Engine/Transmission (1994 - 1998) High Egt's - Why?

[Reddog1]

I must be missing something. Am I the only one having problems with EGTs? Normal driving (empty) no issue, hard acceleration, it does not take long to hit 1500 degrees (pyro pre-turbo). I have no reason to believe the Pyro is bad.





Here is my set-up:



1. ’96, 2WD

2. 3. 54 (?) gears, w/aux US Gear Trans (as under drive)

3. Transmission – DTT (did it all)

4. TC - DTT 89 %

5. ISSPRO Pyro

6. BHAF

7. 3K GOV Kit

8. #10 Plate (adjusted all over the place, currently in stock position). Boost elbow (38-lbs).

9. 370 Marine Injectors

10. 3 ½ inch straight exhaust.

11. Timing – still stock, unless it slipped.

12. Valves – just adjusted them.

13. AFC – stock parts. Adjusted so many times I replaced the screws with Allen head. I think I am qualified to write a book on the AFC (minus the AFC Spring).





Numbers 7, 8 and 9 were from Piers, as he suggested.



Obviously, my next major mod is the turbo (or housing). However, when I read signatures, others have my mods without turbo mods, and I don’t hear about EGT issues.



With CAT and Muffler, ran 250 HP on Mustang dyno. Could not run full power because EGT’s were to high. I have installed straight pipe, and cannot see a major change although have not put it back on the dyno.



I am interested in thoughts and/or suggestions. If you have the same combination as I, let me know.





Wayne



P. S. Long post ok.

 

[Boldt's Wagon]

What mileage do you get? Trying to get a feel if timing has slipped.

 

[Reddog1]

What do you mean “mileage”? After doing the mods, I have been to embarrassed to check.



Actually, I get 17 to 18 when I keep my foot out of it. Before BOMBing, I was at 18 to 19 MPG. I do have a heavy foot, and can do as bad as 15 to 16 MPG.



I live in the foothills with very little city driving.



I am the second owner. The original owner is deceased. It appears a socket has been on the #1 Delivery Valve, suggesting the timing has been at least looked at. I doubt that it would have been changed more than 13 degrees.



Wayne

 

[The patriot]

Only thing I can think of is:

Set timing to 15-16 degrees.

16cm2 housing.

IMO if youre getting the high EGT's @ high rpm's under a load, these will help.

Eric



PS Is the BHAF reasonably clean?

 

[Reddog1]

patriot - thanks for the response.



The BHAF is almost new, had same problem when it was new.



Timing will definately be done.



Still undecided what to do on the turbo, that's one of the reasons for this thread. It would be nice to have someone say, "Gee, I have the same combo as you. I changed the ???? and now, no problem. "









Wayne

 

[SlyBones]

Well I might as well be the one to start the controversary and finger pointing... .



With #10 plate, 370's and a gov kit for fuel related mods, and a 3-1/2" exhaust and a BHAF for air flow mods, on a 12v you will be able to hit 1500 on the pyro. The question is about how long it takes. -- At 60mph on freeway about 600* lets say, and you floor it. My guess it about 6-8 seconds and your at 1500.



( The complaining part ) this is one area where I have a hard time with this board. Many people out here with a pile of HP state how controlable EGT's are with with only the basic air flow mods ( air filter, exhaust, housing ) and maybe a turbo. And no where near a ported head and cam and goodies like that.



This complaint stems from the fact that there are no measurement baselines or standards to we can use to get an apple to apples comparison. This is very subjective and based largly on peoples personal level of what is accectable.



People will tell you how controlable EGT's are. But in reality its quite easy to get yourself into trouble in their truck if they dont drive smart. Would these people let a neighbor who does not know a thing about diesels, borrow the truck. HELL NO. They would fry it.



This complaint stems from an opinion of mine, that people new to BOMBing may not get a accurate idea of what EGT's are really like. And dont recieve proper education on what driving smart means before they added 200hp to the truck.



