HELP...guages...what are they trying to tell me?

[JEBar]

My truck goes into a shop tomorrow to have a 15,000lb Waran Winch w/ stainless mounting kit installed ... I know how to use a winch so no problems anticipated. However, largely due to reading about them here, am also having EGT and Boost gauges installed. I have no ideal how to interrupt the readings the gauges are designed to give me. What is high? What is low? I should be concerned when a reading of ???? appears? I've been told to let my truck idle a few minutes before shutting it off. With the EGT guage tell me when it is OK to do so? Any help would be sincerely appreciated. :confused:

[mackin]

JeBar,

Since your stock you can build your own base numbers ...... Boost stock you'll probably see nothing over 22 PSI under load, climbing heavy on the go peddle.
Normal driving runs 10 PSI or under ........ EGT stock again, You can see as high as 1200 degrees F under load like above ..... Normal driving runs 400-800 degrees F ....... It all depends on your terrain and driving . Once you toss in some mods, whole different story ...... I would recommend pre turbo on your PYRO .......... Most accurate ....... Boost pressure sensor, well most tap into wastage it's pretty accurate ..... What guages did you go with? ...... If you want, see my D/A PICS of my guages ....... I've seen 30 PSI boost (wastegate plugged).... A 1300 degree F EGT , both a spike reading with the JUICE ......
Good luck ......
MAC :D
On edit: Idle down, I try to shut mine down at 300 degrees ... Sometimes it's a pain in the arse ...... Takes about 1 min or so to idle down 100 degrees seems like eternity ....... Especially to my wife ..... She's all ways. COME'ON will ya .. LOL :rolleyes:

On edit : fixed post turbo to pre turbo

[ 05-20-2002: Message edited by: mackin ]</p>

[JEBar]

Mackin...thanks for the info, printed it out and will refer to it more than once. Am not sure about the brand of gauges, I'm leaving it up to the owner of a local truck specialists who's consistently made good recommendations over the last few years...have already seen pictures of your gauges, liked them so well, mine will be mounted the same way. I have a Duramaximizer on order so thought I'd get the gauges in now so as to have some before and after numbers...do you let your D'max idle a while prior to turning it off?

[mark45678]

there seams to be a little problem with mackin's numbers 1300*f PRETURBO and 1000 post turbo are the same or there about....IN anycase any hotter and your going to hurt it... as far as boost mine is in the intake manifold right at the heater and I have never seen more then 19psi in stock trim.... the stock wastegate as far as I know is set at 26~27 lbs... Over boost can cause high egt due to the intercooler being to small or can blow head gaskets or worse... smile.gif

[mdrag]

JEBar,

http://forum.62-65-dieselpage.com/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=3&t=002238&p=

Here is a good link discussing EGT probe placement. Exhaust manifold probe placement will give you a more accurate EGT reading. With the SPA DG-111 boost/EGT gauge, I can immediately see the EGT go up or down 15-30 degrees by turning on/off the AC or high beams. Post turbo will give you a better idea of temps at the turbo and idle down time - most seem to use about 300* for a shutdown temp.

As mackin pointed out, wastegate boost levels will max at about 22 psi in a stock Dmax. The wastegate reading will be a little higher than measuring manifold boost - my guess is 2 to 4 psi higher. Forum members have posted max boost levels of 26+ on modified engines...

I think a sustained post turbo EGT of 1200* may be pushing it a bit - my max for a near manifold EGT probe placement was a brief 1286* F spike in a stock engine, and usually below 1200*. To the best of my knowledge, none of the 'experts' have come out with a safe max EGT for the Dmax and all seem to dance around reporting this number - most likely because they do not yet know...

Once you have your gauges, you will get a feel for what is 'normal' for your vehicle, and if you notice abnormal EGTs or boost levels - it should help troubleshoot the problem before major problems develop. Others use the gauges to modify their driving habits to get the best fuel mileage...doesn't work for me - I'm always trying to peg the boost level and see that little warning light flash... The SPA DG111 has programmable warning LEDs for max boost and EGTs, I set the boost warning at 22 psi just for fun... :D

[More Power]

The easiest place to install a pyrometer is post turbo, likely in the downpipe or the first section of the exhaust system.

However, that is not where the most accurate EGT numbers will be found. The turbocharger is a dynamic device, and will absorb heat differently depending on the engine load and RPM. EGT's can vary as much as 100-300 degrees across the turbo. Measuring EGT's post (after the) turbo is only a estimate.

The best location for a pyrometer is pre-turbo - anywhere from the exhaust manifold to the turbine inlet.

The Duramax 6600 is the only light-truck diesel with an oil cooling channel incorporated in its piston design. This helps improve durability in high load situations, but pushing beyond 1250 degrees EGT comes with increasing risk.

MP

[mackin]

JEBar,

Yes I do let it idle down to 300 degrees .. Takes less than a minute from 4-425 degress ......... My numbers are pre turbo not post sorry ...... I'm going to edit my oringinal post ..... My mistake ......

Thanks mark45678 for pointing that out ........
MAC :D

[mdrag]

Thanks MP!!!