fuel pressure gauge

[dickita15]

I am looking to add a fuel pressure gauge in the cockpit with an isolator of course. Most of the usual suspects have them 0-15 psi. I would prefer 0-10 to give better resolution. Am I being too picky? Any other sage advice on this topic.

[Greg Amy]

How critical are the details on fuel pressure for your car? Will it, for example, stop filling the bowl at 7 but run fine at 9psi? Also, what's the max pressure you're expected to see?

I suggest picking a range that encompasses both the maximum possible pressure and the minimum permissible for proper running. No point in getting one that goes to "11" if you'll never see over 10 (or, just make 10 louder).

Then again, if the 0-15psi gauge costs $50 and the 0-10 costs $150, then screw that...

[tom_sprecher]

I would prefer 0-10 to give better resolution. Am I being too picky?[/b]

I for one do not think you are being too picky and wish you the best of luck findiing one. I tried to find one that was 0-5 and there was absolutely nothing except one out of a industrial supply house (MSC) that was not suitable for dash mounting so I use it as a hand held unit that attaches to the fuel test port to spot check and troubleshoot. It is too delicate and expensive to ride around with me.

0-5 seemed like the best choice as I was told the Yaw carb is supposed to only see around 2.5 psi.

[dickita15]

Yes Greg Fuel pressure is super critical with these carbs. It is not about busting a line it is about overrunning the floats and flooding vs. leaning out from lack of delivery. I would kill for a Holley.
Thanks Tom. I have Summit liquid filled under the hood (0-15) and it is crap. Maybe I should buy one like yours for fine tuning. In the last race at Ohio the car I was having a pretty good race and was finally running down Phil Alspach for the first time all weekend when the car started cutting out at 7000 at the entrance and the exit of the keyhole. The entrance did was no problem and once I expected it I could short shift at the exit but then it cut out in the middle of that off camber turn leading to thunder valley and I almost went for a ride. There is really no way to diagnose the problem in the garage so I figure it is time to put in a gauge and at least eliminate that possibility.

[lateapex911]

Dick, I have a mech in my car, and use the super precise one when needed to adjust the regulator. It lives in my toolbox, and was semi pricey. You're welcome to borrow it anytime. I can ship it to you in a day if you like.

My in car guage has proved useful in troubleshooting, so that I know if, when I have issues like yours, that it is a case of lack of fule getting to the carrb (out of, errr...gas, clogged fuel filter, fuel pump issues, etc) or it is in the carb itself. Saves time at the track.

(Actually, my new 7s Only carb needed adjustment at MO, and I jumped right on float level fine tuning based on my on track observation of proper and steady fuel pressure.)

[ddewhurst]

Dick & folks, please take a look in the "For Sale Parts" forum because one of the arguementive users of this site today posted a bunch of 1st gen RX-7 stuff for sale including a RUST free 1982 RX-7 GSL from Oregon along with the stuff listed below. As you can see the gauge will do the trick. It's accuracy is better than Paul's. The Yaw carb works well at someplace around 2 psi depending on jets & the current weather.

The prices are Original new/Sell today.

Would like to sell fuel pump/reg/gauge as a group for $86.00
Holly red fuel pump/97 gph/7 psi $94.00/$47.00
Holly fuel pressure regulator/1 to 4 psi $40.00/$20.00 (Not sure of the Original cost but shown is close)
0 to 5 psi +/- 1.5 % of full scale Noshok pressure gauge 2 ½ inch dial $38.00/$19.00

Yaw carburetor/had a cold air tube intake with K&N $385.00/make offer

[lateapex911]

0 to 5 psi +/- 1.5 % of full scale Noshok pressure gauge 2 ½ inch dial $38.00/$19.00


[/b]

That would do the trick. 3% of 2.5psi is what, .075 of a psi? Thats well within the "noise" level, I'd think.