What's the average EGT?

[USAFFLYER]

Hello All,
Just got a boost gauge and a EGT gauge installed,(professionally done), and I was just looking for some figures. It looks to me like right now my EGT is about 500 to 700 just driving around, but what would be considered the average EGT while towing say a 5000 lb trailer? Also, what's the "danger zone" and what should I let it cool back down to before shutting her down? Thanks so much for the info! - Tom

[NickKent]

I think the consensus is that you're ok to 1250 and then you should back off. This is all pre turbo though. Hopefully your pick up is pre turbo.

[SmokeyWren]

Yeah, be certain your installer put the thermocouple before the turbo, i.e., pre-turbo. Then anything less than 1,250º is okay. 1,250º is the red line.

You should't be seeing over 1,000º when running around empty, unless you have pedal to the metal such as passing on a two-lane highway, or drag racing. Normally you shouldn't need to worry about EGT unless you're towing a heavy trailer up a mountain pass, or a long, steep hill. I never get up close to 1,250º when the tranny is in drive, but if it downshifts to direct drive when towing up a grade I must pay attention to the pyrometer. If it gets up over 1,200º, then I kill cruise control and feather the go pedal to maintain 1,200º to 1,250º until I top out the pass or hill.

Towing on the flats shouldn't add much EGT. If you're at 700º to 900º empty, then you should be maybe 800º to 1,000º towing.

My truck when upgraded to a straight-thru performance muffler (Walker BTM), performance intake system (TurboRamAir), and a mild towing chip, and grossing 15,000 pounds with a small 5er:
Zero to 60 with pedal to the metal maxed out at 900º
50-to-80 maxed out at 950º.

Same rig without the trailer and grossing about 8,000 pounds maxed out at 825º during zero to 60, and 875º during 50-to-80 runs with pedal to the metal.

But when towing up a grade, when the tranny downshifts to direct drive and the RPM is around 2,500, then the EGT gets up there in "pay attention" zone.

[USAFFLYER]

Well, this is funny but then again not so funny! The thermocouple is located in the banks exhaust brake housing, which I do believe is AFTER the turbo. Only in my world would this happen. Yes indeed in my world your brand new hotshot rims get scratched up while the tires are getting installed, and the thermocouple is after the turbo. Can you rely on anyone to do anything right anymore? O.K. is there a good formula for EGTs after the turbo?

[kc_maverick]

Post turbo temps are variable. The only way to get meaningful readings is to locate it pre turbo. Post & pre turbo readings will be close with no load on the engine, but add load and the temperatures can vary by 400 degrees or more. And it is not consistent so you will always be guessing. Do yourself a favor and have your probe relocated ahead of the turbo.

[T_Bone]

Hi Smokey,

Do you have any idea where the 1250º number came from ie; source?

I asked this question a couple years back and never got a answer from anyone.

I'm currious to know.



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[SmokeyWren]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: T_Bone</div><div class="ubbcode-body">Do you have any idea where the 1250º number came from ie; source?</div></div>

International engineers, with Ford engineers present and nodding their heads.

TheDieselStop (when the name was still Ford-Diesel.com) had a national rally in Louisville, KY on Memorial Day weekend back in 2001. The rally included an optional tour of the International engine plant in Indianapolis as well as a tour of the Ford Kentucky Truck Plant (KTP) near Louisville. About a hundred members showed up from all over the country, including me from west Texas. We had a big question/answer session in Union Hall at KTP, with several engineers from Indianapolis and a bunch of Ford engineers from Dearborn.

One of the members bluntly asked about hot-rodding the 7.3L, and the head honcho for the PSD project at International responded in plain English - which surprized me. He said the max safe pre-turbo EGT for more than a few seconds was 1,250º, and the max boost with the stock turbo was 25 PSI. He warned us not to try to use post-turbo EGT because it varied too much and was misleading.

The big door prize provided by Ford for that meeting was free use for one year of a brand new pre-production 2002 PSD. One of our guys won it. Sadly, it wasn't me. [img]/forums/images/%%GRAEMLIN_URL%%/cry.gif[/img]

The rewards for all the work and effort involved in organizing and conducting a huge rally like that are few and far between. Jason Lester and his beautiful wife Cristie organized that first one at KTP, with help by several folks from all over the country. One guy drove from Maryland to Louisville several times to help get it set up. There have been a coupla other "national" rallys in Indianapolis, hosted by the Ford Ohio Kentucky Indiana SuperDuty (FOKISD) club during the Brickyard 400 weekend, and sponsored by International Truck and Engine, but those folks are pretty much worn out. I've been to several regional rallys in New York, Houston, and Lake Texoma (north Texas), where Ford and/or International folks showed up. But the Northeast bunch is worn out too, and needs new blood to do the work. The Dallas bunch are a bunch of nuts that continue to host the Texoma rally every year, but the big sponsor (biggest Ford dealer in the world) retired and sold out his Ford dealership so the money might be gone now to continue that one without another sponsor coming out of the woods. Anyhoo, if you want to organize another national rally, let me know and I might show up. [img]/forums/images/%%GRAEMLIN_URL%%/smile.gif[/img]

[SmokeyWren]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: USAFFLYER</div><div class="ubbcode-body"> O.K. is there a good formula for EGTs after the turbo? </div></div>

No. When I had two pyrometers, one pre and the other post, I often noticed when my pre-turbo pyro was showing over the red line at 1,300º my post-turbo pyro was still lagging back at 850º. So if you use 850º as your post-turbo redline, then you'll probably be safe.

But I also noticed that under other conditions when my pre-turbo pyro was showing 1,300º, the post-turbo pyro was right up there near it at 1,200º. So that means if I use 850º as the post-turbo red line, I'd often be leaving a bunch of horses in the stable.

It's not hard to move the thermocouple from post to pre. If it's screwed into the exhaust brake, then simply unscrew it and plug the hole with a pipe-thread plug. If it's clamped in, then find a bolt that will fit snugly into that hole, cut off the bolt so that only about 1/8th inch sticks into the hole, and clamp it in with a big hose clamp.

If it's screwed in, then drill and tap the exhaust manifold and screw it in. Best place is put your head under the oil filter and look up to the exhaust manifold. Drill and tap about an inch from the flange for the up pipe.

If it's clamped in, then look up from the oil filter and drill a hole in the neck of the exhaust manifold, and clamp it in there. When you finish it would look like this. That photo might be confusing unless you realize that white blob at the bottom is the oil filter.

[Cool_Canuck]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: USAFFLYER</div><div class="ubbcode-body">Well, this is funny but then again not so funny! The thermocouple is located in the banks exhaust brake housing, which I do believe is AFTER the turbo. Only in my world would this happen. Yes indeed in my world your brand new hotshot rims get scratched up while the tires are getting installed, and the thermocouple is after the turbo. Can you rely on anyone to do anything right anymore? O.K. is there a good formula for EGTs after the turbo? </div></div> You are not alone. The shop that installed mine wanted to put it in post turbo. They only did the pre turbo cause I made such a stink and the customer is right. So now I have a pre turbo thermocouple hooked up to a post turbo gauge. (the yellow and red bands are out of wack).

[turbodave]

Smokey's correct. Never let anyone talk you into mounting the egt probe post turbo (unless you also have one pre turbo).
The post turbo egt's are far too unreliable in most cases, depending on load, turbine speed, etc. the output could vary widely even at the same pre turbo temps as he has stated.
Post turbo is more dangerous than useful.

[T_Bone]

Thank You Smokey,

That sounds like a great tour and some good info that would be well worth attending next time.



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[USAFFLYER]

Thanks Guys - I'll get it done right, before I pull anything. - Tom