Different height drivers, same fixed seat?
 

Anyone out there running a Miata with a fixed mount race seat with two drivers of different heights?

My wife is getting more into HPDE, but I don't want to turn her '13 Club into a total track rat, and it's also not really feasible to take both cars to distant tracks. I'd like to make my NA fit both of us, and we're pretty close. I currently have aftermarket street seats on fixed mounts. They're good for me, but probably 2-3" too far back for her. She can push clutch in, but not comfortably.

I'd like to replace the current seats with a race seat, and was thinking a removable pad could push her far enough forward for it to work... I know pro race teams use molded inserts ($$), but is there anything for us low budget amateur types?

Thoughts, ideas... solutions?

DIY molded insert?

Add sliders?

I'd like to avoid sliders for height reasons, and messing with the seat back brace if I end up with an aluminum seat.

DIY molded is a possibility... any good links?

OK, found this... https://www.miataturbo.net/og-racing...ur-seat-83148/

XL is recommended for filling in larger spaces... so, at $600+, not exactly the solution I was looking for.

Kirkey has essentially the same product for $250, but I would assume that's equivalent to the small kit since they recommend a second kit to fill large gaps.

We used to build foam inserts for kart seats, and open wheel teams do it all the time. You can buy the expanding two-part foam at a plastic supply store. Throw a big trash bag in the seat, have her sit where she's comfortable, pour it, and wait. When it's hard, remove the trash bag and wrap in duct tape.

Helpful hint if going the foam insert route: use two trash bags for insurance, cheaper ones tear easily. We did this for a Lemons build and it worked perfectly.

yep XL is a kit we use for the NPO1 cars. if your trying to make up room in a GT car seat you'll be good to go with a Large kit. don't worry about the double bag with the bsci kits that we offer. I've done about 15 seats this year and haven't had any of them tear.

Word of advice, when you're trying to space out a driver make sure you use some foam to hold them in a position. don't just try to hold a position by flexing. people that try to position themselves generally have a very uncomfortable seat. call me when ordering and i can send you the hard foam you need and talk you threw the install.
770-880-7579

Something like this? 2 lb Polyurethane Mix & Pour Foam in stock ship same day | Fibre Glast

GRM did an article on using that stuff for a seat. the BSCI kit that we offer will get to 90*. the two part foam for boats will get much much hotter. they where burning themselves molding the seat. funny that never made it into the story. :/

polyurethane also melts at low temperatures. so if there is a heated area like a muffler or a fire, it will melt the poly threw your clothes and into your skin. this can only be removed surgically. also funny that never made it into the GRM story.
When items with polyurethane burn, they produce toxic smoke composed mainly of carbon monoxide, and the smoke also contains hydrogen cyanide and nitrogen oxides.


the BSCI kits are made up of the same stuff Roll bar padding is made from. so it's fame retardant, impact absorbent, and makes for a very nice seat.

Wow that's some scary stuff

I have made a bunch of rigid urethane seat inserts. So far they haven't lasted me more than about a year of use. I ordered samples of smooth-on's flexible urethane foam 25 and 17 (these are the firmest flexible foams) and am hoping to make a small lumbar pad with it. They also sell flexible foam 7FR which has a cert for being flame retardant but I think it would be too soft for insert use.


OP, you also could try something like the garage star seat bracket. It supports moving the seat several inches with minimal use of tools but is more secure than sliders (and less than a normal bracket).

Common complaint that I hear. Same goes for the bead seats. They just brake down over time.
The bsci seats take a lot more abuse and can bounce back. They are good for a few years as long as you keep them in the car, and keep them covered. The two reasons I've see for the BSCI seats to fail is UV exposure, and tearing when you remove them from the car. the pro teams that i work with will yank the insert from the car (driver change). most of the time tearing it in half. if you remove them with care they shouldn't tear. or even better just keep them in the car. the BSCI foam is roll bar padding, and we have all seen what roll bar padding looks like after a year in the sun. we cover them with a carbon-x material. keeps the sun off of them and extends the life.