guages: which ones do you think I need?

[fiznat]

So Im thinking about guages now for my KA-T... I would like to put 3 of them in the place of the vent right in the dash (sorta like Adam HU's car...), but I'm having trouble deciding which ones I need.

Obviously I need the boost gauge, but then I'm stuck between EGT, A/F ratio, and Oil or Fuel pressure. I only have space for 3 guages in that spot-- I might consider putting in more later but I would like to start with 3. I've got some questions that might help me decide:

-Is the EGT as good a predictor of A/F ratio as the A/F ratio gauge itself is?

-Which would you say is more important, fuel pressure or oil pressure?

-Is the digital (non-wideband) A/F ratio gauge even worth having?

Any advice you guys have would be helpful

[fiznat]

just for reference, heres a pic of adam's gauge setup:

[02_silver_wagon]

I would say Boost, EGT, and Fuel pressure.

My firend had a cheap A/F and it did nothing, just jumped around. If you decied to get an A/F I would get something worth the $ like the inovative wideband.

Yes EGT will let you know when something is wrong with you A/F.

I'm not 100% on the fuel or oil. You want to keep an eye on your fuel pressure because you don't want to go lean, but oil pressure would be good to let you know if something is going wrong before your engine is fired. Either one is good, I'm just not sure which one would be better.

[BoostFab]

narrow band a/f gauge is useless.

i would go with the guages mentioned by WAGON Quote »Boost, EGT, [/quote] and oil pressure; maybe throw water temperature in the mix. i don't know if fuel pressure is essential, but help debug problems.

[240marcuSX]

i have a boost and egt, on an a-pillar pod, not exactly sure how im going to run the egt yet though, maybe i should go read the directions....

[C-Kwik]

If you must have guages, I'd say the only two I really see a good use for on a turbo car is the boost and EGT. But even then, I'd say neither are truly necessary. Perhaps a boost gauge to make sure it's not overboosting. EGT's should not be something you need to keep an eye on provided you are running a reliable and consistent fuel set-up but I'd put this above others. A/F ratio guages are rather pointless unless you go wideband, but even then, like with the EGT, if the fuel system is good, there's no need to have to monitor it. Fuel pressure gauge...hmm? Again it goes to fuel system reliability. Unless you are raggedly overworking the pump, probably not going to be of much use. And oil pressure guages are rather useless. By the time you notice there is no oil pressure, you'll probably already have damaged the motor and/or turbo. A coolant temp gauge can be useful, but the car already has one. It's not going to tell you specifc temps, but it's sufficient enough to tell you if you are overheating or not.

I'm not a big fan of having too many guages. I only have a boost gauge and I rarely look at it. And I can think of better things to spend my money on. The only thing I can see someone using guages for are to tune the car. But I'd rather use a datalogger for that. It's a bit tricky trying to tune using guages as it's hard to compare what RPM you are at to specific inputs.

[andrave]

if I could only have three and was doing my own tuning I would say oil pressure, boost, and EGT, if I had something that took care of the tuning for me water temp, oil pressure, and boost.

[WDRacing]

Once fuel pressure is set, it should stay set unless your regulator takes a crap, which extremely rare. Oil pressure is a better choice, since you could have an oil pressure problem do to several different causes. Boost is a must have in my mind. I use a wide band, so AF would be my choice, but EGT would be far better if your only using a generic AF gauge. Just remember though, timiung will seriously effect your EGT's as well as AF ratio. So be sure your timing is set where you want it.

My pic, Boost, EGT, Oil Press.

WD

[j-z]

boost, egt, and oil pressure for sure. without oil psi you have no motor or turbo.

[C-Kwik]

boost, egt, and oil pressure for sure. without oil psi you have no motor or turbo.

But by the time your gauge tells you this, the damage is already done.

[trpower7]

You can see low oil pressure before your engine toasts. The stock light will go on at 5PSI when you're engine is toast. I've had several cars develop oil pressure problems and had them fixed without major engine damage becuase of a simple Autometer gauge. In my opinion boost is an ABSOLUTE must have. Your wastegate takes a crap and it's bye bye engine when you boost to infinity. I've seen this happen more than once as well. Water temperature is also good; the stock gauge has an "off", "normal", and "new headgasket" setting. EGT is a better indicator than a narrow band 02, but I'd save your money for a wideband. Here is what I think you MUST have in order of importance:1) Boost2) Oil Pressure3) EGT4) Water Temp5) Fuel Pressure6) (WIDEBAND 02) if you can afford it7) Oil Temperature

If you are going for a budget setup, grab an autometer boost, oil pressure and EGT. Should be more than enough for a street car assuming everythign is kosher otherwise. IE, get some good cooling fans, maybe a bigger better radiator, etc.

[C-Kwik]

Yes, but how often does it occur? I've never seen it myself. I'd speculate that most oil pressure problems are induced by problems caused by improper modification.

