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WonkoTheSane
WonkoTheSane GRM+ Memberand Dork
2/6/17 9:22 p.m.

I was thinking about track prep for the upcoming season for the miata, and I was wondering what the hive's thoughts were on a 5 point using the stock seats? I don't really have any desire to switch the stockers out, but they will have a foamectomy. It would be secured to a bar that's fitted either to my roll bar or to the seat belt towers, I need to go stare at it a bit to figure out where I'd attach it.

irish44j
irish44j UltimaDork
2/6/17 9:28 p.m.

Can't say for sure, but I doubt most tech inspectors would approve using a 5-point with a stock seat. I could be wrong though...

Stefan
Stefan GRM+ Memberand MegaDork
2/6/17 9:33 p.m.

Yeah, the harness needs a full cage (or at least a proper 5-point bar) and race seat to be effective.

It's part of a safety system. You need all of it together to have it work properly.

Get a CG lock for the stock harness and go have some fun, which is what track days are all about.

wae
wae Dork
2/6/17 9:41 p.m.

Schroth makes a pretty nice 4 point harnessbelt that has a FMVSS number making it street legal.

Stefan
Stefan GRM+ Memberand MegaDork
2/6/17 9:53 p.m.

I don't think it's DOT legal anymore.

Still might be a better option for a trackday though. Depending on the club and rules set they use.

Stefan
Stefan GRM+ Memberand MegaDork
2/6/17 10:40 p.m.
snailmont5oh
snailmont5oh Reader
2/7/17 2:06 a.m.

One of the most important things to know about harness installation is that the shoulder belts must not be lower than your shoulders. If I am remembering this correctly, the maximum downward angle is about 10°. This is to keep the belts from compressing your spine in a frontal impact.

WonkoTheSane
WonkoTheSane GRM+ Memberand Dork
2/7/17 6:50 a.m.

Right, I'm well aware of the proper installation of the belts, I'm just hazy on the implications of using them with a stock seat :) I'll be making the harness bar myself, so I can ensure they're at the right angle and all that.

I also happen to have a very nice set of camlock belts that have been on a shelf inside for the past 5 years or so. I know they're out of inspection, but that doesn't matter to much for most track days it appears.

alfadriver
alfadriver GRM+ Memberand MegaDork
2/7/17 7:07 a.m.
irish44j wrote: Can't say for sure, but I doubt most tech inspectors would approve using a 5-point with a stock seat. I could be wrong though...

I raced in stock seats with a 5 or 6 point harness for 15 years. Nobody batted an eye over that. They looked more at the fading of the harness than the fact that I didn't have a roll bar.

mazdeuce
mazdeuce UltimaDork
2/7/17 7:08 a.m.

It depends on the seat. Usually inspectors like to see the shoulder part pass over or through the back and not just past the sides. This means that seats with an adjustable headrest will often work, but those with a fixed integrated headrest don't. The best ones are ones like the current Corvette that have the cutouts.
So, back to the Miata. I think NC seats would work, but NA and NB seats are iffy. Ask your local tech guy, there is about a zero chance that this hasn't come up locally.

alfadriver
alfadriver GRM+ Memberand MegaDork
2/7/17 7:09 a.m.
wae wrote: Schroth makes a pretty nice 4 point harnessbelt that has a FMVSS number making it street legal.

On the other hand, my club had rules specifically banning all 4 point harnesses, in spite of the FMVSS.

In other words, one should specifically ask the groups you are planning on running with.

Woody
Woody GRM+ Memberand MegaDork
2/7/17 7:55 a.m.

I had one of those Schroth four point harnesses in a former Miata and I didn't like it. The shoulder straps are sewn to the lap belts but they were too far out from the center for my liking. I felt like I would shoot right out between the straps. I also think that the mounting points in a Miata aren't back far enough to make them easy to use. The part of the lap belt that is doubled up and sewn is too thick to be part of the adjustable range. I was trying it with a Cobra Monaco race seat, so it might work a little better with a stock seat.

paranoid_android74
paranoid_android74 SuperDork
2/7/17 8:51 a.m.

