RV7-RV9

[PerfTech]

Originally Posted by Captain_John

Lol, I love it!

I always say that there are two kinds of planes out there... RV's and everything else. I suppose we could all say that there are two kinds of RV's also... Mine and everyone else's!

Hahaha

I did a little math. If you take your 155 knots at say... 7 gph (I am not bringing oxygen to Oshkosh, so 7 gpg at 12,500 will have to do), it comes back at a little over 22nmpg. Lets say I plan 160 knots at 8 gph, it comes back at exactly 20 nmpg.

I wonder what happens if I bring the black knob out a little bit farther and dial in your aforementioned 155 knots?

I will let you know what I discover!

CJ

....I cruise and plan cross country at 175 knots on 7.3 gph! Not to bad?

[RVbySDI]

Originally Posted by PerfTech

....I cruise and plan cross country at 175 knots on 7.3 gph! Not to bad?

Is that TAS, IAS, CIAS, GS? What altitude? Van's numbers for the 9A (9 is 1-2 MPH different): at 8K DA: Vne = 209 MPH, Top Speed = 195 MPH, 75% Cruise = 187 MPH.

Your 175 knots is right at 201 MPH. That is very close to Vne. There is no way my 9A can cruise at that TAS number. And I have even put more engine in my plane than Van's engineers recommend (Why can't I use a larger engine?, page 4). I have done many GPS speed tests with my 9A at 8K DA. I am pretty much hitting Van's numbers every time I do the tests. If you truly are cruising at that speed I am all ears hoping to hear your secrets. Secrets on how to achieve that cruise speed and secrets on how to protect the airframe structure while traveling in that speed regimen.

[airguy]

Originally Posted by CubedRoot

You guys with your fully built RV's, bragging about which one is faster and/or more efficient...

And here I am, poking around in my 47 year old Cessna wishing my RV was done. HAH!

We do these things.... because we can!
Keep pounding those rivets!

[PerfTech]

Originally Posted by RVbySDI

Is that TAS, IAS, CIAS, GS? What altitude? Van's numbers for the 9A (9 is 1-2 MPH different): at 8K DA: Vne = 209 MPH, Top Speed = 195 MPH, 75% Cruise = 187 MPH.

Your 175 knots is right at 201 MPH. That is very close to Vne. There is no way my 9A can cruise at that TAS number. And I have even put more engine in my plane than Van's engineers recommend (Why can't I use a larger engine?, page 4). I have done many GPS speed tests with my 9A at 8K DA. I am pretty much hitting Van's numbers every time I do the tests. If you truly are cruising at that speed I am all ears hoping to hear your secrets. Secrets on how to achieve that cruise speed and secrets on how to protect the airframe structure while traveling in that speed regimen.

....Mine originally performed as yours, right on Van's numbers as well. I have made many subtle changes, and a few not so subtle ones over the years. these changes in drag, along with engine peak performance and many many hours of propeller work culminated in the performance numbers I now achieve. The quoted performance is true airspeed, and I do fly as high as possible when going any real distances. Also I will add this, I do slow down if I begin to feel any turbulence at all. I worry sometimes at these speeds about there being a big, unexpected bump or wind shear that could damage the plane as it is almost at VNE. Thanks, Allan..

[apkp777]

As you can see, both are GREAT airplanes and everyone loves the plane they built. Even thought the -9 is a better airplane, a -7 is still a really good choice.

[bret]

Originally Posted by PerfTech

....Mine originally performed as yours, right on Van's numbers as well. I have made many subtle changes, and a few not so subtle ones over the years. these changes in drag, along with engine peak performance and many many hours of propeller work culminated in the performance numbers I now achieve. The quoted performance is true airspeed, and I do fly as high as possible when going any real distances. Also I will add this, I do slow down if I begin to feel any turbulence at all. I worry sometimes at these speeds about there being a big, unexpected bump or wind shear that could damage the plane as it is almost at VNE. Thanks, Allan..

Sooooo......are you injecting NOS or what? please share, we are all family here right?

[RVbySDI]

Originally Posted by RVbySDI

If you truly are cruising at that speed I am all ears hoping to hear your secrets. Secrets on how to achieve that cruise speed and secrets on how to protect the airframe structure while traveling in that speed regimen.

Originally Posted by PerfTech

....Mine originally performed as yours, right on Van's numbers as well. I have made many subtle changes, and a few not so subtle ones over the years. these changes in drag, along with engine peak performance and many many hours of propeller work culminated in the performance numbers I now achieve. The quoted performance is true airspeed, and I do fly as high as possible when going any real distances. Also I will add this, I do slow down if I begin to feel any turbulence at all. I worry sometimes at these speeds about there being a big, unexpected bump or wind shear that could damage the plane as it is almost at VNE. Thanks, Allan..

Originally Posted by bret

Sooooo......are you injecting NOS or what? please share, we are all family here right?

As I said, "I am all ears"! Speaking from experience with increasing HP on my 9, I don't think increasing HP will get you there. Allen, I would love to know some details on what you modified to reduce drag. I have my ideas although I have yet to implement any of them yet.

[Captain_John]

Allan I've heard you say this before. I still don't believe it. I think you need to check your pitot static system.

CJ

[workky]

I apologize for kicking off a firestorm here. I was just curious what made it stronger.

I so appreciate all the responses though, very good info.
I'm not sure what my mission is ' and I think that is my main issue.

The whole point in flying for me is to get somewhere fast, and I have a legitimate business reason for flying an airplane in the SE. By fast, anything faster than sitting in Atlanta traffic.

I really like the fact the 7 is faster and appears to have more useful load, but it might be twitchy on the stick, which I guess is something you get use to.

All though aerobatics are not very appealing to me right now, one day with the proper training it might be fun to roll, and loop. And I could see that happening

[grubbat]

The -9 don't seem to loose their tails at the same rate the -7 do. As a matter of fact, I don't think the -9 has lost it tail yet.

just sayin......