I have a boost guage that is an obvious one.

I would just like to know of the main guages I should have visible to my eye when i am driving.

I was looking to purchase a Air/Fuel guage. Is this necessary to have?

I will be picking up a PFC in the near future. Is there anything that is not displayed in the PFC that I should keep an eye on all the time ?

 

I think a wideband is key. The rest are of secondary importance.
1. Wideband
2. Boost
3. Coolant T (that works)
4. Oil Pressure

 

Ok cool.

WEll i was just looking at a few web sites and they are quite more expensive then boost guages=)

are they harder to install then boost guages?

 

Does a wide band replace the O2 Sensor or is it completely different?

Is it possible to buy an aftermarket O2 sensor and hook it up to a wideband controller?

 

The stock O2 sensor measures narrow band AFR's. Some company's will sell you a "wideband" AFR setup which could/would utilize the stock sensor, though this is not a true 0v-5v Wideband reading. The standard, quality, WBO2 kits can be a little pricy (though they are worth it if you will be seriously modifying your car). If you don't plan on going all crazy than an Exhaust Gas Temp (EGT) gauge will suffice (hotter = leaner, cooler = richer) to give you a general idea of your mixture.

The PFC Commander is great and, when mounted in view, will provide easy access to many measurements at a glance. Personally I have mine show Injector Duty Cycle (IDC), boost, Water Temp, and Air Temp at all times.

Boost is critical and the PFC is slightly off (unless you put in the time and effort to calibrate it) I keep it up because it will track peak boost.

Aside from my Boost gauge and PFC Commander I have a (broken) Oil Pressure gauge (the stock gauge works great and is very accurate, so I've never bothered fixing this, though I will replace it when I get A/I), an AFR gauge (analog) from my LC-1, and a Fuel Pressure gauge.

If you have an A/I system it's also a good idea to have a flow meter visible, that way you know if something gets messed up there..

 

I'm a complete newb, so consider the source here. I only want to see things that:
1) Are critical to engine health/performance.
2) Give me information that I can act upon.
2) Something I actually understand.

When I'm driving there are only four things that I really want to be able to know with a cursory gauge scan: Fuel level, coolant temps, oil pressure, and boost/vacuum.

So, given the above criterion for myself, there are only two aftermarket gauges that are important for me, coolant temperature, and boost/vacuum.

The stock oil pressure gauge works fine as long as the sending unit is in good shape. The stock temperature gauge is NOT good and since it is important to not boost the engine until it is fully warmed up, and since it is important to not overheat it, I think a good temp gauge is vital. As you mentioned, the boost gauge is obvious.

Keep in mind that I don't have a PFC (as of yet), and even if I did I would never presume to tune the car myself. Hence additional information such as A/F ratios, intake air temps, etc... are data sources that I wouldn't know what to do with even if I had them. When I drive I want to drive, not study gauges. Give me those four bits of information and I'm happy. YMMV of course. Keep in mind that I'm an idiot.

 

Air temp isnt just for tuning, you should be monitoring it while driving hard. Also, since the pfc commander has peak recall for boost and water temp you dont have to spend lots for peak recall gauges, just the cheaper basic ones will be fine. Like you said the stock oil pressure gauge is good but i would really consider oil temp since the pfc wont show you that. And as far as not knowing what to do with the data from wideband, ect. even if you are not tuning yourself you will atleast be able to recognize if something is up and take back to your tuner and maybe save yourself an engine.

 

I'd go with Oil and Water temp, and oil pressure
Boost is useful, however, I personally don't really use it - to be honest, when i'm in the sort of conditions whereby i want to see what the boos tI'm hitting is (i.e. WOT) I really don't want to take my eyes off the road and refocus onto a gauge. In this situation I tend to just look at the peak/playback readings on my PFC commander, or get a passenger to look at the commander.

I guess what I'm really saying, is that for me, when i have a PFC commander, a boost gauge isn't as useful as others unless it's got a peak hold/warning function. But that's probably just me

 

Water temp is the most important, imo. It has saved me 2 times. Once I had a hose with a pin sized hole and once the radiator cap was not properly secured. (I must've bumped it when working on the car). Saved my **** on 2 seperate instances.

