Jump to content
Mopar1973Man.Com LLC
  • Welcome To Mopar1973Man.Com LLC

    We are a privately owned support forum for the Dodge Ram Cummins Diesels. All information is free to read for everyone. To interact or ask questions you must have a subscription plan to enable all other features beyond reading. Please go over to the Subscription Page and pick out a plan that fits you best. At any time you wish to cancel the subscription please go back over to the Subscription Page and hit the Cancel button and your subscription will be stopped. All subscriptions are auto-renewing. 

Recommended Posts

Sorry can't be done with my rig. 2 problems.

[*]Idaho state laws limits towing speed to 65 MPH period.

[*]ST trailer tires are designed for a maximum speed of 65 MPH. Most RV tire blow outs occur at 65 MPH and above.

So I'm stuck at lower speeds.

What does this have to do with Idaho's laws or what's on the side of the tire? It was an example.....The point was that the fan doesn't do as much for the intercooler as going highway speeds does. It has a radiator in front of it blocking the intercooler.. I'm sure it does something or else the A/C would get hot but the a/c only needs 5mph air moving acrossed it so it shouldn't be a factor here as all it needs is a person waving a chinese fan at it. I don't think the intercooler gets as much airflow as it needs doing 5mph to cool it down to what it goes down to at highway speeds. So EGT's go up as a result of the hotter incoming air.

There is the question of how much the turbo was actually doing at 5mpg in 1st though. If it was a big hill I believe there was more lugging going on than anything and that causes the 900F temps and the turbo wasn't spooling much since there wasn't enough fuel to get it going. A lot of this is variable though because its an auto meaning it's unlocked meaning the RPM's coulda been at the stall speed or they coulda been at 2500. He said 5-10 which my truck is topped out in 1st at maybe 10mph but autos have a much higher 1st gear so they can go a lot faster.

If it were my guess I'd say the main contributor was the lugging factor, not enough RPM's to keep it cool. However, 900F is fine. The truck did it's job just like it was supposed to. Mine sorta stops climbing around 1100 so even if it's at 1000 all day it's no concern of mine because it will stop climbing at 1100, reaching some sorta equilibrium. If I floor it it will get hot fast but sane driving it will stay where it's supposed to.

Link to comment
Share on other sites

1st unlocked going up this particular hill just after a switch back, very rough gravel road, around 1900 rpm. Boost was at about 15 PSI.This may be a stupid question, but would moving the fuel plate back cause a little higher injection pressures, sooner, thus helping atomization of fuel and helping bring boost up sooner, creating cooler EGT, especially down low? And would it increase fuel milage? Mopar man would always say hooking up the fuel with an Edge Comp box helped him get better milage.

Link to comment
Share on other sites

  • Owner

Mopar man would always say hooking up the fuel with an Edge Comp box helped him get better milage.

Actually what I'm finding out regardless of 12V or 24V. It the fact like ISX always said right along is to have the timing set just right for your way of driving. Like I changed my programming just to try different things and finding out differences in timing make a huge change in power. But in the same token the wrong timing can reduce or increase MPG's depending on where you sit in the RPM range vs. your timing. Yes ISX I did listen to you... :smart::thumbup2:
Link to comment
Share on other sites

  • Staff

Well I just took mine out and although it's 2wd and a 5spd, it should be close enough. But I as only seeing 550F at 2psi up a 6% grade in 4th (same as your 3rd).

That's so low that I would question the accuracy of your pyro, if I hadn't already done so in the past. :banghead: I am guessing 50-55 mph? I would be at 800° easy. My EGT's are very much inline with the OP, but you can't compare HPCR to 12V. As we have talked about in other threads the static timing really effects EGT's at low load, you run about 10° more timing that I do in that area. I also run exhaust blankets that ups the low airflow EGT's, and a looser exhaust housing on my turbo.
Link to comment
Share on other sites

1st unlocked going up this particular hill just after a switch back, very rough gravel road, around 1900 rpm. Boost was at about 15 PSI. This may be a stupid question, but would moving the fuel plate back cause a little higher injection pressures, sooner, thus helping atomization of fuel and helping bring boost up sooner, creating cooler EGT, especially down low? And would it increase fuel milage? Mopar man would always say hooking up the fuel with an Edge Comp box helped him get better milage.

If you were at 15psi then you must have had a pretty good load. The 900F sounds better in that case. Ya know, I just read the whole post again and your basically posting the same numbers loaded and unloaded.. See if you can get some more numbers and record all the conditions and such. Numbers when the TC is locked up would be best. Oh and the fuel plate really doesn't do anything unless you are really stepping on it. The boost can be brought up faster by tightening the valves up and moving the starwheel forward but I'd like to see some more numbers. You kinda got some weird data if you got the same numbers towing or not.

