Comp Harness Anti-Sub strap solution for TT/ Street Cars

Mark Vitacco · **Posted:** Sun Jan 11, 2004 6:16 pm

Guys:

I was re-reading the GCR and fould what could be a anti-sub strap
mount/routing solution for a lot of people.

The SCCA GCR states it IS PERMISSIBLE to use a 6 point harness
and mount the anti sub straps to the same mounts as the lap belts.
YOu can then run the anti sub strap up under the seat back under
the driver and sit on them.

There is at least one Miata that showed up with that, I don't remember who
it was but I did look it up and confirm that it's ok. This is not on any of
the manufacture's guides but its in the GCR and thats what we go by
so you are totally cool.

Cheers
Mark V

Matt Graham · **Posted:** Mon Jan 12, 2004 2:45 am

I used this same solution in both the Corvette and the M3. Worked like a charm. As I've posted before, this same setup is used in F18 fighter jets (as per an F18 pilot I met at VIR once). If it's good enough for jets, it's godd enough for my race car.

-Matt

Frank Catena · **Joined:** Wed Aug 27, 2003 1:08 pm **Posts:** 418

Mark,

The Miata was mine, the under the seatback approach seems to be the only solution with a stock (no sub strap hole) seat.

And *thanks* for spending the better part of a Saturday doing tech.

Frank Catena

Ron Spencer · **Posted:** Mon Jan 12, 2004 2:28 pm

I would suggest that while it is permissible ask your self men, what happens if the strap you are sitting on is ever asked to do its job which (as we all should know from paying attention in class!) is to keep the lap belt from riding up off your hips.

Do you REALLY want THAT area of your anatomy to be what absorbs some of the forward motion of your body?

An alternate solution that I have used years ago with my Audi is find a junk yard seat and cut a hole in it to run the 5th/ 6th point belt up through. I've even heard of folks that took their existing seat to an upholsterer and had them put in an opening while sewing up the cloth/ leather so it looked nice.

Ron

Keith Quistorff · **Posted:** Mon Sep 20, 2004 3:36 pm

So where do the harness manufacturers recommend mounting the sub-straps in a 6-pt system? Am I interpreting the THSCC Tech Spec Guide sub-strap recommendation ("anchored just behind the drivers chest to where the plane of the spine would intercept the floor board and pass up directly between the legs through the bottom of the seat") to apply to both 5- and 6-pt harnesses? If so, what's the point of having two sub-straps (6-pt) running from/to exactly the same mounting location as a single sub-strap (5-pt), especially considering the sub-straps' purpose is supposedly not load bearing but just to hold the harness buckle in the correct location for the lap belts to bear load at the pelvis area?

I'm working on setting up my car to run some TTs next season and plan to use a Sparco recline-able seat (to keep it all STX legal) that does not have a sub-strap hole. Aesthetically, I'd much rather run a 6-pt harness w/sub-straps mounted to the same locations as the lap belts than cut a hole through my seat bottom and drill through my floor board to route the sub-straps like a 5-pt sub-strap.

Comments/suggestions?

Kevin Allen · **Joined:** Thu Aug 28, 2003 6:42 pm **Posts:** 3479

Quote:

plan to use a Sparco recline-able seat (to keep it all STX legal)

You don't have to have a reclinable seat to be STX legal.

Keith Quistorff · **Posted:** Mon Sep 20, 2004 4:32 pm

Kevin Allen wrote:

You don't have to have a reclinable seat to be STX legal.

Kevin,

The way I'm understanding the rules, I don't see any other options.

Per the STX rules:

"Alternate driver and front passenger seats are allowed, but they cannot be constructed of a solid outer shell and must have a suspended bottom cushion and be fully upholstered."

To me, the "solid outer shell" exclusion eliminates all the real race seats, leaving only "street" (reclining-type) seats as options. Am I missing something?

Matt Graham · **Posted:** Mon Sep 20, 2004 4:46 pm

Keith,

I believe what Mark referred to is the rule in the GCR (SCCA Road Racing rules) permitting the use of the lap belt mounting points for the mouting points of the two sub-straps in a 6 point harness system.

In this case, mount the lap belts according to the Tech Guide (or GCR) and mount the sub straps to the same point.

It is my understanding that the net result is the same (from a safety stand point) as mounting the single strp in a 5 point system according to the section you quoted.

Does that help?

-Matt

Kevin Allen · **Joined:** Thu Aug 28, 2003 6:42 pm **Posts:** 3479

Where are you reading that? On the Internet, or in the 2004 rule book? :wink:

There are guys running STS in Civics that are using Kirkey race seats.

Keith Quistorff · **Posted:** Mon Sep 20, 2004 4:56 pm

http://www.moutons.org/sccasolo/Rules/street_touring.html

See 17.11, #8

My bad, I guess. Can't trust the Internet.

shawnwhipple · **Joined:** Wed Aug 20, 2003 6:28 pm **Posts:** 603

Quote:

My bad, I guess. Can't trust the Internet.

The rule changed this year. Currently you can use any seat that weighs at least 15lbs. Of course the rule may change for 2005 so plan accordingly.

Shawn

Keith Quistorff · **Posted:** Tue Sep 21, 2004 9:10 am

Matt Graham wrote:

Does that help?

-Matt

Yes, thanks Matt.

Tom Hoppe · **Joined:** Wed Aug 20, 2003 10:16 am **Posts:** 387

The SEB already stated that the seat rule for STX will NOT change for next year

-Tom

THSCC Forums

Comp Harness Anti-Sub strap solution for TT/ Street Cars

Who is online