In reply to Woody:

Like this one?

snailmont5oh
snailmont5oh Reader
2/8/17 1:19 a.m.

Whatever you do, just try to make sure there's enough room in the adjustments for a fat guy. You never know when you'll have to stuff one in there.

Woody
Woody GRM+ Memberand MegaDork
2/8/17 5:23 a.m.

Yup, that's the one I had, the Schroth Rallye Cross. I chose that one because I needed lap belts that pull up to tighten.

paranoid_android74 wrote: In reply to Woody: Like this one?
WildScotsRacing
WildScotsRacing Dork
2/8/17 6:16 a.m.
Stefan wrote: Yeah, the harness needs a full cage (or at least a proper 5-point bar) and race seat to be effective. It's part of a safety system. You need all of it together to have it work properly. Get a CG lock for the stock harness and go have some fun, which is what track days are all about.

Speaking of the GC-Lock, has anyone ever used two on the same belt? As in, one to lock the lap portion and one to lock the shoulder belt?

nasaZach
nasaZach New Reader
2/8/17 6:50 a.m.
snailmont5oh wrote: Whatever you do, just try to make sure there's enough room in the adjustments for a fat guy. You never know when you'll have to stuff one in there.

Laugh at this, but I had it happen to me. Im a big guy. 5/10 250. I went to get into a full race prep E36 for a check ride. I could not fit. The seat was way too small. The belts were too short without a way to adjust them. It was embarrassing and frustrating to say the least. We found another instructor to ride, but please one size does not fit all.

z31maniac
z31maniac MegaDork
2/8/17 7:01 a.m.

I wouldn't do it, but I take safety differently at the track after having wrecked one 2 wheels and ended up with a banged up hip and post-concussion syndrome.

My old track rat Miata had a roll car, fixed back seats, and 5-pt harness before I would go on track with.

YMMV, your personal risk tolerance, etc

GameboyRMH
GameboyRMH GRM+ Memberand MegaDork
2/8/17 7:05 a.m.
WildScotsRacing wrote:
Stefan wrote: Yeah, the harness needs a full cage (or at least a proper 5-point bar) and race seat to be effective. It's part of a safety system. You need all of it together to have it work properly. Get a CG lock for the stock harness and go have some fun, which is what track days are all about.
Speaking of the GC-Lock, has anyone ever used two on the same belt? As in, one to lock the lap portion and one to lock the shoulder belt?

You shouldn't put one on the shoulder belt.

Also you can use a seatbelt locking clip (as used for child seat/extended seatbelt installation) in place of a CG-Lock, they're cheaper but not as convenient to install or adjust.

WonkoTheSane
WonkoTheSane GRM+ Memberand Dork
2/8/17 11:18 p.m.

Don't worry, I fat guys will still be welcome :) I was planning on leaving the 3 point in there anyway, so worst case scenario is someone doesn't like it, so I use the 3 pointer instead.

For anyone mentioning roll bars, I do have a roll bar in it, I just didn't build in a harness bar to it (yet):

z31maniac
z31maniac MegaDork
2/9/17 7:15 a.m.

I doubt that roll bar is going to pass tech anywhere that takes safety seriously.

Stefan
Stefan GRM+ Memberand MegaDork
2/9/17 8:05 a.m.

Yeah, that's a style bar. Not a roll bar.

drdisque
drdisque HalfDork
2/9/17 4:20 p.m.

Harness with stock seats is just for holding you in the seat for autocross.

For safety, you need a proper seat, doubly so with an open cockpit car.

WonkoTheSane
WonkoTheSane GRM+ Memberand Dork
2/9/17 6:15 p.m.
Stefan wrote: Yeah, that's a style bar. Not a roll bar.

Why's that? It passed tech twice last year before paint. It's got 6 mounting points and is made out of the proper DOM for the vehicle weight. It uses the same bottom four mounting points as the scca approved hard dog double duece.

Stefan
Stefan GRM+ Memberand MegaDork
2/9/17 6:59 p.m.

The main hoop isn't a single piece.

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