93 f350 7.3 idi with CDD stage 1 GTX3582 waste gate adjustment

[Jef_nik]

Hi all! As title states, I have a 93 7.3 idi, pre PS, and I've upgraded injection pump, injectors and turbo (GTX 3582), all from CDD, all stage 1, I've set the dynamic timing at 8° btdc (per CDD direction) with DTI 3300s (using DTI timing light method) and running well, but not getting above 8 lbs on the turbo, currently the adjustment is all the way closed on the clevis adjustment and test driving unloaded- shouldn't I be getting higher pressure? No mods on intake, factory completely and stock dp with 4" exhaust to 5" tip. Have went 3 turns open, then test drove, went 3 more then test drove and put back to closed (opening seemed to drop lbs). Any thoughts? Thanks in advance

 

[FrozenMerc]

test driving unloaded-

This may be your problem. Hook a trailer to it, preferably something with alot of heft and wind resistance like an enclosed car hauler, and report back us.

2nd step would be to unhook the waste gate linkage entirely, and wire it closed, then test drive. My guess is the gate is remaining closed at 8 lbs, but it would be nice to verify.

If the gate is remaining closed, and you are still only getting 8 lbs, look for any exhaust leaks, pre-turbo.

Do you have a stock cam in the engine? How much boost are you expecting? On a stock engine, I wouldn't want more then 12 psi. Where is your pressure transducer located?

 

[ih8minimumwage]

With the clevis turned in, you'll be limited to what the spring pressure in the wastegate actuator will hold before it blows off the extra PSI.

There's the option to disconnect the actuator and wire it shut, or turn the clevis even further in so you'll have to physically pull the rod out from the actuator to connect to the wastegate to have more pressure holding it closed.

I went with the latter method for now, easily hitting 10-12psi (and accidentally 14+psi if not careful).

What are EGTs looking like when you really get on it? Driving unloaded on flatland won't show as much boost compared to loaded up a hill or onramp.

 

[Jef_nik]

Thanks for the replies guys, I actually went and unhooked the vacuum line and plugged- 12 psi no problem. So I am assuming the spring is only good to 8 or 9 lbs then the vacuum opens her up. Egts have only gotten near 850-900, when pushing 2800 rpm, 4th gear, up hill, unloaded, and returned to 500-600 almost immediately when I backed out of her.

Frozenmerc- I'm more than content with the 12 psi, I was just certain I should of been able to get more than 8 is all, out of curiosity "where is your pressure transducer located"- sorry, what is this transducer your asking about? And stock cam, only mods are exhaust and updated ip, injectors and turbo

 

[frankenwrench]

I have the stage 1 injectors, cdd 110 cc ip, intercooler, and 3582 turbsky as well. Running empty on Texas flatlands can hit 18 psi easily in 3rd, 4th, and 5th gears. Loaded I've buried the needle on my boost guage that only goes to 20 psi quite regularly but my egts also hit 1000 f* if I'm not careful. I have an early 110 pump so my fuel curve isn't so flat. According to my flow chart I see 147 cc at 2800 rpm.

 

[FrozenMerc]

The pressure transducer is what sends the voltage signal to the gauge in the cab. It's location within the intake track can affect the reading. Mine is located in the center of the intake hat, as seen in the pic below. On a non-intercooled stockish type setup, there likely won't be much variation in reading between the intake hat, and say an individual intake runner, but there can be big difference on intercooled setups with a bunch of piping, bends etc. Remember, pressure is just resistance to flow. Anything that restricts flow causes a change in pressure. This is why Gale Banks and other high end engine builders focus on manifold air density rather than boost pressure. The boost pressure can be somewhat arbitrary and very much a function of measurement location and temperature.

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[frankenwrench]

My guage reads from the intake hat as well.

 

[frankenwrench]

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