FritzMan

Dunno if this has been talked about before, but have any of you guys considered how a 4-point harness would work with the OEM seats? I plan to AutoX the RX-8, and the harness was probably one of the best performance investments I made, regardless of price. It's the first thing I would like to get, especially with OEM leather seats this time around. I recall on my previous FD that I was able to slide the shoulder straps through the headrest. Doing the same thought the rotor motif of the 8's seats look like that wouldn't be large enough nor comfortable. Going around the headrest and onto flared shoulder portion of the backrest could work, but I'm not sure if the shoulders are high enough to be the first point of contact instead of the seat's shell. Mounting location for the shoulder straps would probably be with one of the those replacement seatbelt eye bolts for the rear passenger lap belts eh?

Sputnik

You need to find a better mounting point than that for the shoulder straps. If you don't find a proper mounting point, those belts could cause more harm than good. Although I haven't been able to look through everything, I don't see any proper mounting points short of mounting a harness bar. And even then, it is not wise to install a harness bar w/o a rollbar.

---jps

FritzMan

I hear ya on safety and all but for AutoX, there's little chance of hitting anything and even if you did it would be a relatively low speeds. In fact, I used the rear shock tower in the FD to mount my should straps. Totally unsafe in a heavy impact, but extremely effective in keeping me still in the cabin. Also, for the shoulder belts to be track legal, I thought I read that there's a maximum distance the shoulder mounting points can be below the driver's shoulders. Too low (definitely in this case) and injury can occur.

Maybe I could use the rear child seat anchor for a mount to the shoulder straps. Still not ideal safety wise, but it's a solid mount meant to handle some impact. It would also satisfy the shoulder height mounting issue.

Speed Racer

Has anyone mounted a harness or aftermarket seats in their RX-8? If you have please post some pictures and list the details of how you mounted the harness. Thanks!

Sputnik

"Track legal" really depends on sanctioning body and the track. But a few things to consider, and why:

First, as we all know, safety belts stretch. They are supposed to, so that the impact is not as severe on the occupant. The longer a belt is, the more it will stretch under a certain load. If your belts are too long (I.E. stretched all the way back to the child mounting belts), they would have too much give in them in an accident, and they won't work properly. Several sanctioning bodies have rules regulating the max length of the safety harness.

Second, even merely considering support during an autocross, and assuming you will not have an accident, it is important to have the belts mounted directly behind the user, not offset to a strut tower. Under high Gs, the stress would put un-even loads on your spine and shoulders.

Third, the rule for the height of mounting points is not a distance, but an angle. The angle from the shoulder down to the mounting point should be no more than 45 degrees. The reason is because when a body goes forward under an impact, a severe angle will actually cause the belts to pull down on the shoulders as much as it holds the occupant back. Immense forces are generated in an accident, and some of that force will be applied to the shoulders of the occupant, and something in the occupant's body will give before the belts do (causing shoulder and back injuries). The percentage of that force that is applied down depends on that angle from the occupants shoulders to the mounting point.

---jps

MrSuicideDoor

bringing this one back almost 4 years later. i'm new to auto-x, i'm not going to track my rx8. i just don't want to bang up my knees anymore. I'd like some help with a 4point harness install.

1) no i'm not going to wear it during daily driving
2) yes i know if the angle is wrong it'll crush my spine
3) yes i know i can submarine in a harness
4) yes i want to stay BS legal, so i need my back seats in place during auto-x

secret8gent

https://www.rx8club.com/nw-rx-8-forum-33/ok-here-ya-go-seat-belt-lock-holds-you-place-something-we-can-all-use-cg-lock-112751/

^^^^^^^^^^
ppl say it is almost as good, and is cheap by comparison.

I haven't tried it yet.

PoLaK

iTrader: (1)

I use CG-Lock myself... mainly because its a daily driven car and I didn't want to deal with that.

Carrera26

Honestly, I use a wide nylon belt with a plastic clip. Clip it around my torso and tighten it down right before I go. Holds me in place perfectly, super-cheap, no muss no fuss. Even on the small raodcourse we use sometimes it's worked perfectly.

I've heard many stories about the CG lock breaking on people, and fairly quickly. Not to mention it still doesn't give nearly the lateral support.

mlx8

Well, since you've said you are using this for Auto-X events only, you CAN run a single strap 4 point harness through the rotor opening in the seat back and attach to the child seat harnes clip on point in the rear window deck. A carabiener clip will fit through the latch clip in the rear deck child seat clip. I'm not confident however that the child seat rear clip is really reinforced enough to be an adequate anchor point for shoulder belts on a 160#+ to 200#+ adult, but you can use the belts to hold you in place for driving purposes

dbullock

That's a great idea using the upper child lether mounting point. The mounting point might not be able to hold an adult in a crash, but it doesn't matter since that's not needed. In this case, the 4-point harness would only be used as support for the driver. The existing factory seat belt would still be used and the seat belt is what would protect the driver in the vent of a crash.

Or would using both at the same time be dangerous? Would this setup pass tech inspection at a track?

I did some more searching..

I don't know what a "Tuner Belt" is but this 4-point harness looks less-substantial than others and looks like it is used for support only.

Maybe this will work?

http://www.gforce.com/products/harness/9000.php



or this:

http://www.turbojohn.com/mall/index....roducts_id=300

dbullock

Replying to my own post, but I found out more info. (maybe all this info is old news to some, but I'm still trying to learn about it.)

It looks like a 3 or 4 point harness would be perfect, 3-point being my choice. Mounting doesn't look to be a problem either. We can use the rear seat-belt buckle. I think I might even use the child tether point.

These harnesses are in fact supplementary to the OEM seat-belt, since we need to ensure the airbag functions properly.

According to the doc below.. the harness must go through the center of the headrest and not around it.

http://www.soloperformance.com/schroth.htm