unknown_host

iTrader: (1)

I am interested in putting a harness bar in my street/strip car. I have no intention of running faster than 11.50, I had a roll cage in my old car and am interested in just running a removable harness bar.

Here is a bolt in unit I found:


However, I am wondering if I weld plates behind the stock plastics, if I could weld mounting points similar to this:



That would allow me to bolt a harness bar in for track days, and unbolt it when I want to take my kids around the block.

Thoughts?

InfernalVortex

iTrader: (4)

I wanted to do the same thing but no one saw the point. I wanted it for autocross to help hold me in place through the course, but in the end the fourth gen firebird seats I found do a much better job than my factory seats. I always wondered if the fourth gen setups will fit our cars at all. You'd think they should... Im guessing you think you can copy that setup for a lot cheaper?

redneckjoe

i wonder if they make break away fittings like these, but out of steel?

http://tacomarine.com/item--Breakawa...away+pins.html

might give you some ideas anyway?

Formula 305

I don't know if I would trust those break away fittings for something as important as a harness. The bolts are in single shear, which is generally a bad idea. If you were to try something like this I would go more the route as the first picture in this thead. The bolt there is in double shear, which is much better.

If anyone tries this, please post something up. I kind of want a roll hoop & a harness bar, but I also like having access to the rear seats if I want them.

Tibo

iTrader: (15)

Where is that bolt in unit? I also would like to have a bar just for attaching the harness.

87350IROC

iTrader: (2)

A properly designed bolted joint is not in shear at all. All the fastener is doing is providing the clamping normal force to create friction in the joint between the two pieces. The frictional force between the two pieces is what resists the "shear" force. Threaded fasteners are terrible in shear or bending. You might be thinking of a pinned joint.

LX_SS

interesting one, so imagine rear seats fold down. Mounted behind the seats are 2 anchor points, one left one right, these allow the mini wheelie bar(like that style not actually a wheelie bar) to fold over behind the front seats giving you a harness bar ?
lock in the pins on the left and right of the anchors after the bar folds out should lock it at the height you want. Then if it was ever in the way for anything in the back at all, just unbolt from said anchor points.

The other way would be brace the floor just at the b pillars/behind front seats and then run a bolt in half loop that has a bolt on bar to bolt behind the back seats on the floor again. little bit more simple, but more hassle to use i guess.

There's plenty of ways, just how you want to do it.

Formula 305

We aren't talking about a properly designed joint. We are talking about weekend warriors putting this together in their shop. I would assume a lot of people wouldn't think to preform the calculations to determine the proper torque spec for the clamping force they need.

redneckjoe

i've used those fittings many times over the years with no problems, and that was aluminum. steel would be fine, especially if you rotated the fitting correctly. can you imagine the shock that an aluminum tower takes under full throttle, in rough seas, with high winds, a few guys up top, out riggers pulling and twisting, etc.? never had a failure.





and these get un-bolted quit often to pass under bridges.

Gsoleski

Not sure if you're still thinking about a bar but I bought some seats from a company called Cipher and they have harness bars. I doubt there's one that actually fits our cars, or if these are even safe but this could give you some ideas

http://www.andysautosport.com/chevro...h90000037.html

or something like this maybe

Juve88GTA

This is what i came up with, is bolted on. Pretty sturdy.

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