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  #1  
Old 03-08-2014, 01:21 AM
Tapani Tapani is offline
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Trans temp gauge with output for external relay?

Do you guys know other products with a programmable output for an external relay / warning light?

http://www.marshallinstruments.com/products/5037.cfm

Thanks,

/T

edit: Here's another one: http://www.spa-uk.co.uk/Products/View/67

Last edited by Tapani; 03-08-2014 at 06:37 AM.
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  #2  
Old 03-10-2014, 11:24 AM
NiftySVX NiftySVX is offline
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Re: Trans temp gauge with output for external relay?

That is cool! The dakota digital one we were discussing had that capability, not sure if they still do or not. But I like that analog one better than the digital dial. Thinking of using it to run the fan are ya? Or the AT OIL TEMP LIGHT?
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  #3  
Old 03-10-2014, 11:42 AM
Tapani Tapani is offline
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Re: Trans temp gauge with output for external relay?

The cooler fan

I agree the analogue one is cooler , but the double digital would allow monitoring true engine coolant temp too - instead the dead zone OE gauge

/T
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Old 04-26-2014, 08:58 AM
Tapani Tapani is offline
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Temperature readings from gauges vs TCU?

Does anyone have transmission temperature gauge readings compared to numbers from the TCU?

I installed the Marshall gauge - very nice and controls the cooler fan too :-)

I drilled and tapped the drain plug ofr the sender - see photo. I know theres a bit mass and hysteresis involved here, but I drilled as large a hole as I safly could so that the sensor would be immersed in fluid even though it is sort of "inside" the plud....

When on the move the gauge reads app 25 F lower than the TCU. Measuring the pan surface temp with an infrader thermometer it is very close to the gauge reading (right after coming to a stop). The transmission case is quite a bit hotter - approximately the same as the TCU reads.

When idlling with heat soaked engine and tranny the gauge reads 10F lower than the TCU. The TCU is 186-188 F very constantly, the gauge 170F - I have the thermostatic bypass valve set at 180 F cooler line temperature.

I insulated the plug/sensor so that airflow would not cool it from the outside - have not taken it out after that.... chose a beer over another drive :-).

If any of you have any numbers it would be very interesting to compare notes :-)

Kind regards,

Tapani
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  #5  
Old 04-26-2014, 04:17 PM
NiftySVX NiftySVX is offline
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Re: Trans temp gauge with output for external relay?

My friend I would assume that you are seeing this disparity due to the fact that the sensor for the TCU is placed in contact with the valve body. One would guess that the metal of the valve body itself would be of a different temp then the fluid in the sump as the ATF can dissipate heat so quickly and the aluminum cannot. That would be my guess.

Also, nice plug design. I did one like that myself

EDIT: Pics of where you put the gauge? Mine is in place of the ash tray.
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Last edited by NiftySVX; 04-26-2014 at 04:22 PM.
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  #6  
Old 04-27-2014, 05:24 AM
Tapani Tapani is offline
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Re: Trans temp gauge with output for external relay?



Yeah, my thoughts are a long those lines too. The tranny goes in overheat mode at 101C (214F). And this is naturally sensed by the TCU.

I've adjusted the cooler fan to kick in at 190F measured by the external gauge.

Adjustment is very easy, so I will just have to drive more to get a good feel what's going on.

I took out the boost gauge - so now I have the wide-band and the trans fluid gauges where the ashtray used to be .

/T
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Old 04-27-2014, 08:51 AM
NiftySVX NiftySVX is offline
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Re: Trans temp gauge with output for external relay?

I need to build a panel like that for mine. I am considering switching back to analog and using a mechanical pressure gauge to measure main line, but am worried about having a pipe running ATF into the cabin.

Are you using custom software? Or is the JDM tcu different? I thought that over temp & light was 220. I know you mentioned the two stage overheat which is a new bit of info for me.

As we discussed, I have never seen or heard of anyone heating the fluid in the pan to that level except for one who's trans was slipping very bad and was trying to get home.

I am not sure why I didn't think of it, but I should have put my sensor inside the pan and run the wire outside with the main loom.

Are you using a stock TC? I should send you my old level ten one.
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  #8  
Old 04-27-2014, 09:31 AM
Tapani Tapani is offline
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Re: Trans temp gauge with output for external relay?

Two laps on track used to cause mine to go into overheat mode.

From Phil:
According to my notes:

Overheat mode turns on at 101 C and off at 99 C.
AT OIL TEMP light turns on at 107 C and off at 104C.
I used to run a TC from a 1996 4 cyl Outback - this gave me a stall speed of 3200 rpm which is way too high for my engine .

Now I have the stock JDM SVX TC and the stall speed is roughly 2700 rpm. I wouldn't mind an even lower one :-), maybe 2500 rpm. There's plenty of mid range in my engine with the small turbo and 5-6PSI boost and this is wasted with a high stall converter. Thanks for your offer, though !

I run stock 1996 JDM firmware and the QC from Harvey + power mode switch. Adjusting the TPS to 0.55V this seems to be a very good setup.

I drove bit, tried a few short wot runs but could only reach 189 F at TCU. The gauge was spot on after I let the car idle for a few minutes, but roughly 15 F behind when on the move - I put some pipe insulation on the sensor/plug to prevent air flow from cooling it. I need to think about what you said - attaching the sensor to the valve body and running the wire along the others.

The fan had no effect - I bet the thermostatic bypass is only starting to open the cooler circuit and the cooler itself it plenty efficient even w/o it.

I need to get on a track to get some heat to the tranny. Not possible in traffic w/o loosing my license .

Interesting stuff.

/T

Last edited by Tapani; 04-27-2014 at 09:34 AM.
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  #9  
Old 04-28-2014, 08:12 PM
Tapani Tapani is offline
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Re: Trans temp gauge with output for external relay?

I made another plug - this time as hollow as possible - no effect.

Anyone else with real life numbers from the tranny?

What do you gius think about the bypass valve? Would it be better to run the cooler w/o the valve in the summer? I would have thought the 180F temp range would be perfect.

/T
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  #10  
Old 04-29-2014, 12:19 PM
Tapani Tapani is offline
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Re: Trans temp gauge with output for external relay?

I made an extension to the sensor 0,1mm tight fit, brass was easy enough to press in place. 17mm inside the plug, 8mm protruding, 13mm diam. See photo.

The heat flux from the fluid to the sensor should be much, much closer to the TCU sensor now - maybe not identical, but closer than before.

Too late to go for a spin. I will report tomorrow....

/T
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