overhead gage console

[dshockley]

I am ready to start modifying, but as just about everyone has said, the first thing on my list is a few gages. I am going to add four: pyro, boost, ATF temp and a tach. The thing that has been bothering me the most is what to do with four gages (I know that I could cut it down to three by using one combo, but don't like the looks). I have thought about using a two gage a-pillar mount and a one gage a-pillar mount, but with all that I hate to put a gauge on top of the dash, too. After a lot of day dreaming I have come up with a solution that I think I like and I am looking for input. I mocked up an overhead gage console(see picture) that would be located between the sun visors. It would hold three gauges. The fourth would either go in a single a-pillar mount or in a gage cup on the dash. I think that this solution maintains field of view and keeps things from looking too cluttered.



Now, does anyone make anything close? I am not opposed to building it myself, but if there was someone who made something similar (even for a different application) it would save me a lot of time. My plan is to make a fiberglass pod and then cover it in headliner fabric or vinyl.



Of the three gages: pyro, boost and ATF temp, which is the shallowest and what would that depth be? I know that they will vary from one manufacturer to the next so just an estimate will do. With my current configuration I may have a clearance problem on the far right gauge.



Thanks for all of your input and ideas,

Dan



What have other people done?

 

[Philip]

I haven't found anything like you mocked up. It looks nice. Better check the length of the leads you might need to run a pyro up there. My auto meter leads are 8'. It might be a little tight getting one up there.



Auto meter does make a 10' one= $165. ouch



I'll get some gauge measurements tomorrow morning. I have to head to work in 10 minutes.



My gauges are still on the self. I have a 2 pod pillar mount for them.

 

[Philip]

My gages are Auto Meter Sport comp models, black face.



The body is 1 1/2" long from the mounting face to the end of the body.

From the mounting face to the end of the mounting screws is 2 1/2".



Both gages are the same lenghts. I would bet all of the Auto Meter line in this series is the same dimenisions



If you need pic's or anything let me know.

 

[dshockley]

Thanks Phillip. They will fit. What is the lead to the pyro? I thought that the pyro gage was just a thermocouple. They cannot be modified? The boost and temp gages are elctrical gages that use a sending unit so no issue there. I guess I could put the tach in the overhead console and the pyro on the dash.



Thank you very much for your input.

Dan

 

[Philip]

The pyro is a gage. It reads what a thermocouple sends to it.



In use a thermocouple makes a small amount of voltage for any increase in temp. The gauge just changes the voltage reading to something we can understand.



The Auto Meter gages use a type K thermocouple. They only show a 10ft as the longest one. It might not go to the upper console you are thinking about building.



It might be possible to use an aftermarket one. Type K is a common one used in the plastic's industry. The hard part would be finding one with the correct type of end to withstand the exhaust gas thrown against it. I would bet that Auto Meter doesn't make their own thermocouples. They are out sourced.

 

[zjones]

Why not use a combo EGT\Boost gauge?? My father has EGT\Boost, tach, & ATF temp gauges mounted in a dash pod, it looks very good & is easy to read.

 

[Paul Herioux]

JC Whitney sells what they call a Speaker Liner. It is a plastic headliner with four 4 1/2" speakers, a center pod for mounting a radio about where your set up is and a pod that ends up over the driver's visor with room for four 2" gauges. Mine was in my 79 Power Wagon when I bought it. Happened to save it when I scrapped the truck and installed in my Ram this spring. The radio pod would work for mounting a 2 5/8" gauge. I had the speakers hooked up in the 79, worked really well as it puts a speaker just above each side of your head.

Just an option.

 

[dshockley]

Phillip,



I am sorry that I was not clear, but after rereading my post I understand that I should have slowed down when I asked the question.



I understand what a thermocouple is and that the pyro converts the analog signal into a temp. However I don't understand why the leads cannot be lengthened. While in college and working in our department foundry, we made thermocouples all the time. We would use about a foot of the two different alloy wires for the thermocouple and then extend those wires. I realize that shielding is kind of important, but still think that the leads could be extended. Anyway, if it is a type K I will just make my own. Any comments?



I have not seen any of the double gages that look similar enough to the singles to meet my tastes. I am thinking that the VDO gages are the best bet. They look very similar to the original gages and all four faces match.



Thanks for your input and I will be checking out the JC whitney catolog to see if it may be something that I could use.



Thanks for all your input,

Dan

 

[Philip]

You can try to extend one. But with the small voltage that the wire makes. It does not take much of a bad connection to throw the readings off.



You need to use the exact same mfg brand of wire to extend with. Different mfg's wire can have different proprieties. This would throw the readings off also.



The hard part about making your own is getting a tip to go into the exhaust stream. Most industry type of thermocouples you are used to are surface mount. This won't give the correct reading. The manifold temp outside would be up to 250 degrees low I bet.



I might try one of the industry types when I get mine mounted. I do have access to them.

