Boost gauge (not using forscan) and more

[Mark S.]

It's a very small technicality that you probably don't even need to get to understand the rest of the system. I just read about it many years ago. Thought it was a very interesting point. Makes sense to me. If It doesn't make sense to you.

I found the source of the statement you posted here. I think if you had posted the link instead of the out-of-context statement you would've gotten less negative feedback. The statement you posted is in the context of making mechanical modifications to get more air to an engine. The engines in our cars are mature designs; boost and exhaust are carefully controlled to get exactly the amount of air to the engine the programming in the PCM demands. In other words, there is no left over boost in this context.

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[Meanderthal]

I think y'all are trying to make this more complicated than it has to be. Literally it has nothing to do with anything before the throttle body and nothing to do with anything after the intake valve. We're measuring pressure from the intake manifold that the turbo made from exhaust gases. That pressure or boost is forcing more air and then the engine would normally be able to consume with just the pistons moving down and drawing in air.

So the turbo is forcing extra air into the manifold and it's forcing as much air into the combustion chamber as it can. Into meanderthals comments? Yes then if the turbo makes more boost sure it's going to make more pressure there's going to be more pressure in the combustion chamber. There's also going to be more pressure in the intake manifold and when that intake valve closes it didn't suck all the air out of the intake manifold. There's still pressure in there and that's what your boost gauge is reading and that's all this is trying to say. Yes, it's kind of a strange concept. You could just say it's the pressure in the system and be done with it. But technically if there was nothing left over there would be no air. No pressure left in the intake manifold, which is where the boost gauge is reading from. Unless you could somehow read from the combustion chamber, but I think the combustion process would mess with that so you could only read from the combustion chamber while it's being filled. And actually, since the volume is constantly changing, it would give you different readings the whole time.

It's a very small technicality that you probably don't even need to get to understand the rest of the system. I just read about it many years ago. Thought it was a very interesting point. Makes sense to me. If It doesn't make sense to you. Totally fine but don't make fun of me for it. I'm not making fun of anyone else for their ideas. Be it right or wrong. And I'm not just making up some random thing. I could find multiple places where engineers who work on cars and turbos also say this. That's where I got this from.

Everything else about a turbo system still applies. Nothing else is different.

I'm so glad that everyone could act like a civilized adult on here and we could discuss this in a normal professional manner.

I understand what y'all are saying and it is a kind of strange way to think about it. Yes you can just think about it as the turbo makes pressure in the engine and that's your level of boost too.

I think one thing we have not been including here is that this system is very dynamic. Meaning that the engine is pulling air from the manifold and the turbo is pushing air into the manifold. The control unit is trying to maintain some level of pressure in the intake manifold, so the wastegate is opened/closed by some level in order to do that.

Measuring the pressure in the cylinder directly would be a fairly difficult thing to do and also be very dynamic. On the compression stroke the cylinder pressure goes up dramatically. Then on the exhaust stroke, it goes back down dramatically. On the intake stroke the pressure is then very close to the pressure in the intake manifold. I think that is where the thinking of "left over" pressure just doesn't seem very logical. Obviously, none of us here are internal combustion engine designers. The ideas we are expressing are usually simplified versions of complex engineering/mathematical systems. If you have sources for your ideas/beliefs it is always a good idea to link to them. I know you posted an image of a site that had a little bit of the overall information but having the full context of the article is a better practice.

 

[Ksnau]

Well that's actually not where I read it from it was just the first I found but Honestly it doesn't matter to me and I've moved on, it's there with y'all's comments for people to read and figure out I really can't explain it anymore than I have except if I find the original article I'll post it. It was done by 928 motorsports but like 10 years ago and they've updated their website since and I can't find the part where he explains it.l but that's where it originally came from when I had a powerdyne supercharger I bought some of his parts to upgrade it (which was a waste powerdynes are just garbage no matter what you do) and happened to see it.

Like I said in another post I have the catch can routing figured out I just need to get one more tee and I'm going to use that vacuum line to reference boost from.

One thing I'm sure I'll get roasted on is the different hoses but I'm using an old catch can that was for a vehicle with smaller vacuum lines so mine will have some reduction fittings and I'm going to link mine to the turbo intake and have check valves so it's a little more than the basic catch can but hopefully it'll be enough to show how easy it is and anyone who knows anta to do one can for cheap and fairly easily.

So the big obstacle now is just where to get power and ground from. I should have a video for the catch can soon which will also show where I reference boost from and how to get the dang PCV line out easy or kind of easy.

 

[Ksnau]

I've been busy with work but I did get to do a little bit of stuff this week. I got my adapter for the blow off valve but they didn't drill the holes in the right spot. The one that's off you can even see where they made an indent of where they were supposed to drill and then how they drilled like an eighth of an inch off.

I didn't want to have to deal with returning it waiting like a week for the new one to come in. So I used my drill press. I was able to just drill out the hole to where it was supposed to be and it seems like it should work. I'll be putting it on later but when you order these parts make sure that you give them a good look over because while this one doesn't take much to put on it's still sucked and cost me like 10 minutes when I realize it wouldn't fit after fiddling with it for a while.