My favorites are the ones where 450hp people can tow at huge 5er up a 7% grade and never go over 1200*. What this doesnt tell newbies is that you can do this when you hit the grade already going 70mph and only added enough thottle to maintain 70, the "maintaining" 70 EGT's can barely hold 1200*. If your lucky. And it doesnt explain that if they add any throttle at all for any reason, the EGT's will blast past 1300* in an instant. It doesnt explain that if they get slowed down behind a semi, and then try to accellerate back to 70mph on a 7% grade, towing a big 5er, they cant just put their foot into it. They will be feathering the throttle and applying power very slowly or the pyro will peg 1500* in an instant.



Yeah, I understand it depends on the mods, the air flow improvemets, setup and all that. 24v generally do better than 12v's with regards to EGT's, etc. bla bla bla... .



Sorry for the vent, guess I woke up on the wrong side of the bed. Suit on, flame away...

 

[gitchesum]

I think most of your problem is the #10 plate.

It isn't recommended for the auto transmission trucks. I think it's a matter of too much fuel too soon. I can peg my pyro at WOT in 4th and 5th gears. I run empty 99. 9% of the time so I can just control the EGT's with my right foot.

You might give a #5 or a #4 plate a try and see if that helps you out any.

A bigger exhaust housing might help too.

 

[shendren]

your timing is still probably 11. 5 deg if you haven't set it. it came from the plant screwed up according to cummins.

 

[JohnE]

The #10 plate is cooler and much less hp in the automatic pumps than in the manual trucks. It is a recommended plate by Piers and Al for the auto trucks with governor springs and/or 370's.



A #10 plate in a 96 stock automatic is rated for around 220 bph and 570 ft-lbs torque. I'm not sure what happens with governor springs and/or 370's.

A side by side comparison of a #10 and #4 shows a similar profile. The #4 is by far the hotter profile with more middle cut and less defueling up the curve. A middle position with a #4 should give around 290 bhp & 745 ft-lbs torque. I have my #4 slid all the way <b>back</b> and have to watch my EGTs when I get 3,000 + rpms and really give it the go pedal.



Wayne sent me his dyno results a couple weeks back. I deleted my reply, but hope I wrote timing along with the (recently deceased) cat.

I used my dyno sheets to compare. With 12. 5&deg; timing, stock plate, and GSK, my peak hp was around 2700rpm as is Wayne's.

My timing was upped to 20&deg; and peak hp climbed to around 3,100 rpm. It also cleared higher rpm smoke. I haven't been back to the dyno after the #4 due to tranmsission (TCC) survival concerns.

 

[Reddog1]

SlyBones - I would be greatly disappointed if you were flamed for your post. I am particularly impressed with your comment on your "favorites". I had your "favorite " experience with my slide in camper. When trying to solve the problem, I am constantly led to believe no one else has the same problem. I would feel more comfortable in knowing I am not the only one having this experience. Strick-9 once stated "there was a lot of misinformation out there". How true, usually untrue because it is incomplete.



gitchesum - As pointed out by JohnE, Piers recommended the #10 plate. Actually I did not have the problem until the 370 injectors. At least if I did it was not as obvious.



shendren - Assuming I understood correctly, Al (at Piers) recently told me moving the timing to 15. 5 degrees would provide about 100 degrees less EGTs.



SlyBones is absolutely correct in his driving smart statements. The problem is, our society does not want to hear negatives. We get our feelings hurt, when someone disagrees, tells us the truth, etc.



Keep it coming guys, maybe we won't solve my EGT problem, but I bet we can make it less of a problem.





Wayne

 

[R.ebel]

EGT's

38 PSI is definatley out of the "map" for an HX35, you are pumping to much hot air into your engine at 38 psi. Take care of the airflow and timing and you will have lower egt's

 

[drees1]

I'm with R. ebel on this. Not only do you stuff hotter air in at that pressure, but because you get way off the efficiency of the turbo, the exhaust pressure in the manifold, pre turbo, increases greatly. In other words, high exhaust pressure over inlet pressure means the engine has to do more work to pump out the exhaust to the turbo. And thats where your pyro is. Just lowering the exhaust manifold pressure (pre turbo) will drop the temp considerable. And getting the turbo on an efficient part of the map will do that. (so will a housing change) Timing check is a no-brainer. The rest of your setup looks good.



