Scooter70

The diagonal on my cage goes right behind the passenger seat so the normal brace can't be mounted to the horizontal directly behind the seat. Has anyone come up with an alternative way to mount a brace to support the back of an Ultrashield/Kirkey style seat or does it NEED to go straight rearward?



Thanks,
Matt

johnny c

DO NOT use a i/o port brace. those are for expired FIA seats.

Aluminum seats need to be mounted with 4 Attachment points 2 in the seat and two on the bar. below is the easiest way of bolting one up.

FASTFATBOY

Here's mine, homemade

Scooter70

My issue is that the X where the horizontal and diagonal bars come together on the passenger side is right where the brace wants to bolt in. Could I make it such that there are two attachments that come together like this, so that they can bolt on either side of the X? (Excuse the MS Paint skills.)

FASTFATBOY

You can't rotate the collar to get on any bar to mount it? BTW, those 2 little plates that come off the back brace at the seat need to have gussets so it cant fold over.

Can you put the seat in the car and take a pic?

Also, those collars sitting on one another and welded make me nervous also, I notched both of mine a little so they had more intersection.

Not cracking on you, that's just what I see.

Scooter70

The brace that I have is more like this one. I just grabbed that first picture to have something to draw on.



I don't have the car here yet so I can't take any pictures of the seat in the car. Hopefully it gets here next week. I'm just thinking about it now and wanted to see what others thought.

brkntrxn

To clarify, you are asking about bracing the PASSENGER seat, correct?

To be honest, I don't brace my passenger seat when I do have it installed... which is rarely anymore. Same for the harnesses on that side, they are in very good shape, never in the sun, but expired.

Scooter70

Yes. I didn't know that you could run an aluminum seat without back bracing. I assumed that they were flimsy and needed it to be held up.

FASTFATBOY

Much less flimsy than a composite seat, no idea why they require a back brace.

johnny c

yea that's not good. you really need 4 mounting points. or this will happen.

johnny c

yea the aluminum seats are much more flimsy.

this is the actual way you need to mount an aluminum seat. that is if you want to have a hope of walking out of a crash. . http://www.hotrod.com/how-to/additio...-seat-install/

FASTFATBOY

My Kirkey is much more rigid than a one piece composite seat.

That pic you posted, that happens if the bottom mounting fails. I am mounted in multiple places with the seat. Do you mean 4 places across the back?

You can't mount a seat in a Vette like in that Hot Rod article.

Bad Karma

The only problem I see with your split idea is it will bolt to the cage right where the belts are and interfere with your shoulders harness.

http://www.ioportracing.com/instructions/seatbrace.htm

Bill Dearborn

Matt, I don't know if I can find them but I have two brackets that bolt to the back of the passenger seat. They curve around the shoulder area and the flat section of the bracket attached to a similar bracket welded to the roll bar I used to have in my C5. I had the same problem you do the rollbar behind the seat was constructed so there wasn't any way to attach an I/O Port seat brace.

Since I moved to Charlotte they have been lost in the boxes. If your builder takes off the seat cover he can see where the bolts for the bracket held it to the seat. The guy who built the passenger side seat mounts took two flat pieces of steel and curved them to fit around the shoulder supports on both sides, then he welded a flat plat to the top of each curved section and shaped that so it would blend with a similar flat plate welded to the cross bar. He used Porsche Pins to hold the two parts together. It made for a very solid seat mount.

Here is a picture showing the flat plate welded to the roll bar.



The two bolts shown mounted in the plate permitted bolting the shoulder harness to the roll bar since there was no way to properly wrap the harness around that section of the bar.

I don't know if I can find those curved plates. However, it only took my builder about a half hour to 45 minutes to make them from scratch while I stood around and kibitzed.

Bill

trackboss

with a rollbar or cage a proper seat back brace should not be a problem to make. It may take more time than you expect depending on a number of things.
A strong seat back brace or some form of upper seat mounting along with a solid base is a must with any seat. Some will argue that composite seats do not require a seat back brace. While rules may not require it your life will. I've said it many times before. A composite seat will move around a lot in an impact (any seat not mounted properly really). Because of the fact that the shoulder straps are mounted to the car (cage) and not the seat the movement could cause the driver's shoulders to slip under the belts and the rest=bad things happen.
The only composite seat mfg. that gets it is racetech. They actually have a place to mount a back brace.
IMO, if all the belts were mounted to the seat then the seat could flex around all it wants and still keep the driver safe so long as the seat is properly mounted at the bottom. That would not require any form of upper mounting. Why the rules makers don't allow/require that I have always wondered.
Furthermore, many builders connect the door bars to the seat mounts. Seems like a great idea until a hard side impact moves those bars and transers the energy to the seat.
Anyway, here is what I did on my street car. It obviously has no cage so in order to safely mount my kirkey seat I made a back brace and attached it to the bulkhead. I realize it is a compromise, but it works really well.

carefulnow

w/ and w/o back brace crash test video here - composite seats - skip to 40 seconds or thereabouts.

3on8

Great find; thanks for sharing.