data and review, I am just anticipating that I have a lean condition above 3500RPMs. Getting ready to have to diagnose it. I don't trust the narrow band all that much, but it seems to want to hang to the lean side and I don't think he car is making the power it should. Or is it perception since my other cars have more gears and more power? Working to get data to verify.

Kingtal0n

The thing with multi-data logger is you can use it for fuel pressure, oil pressure, crankcase pressure, manifold pressure, throttle position, i.e. majority of vehicle sensors can be logged.
Useful if you do not already have a data-logging computer. Mainly for oil pressure because there are some very fast carb cars that launch and oil pressure drops... nobody can see that. Should be able to make something like this for $10-$20 also as a temporary resort. For example it should be fairly easy to light an LED when oil pressure drops below X amount using any 0-5v oil pressure sensor and the proper circuit. Lets see, zener diodes, resistors, transistors, basic components with an LED and some capacitors sounds like most of it.

Somebody here would be very happy to help also
https://www.edaboard.com/forumdispla...onic-Questions

The components are maybe $5-$10 for like 10 packs of each thing to make something simple like an LED that lights at specific voltage.