Hopefully you can see the indent where they were supposed to drill and how they drilled too far outside and then you can see where I just took my drill press and drilled down from where the indent was to expand it so that the bolt should fit now.

And when I put this on I'll also be putting on my catch can which will include the outlet of where I'm going to reference boost for the gauge. So hopefully soon the whole point of this thread will be shown of how I do the gauge.

 

[Ksnau]

So I finished my catch can routing. There are some different sizes hoses and I left them extra long in case I don't like where can is now but I wanted to put a pic of the stock PCV hose cuz it seems like a huge pain and I even pulled the intake manifold completely off on my 22 Badlands to get to it but you can easily reach it and take it off with one hand.

You can see me pointing to the blue part in the 2nd pic. You basically just got to get your finger and push that clockwise or to the side and that'll open it up so it's slides over the lip where the hose connects to. You need to do that for the one on the back of the intake manifold and there's one like an inch to the right of it. That's on the back of the block that goes to the PCV valve.

You might have to do some feeling around but you want to start in that kind of opening to the right of the intake manifold and you're going to reach under that metal EGR pipe that you see and kind of go under it and then raise your hand up again a little bit and you'll feel the hose and just follow the hose to the connectors and push the tab on each of them to the right and they'll slide off as you pull back.

The first picture is the catch can hose routing and it looks kind of crappy because first there's black heater hose and then it goes to clear plastic hose and there's all those clamps but leaving it like this lets me move the catch can around if I don't like the position it's in right now and then eventually i'll cut it down shorter and make it look better once I know where I'm keeping it.

You can also see there's a tee fitting. Well it's really the shape is a y and that's going to go to where my boost gauge sensor is that references the boost or vacuum. And if you're doing a catch can

yourself, the hose you want is 5/8. So you want to make sure that the nipples going to your catch can or 5/8 mine or smaller. I think they're 3/8 and that's why I have two different types of hose but I only did that because I got this catch can for another car. So just make sure that your catch can has 5/8 nipples on it to connect the hose and it should only have to have two hoses. And then you'll want to put a check valve between the intake manifold and the inlet of the catch can because you don't want boost blowning in there.

 

[Ksnau]

Quick update. I was trying to find a power source for Mike boost gauge and I use the fuse box by the passenger seat for well and I use the fuse diagram online and evidently it was wrong because I pulled out a fews and all of a sudden when I went to turn on my car to check if I was actually getting power from it. A whole bunch of warning lights came on and it said I had no hill to send control. No traction control whole bunch of stuff so I won't be using my ad if use.

At this point I'm going to try and pull out the cigarette lighter 12 volt power outlet down below the radio and air conditioning and see if I can just tap into the power and ground off of that. Because that was scary as s*** getting all those worrying lights all of a sudden.

Also, I don't remember the exact mileage when I put the catch can on but I think it was about 200 miles ago and those clear hoses are already turned oil-colored and already have like a tablespoon of crap in the catch can so it's definitely worth it to put a catch can on these. And I haven't even been up north where it's colder. And you get that chocolate milk stuff because of all the moisture from cold weather and hot engine and this was just normal driving and really nice weather.

 

[Ksnau]

So with the warning light scare when I was trying to take out fuses and use the add a fuse power source, I've decided to just use a 12-volt adapter that plugs into the cigarette lighter under the AC controls and use that for the power and the ground. And I mounted the boost gauge with some double-sided tape that the gauge pod came with. You can see in the picture.

Since my trip to Yellowstone's coming up soon I'm just kind of tuck and wires away for now. I'm trying to be real careful not break anything but these interior parts just don't want to come off. So I'm just going to route the wires outside for now but I'll at least hopefully by the end of Friday be able to get everything wired up and powered on and I can do a short video for y'all and we can see what it shows the max boost as at least I guess

 

[Ksnau]

Sorry I haven't posted in a while. I got busy with some stuff but I got the boost gauge done. I'll post a couple pictures where I put the wires and how I got power. It's not up really permanent way with the wires. Really hidden that most peoplr would want, but it's really easy to take off and it doesn't leave any permanent changes to the car and it was just easy. And maybe it'll help people get ideas on how else to do it.

Also, when I was trying to use an add a fuse the fuse diagrams weren't right or there was something else going on because it was messing with some of the systems so I was lazy and I'm just using power from a 12 volt plug-in adapter that goes in the DC outlet by the wireless phone charger So the actual power source isn't like hardwired into anywhere.

Basically I just used a vacuum tee from my catch can before the check valve to reference vacuum and that just goes off of the PVC nipples on the intake manifold and the block behind the manifold and then ran the wires between the battery and the fuse box on the driver side of the engine bay and then through a little rubber grommet that's kind of just below the brake master cylinder and the rubber on the grommet is easy to poke a hole through and it kind of like flexes around the wires so it seals around them without having to do anything extra which is nice and it's pretty easy to get to.