That's so low that I would question the accuracy of your pyro, if I hadn't already done so in the past. :banghead: I am guessing 50-55 mph? I would be at 800° easy. My EGT's are very much inline with the OP, but you can't compare HPCR to 12V. As we have talked about in other threads the static timing really effects EGT's at low load, you run about 10° more timing that I do in that area. I also run exhaust blankets that ups the low airflow EGT's, and a looser exhaust housing on my turbo.

You havn't questioned them in the past as far as I know and my gauge is digital and matches the overhead exactly in the morning. Remember, he said in 3rd locked up on a 6% grade..3rd for an auto is 4th for my 5spd...do you realize how much effort the engine has to put out with my small tires and 4th gear at 55mph (2000RPM on mine)....there is nothing but leverage and evacuation of heat. I would think something was wrong with yours if your seeing 800F for the same conditions.
Link to comment
Share on other sites

  • Staff

Sorry can't be done with my rig. 2 problems.

[*]Idaho state laws limits towing speed to 65 MPH period.

[*]ST trailer tires are designed for a maximum speed of 65 MPH. Most RV tire blow outs occur at 65 MPH and above.

So I'm stuck at lower speeds.

Where is Idaho law that you cannot tow above 65?

The 65 mph speed limit on the Interstates is for trucks, in Idaho that is defined as 5 or more axles, or over 26K GCW. Your truck and TT doesn't fall into a "truck" category.

I have never seen anything that says I can't tow at 75 in a 75 zone in Idaho, other than my ST trailer tires :-)

You havn't questioned them in the past as far as I know and my gauge is digital and matches the overhead exactly in the morning. Remember, he said in 3rd locked up on a 6% grade..3rd for an auto is 4th for my 5spd...do you realize how much effort the engine has to put out with my small tires and 4th gear at 55mph (2000RPM on mine)....there is nothing but leverage and evacuation of heat. I would think something was wrong with yours if your seeing 800F for the same conditions.

I think I have remarked in the past how insanely low your EGT's are at certain loads. Even on my brothers 12V VE truck they were never as low as you run.

A 6% grade is still a 6% grade, with 3K lbs in the bed of my truck at 55 I pull 6% grades at 950-1000° (before UDC), and with a 8K TT behind me I pull them at 1100-1200°. I do 2250 rpms at 55 mph. The engine still has to make power, and 550 isn't hot enough on a CR to coast down a hill :-). Most CR's don't even run 550 at 70 mph, let alone up a hill. I only see under 600 (with the blankets and looser turbo) at 45 and below on the flats. The stock turbo ran cooler unloaded in some circumstances, but ran hotter 90% of the time when towing. I'm not even going to get into the 2 psi of boost; however, are you sure your speedo is correct? Based on your numbers I would say you were doing 35 not 55.

I literally would be buying a new pyro if it showed what you report as EGT's.

- - - Updated - - -

Does anyone know if these problems I am having could be related to accidently getting 155* marine injectors as opposed to the 145* injectors I was supposed to get. Did some towing yesterday, about 6k lbs. I was running 700-900 degrees running 55-60 on the flats. Once I hit a hill, it would climb to 1,000 which I wouldn't let it get over. I was really only running 15 PSI boost at that. Alittle disappointing.

Assuming your pryo is in the exhaust manifold, why stop at 1000°? 1200° is safe for all day operation, assuming your not running over 18-20° of timing.

Really nothing in this thread sounds out of the ordinary.

What do you run EGT/boost wise WOT?

EGT is determined a lot by air flow and the temperature of the air. In 1st gear you saw 900F because the intercooler wasn't getting any air through it. I'm sure the fan helped but nothing like when you go 70mph. RPM is also something that helps because it not only gives you more leverage (such as the leverage 4.10's give you) but it also pumps the hot air out. I also pull stuff at 2000+, no EGT issues whatsoever.

I watch IAT's all the time, and have some places I go camping that run 1000° in 2nd and 3rd. There still isn't enough heat being generated by the turbo to increase IAT's enough to notice a EGT change. Regardless of speed and load the most I ever see over ambient temp is about 35°, normally MUCH less. The biggest increase is at high speed, at low speed it's not near as much.

Now that's a 3rd gen, but an intercooler is an intercooler.

