Superior XP-TNIO-360

I was looking at Superiors website this morning and dreaming about engines when I came across this beauty.

http://www.superiorairparts.com/xp360.asp#
see the product specs at the bottom of the page.

Evidently Superior teamed with Lancair to build a turbo normalized IO-360 for the Lagacy FG. I think would be a sweet engine for a cross country bird. The only draw back is the 360lb weight. Has anyone heard any details about this engine? I looked at the Lancair's site and they are saying the price is a little below $35k. I don't think you'd get much more performance down low, but the gains up high would be huge.

We seriously contemplated this option when we were on our engine hunt one year ago and did a lot of research. At that time Superior did not want to sell this engine for use in an RV (or any other plane but the Lancair) because of weight-, space- and cooling issues. Mahlon Russell (the Lycoming-type Guru) was not too enthousiastic as well for the same reasons. Maybe the situation has changed, call them or send a mail to Mahlon! On S&F I had a look at Bruce Bohannons Flying Tiger, quite impressive to see this extremely modified RV-4 with it's huge turbo (secretly Van's must be proud on this)!

With the exception of air-cooling issues or CG, I can't think of a single reason not to put one of those in an RV.

What seems to be the issue? From my perspective, it would be a good choice.

What am I missing?

Flutter

Flutter margin is not based on indicated airspeed, it is based on air velocity, and the gap between the air's velocity and the indicated airspeed grows with altitude.

So, you are flying along at 15,000 feet mindfully staying below (just a little) the yellow arc when all of a sudden, flutter sets in and your plane desintegrates. Why? because your true airspeed was something close to the critical flutter speed, because you can get good power at an altitude where the air is thin...more TAS, higher air velocity, smaller flutter margin.

In addition, there is weight, cost, heat, and complexity.

Vans has a series of really good articles on this subject.

Here is a link to a really good article on the subject and the scary experience a pilot who flies combat jets had when he exceded these limits. He did it with a stock O-320 on an RV4, inadvertantly. He was very frightened....

Makes me think that INTENTIONALLY playing with those varriables is just plane ludicrous.

http://www.vansaircraft.com/pdf/hp_limts.pdf

I'm a big-engine guy now, not a turbo, but I did consider it for a while. I didn't believe the flutter think initially, but it could be an issue. Half of me really doubts it, but it could be an issue.

You *can* get this engine if you want

The below is the new TNIO-360 (angle valve) engine from Performance Engines (www.performanceengines.com - talk to Stuart Featherstone if interested). 220HP I believe complete with intercooler - and good to 18K+ feet. Can't wait to hear how this works. It's going in a friend of mines eglass Legacy.

Couple of quick notes. There is no FWF kit for an RV that I'm aware of. it will fit on a standard Lycoming mount, but for baffle, cooling ducts, etc. You are on your own.









See the rest of the pictures here http://www.eaa62.org/progress/show-item.php?item=blog1/20060514.itm&bid=blog1

Lastly, the guys at avworks (www.avworks.org) are also making one on the 390 engine base. I don't have any details around it. You'd have to contact them.

Performance engines... mmmmmm... money.

They wanted $17K to overhaul out O-360 A1A, without any special work, got it done for 11K at another local reputable shop.

But they sure are pretty!

aadamson said:

The below is the new TNIO-360 (angle valve) engine from Performance Engines (www.performanceengines.com...

Click to expand...

Check out this plenum setup on their website:



Click for large version

TSIO-550 for Daryl G. of Reno fame

Alex said:

Check out this plenum setup on their website:



Click for large version

Click to expand...

Alex,

Yes, that is a TSIO-550 that the guys are Performance Engines built for Darryl G. of Reno fame, he races it in a Lancair Legacy in the Sports class and last year ran a little over 350mph. It puts out around 600HP when it's "cranked up".

The Plenum and design was also pioneered by Andy Chiavetta of Aerochia.com. Interesting story, Andy is a Surfboard maker that got into composites and then helped a few people build "race airplanes". Now I think thats all he does.

As mentioned over in the "cooling drag" thread, he also does plenums for regular "Normally Aspirated" 550's and I'll most likely put one on my 550.

Nice guy, great builder, and has built some really fast airplanes... Performance did the engine, Andy did the composites work on it.

I fly a turbocharged 6A (Subaru) and there are no issues below oxygen altitudes with flutter/TAS assuming you don't run stupid manifold pressures. You'll gain 10-15 knots over your atmo cousin at these altitudes but at quite a high weight/ complexity/ cost expense. With the relatively low limiting speeds of RVs vs. something like a Lancair or Glassair, high output turbos up high might not be the best plan.

You are a bit better off with a 7/8 as they have slightly higher limiting speeds over the 6 but it is very easy to exceed the TAS limit at even 15,000 feet and modest power settings. I can true over 180 knots using 35 inches on the small 134 cubic inch Subie at 15,000 so one of these turbo Lyco beasts would put you way into the danger zone under similar or higher conditions. While lots of Rockets and similar RV based designs do this all the time, prudence is recommended when dealing with potential flutter conditions and you don't want to hit any major turbulence at these speeds.

Vans approach might be overly cautious but it is a very safe recommendation. Nobody wants to collect wreckage after flutter and a structural failure.

Half doubt

osxuser said:

I'm a big-engine guy now, not a turbo, but I did consider it for a while. I didn't believe the flutter think initially, but it could be an issue. Half of me really doubts it, but it could be an issue.

Click to expand...

Get the " half of you " that doubts it to read the article by the F-16 driver.....

It sure illustrates flutter theory better than any textbook !

I've read it... thats what got half of me to believe it might be an issue. Before that, I just thought it was a joke.