When i drive the truck i sometimes watch the mpg and at 60mph i usually get about 19, the boost is usually somewhere arond 5psi and egt is usually around 5-600. But when i was driving it the other day the mpg was 13 and the boost was around 10psi, and the temp was at 750-800, this is all happend in 6th gear going 45mph. and i couldent get the temp down untill i took it out of gear and let it idle.

What temp do you start doing damage to the stock turbo?

would something be sticking in the turbo? what tells the turbo to produce boost?

 

What rpm is 6th at 45mph? Your cruising at 60mph numbers sound normal. I'll bet you were lugging it and that will definitely cause EGT to spike. 800 pre-turbo is nothing to worry about. Where is your thermocouple (pyro probe) located - pre or post turbo? Fuel makes boost. And heat (EGT). Fuel at low rpm without boost to flow it through the system makes excessive EGT.

Don't lug it, that's all.

 

Danger zone is above 1250*!

Your way ok... NadirPoint had great points! Legging it was probably the cause... I hit 800* hammering on it on stage 10 on my Quadzilla...

Boost is increased by and increase in exhaust flow through the turbine wheel.

You don't shut the truck down that hot do you? I have my Quad set to shut the truck down when the EGT's reach 300*

 

so your saying that it just got hot normally then when i slowed it down it just stayed hot! If that is the case why would the turbo still be producing boost while slowing down? and the probe is located just aft of the turbo. And i have no idea on pre or post, what is the difference?

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yes i allways make shure the egt is around 300 when i shut it down. I was just worried it could be a sticking injector or something making it hot.

 

After the turbo is not a very good spot for the EGT probe. Because the exhaust gasses have plenty of time to cool down through the turbo. Your probe should be located PRE turbo in the exhaust manifold itself...
I think what he was telling you was that because you were driving 45 in 6th gear that its way too low in rpm... Trying to maintain that speed in such i high gear means that your dumping allot of fuel and boost trying to maintain that speed. You should try to match your speed to the top of your torque curve for best fuel mileage and power.
Im sure it wasn't just the EGTs that were hot but engine coolant, oil, cylinders and such. So it will take time to cool everything down just idling.

 

should i move the probe to in the exhaust mainfold? When my uncle owned the truck he had it installed by the dealer.

 

Dealers and shops have been know to cheap out on pyro installs post turbo because it's usually easier to stick it in the exhaust pipe than to properly drill and tap the manifold, "if" they even know the correct location to place it.

800 post turbo for any length time lugging around 1500 rpm would definitely heat things up, especially if you were putting any decent amount of fuel to it. I'd relocate the thermocouple something like this:

http://stuff.is-a-geek.net/PhotoAlbu...ics/CRD_24.JPG

 

NadirPoint is correct... Dealers cheap out. Its tougher to do a manifold install. Plus you should be running truck when you drill and tap so that chips blow out the hole so they dont nuke your turbo!

This is where mine is place... I would suggest similar...

 

No need to do anything but drill, tap and check it. After install, pull intake hose from cold side and start truck. Look to see if turbo is spinning. 99.99999% of the time it will be. Replace intake hose, done. If turbo is not spinning, shut off truck and turn impeller beckwards to dislodge chip. Check again, done. Any chips go right through harmlessley into the exhaust pipe.

 

Hmmm did you tap it to while its running?

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That is some hot air!