Link to comment
Share on other sites

I think I have remarked in the past how insanely low your EGT's are at certain loads. Even on my brothers 12V VE truck they were never as low as you run. A 6% grade is still a 6% grade, with 3K lbs in the bed of my truck at 55 I pull 6% grades at 950-1000° (before UDC), and with a 8K TT behind me I pull them at 1100-1200°. I do 2250 rpms at 55 mph. The engine still has to make power, and 550 isn't hot enough on a CR to coast down a hill :-). Most CR's don't even run 550 at 70 mph, let alone up a hill. I only see under 600 (with the blankets and looser turbo) at 45 and below on the flats. The stock turbo ran cooler unloaded in some circumstances, but ran hotter 90% of the time when towing. I'm not even going to get into the 2 psi of boost; however, are you sure your speedo is correct? Based on your numbers I would say you were doing 35 not 55. I literally would be buying a new pyro if it showed what you report as EGT's. I watch IAT's all the time, and have some places I go camping that run 1000° in 2nd and 3rd. There still isn't enough heat being generated by the turbo to increase IAT's enough to notice a EGT change. Regardless of speed and load the most I ever see over ambient temp is about 35°, normally MUCH less. The biggest increase is at high speed, at low speed it's not near as much. Now that's a 3rd gen, but an intercooler is an intercooler.

Yes yes I've been starring at my intercooler thing ever since I typed it. Still have thoughts on it though. I went through the whole thread again and your quote left out the 1200RPM deal on my quote and you said "guessing 50-55mph" which made me assume my quote was at 55 (I never do anything at 50) So yes it correlates to 35mph, 550F, 2psi :doh: So there you have it. Thing is, his videos show 900F going from 35-45, which I just realized as well so he was accelerating which will really get the EGT going, then now he is towing and is at 800-900, but theres just too many different things going on here. I will read the whole thread and put together a cumulative chart of what he has said over the course of the thread. I can't keep track anymore and the auto tranny being unlocked for some readings and locked for others makes it even worse.
Link to comment
Share on other sites

Alright from all the things he has mentioned this is what I can gather. Some percentage grades are guesstimates...

Posted Image

Based on that, things don't look too out of whack. However, I ran across the piston type thing and you can do something with the injector washer thickness to fix this though I'll have to research it more. Some of your numbers seem on the high side but you didn't give us a lot of information most times. If you could get a couple more samples that fill out each segment of that chart then it would help a lot. Basically some things look fine like the 70mph things look 100% fine but other things *could* be fine if I had more info to go on. What gear it was in etc. There really is a big different between 2nd gear letting it scream and 3rd gear letting it lug.

Link to comment
Share on other sites

I have just read through this thread for the first time and while i have a 24v I can maybe offer a little insight to the op. Ive noticed in a few of your posts where you are getting higher egts while running in od, maybe either puling a grade or while pulling a trailer. Our auto trans are geared quite high, actually higher than I think they should be at times particularly when gtowing heavy. Rather than letting the trans shift into overdrive when towing, I will tend to use the od button to keep it in 3rd gear if Im running under 50 mph. If im towing heavy and/or a steep grade, I may even hold it in 3rd until 55. Even at that speed, Im still only turning about 2200 rpm. This drops the egt substantially, while leaving gobs of power on tap. At 50 mph, if i let it drop into od, that will drop my rpm down to 1200 to 1300 rpm. Now i can run that speed empty on flat ground, but any other combo will produce higher egts. Do you have a lock up switch for your tc? I installed one and it makes a difference at those lower speeds esp when towing. Just my .02, its a topic I havent really seen anyone hit on yet maybe worth trying...

Link to comment
Share on other sites

  • 3 weeks later...

Sorry for the length of time getting back.Just got back from a 1,000 + mile trip pulling a little 2 horse bumper pull trailer and have some numbers.70mph 4th gear locked 0% grade 65* ambient temp. at about 1800-1900 rpm 800* 10 PSIsame as above with 4-5% grade 900* 15-20 psiEmpty: 65 mph 65* 0% grade 650* 5-6 psiIt seems that I am getting cooler EGT since the ambient temp has gone down. It seems that I have to keep rpm up, even when empty to keep EGT lower than 800 degrees. It seems that my boost will go up to 5psi in a flash, but then will stop and EGT will go up to 800 degrees before boost will start building anymore, especially in low rpm.

Link to comment
Share on other sites

  • 4 weeks later...

I had a similar problem with my truck, but it ended up being that i had some major boost leaks with my twins and the AFC was all out of wack.My intake manifold gasket ripped, two of my compound couplers were leaking and i had a cracked boost gauge line..i would get EGTs in the 1100 range unloaded, and hot weather just made it worse. Towing? Lol Forget about it...with 10k in tow i was babying it and it creeped to 1300 at a consistent 20psi..Since then i have readjusted my fuel (5x14s) and pulled the starwheel back a turn and a half, and set the preboost screw back 1/8th turn and i make a healthy 47-50psi with my twins and I see 800 degrees after being deep into 5th after 75-80mph..not too much smoke either. Timing was Setup at 16.5

  • Like 1
Link to comment
Share on other sites

×
×
  • Create New...