Driver Safety Gear for Time Trials and USA7s@NJMP

[CBuff]

They have collars that fit inside the b24 bracket.  Or it might be a 7/16” bolt that has its own collar already installed.  
 

Sleeves must be used in conjunction with a washer on one side. See picture of assembled bolt in setup. Sleeves are available in different sizes for different bolts. Note if you are using a B24 bracket, you will need the sleeve specific to that bracket. This is true unless you need a 7/16" Bolt. In this case use an SG11 Bolt that has a shoulder for use with the B24

 

 

[savagete2860]

Thank you all for your help. TL;DR After too much trial and error, I finally have 2031 dated Schrotch Flexi 2x2 harnesses installed in my standard s3 chassis, lowered floors, and Tillet seats with sliders Caterham.

 

Seats...

I did not build my car, RMC did so prior to this ordeal, I have actively avoided removing the passenger seat even though I know there is a nice rock collection under there. I can hear every time I take a turn. On the drivers side seat there are bolts that come from the bottom that tighten into a captive nut on the tillet slider. I have removed this seat a few times - its a pain but not that a big deal.

 

The passenger side is different. It has 4 of the most frustrating bolts I have ever dealt with and is pure misery. It has hex bolts going from the top of the seat slider into a nut and washer under the car. The sliders are interesting because there are bolts with a large head that mount the seat to the rail and then there are bolts on the slider with the same sized head that mount the slider to the car. This limits the slider movement because the bolt heads contact one another when trying to move the seat on the slider. This also means installing and removing the seats require bolts to be fastened/undone in a specific order or else you cant get to the bolts that need removed/installed.

 

To remove, I had to slide the seat as far back as it would go and shove my hand between the bottom center of the Tillet seat and the bar running in front of where the seats mount. Its a very tight fit - there were a few times I thought my arm was stuck. If the rear slider and seat bolts didn't contact, the seat would have been able to go back a bit further and make this less challenging. At any rate, when my hand was in place holding the wrench I could feel my way to get a 6mm hex wrench in the bolt, hold it, and undo the bottom side nut with a 13mm socket. With the front bolts out, it allows the seat to slide far enough forward enough you can get to the rear bolts. Same process there there, but without hand and wrist pain gymnastics. This also required a helper for all bolts since you can't reach both the nut and the bolt.

 

Putting the seats back in was reverse order. It is also 10x more difficult for the passenger side, primarily because you have to fully tighten the rear bolts and hope that the front holes line up. My pro tip for this is put the front bolts in upside down and leave them in place (if you can get them in place without falling out) and then do the rear bolts.

 

Old Harness Removal

This was pretty straight forward. 16mm wrench/socket for the stuff under the seat. Then the fun started. The outboard shoulder belts are long. In fact, they are too long to remove if you have a roll bar/cage with diagonals.

 

 

I decided to cut the bolt but none of my cool power tools fit comfortably so I ended up using a little hack saw and sawed away for what felt a lifetime.

 

New Harness Install

For the install, I had to prep the harnesses themselves by removing the clip on end plates and replacing them with the b24 bolt in brackets. I also flipped the side lap belts to be in the pull up configuration since there is no room to pull down. I then used the existing belts to try and adjust the length to match.

 

For installation, I followed what was on the car already (top to bottom)

bolt head
washer
b24 plate
b24 7/16" pivot sleeve

car

 

The factory setup had a wavy washer between the pivot sleeve and the bracket but I left that out for now.

The sub belt mounts were a little different. The factory pivot sleeve is much taller than the replacements, so I also added some washers to take up more space.

 

To deal with those bolts I had to cut, I replaced them with the 38mm 7/16 bolt from HMS

https://www.hmsmotorsport.com/products/schroth-bolts?_pos=4&_psq=7%2F16+bolt&_psid=a425155e5&_ss=e&variant=47230555160676

 

It has a much shorter head than the factory bolts, fit under the roll cage bar and still leaves threads sticking out the side it goes into.

 

Test fit and Finalize Install

 

Once the belts were installed, I did some test fitting of the seat and sitting with the seats unbolts. This is the point I actually switched the side lap belt to pull up instead of pull down because I couldn't properly tighten the belts. Adjusting the sub belt with the cam lock took a bit of patience. I can get to the adjustment brackets at the Tillet seat opening so I didn't have to remove the seat at least, but getting in and out of the car over and over to make them right was not quick. This is one thing I am a bit worried about for instructors/passengers. It also forces use of the sub belt, which I found most people preferred not to use it when it was optional when just on the street.

 

Once everything was adjusted, I bolted the seats back in.

 

Final Results and Thoughts

 

 

I do like the new belts functionally. They're easier to adjust and there is more room for clipping in my simpson hybrid s loops in. They also let me track at NJMP, so hard to argue with that for function. It is a completely other topic, but if NJMP wasn't mandating dated belts, I would have happily lived my life with the Caterham Luke harnesses.

 

My particular harnesses have about 6 feet of excess belt for each shoulder strap. I tied them together and plopped it behind the seats for now. When tightened, the side belts have a lot of excess belt as well since I flipped to the pull up configuration and you lose the ability to pull extra belt out of the way. They can just be tucked  somewhere so not a big deal though.

 

If I was doing this again, I think I would have just went with Caterham Schroth belts (assuming they are actually dated). Belts and hardware, my exact setup was around $1500. That does not include the headache of figuring this out and the shipping costs to return stuff that I messed up on by being a bone head. The Caterham belts would have just worked, fit better since they're made specifically for our application AND you still get the gorgeous yellow color that matches absolutely nothing.

 

[CBuff]

If you fancy giving hms more money.  I got these harness pads, one for comfort and two to hide the yellow that doesn’t match anything.  I do pull them off in track days as they interact with Han’s. 
 

https://www.hmsmotorsport.com/products/schroth-3in-shoulder-pads-with-racing-patch?_pos=4&_sid=82b77f9e1&_ss=r

 

they also keep the uv damage at bay on the harness although with a 5 year dating it’s less of an issue.