RoTARY-ReX

I am looking for info on where i can purchase a guage that can tell me how much pressure is going through my Holley Regualtor. I have seen a few of you with this application. How does it work, do these guages read correctly? Thanks

MarkPerez

I have a machinal guage, it's small,goes from 0-20 lbs.
bought it from kragan auto parts. cheap too. I installed it in-line on the (in) fuel line. had to make something for it to screw in to. used brass, w/fittings, tapped a hole for the guage, easy. it reads around 4 lbs. I'm 12a w/nikki.

SilverRocket

The majority of regular 1-15psi automotive FP guages are so inaccurate in the ~4psi range that they are essentially useless for tuning purposes, they're just toys. I've personally tried 3 different well known brands of guages and found them all useless.

Now, depending on what kind of carb you have and how serious you are, you may or may not want to go to the trouble of acquiring an accurate fuel pressure guage to tune (I did not find it necessary for my street Dellorto for instance, but a racer running a modded Nikki would likely want one).

Some research will be needed to find an accurate guage in the 4psi range. It likely will not be a normal guage you can buy in any autoparts store. Maybe a industrial pressure guage for example? Yaw supposedly has a source for decent guages (not automotive market), but good luck trying to contact him to figure it out - details might be on his webpage, I can't recall off the top of my head.

What you want is a quality, well calibrated guage, with your target fuel pressure in the middle of the guage's range where it will be most accurate. If you find one, post it up, because we will glad to know where they are available.

Rx7carl

Go look on mazspeed for a similar thread, I just posted a link to surplus gauges.

pillage6

I broke mine the first day I got it.

It only reads up to 15psi, and I am assuming the regulator goes alot higher under boost.

RoTARY-ReX

This is exactly the things i needed to know. I assumed all guages would be off. I am running a Weber 45DCOE. Maby its not all that critical to run a guage. I just thought it might be helpful to know if i am exactly at 4.5psi. Thanks for all the help.

damon

I got a 0-8 psi liguid filled gauge (cost $30) and as long as the outside temp is above 70 deg f it is tested accurate to .0125 psi. I will look at what brand it is and post tomarrow.

Wankelguy

You need to be able to view the pressure guage while the motor is under load conditions to tell what's really going on. The common method is to run a rather long hose to the tee fitting and then then tape the guage to the windshield so you can see it while you drive.

specRX7_22

my dad bought his from Yaw. it seems to be accurate. i forget the exact configuration of the hoses but we used boat fitting (the ones where you can switch portable gas tanks) and we just attach the guage to the end of this hose to get the reading, then just pull it off and cap it when were done. its real simple.