EGT too high

[DCreed]

bear in mind that timing advance with high temps = melted pistons!

 

[KLockliear]

Can anyone advise as to the EGT limits when the probe is mounted post turbo?

Post-turbo temps should be used ONLY for turbo cooldown information. For performance knowledge on a non-stock truck, PRE-TURBO is the only place to put the probe. If you are post turbo now, and the truck has ANY mods, move the probe.

 

[NIsaacs]

If you have a high performance turbo diesel truck and drag race or truck pull, yet ignore your pre-turbo pyro when it hits 1600 degrees... ... ??



Or have a stock/high performance turbo diesel truck and "watch and drive" by a post-turbo pyro... ... ... ... ... who's gauge makes more sense??





"NICK"

 

[DCreed]

the word is SUSTAINED temperature. and most RACERS accept the fact of broken stuff that most other owners would not tolerate.

 

[DWeiler]

I've never used a post turbo probe so can't say from personal experience but TDR members generally use 300 degrees less than the pre-turbo limit as their rule of thumb. That would mean post turbo limits would be approximately 1000 degrees sustained.



Harvey

Thats about what mine are pre/post turbo with all the stuff in my sig pulling a 11,100LBS fiver. Mostly flat with some decent hills i can hit pre 1300 with the Smarty on #-3 in 6th in short bursts,drop a gear and let her rev up to 2200-2500RPM and they drop to around 1000 at 60-65MPH,--- Post temps never go above 800---YET with this combo,if it does get a little to toasty for my liking,i "ll just turn the Smarty to stock and run on the Mach 4"s and see how that work or put the 1. 6"s back in but that would really suck. DW

 

[NIsaacs]

the word is SUSTAINED temperature. and most RACERS accept the fact of broken stuff that most other owners would not tolerate.

Yes, I agree and that was my point.



We know the pre-turbo pyro reacts quicker than post, however since quick temporary spikes in temp are ok thats kinda moot info.



The post system will react fast enough to prevent engine damage and to suggest it is worthless or should be moved is just not the case.





"NICK"

 

[ThrottleJockey]

Yes, I agree and that was my point.



We know the pre-turbo pyro reacts quicker than post, however since quick temporary spikes in temp are ok thats kinda moot info.



The post system will react fast enough to prevent engine damage and to suggest it is worthless or should be moved is just not the case.





"NICK"

Yeah, but it's not as accurate as you stated. Why would you want thermal information AFTER it has crossed a heatsink? The only information that is valuable is accurate info.

 

[KLockliear]

The post system will react fast enough to prevent engine damage and to suggest it is worthless or should be moved is just not the case.

"NICK"

I completely DISAGREE. We have seen sustained EGT differences of up to 500*F. The smaller the turbo in a given HP application, the larger the EGT difference.



For instance, stock 220rwhp truck with HX-35, not nearly as much difference as a 350rwhp truck with the same turbo. You can't say what the difference is going to be on any given truck, so you have to measure it pre-turbo.

 

[NIsaacs]

I would like to know the pre and post temps of your test. Also if you sustained any engine damage and if so at what temps pre and post.



I do not have any technical test data, just 35 years of driving big trucks. In the early years of single entry turbos, the pyro was mostly pre with an industry standard of 1300 degrees. With the split entry turbos of later years the pyro was installed post, with an industry standard of 1000 degrees. On the V-8 turbo diesels, they were all post.



Do you recommend two pre-turbo pyro's on V-8's?



Isspro, probably the largest and oldest of pyro manufactures makes both styles. Color coded red line of 1300 for pre and 1000 for post.



All three of my Cummins powered pickups are post, with a combined milage of 700,000. All are modified and all are used hard, however I stick to the 1000 degree max and do not let them spike.





"NICK"

 

[KLockliear]

It's been so long since we did that testing (around 2000 or 2001) that I don't remember it anymore, other than EGT difference was huge with HP trucks. If you do a search, you may find the info in the archives as I'm sure I posted it here.



We have testing trucks to over 2000*F pre-turbo and never had a heat related failure - but I certainly would have never recommended that to a customer.



In the V8's, like the Ford 7. 3l, we would put it at the collector on the drivers side manifold log. On the Dmax's, they go in the passenger side log... mainly for ease of installation.