From there I merge the power wires and ground wire that came from the 12 volt outlet by the wireless charger if you have one with the power and ground wire from the sensor that's in the engine bay so they both take power from that 12 volt outlet by the wireless. The data line from the sensor is merged with it's corresponding where that goes to the gauge to read the data from the sensor onto the gauge and it all tucks under the plastic below the steering wheel kind of nice. I haven't zipped tied anything up in case there's issues, but I've driven it and it's worked fine. The readings are a little weird though.

At idle once it's warmed up, I'm getting like 9 to 10 hg and so far Max boost I got was like 28 psi but I didn't stay in it. So I think that's just a spike from flooring. It and downshifting. It seems to want to rest around 15 to 18 whenever I get on it just every time I have a chance to test it. I have to slow down real quick so I haven't been able to really get on it and stay on it whenever I think about doing it. Also, whenever you are just regular driving and just barely getting on it, it seems to want to stay around 7 psi with just a little throttle which is all I've really needed to get around most of the time. Also, whenever you are accelerating decently it really jumps around and I think that's just from the transmission shifting. And you know it's an 8 speed so it shifts a lot.

 

[Ksnau]

So I just did a test on the highway where I was able to floor it and stay in it for a while and it's literally going up to 30 PSI which is the max of my boost gauge and that's just got to be wrong now. I've never used this particular type of boost gauge but it's got what looks like the exact same sensor that my other boost gauges have had and those that was able to verify were right. But the gauge itself is different so I think I'm going to give it a little bit but probably going to have to buy a different gauge and see if I get different readings because in the focus STs I think they maxed out it like 17 or 18 usually and you could tweak with it and get it up to like 22 which was usually like the max efficiency of the stock turbo but 30 just seems outrageous.

I ran it again at same thing. When you really get on it. It hits 30 psi which just can't be right.

If anyone else is able to see the boost on that card. Love to hear what they're getting.

 

[Bucko]

I used to tinker and modify prevoius PCM/ECU/whatever controls our modern cars today. I spent plenty on the forum posted cool stuff, only to find that my wallet had less money, and my cars really did not increase in power.

Our Broncos are a prime example on how the engineers got it right. No need for a catch can or oil seperator. We already have one. No need for a cold air intake. We already have one. And for me, no need to monitor boost, or change a waste gate as the boost produced for this 3 cylinder has been engineered to do just fine and allow for longentivity of the engine.

I'm just going to drive it as is.

Now my 67 Camaro? I'm done tossing money in it as well. After 30 years of ownership, I have finally come to the conclusion that it too is done with modifications, and I'll just smile as I drive it.

 

[Ksnau]

I get what you're saying but I still like to have it for diagnostic purposes. It helped me figure out what was going on when I was getting a trouble code and not making as much boost as I should on my 2014 with the 2.0.

Also, since I plan on modifying this one, I feel like I definitely want it there. Also I wanted it there because I had a full-size bronco and it came with a boost gauge stock and after having that I kind of felt like I was missing out on that. But mainly it's just a good diagnostic tool that I like to have on all my cars that have boost but for most people's definitely not required.

I am going to have to disagree with you on the catch can though Yes, these do come with a separator built into the PCV which is nice and I'm only at like 6500 miles on this broncosport but on my 22 Badlands whenever I put on the catch can I pulled the intake manifold all the way off and it already had a film of oil on it and I think I was only at like 8,000 mi. Since I only run 87 and this car that runs a pretty decent amount of boost and that oil mixing with the gas can lower the octane even more and possibly cause detonation or at least limit performance.

It does have a lot of sensors and a good computer that can really monitor the engine and you know dial back, timing and boost if needed. But I still want to limit that oil getting in the engine. Also, since I make my own catch can it only costs me like 30 bucks and I feel that it's a worthwhile cost. But I'm sure plenty of people could drive their cars without one. And probably not have an issue, especially since most people aren't even keeping their cars to 100,000 mi. But I saw what it did to my 2014 escape and I had to clean the intake valves on that thing and it was a pain in the butt and I really want to push that out for as long as possible as well as the other reasons and I plan to keep this thing until it or I die.

 

[Ksnau]

So I made a video of my boost gauge working while I drive. Just a warning. I make terrible videos but hopefully this at least let you see it working. Here's the link on YouTube. It's about 3 minutes.

 

[jarred Wilson]

Nice build buddy ! keep it up

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[Ksnau]

Thanks. I was saving up to see if I could afford to do air suspension because It seems like it might be possible to do for cheaper than I thought it would be even though it is still a big chunk of change and a couple people with Mavericks are starting to do them now but they're all to lower them. I emailed a company that's local to me who's made what they call a plug and play kit for the Maverick all-wheel drive to ask if their kit would be possible to use on my bronco sport, but as an off-road kit so we're waiting to see but even if they say yes it's going to take me a while to save up because their kit is like 2500 and I think I could do the install myself but I'd want to save up some more just in case I would need to take it somewhere because I don't do much suspension work. But that's my next big thing I want to do is either a regular lift or an air suspension lift. I was thinking about putting the push bar with the lights on the front and maybe some roof rack lights but I really have never felt like I needed more light driving at night off road and so I want to save that money towards the lift especially if I decide to do air suspension.

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