Economy either 10 or 20 deg layback depending on your preference. I'm seriously considering trying the intermediate 10deg layback just so that I can get a seat cover that isnt vinyl.

The 4100 series seats. They come in a variety of widths depending on your size. I know the 17" wide ones fit in a Miata with no trans tunnel bashing. I am 5'10" 190lbs and have a 36" waist and they fit me perfectly. If you bolt them to the floor they also sit you very low which is awesome. Stock NB seat sit me looking just below the windshield crossbeam. In floor mounted Kirkey's with the padding and cover in them I see a few inches above the steering wheel which is a little lower then the middle of the windshield AKA perfect position.

The seat and the cover from summit come out to under $300 a seat after shipping. You can also find them used easily because every circle track racer uses them. My only gripe with them is that ingress and egress are a pain in the ass for me because of the massive amounts of support they offer. This is the only reason that I am considering a few other seat choices for my car because it is my DD.

IMO a kirkey must be mounted on sliders. My seating position makes it really damn hard to get in the car, even with taking the wheel off, if I forget to put the seat back. Basically my seating position is as far forward as the sliders go. I'm still trying to figure out a good side mount slider system so I can mount the seat lower.

Yeah the vinyl-only kind of put me off. And the cloth seat covers (for other seats) are really expensive.

I just looked at the economy seats and I am not a fan. I like the 4100 series so much better. Yes they are more expensive but have you looked at the covers? There is a reason they are more expensive. Too be honest <$300 dollars a seat with shipping is cheap for a good seat.

http://www.summitracing.com/parts/kir-41700/overview/

http://www.summitracing.com/parts/kir-41711

the 4100 would certainly make for an easier daily driver seat but I've sat in both, the economy with the big rib breakers holds you in a lot better.

They may hold you in better but is it necessary to do so? Sixshooter took me around Sebring with Hoosier's on the car and with harnesses on I do not see why I would need more support. You never move in the seat as it is. The extra bolster would just hit my elbows and piss me off. If I was going to go above a 4100 series I would just get a full containment seat for racing.

Well its really nice to be able to remove the stock seat belt retractors and just run cheap adjustable lap belts (2 point harness lol) and still be very supported. So much weight reduction. I still have stock belts in my car to maintain the illusion of being a street car. But honestly, when I jump in the car to go test drive it I forget to put the seat belt on because the seat holds me in so well (and its not illegal because live free or die mother fuckers).

I like to wear my seatbelt because it stops me from going through the windshield. The 2 points sound like they could cause some serious bodily injury if you crash, especially if you have a no airbag after market wheel.

But who crashes at auto-x?

I thought they would be uncomfortable as hell just looking at them because the frames were metal, but they are much, much better than stock. I love them.

4100 series

Super true. But the OP will likely have trouble finding the big boy seats in stock in a showroom.
Mine are actually 16" size and not 17". There is plenty of room for the 18" and probably larger.

You should be able to run a tape measure across the floorboard and know for sure how much room there is. The seats are only as wide as that width number indicates. Then you can set two cinderblocks or something similar on the ground then sit between them and wedge your hips and ass between them nice and snug. Then get up and measure that distance between the blocks and you will know what size Kirkeys you need. It is that simple.

And if you ever want a little more padding for an 8 hour trip, you can put a little of the cheap foam rubber padding (anti-fatigue floor mat) under the factory padding to make it like a sofa.

From flying economy class transatlantic I already know, that I can squeeze my behind between two armrests that are 17" apart. I'm NOT enjoying it, but it can be done. Even for 8 hours.

I think I saw some 19" wide Kirkeys. That should definitely fit my bottom. I'll measure my floor pan and see if it will drop in.

Any thoughts on the Corbeau FX1 "wide"? That looks like my backside might slide right in.

How does it compare width wise to the Corbeau Forza? I picked up a pair of Forza's used because a friend gave me a deal on them, but it took quite a bit a tunnel bashing on the driver side to make them kind of fit.

https://www.miataturbo.net/attachmen...ine=1371769073
https://www.miataturbo.net/attachmen...ine=1371769073

Looks like the Forza and the FX1 wide are very similar.
Which part of the seat was too wide? Front or rear?

The front, I also used Corbeau sliders to make life easy (I suck at fabbing stuff and don't have the tools either).

At 5'8" I'm close to the wheel and tunnel near the shifter needed a good bashing and the wing digs into the door. Even on the passenger side where I have the seat "permanently" set all the way back.

That particular Kirkey series is available in widths from 15-20 inches.

The Kirkey Intermediate Road Race seat with the shoulders is very nice and comfy. Also, consider the Ultrashield Rally Sport if you want a lower bolster seat.

jump to :35

Curious if any of you guys have tried or have opinions on the dual density (aka "dual durometer") roll bar padding, discussed on Roll Bar Padding: SFI vs. non-SFI: Grassroots Motorsports forum: Grassroots Motorsports Magazine and recommended by Keith Tanner (Flyin' Miata) in his "How to Build a High-Performance Mazda Miata MX-5." Apparently it is what he uses.

As far as I can tell, it is only made by BSCI but available through a number of dealers:

Safe Drives -

Dual Durometer Rollbar Padding, SFI rollbar padding

https://www.pegasusautoracing.com/gr...roupID=ROLLPAD

and many others. Oddly, Flyin' Miata (and the other usual Miata parts dealers) don't seem to carry it.

With this, the inner layer (next to the bar) is SFI rated for maximum protection, while the outer layer is softer but still pretty firm. The idea is that SFI padding is intended for use with helmets and can be pretty hard on an unhelmeted head (or other body parts when used on door bars, etc), so the (removable) outer softer layer acts as a cushion to the inner SFI layer. For cars used on both street & track the softer outer layer can be removed when the car is on the track (and the driver is wearing a helmet) but put in place when the car is on the street.

The downsides seems to be that this padding is bulkier than usual and is somewhat more expensive. I also have not seen any covers that will fit this, but that seems a pretty minor concern.

If this works as advertised, it may go a long way to answering the problem of smacking your unhelmeted head on the roll bar (bad with SFI padding, worse without), especially if/when rearended (which just happened to me a few weeks ago, luckily at a fairly low speed).

Bill

I love my harddog ace. Sits further back so I don't bash my head and doesn't mess up the stock seat belts.