I think you'll find that everyone on here has their own opinion, but I can assure you that 1000*F post turbo does not equal less than 1300*F pre-turbo in all scenarios. I don't believe it to be in good judgement to tell people looking for info that post turbo numbers are just fine, when the evidence shows it can be detrimental to the life of an engine.



As said above, pre-turbo is more consistent and therefore more prudent from a performance standpoint.



I'm not going to talk mileage with you. If you need to quote how many miles you have driven to prove yourself and your opinion as worthy, then let me bow out now... I'm not here to preach or compete with any internet know-it-alls (not saying you are trying to be so). I was in the biz for a while, dealing with performance trucks daily, so I believe I'm qualified to give my opinion. Keith - Formerly of Diesel Dynamics

 

[PJay9]

I have bigger exhaust 4" all the way with a Donaldson Muffler, Cold air in and a Smarty JR... I don't reach near those temps, yet I am not hauling near the load, but do put my foot in it over the passes 70 -75mph and on long grades with an automatic too. I think the SJR helps a bunch plus the other mods don't hurt. I cross the scales at 14400 all loaed up and that is less than what you guys tow, so take it for what it is worth. Plus i added a better TC and VB by BD. All adds up I guess.

 

[NIsaacs]

KEITH, thank you for the discussion. I would like to continue it, however I can see it is going south!



Have a nice day





"NICK"

 

[KLockliear]

Hilda, I hope by now you have the answers you came here to find.



Nick, discussion is fine with me, but if it's just your opinions vs. mine, then I'll bow out as I said. If I can share some info I gained while working in the industry, I will, but I'm not going to waste my time debating to prove myself - that's not worth it to me... I have nothing to gain.



If you have something else you'd like to ponder over, by all means, post it... I'll respond if I feel I can add to it.

 

[hilda]

Keith

I know when I post something like EGT I'm going to get several opinions. I'll listen to them all and make my own decision. I did find what I was looking for. I know there is a lot of people on this board that has spent more time and money than I plan to.

Sometimes we have to agree to disagree try not to sweat it to much.

Hilda

Hilda

 

[PRout]

I would listen to Keith's opinions. He, and his performance business did A LOT of R&D work and were pioneers in the diesel performance arena long before a lot of people even knew the TDR existed. He should know. . I think he was trying to help WITHOUT getting into a "know it all" contest.

As said above, 1250 pre-turbo is about as high as you want to see it stay. 1300 sustained and you are taking your chances considering not all pyros read the same, and cylinder #6 tends to run hotter than the others anyways.

 

[RVTRKN]

hilda:



Your going to get many opinions as you have already found out, but the comment about driving over Cajon pass at 60 mph and passing cars is not any thing to worry about. My 04. 5 will easily walk over Cajon or Grapevine(north or south bound) with my 5ver connected in 5th gear at 60MPH, but you have to keep in mind my truck breath's better than yours stock (4"exhaust & more stock HP). The trick to keeping your EGT down no mater what application or make of a Diesel engine is too keep the RPM's up and don't let it bog on the grades. The reason for mine being in 5th gear on a 6spd trans is too keep the EGT down with it being at high RPM, and at 2500-2700 RPM I could even do better MPH if I wanted too. Your issue with trying to keep up with the other guy wont help you. Remember since 01. 5 the HP and capabilities of all makes have increased (thousands of trucks now on the road), and there will be stories of 60MPH on grades. Your 01. 5 has a stout engine, just a little slower than the newer ones, just keep up the RPM,s and if 50mph is all you get, so be it, you will get 500,000 miles out of it if you do.



An after thought:



My diesel tech stated too me that my EGT well never go over design temps, if stock and you keep up the RPM's, and your within the GCVWR. That was the answer I got when I asked if the EGT temperature probe was necessary, so I have not installed one. After my warranty is up I plan to chip it and add the EGT probe, until then it stays in strict stock form.



Remember this is just my opinion and I,m sure someone will debate what I have written here but it is good advise and is what I do with mine.

 

[Wyomingcowboy]

Put your foot in it and enjoy the power of your Cummins engine pulling the steep grades. That's what it was designed to do.



Harvey

Well said! I too am paranoid about roasting my Cummins but where is the fun in that?? I do not have money to burn and don't want to spend a pile on something new, but I do like the let 'er buck attitude!!

Thanks for all the great opinions and first hand advice guys! I love the TDR!