 

[dmurdock]

Hold on fella's, I have the autometer pyro guage (with race/heavy duty/whatever they call it) thermocouple. The lead from the thermocouple goes into a box mounted under the dash. From there, it's just regular wire to the guage (you could run it as long as you wanted)...





edit... i looked at the receipt



the guage is model 4365

the pyro is model 5244



Competition Series Probe Kit

Complete Probe kit includes 3/16" dia. Stainless Racing Probe with 10 ft. wire plus 3/16" compression- 1/8" NPT connector and weld fitting.

 

[Midnite]

Originally posted by Philip

You need to use the exact same mfg brand of wire to extend with. Different mfg's wire can have different proprieties. This would throw the readings off also.

Why? Wouldn't larger gauge wire allow for a longer distance? We're basically talking voltage drop vs. wire length here, right?



Ie, if I wanted for some bizarre reason to run my EGT gauge to my rear bumper, all I would need to do would be to run sufficiently large-gauge wire such that the voltage drop from thermocouple to the rear bumper is insignificant--right? If not, please explain.



Mike

 

[dshockley]

Voltage drop should not be an issue. There is no (very, very little) current. In order to have a voltage drop it takes both current and resistance. As long as you use roughly the same type of wire (copper for example) you should be fine.



Do all the pyrometers use the intermediate "box" as mentioned above? I have heard that other manufacurers use these boxes and this would simplify my installation.



Thanks for the input,

Dan

 

[Philip]

My pyro # is 3344. It doesn't use the box like dmurdock has. I went and looked around Auto Meter. It doesn't say anything about the box either. That would make it a lot easier for your install.



On the type K> TC's I have worked with. Any splice in it will change the temp reading. If you use a wire that is not a TC wire. It can be off a lot. Just a splice in the TC can make it up to 25 degrees off. It doesn't matter if the splice is with a butt end connector or solder joint.



I wish I could explain the difference between TC wire and regular wire. But I am not an electrical engineer. My experience has been on the working end of the spectrum.



From my experiences if I was to splice a TC with anything but TC wire. I would add 150 degrees to any reading the pyro gives to be on the safe side. I have seen them that far out with non TC wire used for a splice. IMHO

 

[dshockley]

Thanks Philip,



Does anyone know what VDO gauges use? Junction box? Leads straight to the gauge?



Thanks

Dan

 

[JFitzgerald]

My Isspro pyro uses a separate "box" that the thermocouple wires to, then another cable goes to the gauge. I believe you could extend the cable that goes to the gauge, but not the other. Phillip is right, the wire and the length of it is critical to the calibration of the gauge. The voltage from the sensor is very low, and the wire has a specific resistance, for the reading to end up correct. Call the gauge mfr. , and I'll bet they tell you the same. If not, please let us know.

 

[JBlock]

Dash Pod

I got a nice painted to match Dash Pod that holds three guages from -- email address removed --



Great guys, furnish the guages and connections tubing adapters everything at a good low price.



Joe

 

[dshockley]

I just spent a few minutes searching for some sources to support my understanding of the thermocoupling effects. Basically you can splice thermocouple and you can extend them to any length provided that all junctions are maintained at the same reference temperature. I have attached an excerpt from one of the sources that states that they can be spliced. This theme was repeated over and over in different sources. Maybe some of the manufacturer are not using thermocouples. For instance, an RTD is very sensitive to wire length.



Thanks for all the input and now I am going to make a call to VDO to see how their Pyro is set up.



Dan

 

[dshockley]

I just priced gauges and here is what I found out.



I can get four cockpit series VDO gauges (pyro, tach, trans temp and boost), with one vdo gauge cup and sending units for $270. 30. However, I have to figure out the tach signal. I have an early 1991 so it does not have a crank sensor. What have other people done that have not used one of the kits that includes a sensor? Buy one of the other gauge companies sender? Use an alternator signal? I really like these gauges and would like to go with them. The price is great so I can't complain about that.



Thanks for your input,



Dan



And the pyro is 12' so it will reach and I don't have to worry about whether the science will hold up or if Philip's experience would prevail.

 

[dmurdock]

Good luck... lookin forward to seeing the custom pod... You shouldn't have any trouble with the length, especially if you go thru the passenger side somehow...

 

[Philip]

Post some pic's when you get the over head done. I was looking for something like that a while back when I bought my Auto Meter pillar mount.



That 12' thermocouple should reach even going threw the drive side access plug by the booster.



I hope you don't have to test to see some of the problems with extending TC's. Those things cost to much to play with. If it was in a factory where someone else payed the bill to experiment. Then you can play around a little. But I prefer not to do that with my $$.



The testing I did to see what splices did to the actual readings was done with the use of a infrared temp probe,a digital temp probe, and a digital volt meter with a K type temp probe on it. 90% of the time a splice did change the readings enough for our application to cause problems with the mfg of plastic parts. This was only in the 400 to 600 degree range. Our trucks will double that if you bomb it. So the readings could be off a lot in a higher temp range.