Street, Auto-X, track, which roll bar?
 

This weekend I attended the EVO Auto-X school in NJ. It was a present, I wasn't sure, if I'd like it, but I went.
So: I quite liked it. It was fun throwing the Miata around a short track.

Car: 99 NB FM2-ish turbo setup with a bit of suspension, wheels and tires.

Future: I'm not sure if I want to Auto-X for a long time. All the standing around, shooting the breeze may get boring after a while. So I would like to only make investments that make sense for the track and Auto-X. Both non-competitive.

And the first investments are in safety. Seems I need a roll bar and a helmet. Helmet appears easy. It has to be Snell2010, open face and affordable.

It gets trickier with the roll bar. I am NOT sure if a turbo-Miata needs a roll bar or not for regular old Auto-X. The information found online is contradictory. One of the instructors at the EVO school was an old pro and part-time steward and even he wasn't quite certain. I am pretty sure that a turbo Miata runs in SSM. But does SSM require a roll-bar?

Also, if I want to track later on, can I use the same roll-bar?

The application guide for the hard dog bars seems quite definitive. So according to that if I go with an ACE or an M2 Hardcore HT I should be OK. I know that for tracking you want a hardtop, so the regular Hardcore M2 is out. If I don't need the bar for Auto-X, then for track the Deuce also seems to be OK. It would give the most clearance, but it looks wrong....

Now the complicating facts: At 300lbs and 6' I just kill the power/weight ratio. I'm also sitting all the way back with the back-rest on the stock seat forward just one notch from all the way back. My head clears the soft-top comfortably. With a helmet on I pretty much touch the soft-top.

Which roll bar will not generate unattractive lumps on my head while I'm driving on the street and still allow me to do all the fun things I want to do?

Thanks,

ST

And thanks for all the diet-suggestions that I'm sure will be coming forth!

You don't need a rollbar at any autocross I go to (or heard of it).

Hard dog and Boss frog both have rollbars which are "track legal". Basically you can find out which ones from googling it. I doubt an AX will ask you for anything more than that, so its safe to say you can use the same rollbar in autocross as the track.

Roll bars on the street are a bit more "dangerous". I put that in quotes because I think with proper padding its not a big deal. Since you are big guy, you will want to either get new seats and floor mount them or do a foamectomy (google it). If you get new seats you won't have to worry about hitting your head on the bar as most seats are taller and would make it pretty much impossible. That doesn't mean you shouldn't get the padding through (SFI is good for a helmet, but you may want to get something softer to put on top of that for when you drive the car without a helmet)

I have a hard dog xtreme. I like it, but when I had my soft top, the frane rubbed the sides of it when I put it up or down. Seat belts also don't retract like they used to. I'd recommend, I think it's called the "hard core"?

Every track I've been to has required a helmet and roll bar. And they check it.

I'm 6'2" and my head hits the Hard Dog bar over stock seats. It's not my DD so I don't care.

After seeing the above post I wanted to add that my bar does not interfere with the seats unless I try to recline it way back.

Thanks!

Which leads me right to the next question then: If I get a new seat, is there one that will somewhat comfortably fit my size 46 mid-section? I love the Elise seats and it looks like I could ride in them no problem. But the price....

My roll bar came with the car, but I'm ~60% sure it's a M2 HC HT. At 5'10" I wouldn't have passed a 'broomstick' test before I did a foamectomy. So if you haven't done that yet, that is step #1. If that doesn't help, bolt the seats to the floor/get new seats to bolt to the floor.

To be fair, the padding is still designed for helmeted heads.

I occasionally drive mine on the street, but I also have fixed backs and harnesses.

Should fit in the kirkey fat boy seat, not sure if it will fit in a miata though. No roll bar in SSM, they're too heavy anyways.

I missed the 300# part of the first post. You will not fit comfortably in racing seats. I have a Jeep that has Corbeau racing seats with big bolsters high and low. I'm a workout guy and while my butt and waist fit fine, my upper back is squished. My dad is the opposite. His love handles get pushed hard by the bolsters and he doesn't like off road adventures with me. You might be able to get a more comfortable seat from a different car and use some universal brackets to mount it in.

Preliminary conclusion is then: Stick with Autocross for now. No roll bar. Buy a good helmet and sit in other people's Miatas with roll bar and seats to see if anything fits. I should meet some more Miatas at the events I'm sure!

I've got a Hard Dog Sport, it's good for open track days but not legal for sanctioned road racing. It is lower and farther back than the Hard Core bars so it's a little more daily friendly.

