I added a boost gauge that ties into the MAP line. New waste gate actuator. There doesn't appear to be a boost fooler, the MAP line comes direct from the turbo/manifold area to the MAP with nothing in between. New red and green lines. I have not seen anything over 23 lbs of boost. I made the adjustments to the old actuator so it opened about 20 lbs. The new actuator seems to open with minimal pressure, no amount of adjusting, even completely tight on the wastegate, seemed to change the opening pressure. I have unhooked the red line and plugged it. Still, the gauge doesn't show anything above 23, and usually only as high as 20-21. New WW2 added trying to get rid of what I thought was turbo flutter, but is looking like it was too small of an air filter. This weekend, I took the air filter off and unhooked the red line. WOT acceleration and the gauge still didn't go above 20 lbs, but I blew the intercooler hose off in the intake side. This makes me think I'm pushing way more than 23 lbs of boost. With the red line hooked up and the new actuator, it didn't blow the hose, it was when I took the red line off that it blew. Crusin through town around 35-40 mph, my boost reads 1-2 lbs, but I can hear the turbo singing. Moderate acceleration it sits around 7-9 lbs. 1/2 to 3/4 throttle acceleration, it will jump to 13-15, but even most of the time at WOT, it'll not get above 18-19 until I get up above 2500 rpm, then I'll see 20-21. The only time I have seen it hit 23 is with the 5'er in tow going up a hill. Then the EGT is getting up into the 1200 range so I'm letting off and boost drops to 18-19 again.

Is my gauge just faulty? It is a digital gauge. Is boost pressure measuring in psi? Can I hook up my old mechanical vacuum/psi gauge and get a more accurate reading?

 

There are several things to consider here... I will try not to get too convoluted...

1. If you are NOT running a tuner of any sort, you are right about where you should be with boost PSI.
2. If you still have the OEM up-pipes, they may be leaking a bit.
3. If you have not checked for boost leaks in the CAC system, this would be a good thing to do.
4. Removing the red/green lines and tightening down on the wastegate is a common thing to increase the boost PSI.
5. You cannot base boost PSI on if a boot blew off or by sound. T-clamps and better boots can sometimes help with keeping a good seal and not blowing a boot off.
6. A mechanical PSI gauge is considered more reliable than an electronic, but is more challenging to install correctly due to the air line that runs into the cab and to the gauge. This difference is somewhat negligible though and not a concern for 99% of us.
7. Boost is purely a representation of manifold air pressure. The right amount of boost is best, not the most boost.
8. You saw more boost during your 5th wheel tow because there is more load on the engine, this is normal.
9. What other questions, thoughts or concerns do you have sir?

 

I am not running any tuning at all. Bone stock other than the compressor wheel. Up pipes look original. I did replace the top 4 CAC boots with Gates and new clamps, but have not checked for leaks in the system yet. I'm not really trying to get more boost, just wondering if what I am seeing is normal. Totally OK with the right amount of boost. As Long as the truck is doing what it is suppose to do, I'm good with letting it do it's thing. I'm new to the 7.3 game, so I'm not familiar with what's normal. The question about the mechanical boost gauge is more to check against the digital one. I don't plan on running it permanent, I can just hook it to the wiper for testing. I was just wondering if my old psi fuel gauge would work and read the correct boost pressure. I'm not trying to make a race car out of it. I just want to be able to enjoy my retirement days pulling around my trailer and seeing all the cool things this country has to offer.

Thanks for the info, much appreciated. I'll eventually get the normal operations of this truck figured out.

 

You are very welcome and rest assured that your 7.3L engine appears to be doing exactly what it was designed to do 20 years ago. Tinker with it and verify things if you feel the desire, it is your truck, your time and your curiosity.

I don't suspect your old fuel pressure gauge will work as a boost gauge, one is built for fluid dynamics and the other is air/vacuum based. I am not 100% sure of that though...

I commend you for checking around and coming here to the FTE instead of some of the other social media platforms that are riddled with misinformation and aggressive people. We sincerely hope you do have the chance to enjoy your retirement YEARS (not days) and have the opportunity to see this beautiful nation of ours.

 

My gauge is one of the old ones that will measure vacuum and pressure. It's from the old days of carbureted engines. I think I'll give it a try, can't hurt anything. I'm planning on getting many, many years out of my retirement! 20 years on the dark side of the LEO game, I'm getting out at 49, so I should have a lot of good years left in me!

Sous, thank you for your years of service to our country!

 

Congratulations on your retirement and thank you for everything you did in order to keep us safe and comfortable. I support the blue, green, red and gold every chance I get.

You are very welcome sir, but thank you for saying so. Perhaps we will cross paths one day and I can thank you in person for your service.

Below is a picture of our truck and 5th wheel. We normally stay within 1000 miles of GA, but every 2 - 3 years we get out west to ID, CO, WY, MT, NM, TX, etc... You can kind of make out our sticker map (visited states) of the U.S. on the slide.

If you happen to see us one day, say hello!

 

We will be headed to Northeast Wi in August. My wife and youngest son have never seen where I grew up. I have a lot of family out there they have not met. That's our goal for traveling this summer. We're planning on a few long weekend trips around the west to get our traveling legs underneath us. I have family in SC, NC, VA, MS, and FL that we want to visit next year. Maybe we'll cross paths then. I'm always happy to thank a Vet! My Uncle is retired Air Force and has been traveling for almost 30 years. He still loves it and plans on another 30 years. We want to follow him around and soak up the rich history in our great nation. I want to get one of those cool map stickers. I found one that's cool old license plates.

We'll keep an eye out for you, you do the same!

 

Wow, that is quite a setup you have there!

I will PM you my number and details in case you are ever in the north GA lake Hartwell area. There are several great CoE campgrounds on the lake.

Travel safe sir and I hope retired life is good to you!