Just placed my order for what appears to be the last carbon one in the US. Can't wait to see if it works for me.

Huge thanks to Alec for taking a bunch of measurements and pictures for me!

 

This is related to seat mounting so I thought I would ask here- How are very tall people mounting their anti sub belts for 6 point harnesses? I am working with a fabricator on a roll bar/door bar and seat mount set up:



The seat is on the floor with the trans tunnel notched and all the stock mounts removed. Without space between the seat and the floor, how do the anti sub belts get mounted far enough back?

 

it all depends on the harness manufacture. they all recommend to mount the sub straps a little differently. if your seat is going to be mounted that close to the floor, welcome to the world of removing the seat to adjust the sub straps.

 

For the tightest of spaces there might be the only thing possible, but a nightmare to adjust (if you can't place the adjuster above the bottom of the seat)
BOLT IN BRACKET (B59)

Btw, why do all FIA seats with a non-nosebleed pricetag only have a five-point hole?
A true 6-point have two separated holes a little behind you crotch (to enable the sack hanging between the straps).

 

So as a follow up for others trying to get sub belts mounted into a small space- The ideal mounting position is just not possible without raising the seat which makes the car a no go for me. Basically, it is a choice between running the sub belts way back to behind the seat, or having them mount just slightly behind the sub belt opening. After talking with my fabricator, and HMS who I bought the harness from I ordered a few space saving options and I will settle for belts mounted about an inch behind the sub belt opening.

The part that ended up working is the The b23C which is bent so the buckle is inline with the belt and then rides on a bushing so It can swivel:



I tried to retain snap in functionality with these bend/twist brackets but the dimensions don't work out as well and the bracket ends up binding on the bottom of the seat:



Moral of the story is that if you are tall stick to big cars.

 

I just finished prepping the car to drop off at the cage builder tomorrow and I finally got an opportunity to snap some pics of the Tillett mounting brackets I made. The seat is a Tillett B6F, exactly like what was posted on the previous page of this thread. These brackets bolt to the factory front mounting points and require new holes to be drilled for the rear. You can see why new holes are required in one of the pics... the seat completely covers the rear humps. Only a small amount of hammering was required on the trans tunnel.

I left the rear humps in for now, which required spacing the rear of the bracket up about 10mm. The brackets are designed so that the bottom of the seat is flush with the bracket, so removing the humps would allow the seat to be completely on the floor. I'm already on the verge of being TOO low with this seat, so I left the humps in for now.

This setup puts me 1-2" lower than any other seat I've sat in in a miata. I'm pretty happy with how it turned out. I would still rather have a seat with shoulder and head containment, but I'm 6'1" with a long torso and getting my head away from the roof and the cage was the highest priority. I'll definitely be running a center net that covers both my shoulders and my head. My left shoulder is so close to the door and B-pillar that a net won't make a difference there, but I still might add a left side net for head containment. This seat also has really high shoulder belt holes, which is another thing I've struggled with on other seats.

 

My NA with humps removed, tunnel heavily notched, and a kirkey bolted flat on the floor.



VS. the Tillett.

 

Very slick set up! How comfortable are the Tillets?

 

Excellent illustration of how significant recline angle is for head room. And comfort too.

 

Wow- your lay back angle is even more than mine. The tillett seat has a 30 degree layback built in and it looks like another 10 degrees on your bracket?

How much did it cost you to get your bracket machined? Also, how accurately placed are the holes on your tillet? One of mine is about 3mm off and my cage builder end up shimming the mounts he welded in.

 

I didn't measure the final recline angle but yes, it's laid back pretty far. I'd guess that the bracket only adds about 5 degrees. I was able to use the waterjet and press brake to make these at work, so they only cost me time and material. I could reproduce a set to sell for about the same price as the Tillett brackets.

And I didn't have any trouble with the holes being off. They might be off on my seat too but I didn't notice it. With the sides of the seat being on that stupid 5 degree angle, moving the seat up on the brackets also moves the brackets closer together. I had to make the holes slotted on one bracket to accommodate that, so the slots also gave me some wiggle room if the mounting points on the seat were off from the factory.

 

Really comfortable, even without padding. I haven't had any complaints on 1-2 hour trips. I drove it 3.5 hours to the track and back a couple months ago and my *** was a little sore at the end of each drive. I would spend the extra money on the Tillett padding for a true daily driver, but save the money and run without padding for a track only car.

 

I recently bought a cobra suzuka seat, cut the rear humps and have the seat essentially bolted to the floor. It is as low as it can possibly go. I'm 6'2" and fail the broom stick test by about half an inch with my helmet on and the seat cushion removed. so I need to go at least 1.5" lower to get some decent clearance.

If anyone has the TDR ultrashield seat and bracket or a similar aluminum body seat, can they post a pic of comment on roll bar clearance and their height with that combination. I'm to the point or cutting out the floor but I'd really like to avoid that if possible.

 

Im 6' with a 32" inseam (I'm all upper body) and I fit with my ultrashield.

 

An aluminum seat isn't necessarily going to get you lower. You are probably going to have to lay the seat back at a more extreme angle.

The reason JPreston and I got Tillett seats was for the built in 30 degree lay back angle.

 

You can get alum seats with layback

 

This is good news. I am 5'11 with a 30" inseam so I need to get on the aluminum seat band wagon...

 

Yes there are a lot of options with extra layback (20 degrees or more), but all of the seats I've seen still keep your spine completely straight.



From what I've seen, a seat that lets you arch your back and slouch down lower in the car is the most important thing for someone with a long torso. The Tillett is the only seat I've found that does that. I would love to find a seat that does the same thing but with shoulder support, but so far the Tillett is all I've found. One day I'll stop being lazy and design a custom aluminum shell that bolts to the floor and rear shelf and lets me just pour a foam insert right onto the trans tunnel.

Cyotani- I have a regular Ultrashield SM seat bolted to the floor (tunnel notched and humps removed) in my white car right now and it's only barely better than the Kirkey in the picture I posted above. My head is just barely lower with the ultrashield because there are no shoulder wings to interfere with my cage, so I can get a little more recline. It still isn't great because it keeps my back completely straight, but it's way better than the Cobra Suzuka I tried at one point.

 

Aidan, How's your broom stick clearance looking with a helmet on? Also seat bolted to floor?

I have a pretty large recline angle on my Cobra Suzuka seat. I played with that when installing it. Any more recline I become too close to the pedals and the headrest is located in a place where my head can contact the roll hoop too easily. The extra 10 degree or recline gave me about 0.3" or so more head clearance but ergonomics and safety were worse in that position.

 

Thanks for the info and taking the time to help me out. How much was your tillett seat shipped to the states?