gatorbait

Need some advice.

Is there any value in adding a fuel pressure gauge in the cockpit? Is fuel pressure something that bears close monitoring on a basically stock 951?

Conversely, if you upgrade to an adjustable FPR for performance reasons, would it be a mistake to not get a fuel pressure gauge?

TIA

Sam Lin

If you get an adjustable FPR, you need a gauge to set pressure. After it's set, the gauge becomes useless. On a stock car, the gauge is indeed useless.

Sam

Bill

There is value in having a FP gauge.

If your fuel filter ever gets clogged or the fuel pump gets old and pumps less pressure, a gauge would show these kinds of problems. This would advert a potential catastrophic lean condition. Also if an adj. FPR were to fail and allow fuel pressure to rise causing a rich condition, the gauge would again be of use. A gauge would also tell you if the fuel pump is keeping up with the injector demands at high rpms.

Granted an air fuel gauge would also show the lean/rich/rpm condition, but the gauge would be a better indicator of where the problem originates.

RajDatta

Just went through a situation with my car where the guage told me I had problems. I have an adjustable FPR and a fuel guage and noticed that the fuel pressure would drop as soon as I turn the car off, which is not correct. I found the leak on the FPR itself as the vacuum fitting started coming lose. If I didn't have the guage, I would have never known of this problem.
Now the FPR not only had a vacuum leak, but it also started going south where I could no longer go past 3 bar, another way the guage helped me see that. The FPR is getting replaced soon as it was only 5 months old.
Raj

User 41221

A word of caution here, tho... PLEASE be careful with your fuel pressure gauge. Under no circumstance should you plumb a mechanical fuel pressure gauge into the cockpit of the car, and to be prefectly blunt, I don't think having one permanently mounted under the hood is such a good idea either. I have seen WAY too many of these leak and or cause a Car-B-Q, sometimes from the way they are mounted and other times because the gauges themselves were leaking.

IMO, if you absolutely have to have one permanently mounted, spend the money for one of the electronic ones.

After I get my new (to me) '87 951 delivered, I will be removing the one thats installed on it right after I get done doing the belts.

Regards,

Perry 951

If you install a good quality gauge and use top quality fittings and lines, you should be ok. I firmly believe you have about the same chance of a leak from the main fuel lines and fittings as you would the gauge setup.

We all agree, it's nice to have for trubleshooting, and a must if you have an adjustible regulator.

Eletronic is the way to go if you want to spend the cash.

User 41221

Agreed that there are plenty of opportunities to burn your car to the ground, when it comes to a 951... its all the cheap gauges that scare me. I have seen Brian's set-up and would point to his car as an example of how to do it right. But he didn't spend $65 or whatever the deal of the week is, either! lol And no matter how high a quality of line and gauge you run, you still should never plumb a mechanical fuel gauge into your cockpit.

Regards,

86944turbo

If you are aware of what fuel pressure numbers that your car should be reporting at various points, be it idle, freeway driving and maybe some boost numbers, I believe it's a very important tool. It becomes more important as the power increases in your motor. The more power out of any, but in this case turbocharged motors, the more crucial (at times, "drop dead crucial") fuel pressure becomes. I understand that when initially setting fuel pressure, vacuum is removed and I believe that is why many place the gauge under the hood. Other than that useage, placing a FPG under the hood becomes useless. I use one in the drivers compartment and take regular readings. Yes, I can have a laptop hooked up at all times through the pigtail to MoTeC, but it's not practical. Oil press., oil temp., water temp., boost, fuel pressure and for many EGT and or A/F are important. Esp. is any changes to the fuel delivery system are made. 2 cents...More important, even for the street, than speedo.

eastendr

I recommend the Lindsey Racing gauge kit. It comes complete with unions and a VDO gauge that fits directly on to the end of the fuel rail.

This is essential with an adjustable FPR. It also lets you know that the rest of the fuel system is doing it's bit and can tell if you have any small leaks developing by watching how long the rail holds it's pressure after the engine is turned off.

I would not, however, mount a mechanical gauge in the cockpit - if anything goed whong you could hace a high pressure fuel line venting directly in the cockpit ...

Rick.

Black Arrow

My car stopped at a track day for some weeks ago. If I had installed a FPG, i would have earlier understood that is was to fuel pump that didn`t want to be with me anymore... In stead I search up and down on the car, before I asumed it was the pump and removed it for observation.

I`m going to install a Lindsey FPG, mounted on the fuel rail and FPR now! It`s nice to have something to help you find the fault.

RajDatta

My setup has teh guage welded to teh back of the fuel rail and is liquid filled. No chances of it ever hitting the hood either. This way, the welds were tested and no drilling done by an amateur like me .
Raj