H&S BlackMaxx in 2008 Duramaxx

[Burn Down]

I dont know where you mounted your egt probe but the last d-max i did i mounted in in the manifold, well above the 9th injector. the vvt turbo still closes down the veins during regen to restrict air flow and increase egt's to get the extra fuel to ignite in the dpf
it kinda depends on what extended periods were talking about..

gm has this to say about d-max egt's
quote: The Duramax 6.6L in GM pickups (the Kodiak/Top Kick and G-Van use a different rating) has a limit of 1,365 continuous, with 1,435 allowed for transients of five minutes or less.

Ive ridden in trucks pulling straight creek pass and vail pass with egt's over 1600 and i have yet to see one go boom. that more then 5 min when loaded to 20k or more.

here is one i googled for ya for the OP go on the fourms and see for yourself some guys are pushing this motor to 1800 degrees not having issues, I dont recommend that tho.

http://www.duramaxdiesels.com/forum/archive/index.php/t-13011.html

I'm on DuramaxDiesels every day (same user name). If you ask 90% of the guys on there they will all agree with staying in the 12-1300 range for extended periods, especially towing... I would rather err on the side caution and run a little less heat and make sure I don't burn/crack a piston, push a head gasket, hurt the turbo , etc.etc. Besides you know how quick Egts can rise.

Robert you sound like your fairly savy with diesels, I'm sure you watch the egts close & know when to drop a gear, get out of the throttle, etc to control egts. Alot of guys you are giving advice to are new to diesels and they may not be quite as in tune with the engine as you or other experienced diesel owners are. Which is why I caution them on going nuts with these things, cause a destroyed engine/transmission is a twist of the knob away....

A little perspective for some of you on parts prices.
aftermarket rods that don't bend above 650-700hp $2500-3000.00
Arias or Mahle forged pistons (crack & burn resistant) $2000-2500.00
Head gaskets & studs $1000.00
New Mahle Monotherm forged steel pistons $4,400-6000.00
Machine the bottom end for new goodies $600-2500.00
& stock parts are as much or more than alot of the stronger aftermarket parts. Don't forget if you can't assemble one of these yourself... LABOR.

just a little food for thought... aluminum melts at around 1250. which i believe that most impellers on turbos are made of aluminum. so any temps above that will weaken the turbo on a metallurgic level. short pulls above that i would never worry about it. my buddies 06 dmax runs at 1400-1500 all the time with a bully dog tuner on it. and every time you step out of the truck it smells like a smelting plant outside.

You are correct aluminum starts to melt somewhere around there (Im not going to look it up). However the Turbine made of Inconel or some other exotic steel is the part of the turbo that is in the exhaust. The compressor wheel is aluminum and is part of the intake air going in to the engine.

For short burst, the piston and the design of the bowl is what allows it run in higher temps than what the aluminum would typically melt in.