Importance, water vs. oil.

[MassSupra89]

Looking at aftermarket gauges to go with my Apex-i EL2 system. and I'm planning on being able to fit 4 in the center dash.
So far I have EGT,fuel pressure, and Oil pressure, have space for one more, which would be more important to monitor, water temp or oil temp? I know how innacurate our stock gauge is so I'm looking at others opinions. Thanks.

 

[CTsupra]

alex, i'll take "water temp" for $1000, please.

Edit: ...and that's todays' daily double!!!

 

[MassSupra89]

That's 2 for water, damn shoulda made this a poll.

 

[OneJoeZee]

If I had to choose, I think I'd go with water temp. Although they are both important so maybe you should just get both and mount the last one somewhere else.

 

[MassSupra89]

3 for water. Yea I was thinking of putting a few in the glovebox (They're all replay gauges so I could go back and see what I had after a hard run)

The control unit can handle up to 6 gauges and with my boost gauge I've only got 5, maybe both will be an option when money allows.

Going out to make some more measurements to see what space I've got to work with. Might have to be buying a nice custom fiberglass dash

 

[DaemoN]

4 for water.

 

[Mr.PFloyd]

5 for water.

 

[starscream5000]

6 for water, don't trust the stocker . Replace the stock gauges with aftermarket ones, it's been done before...

 

[MassSupra89]

But I don't want to take out my console and hack it apart. I don't usually like the way aftermarket gauges look in the stock locations with the stock tach and speedo. Thanks for the input guys.

I took some measurements and realized I'm gonna need to do alot of trimming to fit all 60mm gauges. I was thinking 3 in the stock CC location(not much trimming needed) and 2 in the ashtray location (a bit more of trimming required for height) Anyone else done this, or something similar?

 

[NewWestSupras]

I'll take air/fuel ratio for $300, Alex.

 

[MassSupra89]

Maftpro with LC-1

 

[Supracentral]

Personally, I'd go with oil temp. But then again I run a PAO/POE based Group IV/V synthetic and go 12,000 miles between changes. I'm hardly the average auto owner.

However I will point out that all of my Supras run like new, even the ones where I went over 300,000 miles...

One thing to consider is it takes your oil anywhere from 10 to 20 minutes longer to warm up after the water is at operating temp. This is why you'll hear many people tell you that you should wait 10 minutes before going WOT in a turbo car after the coolant is up to temp.

Remember while water cools some areas, oil cools everything. Also keep in mind that your oil has the role of keeping the temperature of various components of the valve train at tolerable levels. Valve springs, stems, tips, followers, etc all depend on oil to carry away heat. Engines like the 7M-GTE and 2JZ-GTE use use oil via the sprayers for direct cooling of pistons as well.

Another thing to keep in mind is that cools things in multiple ways. One is by simply carrying away heat as it circulates. The other is by providing the conductor to move heat quickly from one surface and/or engine part to another.

Remember when looking at muti-grade oils (I run Royal Purple 5w-30 btw..) the first number is the 'cold' viscosity. This is an indicator of how the oil will flow when cold. The second number is the 'hot' viscosity or the viscosity of the oil at operating temp. If you to look at your specific oil's data sheet, you'll find how it flows when cold and how it flows at temp. You'll also be able to tell when it's exceeding it's thermal limits.

Search for posts by Jdub about motor oil. The man can teach you more about it than you ever wanted to know.

Also courtesy of Jdub, here are some links worth reading:
http://www.supramania.com/forums/showthread.php?t=31789
http://63.240.161.99/motoroil/
http://physicsweb.org/articles/world/15/2/7
http://www.gi.alaska.edu/ScienceForum/ASF7/747.html
http://www.nordicgroup.us/oil.htm#I...ows better when cold, i.e. 5W30 versus 10W30?

After reading all that, you tell me which measurement you'd want to keep an eye on...

 

[starscream5000]

Both

 

[jdub]

Why thank you SC
You're dead on IMO.

If I had to make a choice, I would run an oil temp gauge...coolant doesn't break down when it over heats and the result is self critiquing. The stock gauge is adequate. Oil on the other hand loses viscosity as it get hotter and will break down due to thermal effects. The data sheets for oil all show oil viscosity at 100 deg C...you really don't want to exceed that temp.

 

[MassSupra89]

Thanks SC and jdub. you both bring up very great points. These are the moments that really deserve a rep system.

My main concern now would be how to mount them. Anyone got ideas/pictures?

 

[bluepearl]

This is only my opinion. Water temp without a doubt. A quality oil will take care of itself. Under most normal conditions, the oil temp will mirror the coolant temp. Here is what I think is the most important----Gauge placement. Why have any gauge if you can't see it at a glance, or a shift of you're eyes. This does not mean craning you're head trying to see what gauge your trying to identify. Gauges are meant to be tools to moniter engine/vehicle operation, not for eye candy.

 

[Supracentral]

This is only my opinion.

Educated opinion or just a "gut feeling" or a guess?

The reason I ask is that, in my experience engine oil temp will vary wildly depending upon how hard your driving and how long you have been driving and what the ambient air temperature is.

Spend some time on a road course pushing a turbo car hard and monitor your gauges (or datalog) and let me know what you find.

 

[jdub]

Not too confident in "gut feelings" myself

Keep in mind the oil directly cools the bearings, valves, cam shafts, and turbo...the effect of heat in these areas is significant. The oil temp will tell you far more about what's going on inside the motor than water temp will.

 

[bluepearl]

Educated opinion or just a "gut feeling" or a guess?

The reason I ask is that, in my experience engine oil temp will vary wildly depending upon how hard your driving and how long you have been driving and what the ambient air temperature is.

Spend some time on a road course pushing a turbo car hard and monitor your gauges (or datalog) and let me know what you find.

I knew this was going to happen. Don't be so defensive. I stand by my post. Are we talking about race cars or normally/agressive driven street cars? 99.9% of the people on this message board, myself included do not drive their vehicles on a race course. If these posts are dedicated towards a racing enviroment I stand corrected and apologize.I must have missed that bit in the original post. I fully understand the relationship between oil/water temps/oil chemistry under extreme conditions. In my original post I said normal driving conditions. Ya better pull over Gertrude, the oil temps are getting dangerous. What about the water temp? Don't worry about it, it's always in the red.

 

[bluepearl]

Not too confident in "gut feelings" myself

Keep in mind the oil directly cools the bearings, valves, cam shafts, and turbo...the effect of heat in these areas is significant. The oil temp will tell you far more about what's going on inside the motor than water temp will.

OK, you're oil temp is starting to rise. What are you going to do about it? Pretend you don't have anyway of checking the coolant temp. What are you going to check? Are you going to check you're cooling system first? I bet you will.