Which Gauges?

[jjohn]

HEY Dkevdog

Originally posted by Dkevdog



The post EGT guage probably isn's necessary, but I like to watch the difference between the two- you'd be amazed how long it takes for the post turbo temps to come down after towing!





Kev

Just curious what kind of temp. difference you see pre and post EGT's in "different situations". unloaded loaded. Does the post EGT reading cool faster at idle than the PRE? I have heard that because the manifold retains and radiates more heat that the Pre side it will reads higher longer.

Thanks JJ

 

[redneckdr]

pre and post turbo probes

i, also, have both pre and post probes hooked to one gauge, so i'll chime in. i have a DPDT switch at the end of the leads, then wire to the amplifier, and then to the gauge. interestingly enough, on my truck, the pre probe T* drops faster than the post for cool down. generally about 50* difference at cool down with the pre cooler. under load the pre will generally run about 150* higher than post.

 

[jjohn]

Thanks Herb

Tell me more about DPDT?/ amplifier (why amp. needed) sound interesting.

JJ

 

[redneckdr]

EGT gauging

ok, jj, here goes... . i have Isspro EV's. with the EGT gauge comes an amplifier (i think most gauges have one--the signal from the probes is quite weak/small, though finite) that goes between the probe, and the gauge. i ran my gauge with just the pre hooked up for about 3 weeks, to get a baseline "feel". i had read that adding wire to the leads would yield false readings, so i wanted a baseline. i then ran the two leads to a mini DPDT (double pole, double throw) switch. from the middle poles wires go to the amplifier, and the same wires from the amplifier as before. there is little or no difference in the readings before and after adding the switch and extra wire. i now have the advantaqge of two probes with one gauge. i placed the switch in the edge of my pillar mount so i can switch on the fly, or whenever i want to. i generally "run" (and definitely pull) with the pre turbo temp, but cool down with the post. in this pic in the reader's rigs, the black DPDT switch is barely visible beside the EGT gauge. https://www.turbodieselregister.com/user_gallery/displayimage.php?&photoid=552&width=2

 

[jjohn]

Thanks again Herb

LOOKs good nice setup. I just ordered gauges and like your Idea, I'll look into ordering a additional probe for the Di-Pricol gauge. JJ

 

[redneckdr]

here's a link to a not very good pic of the probes.

https://www.turbodieselregister.com/user_gallery/displayimage.php?&photoid=551&width=2

jj, if you have any questions about the wiring, PM me.

 

[Dkevdog]

Re: HEY Dkevdog

Originally posted by jjohn

Just curious what kind of temp. difference you see pre and post EGT's in "different situations". unloaded loaded. Does the post EGT reading cool faster at idle than the PRE? I have heard that because the manifold retains and radiates more heat that the Pre side it will reads higher longer.

Thanks JJ

Normally you see about 300* to 400* difference. I found things to be quite the oppposite (at least in my case) to what you seem to have heard. What I found most interesting was that after a long hard pull up a grade, the post temps would take up to 5 minutes to drop back down to 300* ! I attribute this to the Turbo getting real hot and retaining the heat - then taking some time to cool down. As for unloaded, I found the temps to be closer to the same. The point being made though, is that just because a pre T gauge is reading a "safe" shutdown temp doesn't mean the turbo has really cooled off yet. Under average driving even with small load, it could take as long as a minute or two for two gauges to read the same.



Kev

 

[redneckdr]

yeah, kev, my experience is the same as yours. if i have been pulling hard with pre EGT at 900* or above for a awhile, and go to shut down, i find that it takes a long time for the post to drop to 300*. pre will be at 300* some times at least a minute or more before (never put a stopwatch on it) the post T* drops to 300*.

i also don't think i've ever seen more than 200* difference in the two T*s. running or pulling, pre will be higher. at cooldown, post will be higher. obviously, there is a time in cooldown where pre and post are equal as pre "passes" post coming down.

i now pretty much leave my switch on post turbo reading--unless i'm towing. i've now learned that with my setup, in normal driving, i don't need to worry about the pre turbo reading. in normal day to day driving NOT towing, i use the post turbo reading MORE than pre--for cooldown.

 

[Woodenhead]

Autometer from Genos. Boost gauge would stick a little around 10 psi since new. I called Genos, they sent me a new one to swap out. Then I just sent them the old one back. They even sent me the return postage for the old gauge. Amazing customer service and I love the gauges.



Mike

 

[jjohn]

Dkevdog, redneckdr

Thanks guy, Good info.

 

[Mtngoat]

Gauges

I've had my truck all of 4 days so far and I've Line-X'd the bed, installed a rolling lockable cover on the bed, and put nerf bars on so the rib can climb into the truck. Like she says, her name is on the loan, too. Gotta keep her happy. Gauges are the first thing I am doing before anything else. Seems like pyro, boost, and fuel pressure are most important, altho some say trans temp (auto) also. Is there a fuel pressure gauge that is accurate that does not bring fuel into the cab? I plan on putting 3 on the pillar and the other somewhere else. If this is off topic, maybe it should go elsewhere, still learning my way around the TDR.

 

[Sparky10]

I was leaning heavy towards the Dipricol but now thinking about going for the Westach for the combo gauge. Lets me have 4 gauges in the place of 3. Neat idea!



Great info here, Thanks!



Scott

 

[Greystoke]

Autometer x 4

https://www.turbodieselregister.com/user_gallery/displayimage.php?&photoid=22&width=2