Track legal roll bar for HPR & PMP?

[roninsoldier83]

For the guys that regularly track their Miata's:

I'm looking for a roll bar that will get my car past tech at High Plains Raceway & Pueblo Motorsports Park, so I can get out and start racing! As I understand it, HPR seems to be ok with the [small] double hoops that Honda S2000's come with from the factory. Can I also get away with a double hoop design? More specifically, I was looking at the Boss Frog Double Hoop, as I read it was the only double hoop approved by the SCCA.

For reference, the car will really only see the occasional HPDE track day & autoX (i.e. it will still be street driven & will never be a full blown track rat).

Also, do either one of them do the "broomstick test"? If so, I suppose new seats would eventually be in order

Thanks guys!

-Brandon

EDIT: After doing more research on the topic, I've deducted a quick list of my personal priorities:

-The car will remain primarily a street car with only the occasional lapping day and autoX. As such, I'm more concerned with hitting my head in a collision on the street than I am rolling the car.
-I would like the roll bar to work with the OEM glass top. If it works with a hardtop as well, that's even better.
-Because the car will primarily be a street car, available padding for the bar is a plus.
-I would prefer it work with the factory wind blocker, but if not, an aftermarket unit will be sufficient. Although I'm pretty sure the vast majority of roll bars do not work with the OEM wind blocker.

[Saul_Good]

I have the Boss Frog double diagonal with optional harness bar. For track lapping days there is no broomstick test, they just look to see if you have a rollbar -- but like Huzer told me, it's best to make sure the rollbar does the work in an unfortunate roll rather than your head.

For autox, a rollbar is not necessary (at least for me in STR). In fact they look at it as more weight.

I've done a couple NASA events and although they never broomstick tested me during tech, doesn't mean they wouldn't do it the next time around.

My suggestion is to get a harness bar and harness with it to be sure you're strapped down, otherwise in a roll a stock seatbelt might not hold u in place (when you're upside-down portion of the roll) like a good harness. My 2cents on that.

Hope that helps.

[D Walker]

If your going racing, have a cage built, none of the off the shelf cages are that awesome, IMHO. But then, I build cages...

In a miata, get a hardtop and forget the broomstick test.

For trackdays just get a rollbar built, I do those too.

[roninsoldier83]

Thanks for the info guys!

Quick question: on the older NA & NB Miata's, does adding a roll bar increase chassis rigidity by any real perceivable amount? Is it something you can actually feel while driving?

I'm just curious. Thanks again.

[roninsoldier83]

I've been doing a good amount of reading on roll bars over the past few days and have decided that I have a few priorities:

-The car will remain primarily a street car with only the occasional lapping day and autoX. As such, I'm more concerned with hitting my head in a collision on the street than I am rolling the car.
-I would like the roll bar to work with the OEM glass top. If it works with a hardtop as well, that's even better.
-Because the car will primarily be a street car, available padding for the bar is a plus.
-I would prefer it work with the factory wind blocker, but if not, an aftermarket unit will be sufficient. Although I'm pretty sure the vast majority of roll bars do not work with the OEM wind blocker.

As such, I think I've decided on the route I'm planning on taking. I think I'm going to eventually get the Hard Dog ACE roll bar:
http://www.bethania-garage.com/ace.htm

It sits further back behind the seats and a tad bit lower than most of the other bars. Not the best bar for the broomstick test, but certainly one of the better choices for a street car that only sees occasional open lapping day & autoX use. With the higher '01+ seats I can't hardly see myself hurting my head on it in a collision. I'm definitely going to order it with the harness bar and am undecided about diagonals at this point.

The way I see it, if I decide I want to start attending organized events that require the broomstick test, I can just get a hardtop that will also fit with the HD ACE bar and remove the hardtop for normal street driving.

I've seen a couple of wind blockers that seem to work with harness bars as well that I'll probably pickup. Unless anyone has a better suggestion, it'll likely be the one from Project G:
http://www.projectgla.com/windblocker_na.html

Eventually the car will also likely get seats that sit a bit lower than stock as well. Or maybe just a foamectomy of the stockers. Any recommendations for seats that sit significantly lower than stock but still maintain a fairly high headrest like the OEM '01+ seats?

Again, after thinking about it a good bit, I would like to be able to pass the broomstick test with the HD ACE bar- which would be tough since it's a fairly low bar- but the reality is, I'm more concerned with street safety.

Thoughts?

[Justin]

You're right to be concerned about the possibility of a head injury with a roll bar on the street. What about something that you just bolt in for track days? I'm not super familiar with the Miata shell, but it seems like you could tack weld a plate or some bolts on the underside of the mounting point and have a bar that could be added or deleted very easily. I could easily make you a backing plate, and, depending on how easy access is, may be able to weld it on for you.

[D Walker]

bolt-in= bad. I do not approve of bolt-in cages or roll bars in cars that weigh over 2000lbs.

