Is my HO doing HO

[SDrake]

Just added guages to my new to me 2003 HO 4X4 48re. When I put the pedal to the metal at 60MPH it only goes to 22psi. I was already suspicious that the truck was runnin weaker than my 94. The 94 would jump to about 28psi. It had a number 10 fuel plate and a governor spring kit, that's all.



Fuel pressure is about 12-14 psi at the CP3, the engine starts good and idles very smooth, I have never seen any smoke but haven't pulled anything yet. Oil level stays steady over a 4000 mile span of city driving mostly.



Just installed a 4" from cat to tail pipe with FTE Resonator and FloPro muffler so it with no change in boost. Sounds nice though. My guess is it just needs more fuel but what could be causing it to be limited if in fact it is. ? I thinik I read somewher I should be expecting about 28psi boost.

 

[S.Morris]

I believe the waste gate is set for 23-24psi on the early 3rd gen. You will have to put a boost fooler in the sensing line to get higher pressure.

The 03-04 do not have electronic control of wastegate, only 04. 5 and up.

My 04 with a smjr will hit 24psi but needs a good load behind it to do it.

hope this helps

 

[SDrake]

I believe the waste gate is set for 23-24psi on the early 3rd gen. You will have to put a boost fooler in the sensing line to get higher pressure.

The 03-04 do not have electronic control of wastegate, only 04. 5 and up.

My 04 with a smjr will hit 24psi but needs a good load behind it to do it.

hope this helps

Thanks, the explanation about the controls is very helpful. This gives me a good start. I know nothing about how it works on the third gens until this.



But the engine is rated at 305 horse power. Gotta be approaching 30 psi for that I was thinking. Maybe I need to learn a bit more. I have been using the rule of thumb of 10 horse power per pound of boost. doesn't exactly work out when you are cruising with low boost but in the upper reaches that is what I have learned from somewhere. So am I right that I should be expecting to see higher boost if the engine is doing its rated 305 horsepower?

 

[TCDiesel]

Just to check the waste gate Pinch the hose form compressor housing to waste gate,You should be able to hit 30 psi easily.

 

[rbattelle]

Service manual says that at maximum load and rated speed (which I believe is 2800 rpm), boost will be 23-27 psi.



I've never seen more than ~23 psig (37. 1 psia). System is stock.



-Ryan

 

[SDrake]

Thanks rbattelle. I have not had a load on it at 2800 but that is about to change. I am heading out next week on a 800 mile trip up and down the hills of Tennessee and Ky. I'm betting it hits at least 23 on some of those.



TCDiesel I will be pinching that line just for the education. I want to ask though about what the effect would be. is there some kind of sensor that will cause the ecm to add more fuel if the boost is higher. Will I see more power in proportion to the increased boost? Surely there is not a power mod of a new "Boost elbo" or something like I did on my 94 for this truck. Maybe I read about it somewhere and forgot. I am not looking for power mods as such. I just want something like I had in the 94 with the #10 plate. It pulled my 7000 lb trailer up and down all the interstate hills at 65 or 70 without down shifting. When I saw the 22 lbs of boost on this truck i said uh oh.



The 94 was the 160 HP engine with, as I said, a#10 plate. It did what i wanted but was going to be OK with a bit more in this truck. I feel like it may not measure up with out some mods.

 

[jakprince]

for one thing an 03 shouldnt have a cat

 

[SDrake]

for one thing an 03 shouldnt have a cat

Right I have a guilt free 4" turbo to tail with FTE resonator and muffler just installed. the original exhast system was beginning to leak at the seams.

 

[SDrake]

Service manual says that at maximum load and rated speed (which I believe is 2800 rpm), boost will be 23-27 psi.



I've never seen more than ~23 psig (37. 1 psia). System is stock.



-Ryan

Now that you mentioned servce manual I finally found it in mine. I read what you said but it also says "depending on horse power" The HO engine is the higher one so I am back to wondering why I am not seeing upwards toward 27psi which 305HP would suggest.



My sticker and glove box all say HO engine, 48RE transmission etc but my truck acts like a SO. My son has my 94 (#10 fuel plate and advanced timing) now and we do 60mph rollons and the 94 walks away from this truck immediately when you drop the hammer and never looks back. He is doing 80 and climbing before I get to 70. Not what I expected from the HO.

 

[Shadrach]

If your 03 with auto was built after Jan 1 2003 then it will be an HO. My 03 with stick maxs out at 23 # also and it's stock, other than the cam. Shadrach

 

[rbattelle]

Now that you mentioned servce manual I finally found it in mine. I read what you said but it also says "depending on horse power" The HO engine is the higher one so I am back to wondering why I am not seeing upwards toward 27psi which 305HP would suggest.

I think it's because you're not fully loading it, although I'm just guessing. Back when these engines first came out I recall a number of discussions about boost, and I can't recall anyone getting 27 psi stock. Most people were between 23 and 25 indicated on a boost gauge.

I've always assumed that with a very heavy load up a steep grade at full throttle you'd get up over 25 psi.

I'll see if I can find any of those old threads.

Here's one. Read the first post.

Another one.

This one's interesting. Same question as you.

-Ryan

 

[rscurtis]

When I installed the BD on my signature truck, I adjusted the waste gate to match the original. The BD was set at 45 PSI, and the original HE 341 just started to unload the WG at 26 PSI. Add the internal pressure pushing against the poppet valve and you have your 23-26 PSI. The BD and manifold is a very worthwhile upgrade if you don't mind spending the $, even on a stock engine as mine is.

 

[SDrake]

about searching. My searches did not come up with anything like that. Haven't read them all yet but I am digging in.



rscurtis, -- thanks for that helpful info. Some things are beginning to jell finally on how this model can be modded.

 

[Prairie Dog]

Mine would only hit 23-24 when new. I adjusted the wastegate and got it to go to 26. I couldn't feel any difference.

 

[rscurtis]

That is correct. Past a certain point, all you have is heat and backpressure. The stocker would run 5-7 PSI at 65, the BD runs around 2 PSI. This, IMO is the reason the 6. 4 Ford engine was such a fuel hog- it was always making a lot of boost, even if you didn't need it.

 

[SDrake]

That is correct. Past a certain point, all you have is heat and backpressure. The stocker would run 5-7 PSI at 65, the BD runs around 2 PSI. This, IMO is the reason the 6. 4 Ford engine was such a fuel hog- it was always making a lot of boost, even if you didn't need it.

That is interesting about the Fords and would explain my experience around them. About my truck, about all I understand at the moment is that if I am not making smoke I do not need more boost. I do not understand at the moment how to go about adding fuel so that i can then determine if I need more boost. The work of the designer of the engine was to get a boost system that would respond to the amount of fuel added by adding just enough boost. I sort of learned how to work with the balancing act on my 94 and got what i wanted but on this truck so far I know only of getting a box such as a smarty and letting it do its thing with timing and pulse duration of the fuel. On an otherwise healthy engine that is probably all I would want. I am just trying to get rid of my suspicions that something isn't right before getting a smarty. All of you have added to or confirmed my understanding. I need to take a trip through all my old TDR magazines to find the third gen discussions on these engines that I skipped over while driving the 94. Any links of discussions on the fueling of these engines would be good reading for me at this time