Water temp, water temp, water temp.

 

How can boost be a secondary concern?I want it in my line of sight at all times. Theres been too many times ive been working on something/solenoids and overboosted. If i had not had a gauge right in front of me, i may have lost my engine.

 

If any guage is necessary Mazda would have already sold the car with them...
An aftermarket watertemp guage is nice to have because it shows the slightest signs off overheating.
Cars used to have a lot more gauges than they do nowadays but because quages don't tell people crap most off them got replaced by warninglights.
Most OEM watertempgauges are basicly built to act like a warninglight and really have just 3 positions, cold, warm and overheated.
Boost is a popular option but not really necessary for regular driving, it has more meaning when troubleshooting, same goes for (wideband) O2
You could also consider oiltemp to see if the engine is warmed up and at normal operating temperatures. The oil temperature is a better indication for that than the water temp.

 

Your stock gauges, your boost gauge, and your pfc will give you everything need. Don't waste time, money, and space to add anything else.

 

Agreed.

For street driving:

I monitor water temps on the PFC. In street driving, they don't change to an abnormal amount unless there is something wrong with the cooling system.

Oil temps parallel water temps by about 20 degrees iirc. There are a couple of threads on that topic if you want to search. Actually, there are a bunch of threads on this topic too if you search.

Wideband is good if you are tuning the car, however, you really want to run that through the dataloggit so you really don't NEED a gauge for it.

Boost is useful - especially if you find yourself running too much or too little boost.

 

I absolutely disagree with that. Mazda took a few shortcuts with the FD (Plastic AST, Radiator Cooling Abilities, etc..) By this logic there is no need to do anything to the FD other then add fuel and drive... we all know this isn't the case. The FD has a lot of short comings in reliability and longevity in stock form.

 

I'm sure this has been covered somewhere before(read I searched but don't have the time to scan pages of info), but are there any particular brands to stay away from when picking gauges? For instance I know some people who say autometer gauges work just fine, and others who say the tolerances their gauges read at(+/- whatever) is not acceptable.

 

The best advice here.

The only thing I would add is to linearize the temp gauge or add an aftermarket one. The rest are frivolous for a stock car.


Paul

 

For a relative stock car.. I'd say

Boost
Water temp
Oil temp

 

i have 3 aftermarket gauges: boost (with electronic sensor); coolant tem. and oil temp. FD is not my daily driver, i drive it on track time after time. As far as i'm runing just minor modifications (intake, exhaust) on stock ECU and 10psi, i dont need A/F yet.

 

boost / wideband A/F + PFC

 

I'm still waiting to see the answers to these questions of the OP. Anyone?

 

A wideband is slightly more involved than a boost gauge install. However, most of it depends on how you install it. It doesn't necessarily replace the stock O2 sensor.

If you have an aftermarket ECU such as the PFC, you can remove the stock O2 sensor and disable that in the PFC. Then you can install the wideband O2 into the stock O2 bung.

If you don't have a programmable ECU like the PFC, then installing a wideband is a little pointless. But with the stock ECU or rechipped ECU, you need to keep the stock O2 in it's place and have an extra bung welded onto the DP for the wideband O2.

Can you just purchase an aftermarket O2 sensor? Yes, but you need to know what you are purchasing. The stock O2 is a narrow band, hence why you don't use it for tuning. Most of the ones you'll find will be narrow band. You can purchase aftermarket wideband O2 sensors but then you'll need to be able to interpret the signal from the sensor. It just makes more sense to buy a wideband kit that gives you everything you need rather than trying to piece it together yourself.

 

http://www.rx7.com/store/rx7/RPO2sensor.html

would this work ? with an aftermarket A/F ratio guage?

 

That's just a stock replacement O2 sensor.

 

Is it hard to get the old o2 sensor out ?

 

Nope. You'll either need a O2 socket (which you can buy at most auto stores) or a fairly decent sized socket. The area is usually too tight to get an open end wrench in there. Most of the stock O2 replacement sensors come with anti-seize already on them. If your's doesn't make sure to use some but it will need to be the high-temp version.