jimax bro

Over the winter, Jimax and I both went for safety upgrades. Roll bar, HANS, FIA Seats, 6 point harnesses etc. Need to get a fire suit/gloves/suit etc but still learning the ins and outs of those before I drop any more $$'s down.

For you folks that already have racing harnesses, for lap belt and crotch belt mounting locations, give me a critique for my setup. I had to modify a few mounting locations from the harness manufactures suggestion but still believe I got all location within spec.

On both drivers and passenger side, I didn't feel like dropping the exhaust to mount the eye bolt backing plate on the drive shaft tunnel which was my preferred location.

For the 5th/6th point eye bolt on the passenger side, the ideal mounting location for my body, positioned in a race seat, didn't work due to the brakes lines and fuel lines running under the floor. The drivers side was perfect. The passenger side was not quote perfect but close.





Drivers side:


I used caulking around each backing plate to seal the metal to metal surfaces and reduce the liklihood of rust around the eye bolt mounting locations...I'm a little worried the inboard plates, closer to the exhaust, might not tolerate the heat radiating off the pipes... anyone have any experience with this? I probably should have use high temp RTV but didn't think of it at the time.

I did a lot of putting the seat in the car, sitting in it, measuring distances/angles of the belts, taking seat out of the car etc... to make sure I met the harness manufactures guidelines. That took a long time for me but I think I got it within acceptable range the eye bolt locations.

Suggestions before I go for final installation of the entire combo?

John

bobster4

Is it possible to mount the passenger seat a tad forward? If so and still with enough leg room, where you have the eye bolts shouldn't be an issue. Honestly, without being there and viewing it with the seat in place its tough to really critique. But considering the work you put into it with placing the seat in and testing it out, I think you will be just fine.

Potomac-Greg

My only critique would be the sub-belt eye bolts. Most harnesses makers set them 4" apart. Those look about 8".

There are people on Rennlist (Porsche board) that would tell you that backing plates are by definition inadequate, and that you need to basically build a frame connecting to some super solid structural part of the body. I've gone oversized on backing plates.

Jretal

Backing plates sold are 2" x 3" if you look at summit, og, safe racer, jegs, etc. By the looks of things, Johnny boy used those plates, so I'd say he's more than adequate there. If you pull on those mounts and then pull on the one where the bottom of your front belts mount, you will see a HUGE increase in strength on the eyebolts vs the OEM mount. Noticed this myself w/ my installation.

Also, iirc, there was a rule for 6" spacing on the sub belts, wasn't there? I can't rememeber off the top of my head, honestly. That's what I designed mine around. Couldn't have done any narrower anyway, so I guess I'm stuck with it

As for the setup, looks good, John! Only thing I'd suggest adding is some 3M underbody coating to protect the metal. Will also help block some heat. And if you're really worried, I have a chunk of this stuff left over I'll give ya to cover 'em:



Oh, and as Bob said, if you can mount the pass seat forward, you should be golden. Just need to be sure that the belt angle is at about a 30* backward angle when all fastened in. I actually designed mine to fit a taller person just incase someone else used my car, so I'm actually pushing the limit a little if not exceeding it by a slight amount.

And for the orientation of the eye-screws, just make sure they're lined up w/ the load. So the hole in the eye screw should be perpendicular to the direction that they'd be pulled if being used.

Nice work! Look forward to checkin' it out at VIR

Potomac-Greg

The plates are probably fine. He asked for a critique so I came up with something! Seriously, there's a guy on Rennlist that goes crazy when people don't anchor belts with 4x4 beams of solid billet titanium.

And then there's another guy who says that using harnesses without a roll bar is like suicide because if you roll over, you can't crunch down like you would in a 3-point belt.

Jretal

wasn't bashin' ya, Greg. Just saying that you don't necessarily need to build a frame to hold it... b/c if you hit something hard enough to need that frame, you're probably a goner anyway :-P

Potomac-Greg

Schroth diagram. (What's 100mm?)

Jretal

just shy of 4", so you're right on that accord. I thought I read 6" somewhere, but oh well.

jimax bro

Thanks for the comments. I should have pointed this out since the pictures don't make it obvious and it a non-Audi , on the first two pictures, the bottom of the pictures are the FRONT of the car. The top is the rear of the car. You're kind of getting the "dashboard" view in those pics.

On the first pic, the you can see the REAR seat track mounting bolts sticking up through the floor just behind the yellow dotted line. The front seat track mounts aren't in the picture due to the angle so the seats will be much further forward.

To Greg's point about the 4" vs. 8"... for the 5th/6th point distance., I was restricted by the subframe rails beneath the car and other obstacles in placing the backing plate.. its probably closer to 5" - 6". Sparco's guidelines were 4".

Bob, you're right, without the seat in the picture, its tough to assess all the potential flaws. The seats are mounted on sliders so they have plenty of fore/aft room. I'm probably way over analyzing every mounting point but its my first time and I have a habit of doing that.

The mounting plates are from OG Racing. Can't remember the thickness but the bolt is tack welded on for additional backup. Greg, I hear ya about the Porsche "mount it to a subframe" comment. I'm pretty confident, short of an actual destructive test, they'll hold up to your and Justin's point.

Justin, not a bad idea about the heat shielding and undercoating.. I used some Rustoleum paint (not shown) on the backing plates but the undercoating is probably a better idea. The eye bolt alignment I'm still tweaking so they line up with the load path.

Now, anyone have a tricks for easily changing the length of the damn hardness belts?? Its not intuititive and is taking me forever to adjust the lengths with the funky (but safe I'm sure) wrap around the buckles..

Potomac-Greg

Sub belts are primarily just to keep the lap belts from riding up, so IMHO the loads there are not that critical. I'll be at OGRacing tomorrow if you (or anyone else) needs anything. I'm going Birthday Shopping for harnesses (and two more eye bolts).