Side intrusion bars

[Zedn]

Sorry, just remebered your case is a bit different.

Is your car classed as an ICV or modified production?

Most kits have a couple of pieces of RHS or tube. You need to consider the whole picture though and not just the bars. Consider the load path in the event of a side impact. What you have linked may suit that car, but to other cars may be a lot of weight without improvement. In most cases the front of a car wont fit between the centre of the door and sill so the whole lot doesnt need to be filled in with metal. Also the hinge and latch are the weakest link so introducing more steel in the bars is no good if the striker plate of the door does not mount into solid enough steel.

My gallery has some pics of how it is done in my kit.

[OZCOBRA]

Originally Posted by Zedn

Sorry, just remebered your case is a bit different.

Is your car classed as an ICV or modified production?

Peter said it was" Modified Production."

[PeterAllen]

I've picked up a few configuration ideas from this.

Browser Warning (edit) I don't know why the link has come up with the title but it seems to work fine.

My primary concern is not so much with the bar design itself but rather how it might might utilise the door jamb to stop the whole bar entering the cabin. What's the point of a strong bar atteched to fibreglass.

[AC-460]

My primary concern is not so much with the bar design itself but rather how it might might utilise the door jamb to stop the whole bar entering the cabin. What's the point of a strong bar atteched to fibreglass.[/quote]

Most cobra doors use Ford rear door catches or similar not even designed for side impact in front doors....These catches are only held on with three 1/4 inch bolts. All the side intrusion load comes down to the size of these bolts. Its alright to have big heavy bars in your doors but these bars in the doors will spear straight into you after the three quarter inch bolts have shorn off... In a car the doors carry on past the pillar and in side impact the door carries the load all the way up on the pillar all the load is not exerted on the catch.... unlike a cobra were it is...

[Zedn]

Originally Posted by AC-460

My primary concern is not so much with the bar design itself but rather how it might might utilise the door jamb to stop the whole bar entering the cabin. What's the point of a strong bar atteched to fibreglass.

Most cobra doors use Ford rear door catches or similar not even designed for side impact in front doors....These catches are only held on with three 1/4 inch bolts. All the side intrusion load comes down to the size of these bolts. Its alright to have big heavy bars in your doors but these bars in the doors will spear straight into you after the three quarter inch bolts have shorn off... In a car the doors carry on past the pillar and in side impact the door carries the load all the way up on the pillar all the load is not exerted on the catch.... unlike a cobra were it is...

[/quote]
Mine uses 2 3/8 bolts. The shear force required to break these is way more than the traction of the tyres can hold.

[PeterAllen]

Mine uses 3 3/8 bolts. The shear force required to break these is way more than the traction of the tyres can hold.[/quote]

Is it the bolts that shear or would the latch mechanism and/or the hinges, even with spreader plates, pull out of the fibreglass?

One thing in my favour is that I'm running narrow wire wheels and narrow period size tyres. The down side is they might get me into trouble in the first place!

[Zedn]

Originally Posted by PeterAllen

Mine uses 3 3/8 bolts. The shear force required to break these is way more than the traction of the tyres can hold.

Is it the bolts that shear or would the latch mechanism and/or the hinges, even with spreader plates, pull out of the fibreglass?

One thing in my favour is that I'm running narrow wire wheels and narrow period size tyres. The down side is they might get me into trouble in the first place![/quote]

You should not be mounting them in fibreglass. If you want to do it properly you will need to fabricate a subframe to sit inside the body for the bolts to go into. That will then need to tie back into the chassis. As yours is mono you will need to have a fairly large plate to distribute the load.

Do you have any photos you can post to help us understand the situation?