Reaction speed of analog EGT guages/pyrometers...

[zman]

After seeing several other analog EGT guages in action this past weekend, I have come to the conclusion that my setup is VERY slow reacting.

I'm running the VDO vision series EGT guage with their standard thermocouple setup. The thermocouple (TC) is installed post turbo. The readings are very slow compared to what I have seen. Should I be using a different TC to get faster reaction times - or could the guage be bad? Will other TC's work with the VDO guages?

Also, is the temperature fluctuation considerably less post turbo than pre turbo? The guages I saw were all pre turbo and reacted VERY quickly - a couple of seconds to move 600 degrees. My post turbo setup would take forever to make that change.

I'm looking to add a TC pre turbo, but want to make sure that I get something that will work well. If I end up changing TC types, I'll want to replace the post turbo TC at the same time. All input is appreciated!

Steve

[This message has been edited by zman (edited 03-06-2001). ]

 

[Arcticat]

Most likely your gauge is fine. The problem is the spot your probe is mounted. I have mine post turbo and it is way slow reading. Eventually it will reflect what is going on in your engine, but by then the damage will be done. I'll be adding a probe preturbo very soon.

 

[LSMITH]

Steve, the smaller the probe (in the exhaust flow) the faster it will respond. Small probes have less thermal mass and respond quicker, but they will also erode faster. I will take response over life any day. New probes are less than $20 in a lot of cases. I have mine pre-turbo and the response seems instant.

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99 2500 QC 4X4 AUTO SB 24V LARAMIE SLT 3. 5 LSD 285-75-16'S SPA Boost/EGT Everything but leather NRA Member Great Lakes TDR Member

 

[zman]

What type and size of probe are you guys using?

 

[Bigsaint]

Mine moves like a tach. , well, it moves up like a tach. and down somewhat slower #ad
. Not that I have high egt's with my rig, they are very resonable considering the mods. I have. Anyway, my egt. gauge is made by DiPricol and is very responsive in it's pre-turbo location. The thermocouple is 1/4" NPT.

Scott W.

White 2001. 5 3500 ETH/DEE 4X4 Quad cab SLT,tow package and camper prep,Husky liners front and rear,DiPricol pyro,boost and oil temp gauges,Edge EZ,Psychotty air,Bully Dog stage III injectors,ATS 3 piece manifold,HX40 turbo,4" BD exhaust,4" BD E-brake,McLeod clutch,Mallory 4150 lift pump,Mag-Hytec rear,Mopar tonneau,Lund bug shield,PM tractor utility back up lights,Penda bed mat and blow by bottle is bye bye !!! I love the smell of diesel in the morning, it reminds me of... . VICTORY !!!
<A HREF="http://albums.photopoint.com/j/AlbumIndex?u=1231655&a=9089608" TARGET=_blank><font color=red>My Truck</font></A>
<A HREF="http://albums.photopoint.com/j/AlbumIndex?u=1231655&a=9089604" TARGET=_blank><font color=red>THE SAINTS</font></A>

 

[LSMITH]

My probe has 1/8" NPT fitting, the probe is a little less than 1/8" in diameter. It is an SPA digital.

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99 2500 QC 4X4 AUTO SB 24V LARAMIE SLT 3. 5 LSD 285-75-16'S SPA Boost/EGT Everything but leather NRA Member Great Lakes TDR Member

 

[Neal Cassady]

Hewitt makes one of the better thermocouples available. I believe these are the ones supplied by DiProcol in their kits.

Dave D

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2001. 5 QC, LB, 4x4, Auto, 3. 54, Everything but Leather, Bright Silver Metallic, ARE K Series, Diprocal EGT, Boost and transmission Temp in an Autometer Dash Pod, Westin CPS Platinum Step Bars - Black on Stainless

 

[Cooker]

zman,
Do you know exactly what thermocouple you have. VDO does make a couple different probes and some do respond better than others. If I remember correctly the faster probe is a 323-890

I hope the VDO isn't too bad. I have mine on the desk right now waiting to go in.

 

[Koa Man]

My DiPricol EGT gauge moves like a tach also. Nudge the throttle 1/4 inch and you see the gauge jump.

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1996 3500 Clubcab SLT, auto, 4. 10 limited-slip, TST #5, 370s, AFC spring kit, Psychotty, Dunrite converter, Trans-Go, DiPricol EGT, boost & trans temp. gauges, 9 ft. aluminum flatbed and tool boxes with Venco dump. Custom front bumper, Hadley air horn, PowerVision mirrors & 4" Stack Exhaust.

 

[Vaman]

My DiPricol is mounted post turbo and responds very quickly.

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98. 5 2500, 24v, QC, 4x4, 4. 10 LSD, short bed, Line-X liner, tow package, camper suspension, Westin nerfs, camper shell, TST PowerMax3, 275 RVs, EGT/Boost pillar gauges... Love my Cummins, no love for Dodge

 

[zman]

Looks like I need to replace either the thermocouple or the entire setup. For those that are running the DiProcol and Isspro guages, which thermocouples are you using for pre & post turbo and where did you purchase them?

Also, it seems like there are different types of thermocouples - in other words all thermocouples don't work with all guages. My first option is to try a different thermocouple that will work with the VDO guage.

Thanks for the responses, guys!

Steve

 

[Vaman]

There are different thermocouple types which produce different voltages for the same temperatures, therefore, the gauge has to be calibrated for the specific thermocouple type (not the specific thermocouple). My guess is that all our "truck" pyros probably use the same thermocouple type since they are all measuring roughly the same temperature range. Anyhow, after all that, I would buy the whole package from someone... I purchased mine from TST and I am very pleased with it.

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98. 5 2500, 24v, QC, 4x4, 4. 10 LSD, short bed, Line-X liner, tow package, camper suspension, Westin nerfs, camper shell, TST PowerMax3, 275 RVs, EGT/Boost pillar gauges... Love my Cummins, no love for Dodge

 

[boatpuller]

My Vision series is pre-turbo with the standard thermocouple that comes from VDO, it was a package deal. It moves very fast, I was surprised when I first got it how quick it changes when you hit a hill or hammer it, it moves even faster with bigger injectors.
Your location is probably why it doesn't move very fast. It does seem to go up quicker than it comes down, must be an anti-gravity thing,LOL.
Happy Rammin,
Caleb

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1993 LE W250 4x4 CC,Auto,3. 5's,LS. . Diamondplate,PowerWagon injectors,K&N,Egt,Boost,trans temp VDO Vision series, BD 3 1/2" Exhaust, 16cm housing,Mag Hytec Diff+ Trans pans,Transgo TFOD shift kit,Roadmaster Active Suspension.

Caleb Reese (per forum guidelines)