Engine/Transmission (1998.5 - 2002) EGTs on DD2 vs. DD3

[d90boy]

This is kind of a confusing question but here goes. At a given power output will there be any difference in EGTs between DD2s and DD3s? Say you're towing something down the road, at partial throttle using 200hp to do it. Will the EGTs from DD3s be higher than the DD2s doing the same thing?



I've got an 02 ETH with DD2s, an EZ, HX40-16 and may want to do some DD3s but I tow with it. I know max, full throttle EGTs will be higher. I hardly ever use the max output but don't want any higher temps when cruising.



I may be off on this but I had imagined the DD3s would run hotter than the DD2s maybe because the spray pattern was not as fine or different. Thanks guys.

 

[Bob Wagner]

huh

very interesting question? do you sleep at night? just kidding



when you think about it, it would take so much fuel to maintain say 70MPH, so the EGT's should be close with different injectors but maybe not.



I will be changing injectors too very soon





Come on Joe D.

 

[d90boy]

Sleep is very overrated, I'd rather contemplate various Cummins diesel power scenarios.

 

[Morepower]

Good question,

I asked the forum and call BD and PDR about DD3's and towing. BD said that they would not recommend anything past a stage 4 injector and Al at Piers said that he would also not go past DD3's to Super Metals. The forum can be conservative at times but most said DD2 and few said DD3 were OK.

I just installed DD3 and intend to tow a heavy 40' 5th wheel, 16k. What all had to say in common was watch your EGT's. I watch them every hill closely anyways. I just watch not to exceed 1250 pull the hill with just enough throttle. It usually means letting the MPH fall off 5-10 mph and then you’re over the top anyways. I don’t anticipate any problems with DD3's and wanted to pushed this max injector scenario one step further.

What if I was to port the head and put a camshaft in, could I go to Super Metals. Not too many people responded on that one. I guess it was a little to radical for feed back, plus it would require too many options was most peoples comments. The few that did have something to say said don't do it for Super Metals. DD3's can get you into the 400-500 HP range. Most asked how much more to you want? All I could say is I want morepower!

But like you how much gas does it really take to pull a hill towing and not run extreme EGT. If you adjust to a high enough rpm to let the engine breath, say 2,000 or more, how hot could it really get with more horsepower and torque

I wonder what the guys in Colorado would say near the Rockies and climbing for extended periods. I would expect to have to gear down like the big rigs and find a sweet spot. I like this question because it is about how far can you go?

 

[Chipstien]

x amount of fuel gives you x amount of HP. I would think that the reason 3 are hotter is cause they flow more fuel. So to answer your question... . EGT's at a given power output should be the same with 2's or 3's. Keep in mind though that atomization of the fuel would cause it to run cooler... the finer the mist, the less unburnt fuel you would have in the exhaust manifold. Again we are assuming that 2 and 3 injectors are comparable in fuel atomization.

 

[Greg Boardman-RIP]

I run DDII's with the comp on level 1x3 while towing. I can hit 1200* on a long hill. That is with the HX40. When Fred Swanson was coming home from Texas with three 30 foot gooseneck flatbeds stacked. He was running DD3's. I'm pretty sure he had to run on 1x1 to control egt's. That is with a cam and the hx40. I know for sure he went back to the two's for towing. I can pull pretty heavy up to 75 mph on a 6%grade with no problems.

 

[d90boy]

Originally posted by Chipstien

Keep in mind though that atomization of the fuel would cause it to run cooler... the finer the mist, the less unburnt fuel you would have in the exhaust manifold. Again we are assuming that 2 and 3 injectors are comparable in fuel atomization.

That's kinda what I was wondering on the two injectors. I figure the DD3s must have larger holes for more fuel but the larger hole wouldn't atomize as fine. I think we're getting closer to the answer though.

 

[Big_Daddy_T]

to give a simplified answer my egts are very close to the same at 65 as they were with 275s and I have super mentals. So for the same required output I cant see the difference. I think the problem arises when you dont know your exceeding the 200 hp your shooting for. You would need to train yourself with the load on. watch the gauge see what pedal position elicits the sweet spot. It is difficult for me to reach extreme egts with just my normal driving style. I give it just enough fuel to get the turbo spinning and gradually lean into it as the pressure rises. I am able to drive very aggressively with this style. With large injectors dont jump on the throttle, roll into it instead. If you perfect the roll in throttle you wont see much smoke. I can run on 5x5 with mentals and keep the smoke and egts down at the same time. You just need to train yourself to the injectors. I can peg the gauge in 5 or 6 seconds if I romp on it.

 

[d90boy]

200hp was just a number to denote an amount of power needed that would be within the ability of each injector. If I tow a load up a hill, cruise set on 70 with DD2s with some power to spare then tow that same load up the same hill with DD3s at the same speed, which will give the hotter EGTs? I just don't want it running any hotter for towing.

 

[Henry]

DD2's VS. DD3's

I asked the same questions when I was getting ready for my switch. What I came away with was that the spray pattern of the DD2 injectors was more efficient, hence lower egt's for a given fuel flow. I went with the DD2's and my egt's went down from the stock injectors! Power increase was terrific. I couldn't be happier. More is not always better unless you have a money tree to replace broken components caused by toooo much power.

 

[ET]

high egt

I have dd3's and tow a 32' 5th wheel. I have to be real carefull or they temp goes up fast. I run with OD locked out at 65 and have to slow down for hills or the temp goes over 1300 fast. I also have an HX40 from Piers and a PM3. I am also looking for the magic to keep the temps down. I like the 3's when I'm not pulling the trailer so if I have a long pull I either go slow or swap injectors.