kstrongsyj

Be searching a lot on this lately and have many conflicting reports. I should be getting my ISSPRO guages tomorrow UPS, and I wondered what your guys' consensus on pre turbo temps should be before shutting down? 450? 400? less?

TXRAM2

personally, I never shut down above 300 pre turbo, and most of the time I let it come down to 250 my 0.02

Shovelhead

300* pre-turbo here too.

barracuda

250.....pre-turbo......

GrandpasRam

300 to 350 is for post-turbo, as it indicates how much the turbo housing has colled down (and therefore will not "coke" the turbo with frying oil). Pre-turbo cools down to 200 - 250 too quickly for me to have confidence that the turbo housing has cooled that much, so I give it the idle times recommended in the owner's manual. Later this year I will be ADDING a post turbo to my pre-turbo, and replacing the current guage with a dual guage so I can monitor both. The pre-turbo tells you when you are working the turbo too hard (too much heat going into it), while the post-turbo tells you the residual heat coming off the turbo housing. My old '99 had a post-turbo, and I would let it get to 300 before shutdown, and that didn't take very long after driving through my neigborhood to my driveway. For pre-turbo, it appears as though 1 - 2 minutes at 200 - 250 is sufficient for a shutdown.

KATOOM

<br><br>Good luck getting it to reach 200* at any safe idleing time limit. Especialy in the summer heat. Everyone will tell you that 300* is the prefered shut down temp (pre turbo). And it should depend on how hard, not how long, you drive to reach this number. The engine and turbo is not creating a lot of heat unless you are working the motor. <br><br> ???<br><br>A pyro tells you how hard the motor is working, not how hard your working the turbo. Thats what a boost gauge is for. A pyrometer is not for turbo safety untill your trying to reach shut down temp. It's real purpose is to monitor the temp that the cylinders are reaching. 1300 plus degree's coming out of the motor means your close to the safe working temp of the Cummins. Turbo's can work at much high temps than that. Pre turbo shows the real temp coming out of the motor, and post show the temp after it has exited the turbo (cooler temps). Thats why you need to add 300* to post turbo readings for safety.<br>Sorry, not trying to prove anyone wrong here.

OverFueled

You mentioned ISSPRO gages on the way. Were you talking about the turbo temp monitor? I believe you were they also make other gages as well. So that is why I am slightly confused. The turbo temp monitor is automatically set to shut down your T.D.C. at 300 deg. It can be changed from 200-500 I have tried to “play “ with this it is very sensitive. To change it, it also has some glue on it to keep it set on one place. The diesel will change the setting with all the shake rattle and roll. I know it does not say that in the owner’s manual to shut down at 300 deg. but it does mention to give it some time to cool down before shutting off. About the turbo temp, I got one. It works slick, set parking brake, turn key off and walk away! It won't let the engine run any longer than necessary unlike the timers which are a guessing game. It attaches to the pyrometer that I installed previously, a fused wire to the battery, and the other end to a large blue wire on the steering column, I have an 02 the wire color for you could be different. Also I just installed a immobilizer that works great with this turbo temp as well. Life is GOOD. When I know my truck will be where I parked it. OverFueled

KATOOM

I had the ISSPRO turbo temp monitor also and returned it. I couldnt stop the AIR BAG/ABS lights from blinking and alarming when I shut down. Plus I couldnt set the truck alarm system with the TTM working. If I have to stand there and wait for the thing to cool off enough to shut down and then set the alarm, I might as well sit in the truck and save myself the money!

CTD99

I've noticed that after shutdown the gauge will go back up about 25 degrees from the shutdown temp. Does anyone else experience this and do you take it into account when shutting down?

KATOOM

Yes, it is the heat soak from the turbo and manifold. If I have been driving hard for a while without idling around where ever I have gotten then I will let it idle for a while longer. The same thing happens to your coolant temp. The water sitting in the block soaks up the residual heat.

Homestead

Hey Overfueled!!<br><br>I'm curious about your immobilizer. Where did you get it, do they have a website, etc?<br><br>Thanks

OverFueled

Homestead, I picked it up at http://www.bluechipdiesel.com I call it the awesome Dodge Diesel Immobilizer switch this will fit any year truck electric fuel pump or not. It also works with Ford, chevy, toyota.<br>1.)Even if you have the key it will not start.<br>2.)Factory looking install ( no big black box to look for and jump out)<br>3.) It cuts out the fuel pumps ( I have 2) along with the power to the key at the same time.<br>4.)It puts a LED in the overhead display to see it is on flashing or straight on.<br>5.) The on switch uses the door lock or push switch under the bolster in the cab your choice to activate. I use both some times.<br>6.)The off switch is very unique. The best part of the whole thing. It has a special electrical magnetic switch that turns it off only you know where this switch is in the truck.. With out it you don’t go.<br>7.)This also works with other items in the truck like my turbo timer.<br>OverFueled<br>

me4osu

I guess the 03s cool down a lot quicker than the VP-44 ISBs. I have to do a little engine braking and let it idle to come down to &lt;350 when it is really hot outside. I shutdown between 350 and 300 pre-turbo.

doug

[quote author=KATOOM link=board=4;threadid=14777;start=0#138611 date=1053033634]<br>Pre turbo shows the real temp coming out of the motor, and post show the temp after it has exited the turbo (cooler temps). Thats why you need to add 300* to post turbo readings for safety.<br>Sorry, not trying to prove anyone wrong here. <br>[/quote]<br>right, but don't forget that the 300 degree rule applies to stock conditions. If you are modified enough to need a pyro, then you're operating outside of stock conditions and the temperature difference across the turbo is greater than 300 degrees. Seems to me those that are installing both pre and post thermocouples are reporting 400+. so you and agree I'm sure that post turbo, for high HP engines, is a dangerous way to measure EGTs.

doug

and as regards picking a good post-turbo temp at which to shut down -- the oil flash point is about 450 degrees so you don't want the turbo housing temperature (as measured post turbo) to approach that number. Seems to me you could shut down at 400 and be safe, no?