I meant an air to water intercooler as well as control the ecm not trick it. There must be guys who mod these ecu,s to control what they want, if not a stand alone unit should be able to do job. You need the putter to adjust the boost to elevation. You will probably find that running a few pounds of boost at sea level will not add any significant stress to your drive train and if you keep your foot out of the peddle, get better fuel mileage as the engine will be more efficient.

 

A turbocharger is a type of compressor for sure but I wonder if the terrific spinning action does cause turbulence. A flow straightener is a nothing piece of fabrication and could easily be placed in the tube just ahead of the throttle body, for good measure.

 

If the heat/knock thing could be resolved with a small enough intercooler I would consider a manual control with a limit of 5 psig. I would monitor psia to be a max of 14.7.

 

Is there anyone willing to relate what they’ve done using a stock ECM?

Bingo, manifold ABSOLUTE PRESSURE. Apart of my custom control and what I would monitor.

Thanks for the encouragement...it’ll continue for as long as it amuses the group, I guess.

 

Do you have access to everything needed to build a controller as you have designed? I am at the point now that I would like to see it in action.

 

I’m not going to build it until I’m convinced to install the turbocharger but I’ll get a list together of parts, a diagram of the layout, and links to similar projects.

 

I dont see a reason that you couldnt use compressed air, a couple solenoid air valves, a microsquirt (for boost control and enrichment via many methods), a light or no wastegate spring to do this.

the size of the turbine, wastegate, etc will dictate how low of boost you can run at sea level.

If it goes too high for your comfort level at sea level simply back off the throttle a bit.

 

As long as I don't exceed 14.7 psia I won't need any enrichment. That's part of what I'm trying to avoid. I want the operating parameters to stay within factory spec. As has been discussed, one can't run zero boost without destroying the turbocharger so I do need to better understand the specifics of a turbocharger that dictates the minimum boost it will tolerate keeping in mind the max boost I'm interested in is 5 psig on a 2.8L engine running no higher than 4500 rpm.

 

If you are dead set on max of 14.7 PSIA....then a roots style supercharger and a controlled bypass valve would be an easier way.

Low pressure ratios (~under 1.5 PR) is actually an area were a positive displacement "air mover" is generally more efficient (isentropic) then a centrifugal compressor.

 

You can run 0 boost without destroying the charger. You just can't use a blow off to do it. That would overspeed the turbo and ruin it.

 

Earlier we established one could NOT run zero boost under any circumstances. My intent was then and is now to control boost with the waste gate. Separate from that I suggested using the BOV for what it is intended, a fail-safe.

It's not imperative for me to have that clear at this point but I hope for some kind of consensus in the end.

 

Maybe you should look into monitoring your injectors the next time you take it out. Figure out what the duty cycle on them is and see how much overhead you actually have. I think the Torque Pro app and ELM327 module will do this for under $20. You may have to write a custom PID but this shouldn't be a problem for you.

 

That's not correct. People were saying you can't spin the turbo up and just vent off the air as a way to control the boost, essentially a turbo spinning uncontrolled at 0 boost. A turbo runs fine at 0, as long as the turbine side isn't being driven. That's the point people were trying to make.

 

I guess my problem is so off-the-wall that I can’t explain it clearly. My goal is to avoid running the engine outside it’s design parameters. The boost I would add would only be enough to bring the intake pressure up to 14.7 psia (sea level). The benefit of which is about 50 hp at 10,000 ft elevation. That could be as much as 5 psig but that only compensates for the thin atmosphere. There won’t be a need for extra fuel. What I’m after is the extra air...the air the engine needs to run normally with the stock duty cycle. So, instead of trying to climb the mountain with only 120 hp I would have the factory rated 170 hp.

 

Thanks for clearing that up. I can run the waste gate wide open without a problem.

 

Most design solutions involve a deal-breaker. In this case it would seem the temperature of the waste gate shaft. I need to know that temperature.

The simplest solution involves coupling the stepper motor directly to the waste gate shaft. High temperature stepper motors can be prohibitively expensive depending on just how high the temperature.

 

It gets way hotter that you want to touch. I got anxious to turn the boost up a bit on my Buick one night at the track and messed with it earlier than I should have. It didn't take the skin off but it was not pleasant.

Can you use the stepper motor to pull on the actuator? If so, you could pull on the entire actuator, housing and all, with an internal gate. Then you would have a spring to compensate for any extra pull you might get with thermal expansion. Next time I have my Buick out I will try to remember to shoot the actuator with the temp gun and see how hot it gets in different spots.

 

2 stroke snowmobile engines have used remote exh valve actuators for years. Maybe look into those. I'm curious to know if the speed of the actuator becomes an issue. I foresee some boost spikes.

 

I still see a traditional wastegate setup being the simplest, and best. Maybe a mechanical way to open it at sea level, and manually add boost as you go up in elevation. A psi or two either way shouldn't kill it, especially if you're paying attention to what's going on. Most factory ecu's have knock protection of some sort, and a boost referenced fpr (which I assume it has) will keep fueling close. Or take a step backwards in technology, and add an adjustable fmu for when it goes into boost.

 

Yes. A second type has a longer, threaded shaft. A custom nut is used to push/pull. Using the threads is like using a gear reducer. You get more force but slower speeds. I haven't gotten far enough into the details to know if the slower speed would be a problem with respect to response time but it likely would resolve the heat issue.

That would be great.