Turbo or not to Turbo

Turbo or not to Turbo

Postby Bill Casey » Thu Aug 13, 2015 7:14 pm

Hello - I am a new member and joined the ICS to learn about Comanches. Looks like an awesome group of dedicated Comanche fans!

I have been flying my Cherokee Six for years, but now want to try something new (and faster) and have been exploring the Twin Comanche as a cross country traveler for my wife and myself.

I have read a lot of good and not so good about the turbo twins. I am in California and my flying takes me over lots of tall mountains so I like the idea of being able to fly in the "teens" with good speed. Two motors over the high Sierras adds a comfort factor as well.

I have not flown with turbos and I would appreciate input from owners how they feel about the turbos:
- "Best thing ever?" or
- "not worth the cost of maintenance"?
- with a non-turbo Twinkie, how does it do flying in the 14,000 to 16,000 foot range (Many MEA's out here are at those altitudes)
- Do turbo owners fly without using any boost when below 7-8,000?

I have been told by a maintenance shop that the controls for the waste gate and the related components are always in need of adjustment and repair. That the system leaks like crazy and does not provide much boost anyway so it is hardly worth having.

Last question (for now), is the mags. Not being pressurized do owners have problems at higher altitudes with misfiring?

Thanks for the advice.

- Bill
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Re: Turbo or not to Turbo

Postby Kristin Winter » Thu Aug 13, 2015 7:47 pm

Bill,

I went through this thought process in 2006. I live north of the bay area, so I had similar considerations. I decided that unless I had a regular need to fly in the intermountain areas, that I would be fine with the normally aspirated twin. I am very happy with my choice. The ins and outs of my thought processes are more than I can write here, but if you want to chat you can email me at kristin_winter@comcast.net and I will give you my phone number. If your Six needs to be exercised and you want to come up to Petaluma, I will show you "Maggie" and we can discuss the in's and out's of a Twinkie. It is more fuel efficient than a Six and quite a bit faster. I routinely fly between 11,000 and 16,000.
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Re: Turbo or not to Turbo

Postby Clarence Beintema » Fri Aug 14, 2015 9:07 am

If you're considering a turbo be aware that many parts are harder to come by. Unless you're able to do a lot of work yourself or have a good relationship with your maintainer, it will be a bit expensive to maintain.

A normally aspirated version has no troubles getting to the mid teens and is far simpler than the TC version.

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Re: Turbo or not to Turbo

Postby Bill Casey » Fri Aug 14, 2015 6:20 pm

Thanks for the advice.

Kristin - I sent an email yesterday. Hope you got it.

One more thought on the Turbos. We want to fly to "high" places like Bryce Canyon, Truckee, Tahoe, and Wyoming, Idaho, and Montana in general, and I know I would feel better having Turbocharging when taking off at high density altitudes.

With my Cherokee Six when we go to these kind of places it is always planned to be light, go very early when it is cool, and use long runways. Never had an issue but have also avoided the higher elevation airports.

Thanks again,

Bill
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Re: Turbo or not to Turbo

Postby N3322G » Fri Aug 14, 2015 7:07 pm

Bill,

We've used the same approach you have used in your Six for our NA Twin for years and go into all kinds of mountain places. Kristin is the best by the way. Fabulous experiential advice.

We thought hard about the turbo but in the end it was the maintenance hassles that was the deciding factor.

One thing you didn't mention, we keep our props maxed at 2700 rpm until we reach altitude when climbing in the mountains.
Pat

Patricia Jayne (Pat) Keefer ICS 08899
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Re: Turbo or not to Turbo

Postby Kristin Winter » Fri Aug 14, 2015 8:20 pm

Kristin
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Re: Turbo or not to Turbo

Postby Bill Casey » Mon Aug 17, 2015 1:43 am

Thanks for the replies.

I can sure understand that simpler is better and that having RayJays adds to the maintenance headache.

I keep thinking about cross county (literally across the county) trips we are thinking of taking (west coast to east coast and back) and crossing all the mountains along the way and being able to fly airways at or above MEA's, as well as takeoffs from high elevation airports, and the speed the a twin Comanche is supposed to be able to reach in the mid-teens with Turbos. (190 knots?)

I am hoping that a few Turbo flyers will add comments regarding why they have them and what they think about them. What power settings work well up high?, What cruise speeds and fuel flows are typical?

I'm eager to learn and appreciate the input!

- Bill
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Re: Turbo or not to Turbo

Postby Clarence Beintema » Mon Aug 17, 2015 6:01 am

If you want more performance, have you considered a Comanche 400? They will out run any twin Comanche. I've had one for 3 years and love it. There are a few on the market, like any airplane it's harder to find clean no damage ones.

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Re: Turbo or not to Turbo

Postby Kristin Winter » Mon Aug 17, 2015 6:02 am

I just finished a trip from NorCal, to OSH to Upstate NY, to W. Mass to Florida to Texas and back. All between 11 and 13,500.
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