'03 with HE351 same boost and higher egts

[CToney]

I just put on a HE351, 4" elbow, full 4" exhaust and a ATS exhaust manifold. My boost is now lower and my egts are higher. It is harder to get to 26 psi now and when I get there my egts are now 1300. My boost elbow screw is almost all the way in. The truck seems to spool quicker now with the manifold and 4" exhaust but I thought my egts would be super low. I am running the Jr on Performance. What are my problems? Wastegate opening prematurely? Smarty defueling past 26 psi (stock boost levels)? Less drive pressure = less boost?

I have not towed yet but I wanted to lower my egts and free up a bit of power without adding much more fuel. I realize that no one probably has my exact setup. But I was expecting higher boost and lower egts.

 

[CumminsBu]

Pyro in a different location then before? Leaks exhaust and intake? Just some thoughts.

 

[CToney]

The pyro is in the same location. I used new gaskets and it does not sound like there are any leaks. I do not see any soot for a leak either. Maybe I have to tow a decent load to see what it will really do. On another site it sounded like someone else had similar trouble, he does not tow though. He eliminated the boost elbow altogether. He has the big smarty and an ATS manifold. I might have trouble finding someone with the JR and HE351. I will maybe try a boost fooler to see if it helps.

 

[WoodChuck]

Did you feel any increase in performance?

 

[CToney]

I felt an increase in acceleration. It seems to spool quicker. It should with the manifold and 4" elbow/exhaust. I think I need a boost fooler. I have a friend who will let me try his. I think the JR will only let the truck get to 26 psi and go no higher. Stock boost levels and all.

 

[MA2LA]

the jr is suposed to have boost fooling built in. i know i saw high 30s with mine.

 

[CToney]

The Big Smarty will boost fool to 44psi as that is what the map sensor will read. The JR is supposed to maintain stock boost levels. A buddy with an '05 and a JR will see 36psi. The JR would control the wastegate on his truck but since I have the manual wastegate the Jr will "boost fool" only at lower boost levels (to my knowledge). I think it will only fuel to 26 psi. On tow before it would spike to 26 psi and hold steady at 23-24psi. And on POD 80 on Perf it would hold steady at 25-26 psi and spike to 27. That was fine with the 341 now with the 351 I would like to see 30psi or so as the 351 can handle more boost. A boost fooler only kicks in at max boost level from what I have researched.

 

[CToney]

I found out what I needed... . vise grips. The wastegate was opening prematurely. I wish I had my 341 around still. I would test the actuator on it. When I clamped the hose to the wastegate I saw 35psi and low egts. I guess the boost elbow screw was letting boost by and the actuator is different than the 341 actuator. I adjusted the rod on the wastegate after drilling out the lock and turned it in and gained a few psi. I will turn it in some more and set it to 32psi or so. It is nice to have so boost now.

 

[moonranch]

Now that you mention it; I remember reading somewhere that the wastegate "canister" on the 351 was set rather low; so that anytime the ECM opened soleniod, it automaticly opened the wastegate. But since you aren't using the soleniod, you had to "turn-up" the actuator to get some boost. Good find!

 

[CToney]

I hate to be the guinea pig. Anyways anyone who does the swap compare actuators with regulated air and put the one with more psi in then shorten the rod to obtain the boost level you want. The boost elbow I installed has to be all the way in to work. I would like 32-33psi and 1200 F. I only have a 35psi gauge and I want to stay within the limits of the stock clutch. I have lower cruising boost now 7-8 psi instead of 9-10 psi. My overhead mpg is up a little as well. Worthwhile mod just not enough info. I should have done more reasearch.

 

[moonranch]

CToney,
Thanks for the information. Now all I need to do is find a HE351.