Fuel pressure gauge question and flow capacity

Are any of you guys running a pressure gauge inside your car using an isolator? How accurate are they using one of these??
Thanks Tore

what is your fuel system ?? is it dead heading ?

Right now its dead heading but I can rework that.

Tore

I do. As long as the gauge is at the same level as the isolator, it should be dead nuts. If the gauge is higher it will read low, if it is lower than the isolator it will read higher. Mine is about 1/4 lb off on the low side, gauge is about 1 to 2" higher than the isolator. The reason it does this is the weight of the water/glycol mix in the line from the isolator to the gauge.

Thanks for the reply. But I have another fuel system question, I have a car here with a Holley Black Pump with a 5/8 dia line all the the way to the reg. Is this big enough to feed a 1050 dominator going thru the traps at 7k rpm. Its 514 ci?

Thanks Tore

Doug Rahn wrote:I do. As long as the gauge is at the same level as the isolator, it should be dead nuts. If the gauge is higher it will read low, if it is lower than the isolator it will read higher. Mine is about 1/4 lb off on the low side, gauge is about 1 to 2" higher than the isolator. The reason it does this is the weight of the water/glycol mix in the line from the isolator to the gauge.

I have one in my other car and I notice that the gauge is reading pressure when the engine is off and the pump is off. It reads pressure even after sitting long periods...like when it's put up for the winter and re-awaken in spring....I know theres no pressure then, I haven't turned the pump on yet. So that water/glycol weight could be the answer to my situation?

Sorry for the hi-jack.

My Autometer gauges in the car never go to zero when off but are accurate when on.