Hi all,

Currently building my 1st gen up for circuit racing and was looking for advice from some other tall owners. I'm 6' 3 and with the original seat and a helmet, my head was very close to the junction of the roof and side of the car. I imagine with some custom seat mounts I'll be able to get the bucket seat a bit lower, but I'm still worried about head clearance with a helmet and roll cage.

Has anyone got any photos of their custom seat brackets and/or modifications they've made to the floor pan to accommodate with the decreased head clearance?

 

"Circuit racing" to me means FIA or similar rated seat and roll cage.

I compete with my FBs in a series that does not require much safety gear other than a helmet. I like to sit knees up, close to the steering wheel, so I can work the clutch without extending my knee very far. On the one car, I extended the steering wheel about three finger widths (I didn't measure) and this is perfect for a nice 90 degree elbow angle while holding the wheel. I also have used the same seat for about 250k miles so it's well crushed by years of wearing harnesses so tight that breathing is optional When sitting in the car, I can easily see under the sun visor when it is fully lowered.
I'm taller than you.



in my other car, I just wear the thinnest slip-on shoes I can find and splay my knees more so my thighs clear the steering wheel An extended wheel is in the future but I also like the nostalgia of the Series 1/2 4 spoke wheel.

 

Yup, here in the UK we're bound by MSUK rules, and while they don't specifically require FIA certified seats, roll cages need to be based on a multitude of example cages shown in the rule book. I'll still be using an FIA bucket seat anyway, they're needed for international events which we sometimes run.

I gather from that, you're using the original seat? When my car was a street car, I was able to push the seat all the way back, recline it slightly and I'd fit like a glove. Steering wheel was a little bit far away, but perfectly manageable. That same position was where I had slight head fitment issues on track days. Maybe I'm just paranoid, but it seems 2 inch thick tubing plus padding would make it a real tight squeeze, even with the lower seat

 

Oh, I'm building a car for classing that requires a roll cage. We elected to start with an R53 Mini Cooper S instead of an RX-7 or MX-5 Lots more room for a cage there.

Stock seats because both are street cars. Actually both are Series 3 seats which are worse for headroom than S1/2 seats, but the one car is a S3 and the other car had S3 seats fitted by the previous owner because, I assume, the 1981 vinyl shredded as it usually did.

I usually have the front of the cushion slightly ahead of the shifter and the headrest is inline with the door opening.

 

I can't tell by your avatar picture but it looks like you have a sunroof. If thats the case, it eats up some of your head room. Can you just run with the sunroof removed?

 

I removed the adjuster tracks from the stock seats to get some helmet room. Optimized the position/angle to my personal ergonomics, then mounted the seats directly to points thru the floor. Short tubes were welded thru the floor to adjust the angle, now to remove a seat just remove 4 nuts from below. Sorry no pics of that part of the build. When I moved the seats back 10", I also extended the steering column and moved the pedal box and dash using spacer tubes...




Grant

 

Yup, it's got a sunroof, but I don't feel it subtracts from head room too much anyway. I'm less concerned about the space right above my head, moreso where the roof and central pillars tilt in, my head got very close to that junction

 

For the same reasons, I have made custom brackets on factory sliders to mount MKI Lotus Elise Fiber seats.
I have been inspired by the blog of a guy who made the same for his MX5.

 

Not sure what your rules might be, but this is what I did with my E production car. Drop pan allowed me to move my seat down three-quarter of an inch, back 1” and over 1.25 inch. I also modified my steering shaft with a couple of universal joints to center and lower steering wheel. Lots of work but so worth it. Obviously not a street car. No longer race with my helmet against the padding of the cage hoop.

 

Wow, amazing work there! This is exactly what I was looking for so Ill probably copy this if you dont mind. The series I'll be racing in is extremely free, essentially just original engine and gearbox type (so your RX7 must stay rotary powered, but portimg and internals are free), and original exterior silhouettes (no bodykits or fender flares).

Unfortunately my car being RHD I've got that massive hump in the trans tunnel to deal with, but it shouldn't be too hard. Did you then mount your seat straight to the floor? We've got standardised FIA transverse seat rails that we have to use

 

Yep, pair of basic Sparco rails directly to the pan. Bottom of seat touch pan.

 

FWIW, drop pans like that are common in the MX-5 world (it's a VERY popular circuit racing car here) and I have seen them in FC RX-7s as well. There may be a somewhat prebuilt solution available to start from.