I haven't modified my truck in anyway in the past 6 months. I've been driving her on the highway ALOT lately on 400 mile round trips to Austin & back for work. Been noticing an increase in my EGT's at highway cruising speeds.

70mph & about 7-12psi average with no load the EGT is up around 575*
with my pyro probe in the downpipe.

It seems like it used to sit at around 500* before, but even that seems high to me for being in the downpipe. Gauge is an AutoMeter Ultra-Lite 2-1/16" and the probe is about 2" from the turbine outlet flange.

What's causing this? Is my pump crapping out?

Today I laid into her when I was getting on the highway. I pushed it to the floor through 5th gear til my boost started falling off, EGT's were only at about 800* So I know it's not getting too hot. Max boost is 44psi. Pump Mods are 2.5 turns on Power Screw, Starwheel Bottomed Out, Fuel Pin on Deepest Setting with .90" shaved off the nylon washer. Smoke screw in 1 turn. Wastegate is welded shut on the 12cm2.

Mods on truck are listed in my sig.

Any suggestions are appreciated as always...thanks.

 

Could it be as simple as the change in outside air temperature?
Don't forget...1 degree ambient turns into 3 degrees in EGT...or so I've read.
Maybe a little dirt in the air filter as well?
Jay

 

From what I've read, if the full fuel is anything but stock, the smoke screw should be taken flush with the afc housing top---rendering it useless, of course. My smoke screw was cranked all the way down and I never noticed and when I backed it out flush, my cruise egts went down almost 100 degrees! Aside from that, I'd check the fuel pin for sticking---mine stuck halfway down for a while and raised temps pretty good at cruise.
greg

 

I don't see how adjusting your AFC can affect your cruising EGT -- you should be using the same amount of fuel to cruise (at the same speed, etc.) regardless of where your AFC is set, everything else being equal. The AFC only comes into play when you are accelerating while the turbo is spooling. EGT at cruise would be affected by engine timing, air flow, and actual power requirement -- the AFC setting should not change any of these variables.

 

Do my temps sounds out of the ordinary?

Earlier I stomped on it 2nd gear through 4th and the EGT's never made it to 800*...seems like it'll only get up to 800* in 5th gear doing nearly 100mph with the hammer down.

 

I run about 600-650 on the highway at 75mph with 10psi boost, at my max bost of 28psi I see 800deg normal.

Also, I have the exact same gauge, with the probe about 2-3in away from the turbo in the down pipe. What I want to know is how do you get your egts down that low?

 

''What I want to know is how do you get your egts down that low?''

Yeah, me too, 'course I am cold air challenged...I can't stay in it in fifth for too long...maybe 6 seconds or so of WOT and I'm at 925 post...that's as far as I care to push it.

Alec, I see your point, and what you say makes the most since, but when I backed the smoke screw out, there was an honest 75 degree drop in cruise egts with no other changes...I even did back to back runs on the same road, same tank of fuel, etc. It seems natural that a given amount of power (and thus, fuel) would be needed to push X truck through the wind at X speed, but the VE is a very tuneable pump, so maybe one could 'dial in' or 'dial out' some temp, to a point at least. Ah heck, if it gets too hot just throw twins and water/meth at it!

 

Whew!

I've been worrying all this time for no reason! Especially when someone asks ME how to get their EGTs as low as mine, haha.

I guess maybe the outside temps going up recently have maybe made it run a little warmer. This Texas heat is like no other.

G1625S, I'm going to back out my smoke screw flush and see how she reacts to that. I've got another trip planned for this monday, maybe my temps will be a litte lower.

apwatson50, it sounds like you and me have pretty much the same trucks with the same mods, mine being 2wd though. Oh and I got PODs for that added UMPH

 

i have seen 1200 post turbo on 6 percent grade for 8 sec. at 100 plus. control my egt with my foot.