Broom handle test in a miata

So, added a roll bar to the wife's Miata to be able to do some track days with a buddy of mine.

I didn't get the tallest Hard Dog bar - got the Ace, but it's supposedly SCCA Solo I approved.

I'm 5'9" and my buddy is 5'11" The only way to get his helmeted head lower than the roll bar was to mount the seats directly on the floor and against the rear bulkhead - and then it's just by the slimmest of margins.

I was quite surprised by this since I did some research before selecting the Ace, and saw pics of similar sized or taller folks below their bars with seats mounted to rails. Not the same style of bar, but other HardDog products look to be only about 1-1.5" taller, that's about what I think rails would add - so roughly net zero.

So, I considered maybe swapping to a different bar style - like the Hardcore Hardtop - but it looks like the seats would need to occupy the same space as the bar.

I'm not sure the point of this post - maybe informational to others - I don't think I can recommend the Ace bar to anyone looking to do track days (although certainly would recommend Hard Dog/Bethania Garage).

I don't know if the seats I have are just a really bad choice for a Miata install - they aren't very large. Anyone else run into this issue?

Pics:

http://i1084.photobucket.com/albums/j416/sevenracer52/Miata%20roll%20bar/IMG_2554.jpg

http://i1084.photobucket.com/albums/j416/sevenracer52/Miata%20roll%20bar/IMG_2555.jpg

http://i1084.photobucket.com/albums/j416/sevenracer52/Miata%20roll%20bar/IMG_2556.jpg

Holy cow that's low! My Hard Dog Sport M1 Hardtop has got to be around 2" higher than that and still fit the original vinyl window softtop and the Mazda hardtop.

According to Bethania's website, the Ace has measures 18" from the package shelf to the top of the bar. The Hard-Core Hardtop distance is 19".

I have the regular Hard-Core, which measures 20-1/4" from package shelf to the top of the bar. Fits fine under the hardtop, but I use bolt-in plates instead of the latches.

That looks VERY low. Like, maybe the lowest bar I've ever seen in a miata.

You need a bar that's as high as the soft top. That's more of a style bar.

It might be stout, but it definitely will do little in a roll over because your head's the highest point.

I have a similar, but older bar by BSP. The reason it's so low is because it sits much further back than any of the other bars, and needs to be that much lower to fit back there. The advantage to it being so far back is that you're less likely to smash your head on it in a collision.

I'd remove that and weld a box/spacer to the bottom and reinstall. That is just silly like it is.

Giant Purple Snorklewacker wrote: I'd remove that and weld a box/spacer to the bottom and reinstall. That is just silly like it is.

You could do that, but then neither the hard top nor the soft top would fit. It's very close as is.

Peter has it right. It's low because it is mounted further back. Raising it would interfere with the top. I thought this would be best for street driving - the further back part.

I'm disappointed because it is listed as solo I approved, so didn't expect it that low.

I guess my biggest question is do the other versions - hardcore or HC Hardtop- limit seat travel, cuz it looks like the seats would want to be where the roll bar would be. At least with the seats I have. And those don't look like a good option for street driving with stock seats and belts due to proximity to your head.

sevenracer wrote: I'm disappointed because it is listed as solo I approved, so didn't expect it that low.

There's a difference between "made with materials that meet solo 1 guidelines" and "you'd actually be able to get into an event with this".

Corbeau seats sit very high in the car, usually higher than the stock location. Try a Sparco.

Mcarp - Hard dog application guide lists it as compliant for Solo I and NASA HPDE, not "made with materials compliant". It does stipulate diagonal bracing required and harness bar recommended.

Chaparral - The seat cushions as mounted are much lower than the stock seat height - probably 2-3 inches lower. The "butt pocket" area (not the thigh support) of the seat is about 2.5" above the floor. I have an old Momo seat that is about 2.25" for the same measurement.

So, the real issue is the bar is too low, not the seats too high. Still wondering if anyone can comment on whether or not the different bars such as Hard Core or Hard Core HT limit aft seat travel - especially with aftermarket seats. The shoulder wings in particular look to be an interference point.

Thanks

The problem isn't the seat or the roll bar. It's the top of the windshield that's too low. Every Miata I've ever been in, the only way to see out is over the top of the windshield.

sevenracer wrote: So, the real issue is the bar is too low, not the seats too high. Still wondering if anyone can comment on whether or not the different bars such as Hard Core or Hard Core HT limit aft seat travel - especially with aftermarket seats. The shoulder wings in particular look to be an interference point.

This is the HCHT as far as I know (bought the car used). I don't know what model the Momo seat is, but it's mounted on sliders and it goes back more than far enough that I can drive the car comfortably. I'm 5'-10" but I prefer having the seat pretty far back in most cars that I drive.

I also have an identical race seat for the passenger side and neither really conflicts with the bar. The passenger seat is somehwat restricted because the ECM is located behind it.

I can take some pictures or measurements if you wish. The wings are beat up, but that's mostly from ingress/egress rather than hitting the bar.

That does look low to me. Here's my Miata with a Hard Dog bar (no diagonal) I installed soon after I bought it new (in 2001). It's seen lots of track days with no problem as far as tech is concerned. I'm 6' tall and the seats are stock. Raising/lowering top is "tight" but OK.

I had a different car (Sprite) where I added solid 1" aluminum lift blocks to raise the bar to a better height. Maybe you could do something like that?

Since you already have a bar, you could take some measurements and compare them to Hard Dog's application guide.

Could you post a picture of you in your car from the side with your helmet on?

If you like the bar, you might be "okay" even though your helmet is slightly above the bar.

From my understanding, the Ace is a bit lower than the hard core line bars.

Here's a pictureof me in my HDHCHT w/ Ultrashield hardmounted to the stock location. I'm 5'9"

In reply to grafmiata :

are the side latches the only reason why TDR says the non-hard top roll bar doesn't fit the hardtop? if that's the case, then I can deal with bolt-in plates