Roll bar with convertible top

[truegearhead]

I've got an engineer and a roll bar guy, now I need an idea on how to get a role bar to work (meeting scca standards for hill climbs) while retaining my factory top (I'm ok modifying it). Any ideas?

[Brad Roberts]

How tall are you?

I'm not sure about hillclimb, but SCCA typically has a rules that states your helmet cannot be above the roll bar.

I personally don't believe anyone 6ft and over will get under a main hoop and still be under the stock top.

And we have mounted seats directly to the floor in some cases

[truegearhead]

I'm 6'3" and need a huge helmet XXXL, I know wierd. But I do have GT3 seats that are on the floor, even with the sliders the seat bottom is resting on the carpet. I also sit far forward which allows me to go higher with the bar (the top sweeps up as it goes forward so the further up the bar is the higher it can be). My plan is to do a hoop and tie it in at the top of the doors and then have removable back bars. Surprisingly this is legal for class 4 SCCA regulations. The braces will only fit when the top is up unfortunatly but I think this is the only way. I will also have to remove one of the convertible top bars, the roll bar will take its place and will hold up the top. Thats the plan at least.

[Brad Roberts]

The carpet is 1-1.5 thick under the seat from the floorpan. I have NO race cars with sliders at this point. Some of the cars we run have had the actual structure for the stock slider removed and a flat pan installed for FIA seat mounts.

Measure 100 times is my point and ASK the SCCA people. 99% of the orgs out there have what we call a "broomstick rule" from the first rollover point on the car, to the second point, your helmet MUST be a min. of 1inch below the broomstick as it lays across those two points. (and I don't believe this is enough)

1st point: windshield hoop
2nd point: your new main hoop

I wish you luck!! but... you won't make it under the stock top without getting the seat way way down. Porsche actually DROPPED the seat pan in the 9X1 cars. They gained an inch of headroom by doing this. The seat pan is now part of the flat bottom on the cars.

Remember this: safety first. I don't care what the rules state. Shoot for that 1 inch under the broomstick. Hillclimb is exponentially more dangerous than any other form of racing. Not much different than Rally. Every car I've seen "go off" in a hillclimb? is totaled. Every time.

[Brad Roberts]

Ironically? we have a Virginia City Hillclimb out here

[Brad Roberts]

Tidbit of info:

The car is nearly 10miles an hour slower with the top down at speeds over 70mph compared with top up.

Get a factory hardtop.. and gut it.. they are Alum.

[truegearhead]

Originally Posted by Brad Roberts

Ironically? we have a Virginia City Hillclimb out here

Where? So you have a link?

Edith right google...I found it

[The Radium King]

I have the bk floor mounts (r-9044), oem side mounts and gt3 seats - gets the seat min 1" lower than sliders. I am 5'10" and have a huge noggin myself and am about 1/2" above broomstick with the oem rollbar if I sit straight. I keep the roof up just so that it isn't so obvious to the marshal.

precision chassis works (kpaz on this forum) makes a piece you can use if you cut out some of the seat mounting structure on the floor pan.

[Brad Roberts]

Thanks Radium (I forget your name) for 15yrs now, its been odd calling people by their "screen name"

[Brad Roberts]

Some of my guys run with NO seat cushion to get down into the seat better (I suggest this a lot)

[Brad Roberts]

If you roll? Your seat belts will stretch upwards of 4inches as the car rolls and your weight is against the belts. This is assuming your fab guy/wrench mounted the belts correctly behind you at the proper angle to your shoulders.

Move the seat down after the "harness bar" has been welded to the main hoop? you just changed the angle of the belts in relation to your shoulders.

Safety First. No bullsh_t.

[truegearhead]

Originally Posted by Brad Roberts

Some of my guys run with NO seat cushion to get down into the seat better (I suggest this a lot)

That's a good one, I think I can get the bar 3" higher than stock so it'll be close. This is such a bad idea, I love it. I need to find some rollbar/cage build pictures.

[thstone]

Originally Posted by truegearhead

... I need to find some rollbar/cage build pictures.

Several good pic's of my roll cage in this thread: Spec Boxster Build

[Brad Roberts]

True,

I know where a full cage is sitting in Oklahoma. It's out of a wrecked car, and its the first main hoop/cage setup I had ever seen that had all the mounting provisions on it for the convertible top.

Call up Oklahoma Foreign, have them snap a picture of it.