I have a HD HC DD HT (Hard Dog, Hard Core, Double Diagonal, Hard Top)
1. Padding is for a helmeted head. I got the padding too.
2. For me the stock seat was not tall enough to keep my head from hitting the bar if I was rear-ended on the street.
3. I like having a seat with higher bolsters and a 5 point harness for AutoX. I can have soft hands as I don't have to hold myself into the seat.

I did the EVO class a few years ago in KS. I'll do it again if I have that weekend free. I learned a lot and it was lots of fun.

I do also, thats why I never worry about it. I do see a number of guys on track though with pool noodles around their bars (and some use the SFI stuff under it).

revlimitr hit his head on the SFI stuff and got a concussion. certainly better than a cracked skull.



OP: as for comfy seats, that's almost an oxymoron really. I mean more expensive seats are more comfy, but you will have to do some reading. I think corbeau makes some wide versions of their seats, but there is no guarantee that will be an easy fit. Its safe to say if you want a comfy+FIA you will be dishing out big bucks AND spending some time on the fitting. You will have to bang the shit out of the trans tunnel, or even cut it in some cases (look at blackbird fabworx for examples, I think other cars on here have the trans tunnel cut). You will just have to do measuring and asking to figure out what needs to be done.

Comfy + fia is $$$ but comfy + good enough for crashing into the wall on saturday night at your local 1/3 mile circle thats pretty cheap money assuming you have the correct proportions. I still stand that the kirkey seats are the most comfortable automobile seats I've ever sat in, excluding the back seat of the old man edition caprice, that was like sitting on a nice couch.

Hard Dog are the most popular rollbars for Miatas for a reason -- they're well made and offer about as much as you can expect to get with a bolt-in rollbar.

If you want to run your car in SSM, it does not require a rollbar. If you want to run it in XP or DM/EM, then it does. You're unlikely to need to run XP or DM/EM unless you gut the interior or add the FM frame rails. As for the seat time question -- look around at the various clubs in your area, and you might well find one that offers more runs during the day than the 3 or 4 that most SCCA clubs do.

For a helmet in an open car, you probably want a closed-face model.

As for seats, you will get the most space if you cut out the rear seat mount from the unibody, weld in flat metal to cover it, and bolt the seat to the floor. Yes, it becomes hard for short people to drive your car, and yes, it's a mod that's hard to reverse. I had a well-known local race fab shop (TC Design) do this to my car, and it was well worth those compromises.

I have Recaro Pole Positions in my car. They're not cheap, but they're FIA, they fit well and are very comfortable. No tranny tunnel mods required to get them to fit, although they have made small dents in the interior door covers. They're set up so that I can use the factory belt on the street and the 6-point harness on autox/track.

--Ian

Track != 1/3 mile circle. I would have to say when someone says I plan to track my car, I generally assume a road course. Maybe my fault there...

You don't have to buy FIA, it was just a bit of advice on what to expect when seat shopping. And Kirkeys aren't comfortable at all. I don't think they are bad really, but I wouldn't say comfortable.

You just have to meet the rules of the governing body. If the seat is good enough for slamming into a concrete wall 0feet off the side of the pavement @100mph then being t boned 3 or 4 times by other people doing 100mph then rolling over a few times. I dont really care if it has an FIA cert or not.

Kirkeys are all about body type. If they fit you like a glove you dont even notice there is a seat there its like being hugged by a beautiful (but flat chested) women. Just dont slouch or the rib breakers dig into your arm pits.

+1

I have sat in sixshooter's seats multiple times now and those things are so form fitting and supportive that If I tilted it back a bit more I could probably fall asleep in it.

Which Kirkey seats do people normally use?

Seats - I'm also a 46", I have the Marrad seat. (There's a long thread on it)
My problem: to find a seat that fits me and a Miata.

It's a compromise seat, between the stock seat and a full race seat.
1. The bolsters are lower than a race seat, and with all the padding, it's daily drive-able. But a 9 hour trip requires lots of stretch breaks.
2. It has holes for 5 point harness.
3. Without the padding, it gets my head below the roll bar.
4. It's bolt in with no trans tunnel modifications.

It's on sliders and is expensive, but around the same price as a Sparco Evo 2, Planted base and Sparco sliders. The bottom of the seat is below and between the sliders.
With seats it's best to try it before buying.

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.

The dual-density foam is still incredibly stiff. Regardless of the foam, I would still only drive with a roll bar if the car also had fixed-back seats and harnesses.

To me, these three safety items are an all or none proposition. I'm coming it at from an open track/HPDE view point (but I do still occasionally drive my car on the street), so the Auto-X guys may view it differently.

