30 replies to this topic

[HLF]

I just spent several hours mocking up different ways get me (in my helmet) to pass the broom handle test. 

 

I have a USRP Spec Miata Seat. The rear "bumps" have been hammered down flat and I still need about 2" but minimum 1.5".

 

I carry most my height in my neck apparently. 

 

Any tips for finding head room is much appreciated. Do I need more than two seat mounts on the bottom of the seat if I bolt the seat to harness bar?

 

I think I will need to angle the seat backwards and move it forwards. I don't need anymore leg room. 

 

TIA,

 

Kyle

[Ron Alan]

You answered it yourself...seat on the floor tilted back. But you'll still need to attach in 4 places at floor I believe. My guess is there are a lot of drivers that fail the broomstick test...it is what it is!

[Bad Rusty]

Take the padding in the bottom out too!  I speak from experience 

[Bench Racer]

My guess is there are a lot of drivers that fail the broomstick test...it is what it is!

It is not always what it is. If one reads the rule, one will find the broomstick test is for open top cars.

 

[HLF]

Take the padding out of the seat bottom? there isn't much padding to begin with.

[mvzante]

Take the padding out of the seat bottom? there isn't much padding to begin with.

My seat had approximately 1" of padding that was removable, an inch is an inch.

 

I think what you might want to make clear is if you are using a hard top?  If you have a hard top then the broom stick rule does not apply as stated by Bench.  If you have a hard top and are just looking for extra room for your own comfort then carry on.

[Ron Alan]

It is not always what it is. If one reads the rule, one will find the broomstick test is for open top cars.

I knew there was a reason it didnt matter 

[HLF]

So I am having a new main hoop made by Lucas Racing here in Houston. 

 

I bought this kit from someone who decided to not to cage their car a year after buying the cage. He did mock up the seat and shorten the main hoop by 1.125". 

 

I need that 1.125". and I think I am going to make it 2" taller. That way I have a little extra room. 

 

I should preface that I don't plan to race SM with THIS car. For now its just for DE, AutoX and maybe TT after a while. Because of this I plan to use the hardtop money for a FCM suspension package. 

[Bench Racer]

Because your searching for vertical helmet clearance the following is the process used for my main hoop.

Being that your having a new main hoop fabed and installed. Presuming your hoop will be 1 1/2 inch diameter tubing, fab a complete mock-up of the main hoop out of 1 1/2 inch wide 1/4 thick inch wood. Did my main hoop with described wood and also used 1/4 thick plywood at each of the five bends, glued it together. The first bend each side is at approx 3/4 the height of the side window where the roof moves towards the center of the car. The straight length of tubing after the bend is clsoe to the vertical/angled inside of the roof, The next bend on each side is as the roof starts it's radius accross the car. The last/fifth bend is at the center of the roof/car. Five bends total in the main hoop. The cage fabricator bent tube to follow my mock-up and when welded in place, my pinky finger will not fit between the main hoop tube and the inside of the roof. With this finicky direction for the main hoop, the faber then did the side hoops tight to the roof and the front cross tube tight to the roof. From the rear, side or front one can not see and tubing. Anal, yes, the way I wanted the main hoop/cage, yes. The faber has is excellent at what he does.

[HLF]

Bench (and other tall drivers), I'm curios how tall y'all are from the bottom of your seat to the top of your head. (sounds like a creepy personal question)

 

For instance if sitting upright on the floor against a wall? Just curious. 

[mvzante]

I measured approx 38 1/4" per your instructions. Not sure what's considered tall these days. I'd say im 6' 0 1/2". My father in law drove my miata before me and he was 6' 4"ish.

[Bench Racer]

5' 11" Tall, 38 1/2" helmet on, back to wall. I have a Ultra-Shield Pro road race with bottom of seat bolted to floor and tube with small plate (bolts to seat) welded to horizontal of roll cage.

[mvzante]

I measured approx 38 1/4" per your instructions. Not sure what's considered tall these days. I'd say im 6' 0 1/2". My father in law drove my miata before me and he was 6' 4"ish.

That was without a helmet....

[Mike Collins]

MEATHEAD Racing has driver's at 6'4, 6'5, 6'5, and 6'3.  We have managed to get everyone in the car comfortably, however I will tell you that why a lot of the same techniques were used to do it none of the "tall" drivers like any of the other "tall" cars.  The seat really needs to fit you and you need someone who knows what they are doing to mount it and then build the cage around you.  Standard issue will not work.

[HLF]

I'm 39.125" (with no helmet). I am picking up my new main hoop monday and I'll see if I can borrow a HT next week to explore the possibility of using a hardtop one day. 

[HLF]

BTW I am 6'4"

[HLF]

So this is what my main hoop looks like if I want 2" of broom handle space (hoop to dash, not top of windshield). I'm just thinking safety at the moment.

 

http://i116.photobuc...zpsb8c56d41.jpg

 

I need to drop it 3-4" to be eligible for hardtop. I am thinking three possible courses of action. 

 

1) Keep it as is, weld it in (half cage) and never utilize a hardtop. Save the front half of the cage for a future build.

 

2) Drop the main hoop 1.5" and weld in full cage so broom handle test is passed. Never use a hardtop. 

 

3) Drop the floor pan 1.5" and then drop the bar the rest. I should fit very well (allowing for 10% expansion in the event of a roll/crash) according to my mock up today.

 

A well known cage builder here in Houston said the SCCA is going to allow floorpan mod to fit us big guys, has anyone else heard this?  He said it is very recent and I checked the the GCR and CCR for updates and there aren't any about the floor pan.

 

I am considering the car for NASA TTE and/or PTE right now so I think lowering the pan is the best option right now. However, does anyone have a good reason not to drop the pan (other than SM rules)?

 

I have access to any and all machines you could imagine (except a pipe bender, lol) and I think a I could drop a 10"x17" section of the floor 1.5-2" using a .095" sheet metal box and then spot welding it into place. 

 

TIA,

 

Kyle

[RazerX]

Try sitting on the floor to see where your minimum height will be relative to the hoop.  Then you know how much your seat is costing you and if removing foam and a different angle will help.  I have seen a lot of tall miata drivers that haven't dropped the pan.

[HLF]

All those numbers are from my USRP seat with the upholstery and foam removed and bolted to the floor. Plus, I leaned the seat back so much the shifter is almost too far away. If my shoulders get any further away I will need to modify the shifter. 

[mvzante]

So this is what my main hoop looks like if I want 2" of broom handle space (hoop to dash, not top of windshield). I'm just thinking safety at the moment.

 

http://i116.photobuc...zpsb8c56d41.jpg

 

Wow...that hoop is crazy high...just curious if the seat even supports the back of your head.  From the looks of it in relation to the hoop it seem like the top of the seat will hit you about mid neck?