I don't know the problems with Cummins or Bosch, but on rare occasion I have seen mis labeled injectors on CAT. Usually the box says one thing and the injector says another.



Keep us posted.



Doug Rees

 

[Deezul1]

I am not surprised you can make EGTs with your setup. Mine will make as many as I want (or dont want). Yours sounds about right for the setup you have. A 16cm housing helped mine to rise slower, it still gets there but takes longer. I changed from a BHAF to an AFE and I think it helped a little but no promises on that but it most definately cleaned up the smoke a lot. Towing my 6000lb TT up moderate grades the EGTS now stay below 1300 in 5th with cruise control on but as mentioned earlier if I hammer it then away they go. Slowing them down is all you can hope for without extensive mods like head work and cam.

 

[Reddog1]

Thanks for the info guys.



The elbow provided by Piers puts the Boost at 37 to 38 lbs.



I spoke to piers at Tulare, and he suggests a 14 or 16-cm housing. I ask him how would I know if I needed the waste gate housing or non-waste gate. He advised me to block my waste gate, and if the boost was no more than 38-lbs, the non-waste gate was ok.



I spoke to Al (at Piers) last week. If I remember correctly, he said 15. 5 degrees timing would lower the EGT's about 100 degrees.



Does this agree with what you guys have experienced?





Wayne

 

[Reddog1]

Deezul 1 - I might find it tolerable if I get it to the point you are.



Was the 16cm housing worth while, and is it waste gated?



On moderate grades, with my slide-in camper, I have to keep a close eye on EGT's. I have a 35-ft 5er I haven't pulled yet, I am beginning to wonder if I can.





Wayne

 

[Swamp Donkey]

I just may be the Donkey you want to talk too. Just had my timing advanced this weekend to 15. 5 or so... ..... 4. 8mm of plunger lift on a 2147. My stock timing was @ 13 degrees. I am not sure what my signature shows for a plate, but I have had the #10 in for a couple of months along with the 370's, gov spring kit and 4 inch exhaust. I could peg my pyro faster than most guys claim on this site. 1500 + degrees in a matter of seconds. Stock turbo with a dirty ol K&N airfilter in the stock box.



I have not run my truck to hard since the timing adjustments. There is a definate decrease in egt's though. I have pinned it about 3 or 4 times and have not seen 1500 like I normally would.

I think my lack of testing has something to do with icy roads in a busy town with a wife and 10 month old son... ..... More info later if you are interested.



My truck runs wayyyyyyyyyyyyyyyy better now. Thanks MDKram!

 

[Deezul1]

Reddog1

I am happy with the 16cm housing. It helped me to slow down the rise in temps enough that if I want to pass while towing its not a problem. Its not waste gated but the boost is the same as the 12cm with wastegate and boost elbow which is 38-39. From your description it seems that you have no choice except go with the 16 as you need several mods to get you where you need to be. The housing and timing would be my first changes.

 

[SlyBones]

Reddog1,



I have a question after reading a few of your responses here. Are you willing to tolerate some EGT's empty and towing is the main concern, or are EGT's in general the main concern?



I did not really answer your question. I just went straight for furnace. Here is why I ask.



-- I believe the suggestions you have for the housing and timing will help. Empty it will take longer to max out. And with a PDR HX35 you may even get down further. -- Overall these will lower peak EGT's some, definately reduce the rate of the EGT's, cruising EGT's will be lower, and turbo cool down will be much improved. -- But you will still probably be able to push it over 1300 and if you just held yer foot there you could have a problem.



-- Towing. This is why I have taken to towing with the valet switch on. I wish it had a little more power with the valet switch. Piers and I are gonna work on that some day. Anyways the valet switch cut all the top end hp. The botton 1/3 throttle is about the same as full power mode. 1/3-2/3 throttle it just falls way off. The last 1/3 of the throttle is like why bother.



All this will depend on your level of fueling. At your level your results should be like mine below.



