Moving the front seat bottom aft

At 6'5" with a 36" inseam I need all the help I can get fitting in the airplane and yes, I ordered the tall pilot option. Leaning the seat back is helpful but based on the few 8s I have sat in I am still worried about leg room. Specifically knee room near the panel. Yesterday I was working with the seat floors and got to thinking...is there any reason I cannot co-locate the front seat's hinge point with the F-805C-1 support angle (DWG77). This gets me an extra inch or so. I put some parts in the fuselage and read forward in the instructions trying to envision were things might interfere with that plan and I couldn't see any. Has anybody done this and was it successful?

Seat

Moving the seat back gets into two obstacles ,passenger stick and rear chromoly cross member ( seat back support )

Seems to me that there was a recent example posted of a panel with a relief in the lower edge, just to allow the kind of fitment you need.

Probably find it in the 8 forum.

Here you go.

http://www.vansairforce.com/community/showpost.php?p=923340&postcount=536

I saw that thread and made a mental note of the modifications. I was shooting for getting the most knee room while not impinging on the already slightly limited panel space.
I played with it some today and this is what I found.
I had some wide flange piano hinge left over from other projects so I made one up to replace the stock hinge. Between these two pieces and two mounting locations I have four options.
In this picture the narrow flange hinge is the stock hinge and it is in the stock location. The wide flange hinge co-located with the F-805-C1 support angle where I am proposing to mount the new seat bottom.


If I mount the wide flange at the stock location I get about 1/4"
Mounting the stock flange at the aft location I gain about 1 1/8"
Mounting the wide flange at the aft location gets me about 1 3/16"


One minor problem so far though. The front seat lap belt anchors don't line up with the holes in the front seat back.
This is with the seat back at the furthest aft position the 1 3/16" setup.


It is supposed to look like this.


Lots more research and test fitting needs to be done before I make any decisions. For instance, I have no idea what the bracket for the seat belts looks like so I don't know how much I would need to modify the seat back. An alternative is to make new anchors but I am not thrilled with that idea and further investigation into the rear stick issue is required.
Also, I stuck the WD-808 front seat back support in the fuselage. With the seat back in the stock position the tops of the seat rails do not extend above the top of the support weldment. It wouldn't take much to get the top of the front seat to slip under the support. Forgot to get a picture but wondering if that is normal with the tall pilot option.

Been there, done that

Sam,
Go to the thread linked below. See my post with photos.

http://www.vansairforce.com/community/showthread.php?t=42033&highlight=seat+back

Charlie

Sam, I can't help with the seat back relocation, but when you get to upholstery you can make a lot of difference with how you do the foam cushions. Standard interiors tend to have a fairly thick front seat back cushion, and not enough up angle to the seat bottom for the long-legged high knee position. I ordered from Oregon Aero, then did the "try, mark, and send back for re-cut" routine before having upholstery sewn locally. As a result, the seat back foam is firm and very thin, maybe 1.5" in places. It is very comfortable, and boosts legroom.

Charlie,
Thanks for pointing out that thread. I did search for a bit before posting, not sure how I missed it.
Questions:
1. When you moved your seat bottom aft how did you overcome the seat belt anchors being in the wrong place vertically?
2. I can envision issues with the metal tabs on the seat belts that bolt into the aircraft anchors now encroaching into the seat cushion. How did you overcome that? Does anybody have an old set of belts or just the metal tabs they want to get rid of? Not going to use them, just for mock up.

I was looking at it today. With the seat bottom at the aft most position the seat belt anchors are about .75" too low in the opening. One method I thought of to correct is to remove .75" from the bottom of the corrugated seat back. This will drop the seat belt openings back into alignment vertically. I would need to remake the structural side braces but that is easy. Then the only issue is to ensure the anchors are the correct distance back from the seat back so the metal tabs are not stabbing me in the kidneys

Also,
maybe somebody can help with pictures. I can't seem to wrap my head around how the upholstery fits on the front seat back structure and how the lap belts get through or around the upholstery. Is it simply that there a slit in the seat back upholstery that the lap belts feed through?

Dan,
Good to know that. Thanks for the heads up. All input is greatly appreciated.

Anybody know what the part# for an RV4 rear stick is?

knee clearance

suggest you take a look at the last two pages in the Rv8 'show us your panel' thread. There are two examples of panel mods there that will give you substantially more knee clearance.

Yep saw both of those and have stored them in the back of my mind.