Rollbars and head clearance

[John Scott]

I find it disturbing that when I sit with my helmet on, it is firmly against the headliner. I suppose the only alternative is a lower seat height. What are the recommended distances between the roof and your head, also distance behind for rollbar?

JS

[randy 77zt]

if you change seats it might run lower .i run a race seat at trackand my helmet just rubs on headliner.i made aluminum plates to adapt seat to oem seat tracks.these are the things that z car is good for-finding fabrication talent in owners.

[Guest Anonymous]

John,

 

I have a 76 280 and will be using a Sparco Sprint model seat. I fabricated a mount out of 2" wide 1/8" thick steel flat stock. When I am sitting in the car my head is ~3 inches from the headliner. I am ~6'2" tall. Pete was over the day after Thanksgiving and sat in the car as well. Pete is a taller than I am and he had plenty of room between his head and the headliner and commented there should be plenty of room for a helmet.

 

Pete is also using a Sparco seat and fabricated up mounts to utilize the Datsun sliders. I kind of did mine in a rush as I was anxious to get the seat in for cage measurements. I will probably do up a mount to use sliders as well now that I know there will be plenty of room for the cage.

 

With the planned position of my main hoop I would have to say there will be ~3 1/2 inches of clearance between the back of my head of the hoop. I am using a S&W cage and modifying the main hoop to sit in between the rear wells on top of the "shelf" just before the riser.

 

Chris

[Dan Baldwin]

I think SCCA requires the top of the roll bar to be 2" above the top of your helmet. I have a Momo Rookie seat in my '71, mounted to twin ratchet slides also from Momo, which only required redrilled holes in the stock seat supports to fit in the car. My helmeted head is ~3-4" from the headliner.

 

Dan Baldwin

'71 240Z 3.1

COMSCC #7 SPB

[pparaska]

Chris covered my experiences with the Sparco pretty well. I'm 6'2", inseam 36", so my torso is about normal proportional length for my height.

 

I have the Sparco "Road" seat, which is just a fancier and longer wearing material covering on the "Sprint" that Chris has. With the stock slides and the 3/16" high brackets I made to mount them to the seats, I added only about an inch to the overall seat height. I found that this wasn't necessary (having the brackets so shallow) as I still have a good 4.5" of room above my head. So I could have made simpler Z brackets that adapted the stock slides to the seat and still had 3.5" of head room. The wife's seat will be mounted a bit higher like that when it goes in , as she's several inches shorter.

 

How much does a helmet add to your head height?

 

The reason I went with the Sparco was my height and the desire to have adequate room for a helmet. I didn't want a Z seat (not enough support, etc.) I thought about a Miata seat and tested one in the car, but didn't like the support either. Finding seats that are shallow enough in the seat bottom for adequate clearance was a problem for me. Recaros were out. The Sparco was the one that I was able to test out and find that it worked. I have a feeling the Corbeau Clubman may be very similar.

 

------------------

Pete Paraska - 73 540Z - Marathon Z Project

pparaska@home.com

Pete's V8 Datsun 240Z Pages

 

[This message has been edited by pparaska (edited December 07, 2000).]

[John Scott]

Thanks all, for the good info.

 

I'm 6'0 and want to remain that height. Your mods should give me plenty of room.

 

JS

 

[This message has been edited by John Scott (edited December 07, 2000).]