EGTs in hot tune.

[Dieselboy.]

Was doing a bit of testing tonight writing a tune for drag racing. Im leaving the line at almost 1100* and by 80 MPH my gauge (1600*) is buried.

What do you guys normally see in egts by the end of the 1/4. I didnt even make it to the end in sense (judged by my MPH) and I was north of 1600*

 

[sniper_101]

Jeez, cooling mist time?

 

[907DAVE]

Back pressure in check?

Makes a big difference.

 

[Dieselboy.]

Didn't have a glance at my boost or backpressure gauge. I'm leaning towards a small boost leak maybe.

Last time I checked at 40-42lbs boost was 53-55lbs bp. I'm running a 1.10 a/r so its should be in check.

 

[David N]

Hell mine pegs my 1600* gauge in a few seconds. Could be do to the fact that I have so much timing pulled though.

 

[Dieselboy.]

I have a boost leak. Im only seeing 34lbs at WOT.

 

[HaysKSFirefighter]

Vanderchevy18s is buried past 1600 every run with his 250/200s and gtx...scared the crap out of me the first time I drove it hard in the race tune LOL

 

[STROKIN N STYLE]

My gauge pegs going down the track, that's with A2W and a big boy water injection. It'll be alright, its only for 11 or less seconds at a time

 

[Dieselboy.]

Hahah, thats awesome stroken. However I am a little short in the boost factory.

I will say though, this was the first time launching the truck at this power level. OMG LOL

 

[Powerstroked162]

2200 or bust

 

[Dieselboy.]

LOL

And thats fine ? I guess ther 2200 is the gas temp not the actual temp of the parts, ie piston.

 

[PowerstrokeJunkie]

repeated 2200 will bust valve seats...

 

[smokinstroker92]

you could pm hotrodtractor he would probaly have more assuring info. I rember reading somewhere that he post that he peged a 2000 degree gauge on ever pull with his red truck.

 

[Dieselboy.]

Lol, ya but thats a competition calibre engine. Mines just a rebuilt stocker with a few hardparts thrown in her.

Obviously the boost leak will effect this, Im 6+ psi short ?

Junkie what did you see on your old engine WOT ? (Big sticks)

 

[PowerstrokeJunkie]

I don't know what it takes to make headers glow... but yeah. I do know the egt gage will stop at about 6 o clock :doh:

 

[Hotrodtractor]

I had 2200* EGT gauges in my truck - I would bury the manifold gauge and then some on every run that truck ever made - I made sure it was up to operating temp when I started, and gave her some cool down time. The problem is with prolonged high EGTs or with a lot of thermal shock loading. I can't stand here and say yes - you'll be fine with a 2200* EGT on every run - there is just too many variables - but I can pretty well tell you that I wouldn't even worry about only reaching 1600* EGTs by the end of the drag strip.

 

[Powersmoker]

I had 2200* EGT gauges in my truck - I would bury the manifold gauge and then some on every run that truck ever made - I made sure it was up to operating temp when I started, and gave her some cool down time. The problem is with prolonged high EGTs or with a lot of thermal shock loading. I can't stand here and say yes - you'll be fine with a 2200* EGT on every run - there is just too many variables - but I can pretty well tell you that I wouldn't even worry about only reaching 1600* EGTs by the end of the drag strip.

:whs:


You don't want the heat to soak in.

I try not to think about Egts, my guage hasn't been hooked up for quite sometime. LOL

 

[Dieselboy.]

Holy chit, really ?

Im concerned. My dads a diesel mech for hwy/marine. Anything over 1250* I hear about it lol.

Old hands

HRT, I saw 1600+ by 80ish MPH... This was just on a back road but holding it for the last bit at that degree is ok ? I figure I should reach over 100MPH in the 1/4. Not sure how many more seconds that equates to.

I will say I have confirmed a boost leak as in the summer I saw 40-41 psi WOT and now I cant exceed 34-35 psi.

 

[Hotrodtractor]

Holy chit, really ?

Im concerned. My dads a diesel mech for hwy/marine. Anything over 1250* I hear about it lol.

Old hands

HRT, I saw 1600+ by 80ish MPH... This was just on a back road but holding it for the last bit at that degree is ok ? I figure I should reach over 100MPH in the 1/4. Not sure how many more seconds that equates to.

I will say I have confirmed a boost leak as in the summer I saw 40-41 psi WOT and now I cant exceed 34-35 psi.

Both highway and marine are often steady state constant loading situations - running them over 1250* for a prolonged period of time will typically result in high levels of heat soak and component failure. You are not operating under the same conditions during a drag race where you have a short period of WOT full load immediately followed by a period of cool down. Your entire run is what 13 seconds long? There is no heat soak to worry about with a run that length of time. The probe is in the exhaust gas stream and its true that it is what the temperatures of the gases are - but it is not allowed enough time to sufficiently heat up the major components to cause damage at 1600*. Now if you increase the temperature delta up to say above 2200* then you get some more heat transfer and depending on your run you might have something more to worry about - but that gets to still be a case by case basis because there is a big difference between just touching 2200* and holding it there for say 15 seconds.

Fix your boost issue - all of this is meaningless until you fix that.

 

[Dieselboy.]

Will do, thanks for the explanation.