If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
Thread Tools | Display Modes |
#11
|
|||
|
|||
"john smith" wrote in message .. . I've seen some Lance's advertised with Turbo and then there are some that specifically advertise Turbo with Intercooler. Are these two seperate options available or are they one in the same? The Lance I'm looking at just says Turbo in the ad and doesn't mention any intercooler. The intercooler is a aftermarket STC'd modification. Without it, the airplane will not be able to maintain high power settings above about 16,000' without overheating. An intercooler is a radiator that cools a gas (air) instead of a liquid. When air is compressed (what a turbocharger does) it heats up. When a gas is heated it wants to expand (return to an uncompressed state), so you place an intercooler (or two) inline following the turbocharger and before the engine air intake, to cool the heated, compressed air before it enters the engine, providing cooler, more dense air to the engine. Cooler dense air can absorb more heat than hotter dense air and provide greater expansion and therefore more power. Or it can provide the same power with all the temperatures being lower (inlet, combustion, EGT, TIT). Mike MU-2 |
#12
|
|||
|
|||
Thanks for all the info. This is all great stuff and hopefully I'll be able
to make the right decision when it comes time to purchase. |
#13
|
|||
|
|||
I found some readings that said the Turbo Lance has a fixed wastegate and
that there are other systems out there that have a manual wastegate that allows the pilot to better control the turbo. How much of this is really a factor and should I really care? |
#14
|
|||
|
|||
You could interpret a manual wastegate as something that you have more
control over or you could say that it just provides more workload :-). The Turbo Lance wastegate is attacked to the throttle linkage and works pretty well. The best system is a compensated automatic wastegate but that is considerably more expensive and complex. Mike MU-2 "John Doe" wrote in message news:R5nOe.17574$Co1.9024@lakeread01... I found some readings that said the Turbo Lance has a fixed wastegate and that there are other systems out there that have a manual wastegate that allows the pilot to better control the turbo. How much of this is really a factor and should I really care? |
#15
|
|||
|
|||
John Doe wrote:
I found some readings that said the Turbo Lance has a fixed wastegate and that there are other systems out there that have a manual wastegate that allows the pilot to better control the turbo. How much of this is really a factor and should I really care? For my money, I'd care. There is a series of 6 articles on turbocharging by John Deakin at avweb.com. Here's a link to the index of John's Pelican Perch articles: http://www.avweb.com/news/columns/182146-1.html Scan down the list to the "Those Fire-Breathing Turbos" articles. Dave |
#16
|
|||
|
|||
"Dave Butler" wrote in message news:1124732805.292189@sj-nntpcache-3... John Doe wrote: I found some readings that said the Turbo Lance has a fixed wastegate and that there are other systems out there that have a manual wastegate that allows the pilot to better control the turbo. How much of this is really a factor and should I really care? For my money, I'd care. There is a series of 6 articles on turbocharging by John Deakin at avweb.com. Here's a link to the index of John's Pelican Perch articles: http://www.avweb.com/news/columns/182146-1.html Scan down the list to the "Those Fire-Breathing Turbos" articles. Dave Awesome link, THANKS! |
#17
|
|||
|
|||
On Mon, 22 Aug 2005 14:39:32 GMT, john smith wrote:
snip An intercooler is a radiator that cools a gas (air) instead of a liquid. When air is compressed (what a turbocharger does) it heats up. When a gas is heated it wants to expand (return to an uncompressed state), so you place an intercooler (or two) inline following the turbocharger and before the engine air intake, to cool the heated, compressed air before it enters the engine, providing cooler, more dense air to the engine. Cooler dense air can absorb more heat than hotter dense air and provide greater expansion and therefore more power. Technically, an intercooler is a "radiator" placed between a exhaust-driven turbine compressor and a mechanically-driven turbine compressor (a la B-17). Your description of an aftercooler is spot-on. You may not be familiar with the Turbo Lance/'Toga "intercooler" installation. It is a relatively inefficient aftercooler installation that has other very important benefits. It changes the existing lower cowl design from a single common air inlet which is shared between updraft cylinder cooling, induction air supply, and oil cooling air cupply. The new lower cowl has separate inlets for updraft cylinder cooling, induction air, and oil cooling, as well as the aftercooler inlet. Unfortunately, the outlet of the aftercooler heat exchanger is exhausted into the pressure area for the updraft cylinder cooling. The installation will drop operating CHT by approximately 40-60 degrees F, and operating oil temp by 20-40 degrees. Considering that CHT can run 450 F and oil temp 220+F this is a very good thing. I honestly cannot recall the typical induction air temp drop, but the overall package works quite well. IMHO this is as much a result of improved engine/oil cooling air flow as actual induction air cooling. Personally, I would not consider operating a Turbo 'Toga/Lance without this modification. Regards; TC |