The HD unit is nice, but you might want to consider having a custom bar made by someone like myself, there are several people in town that can do a great job of this.

In a rollbar for the street I would not be very concerned about the possibility of banging your head against it UNLESS you do not wear your seatbelt, I would be much more concerned with the rollbar failing because its a "show bar" than banging my head against it. A cage is an entirely different matter, and really are not safe for street driving.

Also FWIW, an ex-gf of mine put a Miata on its lid (softtop) at 75mph, slid across a median and into a barrier, walked away with a bruise on her hip from the seatbelt. The windsheild frame is VERY strong and with a good rollbar in place (preferably welded) I would feel very safe in a miata on track.

[roninsoldier83]

bolt-in= bad. I do not approve of bolt-in cages or roll bars in cars that weigh over 2000lbs.

The HD unit is nice, but you might want to consider having a custom bar made by someone like myself, there are several people in town that can do a great job of this.

In a rollbar for the street I would not be very concerned about the possibility of banging your head against it UNLESS you do not wear your seatbelt, I would be much more concerned with the rollbar failing because its a "show bar" than banging my head against it. A cage is an entirely different matter, and really are not safe for street driving.

Also FWIW, an ex-gf of mine put a Miata on its lid (softtop) at 75mph, slid across a median and into a barrier, walked away with a bruise on her hip from the seatbelt. The windsheild frame is VERY strong and with a good rollbar in place (preferably welded) I would feel very safe in a miata on track.

By "bolt-in" I'm assuming you mean a bar that goes in and out easily? I would assume the bars from Hard Dog and Boss Frog would likely be sufficient? Did your ex-gf have a roll bar in her Miata?

After doing a bit more research, with the taller seats in my '04 MSM, I don't think I would worry much about banging my head with a couple of the bars on the market. Although I would likely still pad them just in case.

I've been scouring numerous forums over the last week or so, and I'm now actually leaning towards the Boss Frog Clearview Maxx (double diagonal) with a harness bar & their SFI padding. Huzer was kind enough to dig up a few pics of the HD sport/harddog, the HD ACE and the Boss Frog bars:





^^^The 3rd pic is of the Boss Frog bars. Interesting stuff...

I didn't realize that the Boss Frog Maxx measurements were that far back initially and still 1" higher than the HD ACE. It seems fairly close to ideal (well, for tall guys it will never be "ideal", but it's not bad for a primarily street driven car).

I was actually thinking to myself: "why doesn't Hard Dog make their ACE roll bar that high for extra clearance?" And after doing a bit of reading, I think I understand why: It appears that the ACE is made to work with both the soft-top and a hardtop. Whereas the Boss Frog claims the Clearview Maxx only fits under the soft-top (contrary to a few individual reports). So if a person was only planning on using the soft-top, the Boss Frog might be the best bar (welded in/custom jobs aside) since it sits almost as far back as the ACE, but is still as tall as the HD bars.

Boss Frog Clearview Maxx Pros:

-Sits almost as far back as HD ACE (28" vs 28.5").
-Taller than HD ACE, which makes it easier to get under bar (19" vs 18").
-Vision less obstructed vs double diagonal ACE due to separation of diagonal bars.

Cons:

-Not quite as far back as ACE (0.5" difference).
-Seatbelts will not retract as quickly due to placement of the mounts. ***Any comments from people running the BF Clearview Maxx bar?***
-Slightly higher cost (negligible IMO).
-According to Boss Frog, it will not work with hardtop (HD ACE will)- although I've seen several reports saying it works just fine (including Saul_Good's).


While I'm sure that welding a bar in is stronger, it seems as though the HD & BF bars hold up fairly well, based on the pictures I've seen of rolled Miata's online. I honestly like the idea of being able to revert the car to relatively stock specs (after plugging a couple holes & replacing minor interior trim) and being able to easily sell the bar if need be (i.e. I decide to sell the car, ect). I think that's something that would steer me away from a custom welded setup, as it seems it might be more difficult to recoup any of the cash I put into it (if needed). If the car was going to be a dedicated track car only I would have a different opinion, but since it also duals as a part time daily driver (that I might sell one day), the HD & BF bars are fairly appealing to me.

[D Walker]

The Miata did not have a rollbar when she totaled it, I mentioned it because I do not believe the bolt in roll bars are worth the trouble, the factory designed the car to be safe, and it is.

Bolt in bars cover all of them, HD etc., which again are a good product but would not be my recommendation. They are also tend to be extremely heavy and use ridiculously oversized tubing IIRC (I may not).

[Justin]

bolt-in= bad. I do not approve of bolt-in cages or roll bars in cars that weigh over 2000lbs.

I disagree. While a bolt-in bar held in only with bolts is bad, a properly bolted bar with a backing plate that is larger than the foot pad of the bar isn't.