-- In valet mode the pyro does not go over 1000* empty. And the worst I have seen is 1200* towing the trailer up a large grade, 15 mi long, 95* day, 3rd gear locked TC, foot to the floor, 65mph at like 2600 rpms, kinda thing. -- I can hold in there all day long and it pyro never enters the red zone.



-- Does not have the power for big hills in OD etc. Must lock out the OD, get the RPM's up, and run with the foot to the floor. Like mentioned above, at about 15K GCVW, I can tow a large grade at 65mph with the foot to the floor. Its a little better than the truck was stock, but not a lot.



-- Any time you want pyro pegging is just the flick of a switch.



-- Also better for your auto trany. Forces you to keep the RPM's up on the large grades, and use 3rd Locked instead of OD.



-- On the minor ups and downs on the freeway I can still use OD just like before. The bottom 1/3 of the throttle is not changed. However then you hit the minor inclines instead of pressing the throttle a micro inch for the additional power, I have to really press down on the throttle. Again better for the auto transmission since line pressure is party controlled by throttle position.



In the end my last trip with the trailer was a 400 mi round trip that went over 1 mountain pass. The vast majority of the time I had no need for extra power and it towed wonderful. There were a few times that I wished for extra power ( which was only a switch away ), but just left it alone. And I could still hold 65 on everything I went over. So far this summer I have towed this way on every trip. And have taken to liking it.

 

[Reddog1]

EGT's appear to have something in common with Aids. They both are more common than we think, and most of us are hesitant to discuss either of them. I am convinced there are a lot of us that need to come out of the EGT closet.



I am exceptionally pleased with all of your contributions on the subject of EGRs. Keep the info and experiences flowing.



Swamp Donkey - You are in fact the Donkey this Dog needs to talk to. Hopefully, you will comment on the post made by others. Our Rams are very similar, and you are one or more steps ahead of me in solving the EGT issue. If your experiences agree or disagree with what is posted, please comment. I am interested, provide more info.



Deezul 1 - Under what circumstances (if any) do you experience excessive EGTs? Have you timed your turbo lag, and if so, how long?



SlyBones - I am exceptionally grateful for your very detailed response.



I must admit, I am greedy on the EGTs. Ideally, they would be a non-issue under any circumstance. However, it appears (so far) that they will always be an issue, under one or more circumstances.



Empty, other than when showing off, or on the dyno, I really do not think I have a problem with EGTs with typical driving. I can accept 1400 to 1500 degrees for 10 to 20 seconds of passing or spinning the wheels. I may stand corrected, but I doubt this is very serious. Using a stopwatch, I make 60 MPH in about 8 seconds. I will hit 1500 degrees for about 2 to 4 of those seconds.



I am more concerned with EGTs when towing. With my slide in, I drive by the PYRO when in strong head winds, hills or mountains. If I snooze I will exceed 1300 degrees real quick.



EGTs in general is a concern, but with a load is the main concern.



I was under the impression that the valet switch was to disable the AFC only. I am also of the understanding that the AFC controlled pre boost fuel. Please advise if my understanding is incorrect.



I have more questions, but I need time to properly form them. I need to digest what you have posted, and get it all in perspective.



I am inclined to think I (and others) should give consideration to the valet switch. Please provide more info.





Everybody - Thanks again for the response. I know there are more questions out there, give me some help. There are other experiences as well, please post them.





Wayne

Oo.

 

[Deezul1]

My EGTs get excessive (1400 or more) at prolonged full throttle. I can make a full throttle run through the gears and dont hit 1400 till about 90mph. The lag is not much worse than with the stock turbo housing. I have tried to figure out how much difference there is but it is such a small difference that its hard to tell. It does have more lag but very little more. I have been very lucky with my truck as it makes more HP than I figured it would for the mods that have been done and the other related problems have not been bad at all. I gained 16RWHP with the 16cm housing as it was dynoed before and after with no other mods done. I think it did better than that but thats what the chart showed. The guy running the dyno let off a little sooner than I thought he should and the HP peak went up and down very sharply rather than tapering down from the peak.