As far as a boost gauge, I would say it's not so necessary that it needs to be seen. If you overboost, you will feel it before you ever look at some gauge. And unless you have your stereo on way too high, chances are, you'll here detonation before anything goes seriously wrong. Anyone who hears detonation and doesn't back off the throttle probably shouldn't be playing with turbos. Or any motor for that matter. Frankly, other than when I first put the turbo on, I don't even look at my boost gauge. The only time I kept track of boost was when I noticed detonation. Then I watched boost to see what it was doing.

As much as you might want to know what is going on, you have to ask yourself. When will I really be looking at the gauges? What are the chances of something going wrong. And what are the results? Each person's definition of need in this case will vary for many reasons. I tend to think though that most people have very little use other than a bling factor. I use a mechanical boost gage and when I first got it, I wanted to get an electronic one later. When I figured out how this would be rather pointless, I decided not to.

[DaveEEE]

Boost, EGT, fuel pressure, and water temp are vital to me... I went without water temp for the longest time, boy did that cost me some money.

[Nathan]

Boost, EGT, oil pressure, water temp No need for fuel pressure as I have that gauge in my engine bay, once it's set there should be no problems (FPR's usually last pretty well). I would like to add a wideband and a good knock sensor later, I just can't afford to now The reason for so many gauges is I dont want my precious investment getting messed up and the more things I can monitor, the less likely things are to go wrong.

[andrave]

if you are the type that figure you can do without gauges, it still might benefit you to outfit some sendors and a warning light panel, where you can select the parameters...personally I can see a lot of potential trouble being avoided by detecting problems before they cause damage. motors are expensive, gauges are relatively cheap, and small.. you can get a trio of perfectly functioning gauges at your local autozone or advance for under 120 bucks for name brand, under 60 for sunpro (which still work fine, and I personally endorse). Thats not much cash to have that "window" where you can monitor your engine.

[fiznat]

true, very good points guys. c-kwik, I know what you mean about rarely looking at the guages and all, to be honest I bet my situation will be pretty much like yours... but still I think I would like to have the OPTION of taking a glance at the dash to see what the engine is doing- especially when the turbo is new and I'm still shaking the whole setup down.

Boost, EGT, and oil pressure seem like a good idea right now.. even though the oil pressure should probably remain constant (and thus "useless?").

Anyways, good points guys- gave me some things to think about.

[BoostFab]

Quote »even though the oil pressure should probably remain constant (and thus "useless?"). [/quote]low on oil can cause some serious damage, i think the gauge would be worth while to have a round.

then again, i hate to my cabin cluttered with guages.

[andrave]

ideally water temp, oil pressure, fuel pressure, even boost (more or less) should stay if not constant then at least consistant... that the whole idea...the reason you want gauges is so when they ARENT constant, you notice it and remedy the problem.

[C-Kwik]

I agree Andrave. However, the stock guages have a water temp gauge. Like I said it's not a perfect gauge, but it should be enough that you can tell if there is a problem.

As far as oil pressure, consider that you will probably only notice a problem if it somehow warns you(warning light gauge). The stock oil pump should have plenty of capacity to handle the additional oil a turbo needs. Therefore, it should not be an issue just because you have a turbo. In either case, even warning gauges have their flaws. At higher RPM's you need more pressure. Unless you want to see the warning light go off all the time, you have to set the warning point a little lower than the pressure at idle. The warning lamp will never go off if there are problems at higher RPM's. The turbo will probably survive this, but rod bearings may not. Chances are, you'll never see from a gauge that this is even a problem unless you make it a habit to watch your gauges all the time.

Fuel Pressure - makes no sense to monitor this unless you are running on the ragged edge of fuel pump's capacity. And like oil pressure, the fuel pressure would have to drop below a set minumum before any kind of a warning lamp goes off. The biggest problem with low fuel pressure is that it might lead to detonation. An EGT gauge can probably detect a problem here more reliably as low fuel pressure under boost should lean out the mixture and cause a jump in EGT's.

And again, boost gauges are a good idea, but not something you need to look at all the time. You could in fact, probably just hide it somewhere until you have a reason to check the pressure. You'll likely feel if there is a problem with overboost or even underboost for that matter.

Not trying to discourage anyone here from getting gauges. Just making sure people aren't just getting gauges arbitratily just because they think they must have one because they have a turbo. There is certainly nothing wrong with knowing too much about what is going on under the hood. To me, it;s just not worth the money spent for something that is so unlikely to happen or something that the gauge won't necessarily help me prevent. I'd probably ditch the boost gauge I have, except it's already there and it would leave a hole in the DIN panel. It does also have a fun effect when I have new passengers and they ask what it's for.

[trpower7]

My best setup has been using DEFI's Link system with a VSD heads up unit with presets and warning lights. On a car that is worked on often bad stuff happens like blowing fuel lines, leaking oil lines, boost leaks, wastegates failing, etc, all of which can be monitored and carefully shut down by such a system. On any serious car I work on I almost demand a large compliment of gauges, it makes monitoring and diagnosing things a bit easier.

PS: The replay function of the DEFI system is unreal cool. To be able to replay a 1/4 mile run at will is fantastic.