Time for Guages

[Fatboy]

The old girl is fourteen and its time for a triple A pillar guage set up. Questions that I have are;



1. On the pyro, pre or post turbo? Considering usefullness of info while driving and ease of install.

2. What range on boost? 0-30, or 0-40?

3. What range on the transmission? 280 or 320?



I am leaning towards Isspro since they seem to look most like stock 97 guages.



Thanks for your input.



Steve

 

[BigPapa]

I like the original Isspro EV's, NOT the EV II's.

1. I would suggest pre-turbo. It's really no big deal to drill and tap the manifold.
   
2. I don't think they offer a 40psi gauge. I would go with the 60psi over the 30psi.
   
3. I would go 280* on the transmission temp. You really don't want to see over 220*-225* in it.
   

My . 02 worth.



Scott

 

[Bob4x4]

The old girl is fourteen and its time for a triple A pillar guage set up. Questions that I have are;



1. On the pyro, pre or post turbo? Considering usefullness of info while driving and ease of install.

2. What range on boost? 0-30, or 0-40?

3. What range on the transmission? 280 or 320?



I am leaning towards Isspro since they seem to look most like stock 97 guages.



Thanks for your input.



Steve

Always pre-turbo if you want to know whats going on acurately,there is too much variation when mounted post turbo

If your truck is a Mass truck IRRC it may have been built with the Cali emisions.

The stock boost will be up around 18-20 psi,if modded go for the 30 if mild and 40 if it is a hot rod

The trans gauge is more of a personal decision,I would never run mine as hot as either of your choices... ... ...

 

[JMarketos]

I'm often surprised how quickly people respond to this question by recommending to install EGT pre-turbo, without asking what is the user's main interest in having EGT gauge.

Pre-turbo temps, that is the temps measured closest to the cylinder head exhaust ports- they respond quickest and reach the highest peak temperatures when the engine is under load. Pre-turbo temps also drop quickest once you take your foot off the fuel pedal.

Post turbo temps- that is the temp measured somewhere on the exhaust output side of the turbo turbine wheel- those temps tend to lag the pre-turbo temps, and they don't reach as high peak temp as the pre-turbo (because exhaust heat is consumed doing work and dissipated at various spots). But... the post turbo temps come down a lot slower than the pre-turbo temps, due to the residual heat retained by the turbo assembly.

If the main focus is on watching peak temps under load, to make sure something doesn't exceed a limit or burn up etc. , then a pre-turbo EGT is appropriate.

If the interest is in cool down, to make sure the oil left in the turbo doesn't get "coked" when the engine is shut off, then a post-turbo EGT is appropriate. (note if you come off the road and stop, especially on a hot day, and shut off when the pre-turbo EGT gets down to about 350 or so, the post-turbo EGT is typically still well above 350, and can remain that way for a significant time. )

Some manufacturers make gauges that have two measurement functions inside one gauge body. That opens up the possibility to have more than 3 measurements in the triple gauge A-pillar. But of course, it also opens a wider hole in the wallet...

Wish you all the best.

 

[HBarlow]

Since the primary reason for a pyro gauge is to monitor cylinder temperature, pre-turbo temp is the most accurate and most responsive because it is measuring exhaust gas temperature (EGT) at the exhaust manifold, closest to the exhaust valves.

Measuring EGT post turbo requires the driver to always guesstimate real temp and add an estimated 300* or 400* to the gauge reading.

It's a no-brainer to me.

 

[JMarketos]

Since the primary reason for a pyro gauge is to monitor cylinder temperature...

=
That's your assumption, not necessarily everyone else's. Note OP did not indicate reason for wanting EGT gauge (and there are at least two significantly different reasons... ). Depending on the user's intent, it might be specifically desirable to employ a post-turbo EGT gauge rather than pre-turbo.
=

Measuring EGT post turbo requires the driver to always guesstimate real temp and add an estimated 300* or 400* to the gauge reading.

=
Not always, and again due to the same assumption. During cooldown, the post-turbo EGT reads higher than the pre-turbo EGT, and can be so for significant amount of time depending on conditions.

 

[Bob4x4]

To add some prospective to this discussion... ... . I have been involved with CTD's in Dodges since '89. I have yet to see an HX35 damaged on a truck that has received anything close to normal maintenance by excessive heat at shut down due to thermocouple placement :-laf.

However I have seen numerous damaged cylinder walls by unsuspecting owners that had t/couples mounted down stream of the turbo. In my independant testing,towing a load with both pre and post t/couples and gauges(known to be accurate) I saw over 600 degrees in variation when hitting steep grades with an unaceptable lag time before temps came significantly close. At shut down the temps are not very far apart at idle.

Dodge has published cool down times in the later year owners manuals and they have been posted many times here on this forum as well.

In my opinion pre turbo is the way to go on a Dodge truck

 

[HBarlow]

I once watched my EGT gauge and counted the minutes the truck idled to reach the shut down temperature of 300*.

Oddly enough, the recommended time delays to reach shut down temps on my exhaust manifold mounted pyro are almost precisely in agreement with the delay times specified in the owner's manual.

Each to his own but I will say it again. It is a bad plan to install the temp sensor downstream of the turbo then guess at what temp the EGT actually is.

 

[NIsaacs]

There are way more pickup trucks on the road without an egt. gauge then with. Any placement is a good thing. My personal choice is post and I don't guess what pre might be. If it gets to 1000* post, thats my max. It works for me.



Nick