LBZ: High EGT's even with supposed EGT Friendly tunes

[rennat_2006]

Noticed a couple months ago when pulling my blazer with a superchips tow tune that my egts were definetely getting warm. This was pulling a good sized grade at 100*so i didnt think much of it.

Fast forward a couple of months and after doing some testing and playing around with different tunes for some reason im still running hot even unloaded. With a superchips towtune loaded i can hit 1300/1350* with the truck empty, Loaded a hypertech max energy level 2 tune and im able to hit about the same with it at wot with the truck empty.

My truck never used to run this hot on tow tunes. If i remember right about the highest i could hit was 1200* empty at WOT at like 90mph with the superchips tow tune loaded. Both the superchips and hypertech supposely are "EGT safe" tunes and hypertech even says you can tow on any of the three levels without worry.

Troubleshooting ive done so far...
-Cleaned the air filter on the sb intake
-Took the MAF out and sprayed it down really good
-checked injector balance rates(highest are -/+ 1)
-loaded the hypertech tune to see if there was a problem with the superchips tune

Anybody got any idea's?

 

[LWATSON]

How are your EGT's on your stock tune?

 

[JoshH]

Have you checked for boost leaks?

 

[Dozerboy]

Maybe the problem is your EGT gauge or its your imagination. Whats level 2 60hp? 1300* doesn't sound out of line to me.

Hows your boost look? Any extra smoke?

 

[rennat_2006]

How are your EGT's on your stock tune?

I will give it a try tomorrow and report back

Have you checked for boost leaks?

Pressure still seems to be there according to my gauge but ive noticed for the last 6 months or so my gauge flutters.I will check all of the clamps but usaully you can hear it.

Any extra smoke?

Not that ive noticed

 

[Philtopgun]

Even at stock I would do 1450*. Wasn't til I did the intake and full exhaust did I get my temps below 1300* at wot with stock tune.....

 

[ltr450ryder]

i hit 1200 today pulling a trailer so i can see why 1300 would be back im stock besides egr delete downpipe and 4in exhaust so i think your fine..

 

[Hot COCOAL]

Sooooo

What is too hot for stock pistons? Assuming thats the limiting factor. What/where is the proverbial line, & for how long can you sustain said temp? Empty or towing?
After reviewing some posts, it seems like there is some discrepancy in this matter?

Some guys dont like to push past 1450 while others say 1600 or so, and yet some pullers have said they have seen like 1800??? WTH?

Is there different known acceptable temps for different engine's? ie lbz, lly's and lb7's.

Thanks in advance

Ive got an lbz with a 4094avant and robs tunes on a dsp5, bd intercooler, bla bla bla
I saw 1400egt, empty @ wot @ like 38psi @ over 120mph? I thought that was pretty good, is it?

 

[rennat_2006]

The problem though is i know my truck never usedcto run that hot.

Ive got a sb intake and 4/5" flopro exhaust on it. I say 4/5" cuz the intermediate pipe right off the downpipe isconly 4" then everything aftrr that is 5".

 

[ikeG]

If your bst gauge flutters, maybe its the intercooler leaking? I know 04-05 LLYs intercoolers can leak. Dont know about LBZ ones

 

[DMAXchris]

1350º isnt hot while loaded. Start worrying when it hangs at 2k for a few miles.

 

[Dirtymaxx03]

1350º isnt hot while loaded. Start worrying when it hangs at 2k for a few miles.

^this. my truck has pegged a 1600* gauge for every bit of 10 solid seconds, multiple times

 

[rennat_2006]

No 1350 unloaded guys. I could easy bury the gauge loaded

 

[Dirtymaxx03]

i never pull a load....

 

[DMAXchris]

No 1350 unloaded guys. I could easy bury the gauge loaded

My truck had seen 1700º probably 1000+ times when it had a stock turbo/motor.
It's really nothing to be concerned about as long as you're not holding it there for long periods of time.

 

[rennat_2006]

1250* stock tune unloaded hammering on it on a freeway on ramp up to like 90mph. 55* outside temperature

1250* is what i used to see max running the tow tune from superchips at WOT doing the same thing. I dont know what stock used to be, Dont think ive ever ran the stock tune in it actaully up until tonight.

 

[adeso]

Sooooo

What is too hot for stock pistons? Assuming thats the limiting factor. What/where is the proverbial line, & for how long can you sustain said temp? Empty or towing?
After reviewing some posts, it seems like there is some discrepancy in this matter?

Some guys dont like to push past 1450 while others say 1600 or so, and yet some pullers have said they have seen like 1800??? WTH?

Is there different known acceptable temps for different engine's? ie lbz, lly's and lb7's.

Thanks in advance

Ive got an lbz with a 4094avant and robs tunes on a dsp5, bd intercooler, bla bla bla
I saw 1400egt, empty @ wot @ like 38psi @ over 120mph? I thought that was pretty good, is it?

Piston life is an equation of temp, time, HP (really TQ and RPM if you break it down) Seems the guys that are making the engines live for long amounts of time at high HP are doing it with low EGTs from lots of air and short PW. Every time you get that piston really hot (I think over 1400-1500 but that is my guess) that you are not helping it at all. Now if you do this for 3-4 seconds on the back side of the run then you are not heat soaking the piston. Do it for 2 minutes up a big grade with a trailer, different story
LB7s and LLY have better pistons

 

[Dozerboy]

IIRC GM says 1350* sustained

 

[RobsDmax]

another thing i just thought of looking from the outside where is everyone reading egts as that could change things

 

[adeso]

IIRC GM says 1350* sustained

I think that number is from the turbo for sustained TIT, and that GM never said anything about pistons. I could be wrong though