[roundel]

BK has both side mounts and a cross-bar for the sub belts that work with OEM 996 sliders. The BK parts are compatible with Sparco Evo seats.

I am more surprised that you are not doing the passenger seat too as stated in the OP. I am sure you are aware that nobody can ride in that seat if the safety system is not equal in nature to the drivers seat.

[TurboPooch]

From the PCA Club Racing rule book:
The anti-submarine straps must be mounted such that they will not allow upward vertical movement of the lap belt due to "crushing" of seat cushion material. Special attention must be given to the manufacturer's and similar common racing requirements concerning the angles of the anti-submarine belt and the lap belts, their routing through the slots or openings in the racing seat, and avoidance of any bends in the angle of pull caused by adjusters, seat slots, or interference of adjusters with the seat or chassis.

From the SCCA GCR:
The single anti-submarine strap of the 5 point system shall be
attached to the floor structure and have a metal to metal connection
with the single release common to the seat belt and shoulder
harness.
C. The double leg straps of the 6 point or 7 point system may be
attached to the floor as above for the 5 point system or be attached
to the seat belt so that the driver sits on them, passing them up
between his legs and attaching either to the single release common
to the seat belt and shoulder harness or attaching to the shoulder
harness straps. It is also permissible for the leg straps to be secured
at a point common to the seat belt attachment to the structure,
passing under the driver and up between his legs to the seat belt
release or shoulder harness straps.
All straps shall be free to run through intermediate loops or clamps/
buckles.
D. Each seat (lap) and shoulder belt of the harness (5, 6, or 7 points)
shall have an individual mounting point (i.e. 2 for seat belt and 2 for
shoulder belt minimum). 6 or 7 point system anti-submarine straps
may share a mounting point with one or both seat (lap) belt(s).
The minimum acceptable bolts used in the mounting of all belts
and harnesses is SAE Grade 5/Metric 8.8. Mounting hardware,
including eye bolts, as provided by the belt manufacturer, may
also be used for mounting belts and harnesses. Where possible,
seat belt, shoulder harness, and anti-submarine strap(s) should be
mounted to the roll structure or frame of the car. Where this is not
possible, large diameter mounting washers or equivalent should be
used to spread the load. Bolting through aluminum floor panels,
etc., is not acceptable. Holes in the roll cage to accommodate the
installation of the harness must be bushed and welded completely.

With this information in mind, it is best to mount the sub straps to the floor or to the common point with the lap belts depending on your routing and angles. I mounted mine to the floor and when both of my race cars were tech'd for the log book, the scruts looked under the car to specifically see that there was some sort of extra metal or large washers to spread the load where the bolts went thru the floor board. It's usually not acceptable to mount belts to the seat or to any part of the seat mount that may come loose in the event of a hard collision. Hope this helps.

[Vicegrip]

Lap belts mounted to seat "above " the slider so to speak not desired even if legal in some circles. All belts to solid points prefered IMO. Seats and sliders break. Not only in theory or at the extremes. Build to scca spec if you can.

[Mark Hubley]

Originally Posted by roundel

I am more surprised that you are not doing the passenger seat too as stated in the OP. I am sure you are aware that nobody can ride in that seat if the safety system is not equal in nature to the drivers seat.

I'm 6'4" and generally happy about it. However, that often presents issues with cars. My plan is first to test fit the one seat--make sure the seat fits in the car, make sure I fit in the seat, make sure my head isn't pressed against the roof of the car, figure out how to run the belts and harnesses, etc. Assuming I'm happy with the setup, then I figure I'll get a twin to match. If not, then I'll stick with the GT3 seats for a while. I've got a few months to figure it out

[Dr K]

Originally Posted by Mark Hubley

I'm 6'4" and generally happy about it. However, that often presents issues with cars. My plan is first to test fit the one seat--make sure the seat fits in the car, make sure I fit in the seat, make sure my head isn't pressed against the roof of the car, figure out how to run the belts and harnesses, etc. Assuming I'm happy with the setup, then I figure I'll get a twin to match. If not, then I'll stick with the GT3 seats for a while. I've got a few months to figure it out

Mark,
did you measure where the shoulder belts come through the seat with reference to your shoulder height? I haven't sat in the Ergo, but on prior Sparco seats, the shoulder belts came out too low for my shoulders. I'm not much taller than you, so unless the holes are higher (or much larger), you could have a problem. This was actually pointed out to me at OG, and is of the main reasons I bought the Kirkey.

[Mark Hubley]

I sat in a large size Sparco Ergo in the showroom, and it seemed OK. The holes are above my shoulders. We'll see how things line up when I get the seat in the car. I think I'm a bit longer in the legs and not terribly long in the torso.

At VIR recently I sat in JVH's car. He has the Ergo in medium. With me sitting in that seat, you can't see the holes at all.

[BikePump]

When I was seat shopping I was originally looking at the Ergos but ran into that same issue - shoulder holes were too low. Ended up with the OMP HTE-R....perfect fit

[N0tt0N]

Not an expert but when I was reading Schroth's installation guide they mentioned that the shoulder belts were not to be supported by the seat holes as the were not designed to bear the load in an accident. I did not know that. Depending on where the line between the top of the HANS and the mount point on the car the hole might be fine some amount below the shoulder. Above the shoulder would seem incorrect by them.

[Dr K]

I'll try to remember to post a photo over the weekend, but I just had an extra bar added to my Miata so the belts would come through the center of the opening rather than touching on the bottom (and being a little too far below the height of my shoulder). Can't wait until the welding class at Chaos!

[Lt. Dan]

Originally Posted by Mark Hubley

Roll bar (DAS Sport)

Wait- what?