I know it has been discussed a million times, but I could not find an exact answer. I got a triple guage holder for the pillar. I have a boost guage and a A/F ratio guage. And I know your opinions on the A/F ratio guage, but it seems to be a little helpful at WOT. I also have a PFC and commander and I was told that its Water Temp guage works just fine. So I have that covered. Now for the last spot, is it to be a Fuel Pressure, Oil Pressure, or Oil Temp? Everybody seams to have a different opinion. It seems that you would always want to know the fuel pressure, because that would be a way to make sure you arent running lean. Also it is a daily driver with DP, CB, and intake, and not a track monster. Any help, Thanks

 

I'd go the the fuel pressure myself, that is a little more important than oil temp, which would be my second choice. Oil temp is second only because that on the R1 model (twin oil cooler model), water temps and oil temps are very close to each other, or so I've read.

Regards,
Frank

 

Oh, and the reason why I would choose the fuel pressure is for a couple reasons.
1st of all it's nice to know how well the pump is running at both stages, and also to monitor any slight degredation of the fuel filter. Plus the fact if you start boosting up your duty cycle on the injectors you can tell if you start maxing the pump out.

Frank

 

I agree with Frank. Other than track situations, your oil temp will almost always closely follow your water temps (mine is 10-15 F hotter with single oil cooler). If you have a good, clean stock sender, the stock oil pressure gauge works fine.

If your A/F gauge uses the stock O2 sensor, do not trust it -- ESPECIALLY at WOT, where it is completely useless. There's a reason the FD uses set fuel maps once you get into boost instead of relying on the o2 sensor....

So, that leaves EGT or fuel pressure. Get the fuel pressure.

 

I have an oil temp gauge. Really pretty useless. It's only benefit is to fill the 3rd spot in my 3 gauge din plate. Oh yeah, it matches the other gauges, and looks nice. Seems to run about 25 degrees hotter than the water temp.

 

If I was going to have 3 gauges it would be boost, egt, and fuel pressure. Course I personally feel the egt is basically useless unless you have a wideband. You can get a tech edge wideband, sensor and all for about $400. Peronally if I couldnt afford the $400 I'd sell the 3 whole pod, egt and fuel press to get the wb and a single gauge pod for the boost gauge.

STEPHEN

 

What about oil pressure? (it drops and your engine becomes toast)

 

I have all the below (figured I had to find out myself and have all controls at my disposal) so here's my 2 cents:

- Oil Pressure Gauge - not needed if your sender unit is fine. Mine never deviates from the stock one.

- Oil Temp Gauge - I have found it useful because I had problems. Several different mods resulted from this and my oil temp is great now. So I differ that it is always a repeat of your water gauge. Not always so.

- Fuel Pressure Gauge - Probably your best option as everyone has said but don't think you are going to be using it as someone mentioned to know if you are going lean very precisely. Mine actually has a fairly erratic pattern and yet my Datalogit with Wideband logs me with rather consistent A/F ratios so infer what you want.

- Water Temp - I have an aftermarket one despite the PowerFC because it's nice to see PROMINENTLY. You could make an argument that this would be better than that FP gauge even with the PowerFC unless you have your PowerFC mounted to where you can always see this clearly.

- EGT - By the time it tells you something, it is likely too late. Mine fills out one of my gauge pods.

- You already have a boost gauge and your AF gauge is likely pretty useless unless it's at least the GReddy 4 wire one in which case it might only be half useless. Had one of those too.

David

 

As I posted above, if you have a good, clean sender, the stock oil pressure gauge works fine.

 

Very good points David, IMO.

I will continue to run a separate water temp gauge after I install the PFC for the reasons you listed.

As I stated above, the oil temp follows the water temp except in racing conditions. If someone was going to be doing any racing, I would recommend an oil temp gauge as well. Personally, the only time my oil temp has substantially deviated (higher) than my water temp was on the dyno. My water temp was a fine 200 F while my oil temp reached 250 F after the 3rd run. I was glad to have that gauge then.....

 

I only have a touring so I do not have the second oil cooler. Maybe I should look into the oil temp. But it sounds like the decision is fuel pressure. I went to look for an feul pressure guage today by auto meter and they don't make a mechanical one that will go in the car for 0-100 psi. I need to have one that has an isolator to run it into the car. Is there a universal isolator that can be used? Or else its get an electrical one for almost $300. Are you kidding me. What did you guys go with for a fuel pressure guage? I need some help and I would like to keep it at 2 1/16 inch. Thanks guys.

 

I would NEVER use a mechanical gauge for oil or fuel pressure or temp!

Why is the autometer **** so expensive? A Defi D-gauge fuel pressure is $176 at the rx7store, a Defi Link series fp gauge is $195.

BTW, you only need it to read up to about 70 psi anyway (actually 60 would probably be fine for almost any FD owner).

 

I thought mechanical guages were supposed to be more reliable. Their reading would be more exact? I guess I might have to look into a different set of guages.