Engine/Transmission (1994 - 1998) EGT Problems...still

[Blackcloud]

I am very disappointed in the money spent to reduce egts on my truck and failing in the process. Over the past couple weekends I replaced the stock exhaust manifold with a ATS 3 piece,turbo housing has been switched to a 16cm and exhaust was converted to a full 4" system. I did my baseline tests before doing any work,and checked it again after. Guess what... . My egt on the same stretch of road with almost identical weather and truck guage readings went UP by 75*. WTF is going on here?Not real happy after all this work and not getting the results I should have. If you need actual testing #'s I will post them. Any ideas?I really don't want to call Piers to spend more $$$,really,I don't!

 

[Jim Fulmer]

I had your exact setup at one time, #4 in the stock position, stock 181 DV's, stock injectors, 16 cm and 4" exhaust and my EGT's would level out at 1300 empty, that was 292/680 at the wheels.



Jim

 

[esommer2500]

I assume your pyro is in the manifold?



Have you done anything to the air filter?



What kind of boost #'s are you seeing?



Are your test #'s at cruising speed or on acceleration? I'm not sure, but I think the 16cm2 will increase your EGT's slightly while cruising.



Eric

 

[Berrigan]

One thing ive done on before and after exhaust mods is unscrew the themocouple on a post turbo setup and plumb in a temporary low pressure gage or manometer. Then you can see exhaust restriction and measure it before and after mods.



I know everyone is into 4, 5 and whatever inch sized exhaust, cat no cat muf no muf. But the bottom line is if your exhaust is at or under about 1/2 psi at wot bigger aint gonna help much.



I cant answer why yours went up (egt) though.

Was you thermocouple re installed in the exact same place?

Ive heard for every inch away from the head the egts drop 50 to 100 degrees.

 

[GGibson]

I have ATS exhaust manifold, 16cm exhaust turbo housing, 4" exhaust with 2 mufflers and no cat, 3K gsk, #10 plate in stock position, stock air filter, 49 state intake manifold.



On 7% grade, pulling 9000 lb trailer, foot in floor, 58 mph, 28# boost I only get about 1150-1200 EGT. Thats with ODrive off. I also have the Goerend tripple disc. My truck weighs about 6200#.



Don't know enough to have any idea's why your maxing out. Maybe #4 a little too aggressive?? That's about the only thing I see different between us

 

[Blackcloud]

Alright,here's some more info for you guys..... Pyro is in the manifold very close to where it would be in a stock manifold... . #4 plate is not in the stock position,it is slightly slid back from stock... . BHAF air filter with turbo sheild



before mods/ after mods

rpm 2000 / 2000

speed 73 / 73

o. d. temp 45 / 34

H2O temp 175 / 175

trans 115 / 105

boost 7 / 7

egt 650 / 725

Timing has been advanced to 16*

Injectors are stock(215 on bench because of egts)

Stock tire size... ... it seems like every time I do a engine mod I either get none of the results everyone brags about or it puts me further in the hole. Any ideas?

 

[formula]

If you're concerned with the 650 to 725 deg increase in EGT at crusing speed as posted above... ... this is nothing to be concerned about. This is simply a result of the bigger turbine housing not spinning the turbo as fast as the smaller housing would at that rpm. What you should be watching is your EGTs at WOT. When I went from a gated 14cm to an 18. 5cm turbine housing, I gained about 100deg on EGT's at crusing speed. But the reduction in EGT on top end, and the increase in mid and top end power was well worth the swap. My ATS manifold doesn't do squat for EGTs. What it did do was take care of the shrinkage problem I had (which was the reason I replaced the manifold) and it gave much better throttle response (spoolup) at 1800+ rpm.



Sean

 

[Mark_Kendrick]

What are the WOT EGTs? I think they're lower than before. Formula is right. cruising egts will often go up with exhaust housing changes.



You're gonna have better top end extension of power due to better exhaust flow but you will loose a bit of bottom end response (more lag) and gain lots more part throttle smoke for the same reason.



FWIW,

Mark

 

[Blackcloud]

Mark-my WOT egts are still high enough. I can still easily hit 1400 while going wot,but the problem is I usually run out of road to see how high it will actually go. Boost remains in the 35-37 psi range as it did before. On a note,I can hit that 1400 from a dead stop in about 6 seconds. I wouldn't mind more power,but I need to correct this problem first.

 

[Blackcloud]

Mark-my WOT egts are still high enough. I can still easily hit 1400 while going wot,but the problem is I usually run out of road to see how high it will actually go. Boost remains in the 35-37 psi range as it did before. On a note,I can hit that 1400 from a dead stop in about 6 seconds. I wouldn't mind more power,but I need to correct this problem first.

 

[Blackcloud]

Wow... how'd that happen?

 

[Mark_Kendrick]

I know how to correct the problem...

You need more air. try a better air filter. I'm sure you could tune your truck a little better and get mild improvements in EGTs.



there are more extreme measures. I'll gladly discuss them with you off line. See my sig for #s.



Power is cheap. 100% duty cycle power is expensive. with NOS and fueling mods you can make 550 or so HP on a basically stock truck. EGTs will be astronomical.



If you want power day in and day out you have to supply air and fuel in large, proportional quantities. the only way to do that is with turbos, BIG flowing air filter, and BIG exhaust to match the fueling enhancements on the engine. none of which are especially cheap.



Later,

Mark

 

[BSoldie]

Re: I know how to correct the problem...

Originally posted by Mark_Kendrick



Power is cheap. 100% duty cycle power is expensive. with NOS and fueling mods you can make 550 or so HP on a basically stock truck. EGTs will be astronomical.



If you want power day in and day out you have to supply air and fuel in large, proportional quantities. the only way to do that is with turbos, BIG flowing air filter, and BIG exhaust to match the fueling enhancements on the engine. none of which are especially cheap.



Later,

Mark

Mark,



This is so true and often overlooked by most guys so far as I can see. I love it when guys brag about 400hp for $600. 00 bucks, but what they never mention is that they can only stay in it for three seconds at a time! Kind of useless really... If you want a good example of this check out the other diesel sites where Dodge guys also post to brag. It's funny.