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Discussion Starter #1
Not which brands so much as what to monitor with guages- here is what I am thinking as possibility. Which ones are crucial to monitoring the car's health? Which ones are nice?

Boost/Vaccuum
Oil Pressure
EGT
A/F Ratio

Any others??
 

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those are perfect. if you could easily toss four gauges in the car, those would be the ones to go with.
if you're limited to three of those (seems like a lotta clusters only have three gauges), i'd skip the oil pressure. pretty much if something happens to dramatically alter your oil pressure, it's the result of a catastrophic failure and you'll know it anyway. another thing, i'm sure there's a/f ratio gauges, but most of the ones i see are digital and odd shapes / sizes, so maybe that would end up somewhere else.
on the other hand, if you could have five, you may want to consider an i/c temp gauge.
i'm hoping for a good engine management system that will provide a few things:
1) knock sensor that, when it detects knock, will cut boost. if i had this i wouldn't care about a/f ration meter.
2) monitor i/c temp and egt temp and adjust mixture and whatnot accordingly. that would eliminate the temp gauges.
then i'd just use a boost gauge, since that's what i care about most (as far as real-time stats go), and keep the computer out of sight. this is what i've done on previous cars and i've found it works well.
 

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EGT is the single most important in a boost car. If you are pushing the envelope or if something goes wrong, that would be the first place to look.

Next, I'd go for boost....just because I want to see it!

AF gauges, unless the digital type are just light shows. They aren't accurate enough to tune off of and they change so much, you really can't gather anything about how the engine is running.

I'd like a more accurate water temp gauge as well.

In SCC this month, there was a cool gauge that was a boost gauge with a digital EGT reading in the middle of it. That would save you a gauge there.

Personally, I'll probably go with the EGT/boost combo, water temp and maybe oil temp.
 

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Discussion Starter #5
According to my color/wheel survey

That Boost/EGT combo guage sounds neat. Who makes it?

Here is what I am thinking now:

Boost
EGT
Oil Temp
Huge tach with A HUGE shiftlight (JUST KIDDING :D:D :lol:)

Either mounted in the A-pillar, right above the stereo, or where the clock is.

What would a water-temp guage do for you that the stock one does not?
 

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In my opinion, no car should leave the factory without an oil pressure gauge. That said, of course it's the first gauge I add to any car. On the Subaru, the idiot light is set to come on at 7 PSI. By the time the light comes on, you're already in a world of hurt. By monitoring your oil pressure, you always have a feel for the health of your engine.

The second most critical gauge is the oil temperature gauge. Not so much to monitor when it's too hot, but rather to monitor when it's too cold. The turbo on most modern engines (Subaru's included) uses engine oil to lubricate and cool it. When oil is cold, it is thick and doesn't flow as well. By getting on the boost before the oil has a chance to come up to temp, you can seriously decrease the lifespan of the turbo. Of course, this holds true for all bearing surfaces in the engine. As a rule of thumb, my WRX does not see anything over 4000 RPM until the oil comes up to at least 100 deg. F. Remember, water temp alone is not a good indicator of the engine temp. Water will come up to normal operating temp far before the oil does.

Finally, I would consider a boost gauge. On a stock engine, the boost is controlled by the ECU, so not much fun there. However, on the vacuum end you can see a lot about the health of the engine.

On a stock engine, EGT and A/F are useless. Arguably, A/F is useless all the time, since most people have found that it bounces around too much to be useful. EGT will not get dangerous until you are running more boost or more compression.
 

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Reasons for the STi Wing?

jbhebert said:
On a stock engine, EGT and A/F are useless. Arguably, A/F is useless all the time, since most people have found that it bounces around too much to be useful. EGT will not get dangerous until you are running more boost or more compression.
I'd have to agree and then disagree with most people on this. A/F is only useless if you use a narrow-band O2 sensor which comes on most cars. Narrow-band O2 sensors are cheap because they aren't very accurate and they only operate well around stoichimetric A/F ratios. Modern cars are run near stoichiometric because of the limited operating range of the catalytic converter. For catalysts to be effective (assume stoichiometric A/F is 14.6:1 for gasonline) they need to run with A/F between 14 - 15.

However, if you really wanted to get a good grip of the engine operating characteristics, you should use a wide-band O2 sensor. This will tell you exactly where you are in the A/F map, and it's a great way to tune an engine's fuel map. The only caveat is these things cost about $1400 for the sensor and readout box.

JDiesel
 
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