#18
|
|||
|
|||
Personally, I would not consider operating a Turbo 'Toga/Lance without this modification. Well it seems that after reading all the articles mentioned on turbos and your comments, my decision has come down to one aircraft with and one without this intercooler mod. I'm assuming this mod can be performed aftermarket. Do you happen to know the cost of performing the mod? The asking price difference right now between the two is about 20k. There are some other factors going into that cost, but I need to be able to justify the extra $$$. |
#19
|
|||
|
|||
On Tue, 23 Aug 2005 11:59:51 -0400, "John Doe"
wrote: Well it seems that after reading all the articles mentioned on turbos and your comments, my decision has come down to one aircraft with and one without this intercooler mod. I'm assuming this mod can be performed aftermarket. Do you happen to know the cost of performing the mod? The asking price difference right now between the two is about 20k. There are some other factors going into that cost, but I need to be able to justify the extra $$$. 10 years ago it was around $6500 + install. Only web reference I could find for the kit says $7495 (no idea how old). Unfortunately, other digging around on the 'net indicates that Turboplus is not currently an operatiing GA entity. Found a post by a guy that says he owns all the paperwork/assets and is looking for a buyer. Could call these guys, I guess: http://www.barteltaviation.com/install.htm Back to airplane shopping: If I was looking at these aircraft, I would want to know EXACTLY how much total time was on the exhaust components. Would NOT recommend running any of them past recommended TBO. Anybody that tells you any different has very likely never seen the results of a turbo lance/toga exhaust failure/engine fire. On a test flight, look/ask about typical oil temp/CHT indications in cruise. If the engine has been operated for any period of time with an oil temp over 210 or CHT over 450 (hard to tell, no numbers on factory gauge) is likely to have cam spalling & accelerated e-valve guide wear. Don't ask me how I know this... TC |
#20
|
|||
|
|||
wrote in message ... On Tue, 23 Aug 2005 11:59:51 -0400, "John Doe" wrote: Well it seems that after reading all the articles mentioned on turbos and your comments, my decision has come down to one aircraft with and one without this intercooler mod. I'm assuming this mod can be performed aftermarket. Do you happen to know the cost of performing the mod? The asking price difference right now between the two is about 20k. There are some other factors going into that cost, but I need to be able to justify the extra $$$. 10 years ago it was around $6500 + install. Only web reference I could find for the kit says $7495 (no idea how old). Unfortunately, other digging around on the 'net indicates that Turboplus is not currently an operatiing GA entity. Found a post by a guy that says he owns all the paperwork/assets and is looking for a buyer. Could call these guys, I guess: http://www.barteltaviation.com/install.htm Back to airplane shopping: If I was looking at these aircraft, I would want to know EXACTLY how much total time was on the exhaust components. Would NOT recommend running any of them past recommended TBO. Anybody that tells you any different has very likely never seen the results of a turbo lance/toga exhaust failure/engine fire. On a test flight, look/ask about typical oil temp/CHT indications in cruise. If the engine has been operated for any period of time with an oil temp over 210 or CHT over 450 (hard to tell, no numbers on factory gauge) is likely to have cam spalling & accelerated e-valve guide wear. Don't ask me how I know this... TC TC, Thanks. That's what I'm worried about. It only has an EGT gauge and nothing to monitor CHT or TIT, etc. Is there going to be problems getting parts for the turbo system ? |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Why turbo normalizer? | Robert M. Gary | Piloting | 61 | May 20th 05 04:33 PM |
Turbo prop AT-6/SNJ? | frank may | Military Aviation | 11 | September 5th 04 02:51 PM |
Opinions on Cessna 340, 414 and 421 | john szpara | Owning | 55 | April 2nd 04 09:08 PM |
OPINIONS: THE SOLUTION | ArtKramr | Military Aviation | 4 | January 7th 04 10:43 PM |
Piper Lance | Renee Purner | Owning | 22 | November 4th 03 07:47 PM |