I've also been banged up on track before (granted on two wheels, but it still wasn't fun), so safety is something I take very seriously. In fact, I've decided to skip this season to prep the car for TT and buy a HANS.

These are good points. At the very least a roll bar should be accompanied by a fixed back seat. And the 5 or 6 point harness makes sense to go with it since having a roll bar allows you to safely run a harness.

And on the other safety. If I ever got pulled into HPDE/TT/something something on a track, an ISSAC Link would be my first purchase, unless I could afford a classic ISSAC.

Good points, but in reality they are unlikely to be followed by very many Miata drivers. Even so, there are still good arguments for having a (proper) roll bar in a street car even without a fixed seatback/harness, not least that Miatas are sometimes driven in a manner and place -- think "spirited" driving on twisty roads :nono: -- that increases the probability of their rolling or flipping.

Given that improved roll over protection comes at the cost of increased risk of head bonking (a technical term that refers to the range between glancing blow and bone crushing impact, inclusive), and the available choices of roll bar padding (starting with "none"), how does the dual density padding compare to the less expensive alternatives (including SFI padding with a noodle or other softer padding over it)? Should the dual density padding get a third layer of yet softer padding (think how bulky that would be :eek: )?

Since it is essentially impossible to eliminate all risk, safety is often a matter of trying to balance the probable effects of various risks that reasonably may come into play against the costs of the means to protect against them.

Bill

the lower duro stuff doesn't look thick enough. If you think about it, its like a 1/2 of thickness vs 1.5"-2" on a noodle or the sort. The idea is to get something soft with plenty of compression available before the hard stuff.

This is a purely speculative view point from the pictures. I would try to google about it and see if there is any test data available (or data from a wreck even).

I think the "softer" layer of the dual durometer padding is not very soft -- only softer than the SFI layer. So it may make up in density what it lacks in thickness. The usual claim for it is that while hitting body parts on standard SFI padding (like the inner layer) may cause bruising, hitting them on the "softer" outer layer is unlikely to.

Here is another alternative -- "Orange+Aid" (see: Orange Aid SFI Approved Roll Cage Padding ). It is supposed to be softer than the dual durometer padding, but still SFI certified. A lot of people seem to be using it for cages and say it is easier to bend than any of the more common SFI padding sticks (which often break when bent). It seem to be be less bulky than the dual durometer padding. Unfortunately, it only comes in orange (large amounts can be special ordered in black) and is priced about double the dual durometer cost (so about $60 per 3-ft stick). But it does seem to fit under the usual padding covers, so the color can be hidden.

I've been unable to find any comparison between the dual durometer padding and the Orange+Aid padding, other than some comments about the Orange+Aid being softer (when pressed, not in an accident) than the dual durometer padding (and any regular SFI padding) and easier to install because it is more flexible.

There is also some SFI padding from USI which is suppsed to be softer, but I can find very little information about it except from the manufacturer (see: Polyurethane Roll Bar Pads Orange County | Rollbar Padding Los Angeles ). Unlike the other two, which seem to be widely used and recommended, there seems to be very little discussion about using this padding.

Bill

I didn't see what SFI certification it got on the website, which is really suspicious (not imply anything, just sayin'). SFI certifications apply to many aspects of racing and safety. Seat belts have a different certifications than roll bar padding. Different certifications are also available for padding, so "SFI certified" is vague here.

Anyways, you need to check with your track/club. The majority of clubs don't require SFI certified padding for the most part (although, its highly recommended). My experience says NASA doesn't require SFI certified for DE and TT (I don't know about racing and thats as of 2011 rules in the Southeast). This forum thread corroborates that.

Personally, I would steer away from dual stuff. Seems like a lot of expensive, for not much more function. Get a pool noodle or equivalent if you drive in the car without a helmet.

It's 45.1 - they don't say it, but if you read the specs you can see that is matches what is defined here: http://www.sfifoundation.com/Spec_45.1_081105.pdf

In the photos of the product on the website, you can see the "SFI 45.1" marking molded into the surface of the padding. I believe this is an SFI requirement to make it easy to identify compliant padding, but maybe not.

I know in the past there has been discussion of some vendors selling the common "black" SFI 45.1 padding also selling what was said to be "the same padding" but without the SFI 45.1 markings at lower cost (I guess the lower cost was due to not having to have the padding certified?).

I am more and more leaning towards the Orange+Aid. It is expensive, but I won't need all that much (2 sticks max, maybe only 1 stick) so the actual cost will be acceptable. Of course, I need to figure in the cost of covering up all that orange! Or maybe the color will grow on me. :2cents:

Bill