After reading a few posts I decided to add my own little FAQ I suppose. Most owners are wondering about buying gauges, and as such are worried they might be purchasing the wrong kind, brand, color... whatever. Here are a few questions you might ask and my answers to them.
Mechanical or Electrical?
Due to today's technology no gauge type is vastly superior to the other in terms of accuracy or operation. There are however, things to remember when buying either.
Do not use a mechanical gauge to measure a liquid substance, and then display said gauge inside the cabin. This goes for oil pressure/temp, engine coolant temp, fuel pressure etc.
If your gauge must actively come in contact with the substance to measure it, chances are the pressure, heat, or liquid itself may have a possibility to find its way to the gauge under a catastrophic failure there by putting you and your interior at risk. You have been warned.
Also, mechanical gauges are generally bouncy and inaccurate in its reading during operation, especially in off road situations. Although your Z may not encounter such roads, bumpy highways and such should be taken into consideration. Many mechanical gauges are now encased in water to deaden the needle's movement; they still may be bouncy at times. This is more a general warning as I doubt many owners will bounce it enough to make a definite difference.
So that being said, mechanical gauges offer some pros to their operation.
- Power free, except if gauge is a light up unit.
- Usually less expensive than their electronic counterparts.
Mechanical units are great for a budget project, a stripped race car with a metal interior, or someone who wants an authentic "mechanical" feel to their vehicle.
There is an exception however…a mechanical boost gauge can be one of the simplest things to set up/troubleshoot in a boosted vehicle. Keep that in mind when shopping.
Some can be simple, others slightly more complicated. Some electronic units use a sending unit that collects all the data, and then sends it to the appropriate gauges. This can be a tough install, but will ease trouble shooting in that if a gauge fails either it's a problem near the sender, or a problem near the gauge. This can also ease installation of later gauges in that it would be a plug and play process.
Electrical units will have to receive some form of power, supplied during ACC and ON positions. Also, they will have to have appropriate grounds, and must be insulated from areas where liquids could contaminate them. (Sorry, no cup holder gauges)
But despite some of the complications, electrical gauges benefit in that:
- Smooth and consistent operation save for a major malfunction
- No major lines to hook up or hoses to route
- Easier to install in close quarters (a-pillar, dash etc)
- Electrical wires can be bent and routed easily
So with all that in mind... lets move on shall we?
What types of gauges should I run?
This question can depend on your application, although some are transferable to either. I'll try to make this easy.
The types of gauges you run is solely up to you and the info you want to receive. Although things like A/F ratio and such are generally accepted, it's really what mods you've put on the car and what information you'd like to know about. Here are some suggestions.
-> Engine Coolant Temperature
o Lets you know when you have reached operational temp
-> Oil Temperature
o Helpful if you'd like to run in your oils optimal temperature, or if you ran an oil cooler and you'd like to know your real-time temp.
-> Oil Pressure
o Warns you of serious problems occurring in your engine and can aid if you have installed an oil cooler or other device and need to monitor for pressure inside the system.
-> A/F ratio
This must be wideband 02 sensor with the ability to accurately measure a wide range of air/fuel mixtures (get it?) If you get a non wideband that simply splices into the stock 02… sell your car and stare at a Christmas tree on the 25<sup>th</sup> of Dec... You'll get the same amount of useless lights.
-> Exhaust Gas Temperature
o Helpful in tuning your car and can show certain conditions your car could be in there by aiding you in troubleshooting or warning you of potential problems.
-> ^See Above
o First thing you should buy. Can be mechanical or electrical. Either works just fine. Don't run an SC or Turbo without it.
-> Fuel Pressure
o Helpful for those in the supplemental injection world. (Meth, alky etc.) Must be electronic for obvious reasons... you don't want gas in your cabin.
Who makes the best gauges?
All depends on who you ask really. Unless you stoop low enough to buy some random off the wall brand that was made out of old clock faces chances are they will work fine. However there are a few things you'll want to look for.
-Ambient backlighting. Probably not the best word to describe this, but basically the gauge will light up the numbers and needle itself rather than simply lighting the thin paper-ish film the numbers and needle reside on. This is important because it will aid in night time driving... and nobody wants to drive around with a Mag-Light in their face.
-Sending unit? No sending unit?
-Will it fit? Gauges usually come in MM sizing, which you can easily convert for your American pods... or vice versa. Generally 2-3MMs over sizing can be negotiated with some lubricant and a warming device (heat gun, blow dryer) but it's a good idea to think ahead.
For those who want to do some searching here is a short list of some known manufacturers.
- Greddy (Trust)
What is better.. PSI/BAR/In HG/..etc?
All are displaying the same thing, just in different formats. Used to if you got a gauge from overseas chances are it'd be in "In HG" (inches of mercury) or BAR (barometric pressure).. so on and so forth. Most if not all have converted to PSI by now and finding one in other measurements is really a thing of personal preference.. and it kind of depends on where you live.
Need to convert something in PSI to BAR or other unit of pressure? Here you go
Which is better.. Sandwich adapter or galley input?.. and what is a Sandwich Adapter anyhoo?
A sandwich adapter is something that will fit inbetween your oil filter and the oil filter's mounting surface that allows the user to run oil pressure and oil temperature sending units into it.
Is it better than using a galley? Depends. If you are just using one sensor or the other you might want a galley.. or if your aftermarket oil cooler already has inputs for one or the other you could bypass it completely. Honestly it's just personal preference, if installed correctly either will work just fine.
That's all for now unless someone gives me some info I can add. Good luck!