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geosnooker2000
08-10-2019, 11:46 PM
I am struggling with a mechanical theory and was hoping for some expert opinions. If someone's intent was to build a 0-320 and turbonormalize it, there are a couple of very expensive "bolt-on" options. But it seems to me, one of the hallmarks of the experimental aircraft is innovation coupled with simplicity and affordability. To wit, a standard of TN systems is this thing called an Absolute Pressure Controller - one of these things that costs somewhere in the neighborhood of $1300:
7997
They run off of upper deck pressure, and tell the waste-gate what to do by use of oil pressure. The next thing to consider is that aircraft waste-gates are about 4 times the cost of an automotive waste-gate.

I keep trying to understand the fluid dynamics of it, and I just keep coming to the conclusion that you should be able to operate a normalized turbo using manifold pressure to an automotive waste-gate (air pressure), but my mind is telling me that that would operate the waste-gate in the exact reverse of what I'm looking for. Do I have that right? I feel like someone has already tried to make this work. Please discuss...

martymayes
08-11-2019, 07:16 AM
I am struggling with a mechanical theory and was hoping for some expert opinions. If someone's intent was to build a 0-320 and turbonormalize it, there are a couple of very expensive "bolt-on" options. But it seems to me, one of the hallmarks of the experimental aircraft is innovation coupled with simplicity and affordability.

You can turbonormalize your engine with a simple manual wastegate controller. Just manually close the wastegate and force more exhaust air through the turbo side of the turbocharger as you climb to maintain SL MAP. Bolt on, inexpensive, simple and affordable.

If the goal is to push the throttle to the stop and have it maintain sea level MAP all the way to the critical altitude, it's takes a lot more gizmos.



FWIW, back when I flew turbocharged engines (in which some were turbonormalized), none of that stuff every worked correctly.

geosnooker2000
08-11-2019, 11:48 AM
Yeah, admittedly, I am searching for a way to have it normalize itself automatically as it does with the APC. I just think it can be done with automotive components which would be a heck of a lot cheaper simply because I wouldn't be using certificated parts. Like, I'm sure if there was a need in the automotive world met with an APC, that the APC would cost about $100 or so. It's just not that complicated of a piece of machinery. Like, a hartzell wastegate @ Aircraft Spruce costs $1829. The same thing (roughly) in a car application costs about $200. That's ridiculous.
So, my mission is to develop a turbo-normalizing system for experimental aircraft that uses nothing but automotive industry parts. I know people use Subaru Twin Turbos in home-built applications, but that's not TN. That's TC. The main hurdle I have experienced is, I have talked to several racing application people I know around town in person about it. People who sell aftermarket turbo systems, etc. As soon as you say the word "airplane", they clam up like they don't know you. I'm guessing liability issues, and I get that.

DaleB
08-12-2019, 07:10 AM
The main hurdle I have experienced is, I have talked to several racing application people I know around town in person about it. People who sell aftermarket turbo systems, etc. As soon as you say the word "airplane", they clam up like they don't know you. I'm guessing liability issues, and I get that.Or they correctly determine that they know nothing at all about aircraft engines and systems, and decide to stay within their area of expertise. The percentage of people in this country that understand even the tiniest thing about experimental aircraft is vanishingly small.

geosnooker2000
08-13-2019, 04:04 PM
Or they correctly determine that they know nothing at all about aircraft engines and systems, and decide to stay within their area of expertise. The percentage of people in this country that understand even the tiniest thing about experimental aircraft is vanishingly small.

I'll grant you that, but that's not true 100% of the time. I know one guy I was talking to was very knowledgeable about the mechanics of it, and he flat out told me I'm not gonna get anyone to talk to me because of liability reasons.

geosnooker2000
08-13-2019, 04:10 PM
So anyway... enough of that. Can anyone here help give direction to me and anyone else wanting to experiment with a cheaper alternative to certificated turbo parts? IOW, non-TSO parts, or automotive parts.