I hooked up an after market boost gauge over the weekend and had a question.

I found the line that runs under the dash for the stock boost gauge and just ran a T connector off of that in order to hook up the after market gauge. So both the stock and after market gauge now works. My question is, do you think the gauge is not going to be as accurate because I have both gauges hooked up to one line? The gauges run off pressure and seeing as I have two lines hooked up it would make me think that the pressure running though the line now gets split into two and is not going to be as strong.

I am going to hook up the after market gauge only after work today but was looking to get some input from other on the board.

BTW Thank you very much speeding Bob for all your help. I finally got around to doing the Voltage, and boost gauge this weekend. At some point I will get around to doing the fuel pressure gauge.

Thanks for any help

John

 

I don't think that should matter because it will "fill" the line with the appropriate boost. For example if you lengthened the line, it wouldn't mean that you would need the more boost to fill the rest of the line to get the right pressure. Hope my example helps.

 

John,

No Probelmo!! I'm glad everything worked out.

I've run both gauges since my install and (in ok air) noticed the Eaton is cramming 12 to 13 lbs of Boooost at 5600 RPM into the motor. YES!! How you say?, a PSP lower pulley made the difference.

You do have a point though. Guess I'll unplug and cap off the stocker side of the line and (my favorite part) go test it out....

Bob

 

I had the same question for when I install mine. I am gonna put a plug in it so I don't have both gauges working at the same time. Cut the stock gauge completely out of the equation.

 

It would make a difference if you were splitting flows but both lines deadhead at the gauges and there is no flow so it will make no difference whatsoever.

 

What aftermarket gauges are you guys using? I have been thinking about installing one since my factory gauge is pegged allot....thanks Jeff

 

Just thought I would chime in and ask what boost both your guages have been reading.

If you have both hooked up what does the stock say in comparison to the aftermarket and which aftermarket did you get?

Thanks
Paul

 

Paul,

My Gauges

Install tips

Boost Guage comparison @ WOT (with lower pulley):

Stock Needle = DEEEEP into the dash.

Autometer Gauge = almost 12.5 lbs. Sorry, not going to lean forward and squint for a definite number.

More pics in my gallery below.

 

Stock gauges are good for telling you your foot is in the throttle or it isn't. It ends there. My stock gauge always pegged, even on the hottest, humidist day of the year. Hooked up the Phantom gauge and on the hot humid days the stock was still pegged while the Phantom read 8PSI of boost. Never got to 10 until it cooled off and the RPM's were up enough. I think it still pegs although I can't be sure, I haven't looked at in months. Pay no heed to your stock gauge unless you can't tell whether your foot is in the supercharger or not. In that case check to see if you have a pulse.

 

My stock gauge goes up into the black in high 2nd and 3rd, the auto meter gauge goes up to 11. If you look at the way the stock gauge is spaced out you would think that the gauge going into the black would mean 12-13lbs. The stock gauge I find just keeps climbing while the autometer one climbs a little bit and then sits at 11.

 

The pressure differential due to the extra ~6 feet of capillary tubing will be negligible (there are equations for pressure loss per foot, but lets not go there...since I don't remember them). The only thing I can see that you might notice a *slight* difference in is the time it takes for the boost to read at both gauges since there is extra volume for the pressurized air to fill within the tubing, but even that is only on the order of .005 ft^3 most likely, so no, you wouldn't notice that either. I'd just leave both gauges hooked up.

In-line...Rotary...Girder...

Oh, I'm an idiot. haha (Nelson voice), later...

garrett