Superior XP 400?

[Dirtbos]

I find it interesting that Superior shows their XP 400 (220 HP) as a possible engine for the 7A. Is anyone using this (or another engine in this HP range) in a 7 or 7-A?

I would guess it would improve the climb and high density altitude performance over the max recommended 200 HP. But with a Vne of 230 MPH, would it be safe?

Mike

 

[cjensen]

There are several flying with the IO-390 with 210hp. Numbers would be close...

Haven't heard of the 400 being installed in an RV yet. Are they even available yet?

 

[gmcjetpilot]

We control the power

But with a Vne of 230 MPH, would it be safe?Mike

The black knob on the panel should solve that concern. However you are right, it puts it on the pilot. More HP could get you in to trouble. If 200 HP gets you 217, than 220 HP would get you 224 mph. So at sea level you would be OK.

At altitude you might get into trouble above 10,000 ft, where indicated Vne is getting lower and TAS goes up relative to IAS. Of course HP drops off and thus IAS and TAS goes down as well. Even with the extra HP you should never "catch" Vne in level flight at higher altitudes, unless you are turbocharged. However with extra HP you will get closer to Vne, no doubt. Again back to the Black Knob, what I like to call "The Rate of Events Lever".

 

[burgundyja]

i am thinking of the 400 in my -8 if people put in io-540 260hp cant i use 220hp? it would still be slower than a super8.

 

[osxuser]

Yep, you would definitely be slower than a Super8. On the other hand, a lot of people think the Super8 is a bad idea. I'm not in that group, at least if you intent to keep the airplane and fly it. I'd be more wary of selling a Super8. I think the XP-400 isn't that big a deal however, 220HP shouldn't be a problem. Guys running a IO-360 with high compression and EI probably make that.