17 replies to this topic

[UFfitz56]

Hey guys long time lurker and have greatly appreciated all the info on here.  We our at the tail end of our first spec miata build but just wanted some verification on seat/harness mounting since the rules seem a little vague.  The cage was built by Paul at No Mo Money Racing and he modified the floor pan to remove the stock seat mounts for more height.  So the Sparco fia seat and harness attachments are mounted directly to the floorpan with grade 5 hardware and 4 inch plates as you can see in the pics.  This is our main concern and was wondering if was legal/safe? Any help or insight would be great!

Thanks,

  Fitz

 

 

[UFfitz56]

Oh and there is a fourth harness bolt on the other side you just can't see it in the pic. 

[38bfast]

if the center bolt is the crotch harness i would not approve it. 

[davew]

Big washers for seats and seat belts.

 

Bolts should always go down, not up. If the nut comes off a bolt pointing down, the bolt will stay in place and offer some security. When a bolt points up and falls off or breaks, the component comes loose and there is no security.

 

Learned this back in my Indy car days

 

dave

[Bench Racer]

With driver seated normal, is the angle of the shoulder harness strap somewhere between horizontal and twenty degrees downward to cage mounting?

 

You didn't ask, is all your tube protection that the driver (rule is driver, not only drivers head/helmet) may touch GCR SFI rated?

[UFfitz56]

if the center bolt is the crotch harness i would not approve it.

 

Sorry I should have clarified.  The two bolts in the very front are for each of the 6 point crotch attachments.  Would this be acceptable or would you still not approve it? Please excuse my ignorance.  That center bolt you're referring to is for the left lap belt. The right lap belt is on the other side of the tunnel but you can't see it.

 

As far as the seat bolts facing upward, they are bolted directly into the seat so that is the only way?  Only way for downward facing bolts would be if we used the seat brackets but that would raise the seat up a few inches and would then be too high.

 

Thanks again for all the help!

[UFfitz56]

With driver seated normal, is the angle of the shoulder harness strap somewhere between horizontal and twenty degrees downward to cage mounting?

 

You didn't ask, is all your tube protection that the driver (rule is driver, not only drivers head/helmet) may touch GCR SFI rated?

 

Yes the shoulder harness is a good angle but thanks for the heads up. The black tubing is SFI but not the blue so I will remove it. Thanks!

[Ron Alan]

Studs on the seat...

[UFfitz56]

Studs on the seat...

 

By studs on the seat you mean they are mounted under seat?  So if the lap belts were mounted outside of the seat it would be ok?

[speedengineer]

With driver seated normal, is the angle of the shoulder harness strap somewhere between horizontal and twenty degrees downward to cage mounting?

 

You didn't ask, is all your tube protection that the driver (rule is driver, not only drivers head/helmet) may touch GCR SFI rated?

 

Technically, SFI padding is just recommended, not required.  Definitely a smart choice to go with proper density padding.

 

All portions of the roll cage subject to contact by the driver
must be padded with a minimum 1 inch of material.

Padding that meets or exceeds SFI 45.1 or FIA 8857-

2001 ... specification is recommended.

[Rob Burgoon]

Worry more about the belts ripping out than the seat ripping out.  But especially if you have a containment seat without a side net, worrying about the seat ripping out is worthwhile too.

 

I'd guess that the sub straps have the lowest load of all the belts, but how much do a few more backing plates really cost you?

[UFfitz56]

Worry more about the belts ripping out than the seat ripping out.  But especially if you have a containment seat without a side net, worrying about the seat ripping out is worthwhile too.

 

I'd guess that the sub straps have the lowest load of all the belts, but how much do a few more backing plates really cost you?

 

Ok thanks! Going to add backing plates and larger washers to all the mounts and move the lap mounts back behind/on the sides of the seat. 

[davew]

Most people use the factory seat belt mounts for the race harnesses.

[Bench Racer]

Technically, SFI padding is just recommended, not required.  Definitely a smart choice to go with proper density padding.

 

All portions of the roll cage subject to contact by the driver
must be padded with a minimum 1 inch of material.

Padding that meets or exceeds SFI 45.1 or FIA 8857-

2001 ... specification is recommended.

Ahhh  grasshopper  please read up front in the GCR. The word must is mandatory. 

[speedengineer]

Ahhh  grasshopper  please read up front in the GCR. The word must is mandatory. 

 

Must applies to needing 1" of padding.  Then there is a period, and the following sentence says SFI is recommended.  Therefore SFI is not mandatory! 

 

I could hot glue marshmellows onto my roll cage tubing, and as long as they were 1" thick in every place the driver can contact, it'd be legal. 

[Bench Racer]

Must applies to needing 1" of padding.  Then there is a period, and the following sentence says SFI is recommended.  Therefore SFI is not mandatory! 

 

I could hot glue marshmellows onto my roll cage tubing, and as long as they were 1" thick in every place the driver can contact, it'd be legal. 

Don't install the marshmellows quite yet. This has been discussed plenty in the past and marshmellows don't pass the sniff test.   SFI 45.1 is only 3/4 inch think.  My take is that the SFI/FIA curved padding is a must on the cage tubing and the SFI/FIA sports car head rest material specification is recommended. 

[davew]

The requirement is 1 " padding. No spec given, Marshmellows would be legal 

 

The recomendation is for SFI padding.

 

I use SFI around the head area. Figuring the helmet has the soft padding inside. I use the standard foam "pool noodle style" around arms legs etc. This acts as more padding over 'normal" race bumps than the SFI rated hard padding.

 

NASA and other sanctioning bodies may have different rules.

 

dave

[surlynkid]

Remove socket head cap screws. Install studs into bottom of seat, so you can use washers and nuts on bottom of floor pan.