GoodfellaFD3S

iTrader: (213)

My BB '95 FD is primarily a street car, with the possibility of a few track days per year.

My Raceshop Rollbar already kept me out of the hospital when I totalled my VR R1 on track, and it's since been installed in another car temporarily. Fits perfectly, no bends and no cracks. Needless to say, it's a very well made piece.

Anyway, I'm wondering about the wisdom in installing it in my 95 FD. I plan to run stock seats with oem seatbelts..... I'd like informed and intelligent opinions on the danger to both driver and passenger in the event of an accident on the street. Ie, head hitting the top of the bar etc.

In general I feel it's pretty safe, and am pondering some buckets such as Bride or Recaro that will sit the occupants lower in the car and thus spacing my brain bucket away from the bar

P.S. This is just the rear bar, no main hoop etc.

ptrhahn

iTrader: (9)

Get some good quality roll bar padding:

BSCI DUAL DUROMETER SFI RATED ROLL BAR PADDING

Howard Coleman

iTrader: (6)

while your cage saved you on track i would be very careful running it on the street. currently mine is in my car but it is up on jackstands til it either is on the dyno or is at the March Texas Mile. fyi my race seat which i love does sit me really low and w race belts does keep my head off the hoop.

what concerns me is you can get hit from all angles on the street and your body does move around a bunch. you absolutely do not want your head to hit the bar w any kind of durometer padding. OEM belts and stock seats do not really plaster you in so you are an immovable object as proper racebelts and seat do.

i will be removing my cage for street use.

howard

Mahjik

iTrader: (1)

With padding, I would not be concerned with a rollbar on the street. A cage is a different story and even with padding, I don't recommend a cage on the street.

turbojeff

iTrader: (30)

Well I'm not a crash expert but I've seen a lot of those NTHSA crash videos (and dash cam crashes) to day that you can move all over the place in a crash. Having hard things inside the car doesn't seem good on the street.

gracer7-rx7

iTrader: (16)

I generally don't feel very good about the concept of a rollbar in a typical street car but I'd say that it depends on how it is setup.


First, the bar itself needs to be pretty far away from your unhelmeted head. Even with SFI padding, it's going to hurt if your unhelmeted head makes contact with the padded bar. I hit my HELMETED head against the SFI padded downtube bar in my Spec Miata on a bad off and I FELT it.

Second, I think you need a seat that won't break and allow your back and head to make contact with the roll bar if you go off rear first. I remember reading about a Porsche 911 driver being killed a couple of years ago when he went off at Lime Rock back end first. I understand the seat slider broke and the seat made contact with the roll bar and the guy broke his back or something. A bit hear-say but something to think about.

Third, you still need to use 3 point belts in a street environment. 4, 5 and 6 point harnesses that hold our torso in place require a Head and Neck restraint system or you'll wind up over extending your neck like Dale. Use the 4,5, 6 points with a HNR and helmet on track.


The only car out there that adds a roll bar to a street car is the Porsche GT3 iirc. Check out the measures they took to ensure safety and model after that.

ptrhahn

iTrader: (9)

All points well made, but the reality is, my track car and my street car are the same car, and are always likely to be so given my means, where I live, etc., so if I'm to balance the risks: Having a padded roll-bar in my street car, vs. not having anything in my track car, I'll take the roll bar any day of the week. It's actually hard to believe how long I tracked the car, and how fast I was going, without it.

Fritz Flynn

iTrader: (263)

NO WAY NO HOW with stock seats. They are designed to absorb impact or flatten out so if you hit something at a high speed in reverse or someone rear ends you your head would likely hit the roll bar.

I'd advise a low race seat on quality rails and keep the bag in the wheel

Mps_hell

... The same cage as in the one out of the crashed car? I would be getting that X-rayed for a start.
Also I wouldn't get in a car with a cage and stock seats and belts. They don't stop you moving around like others are saying

ArmitageGVR4

iTrader: (13)

It really comes down to how much risk you're willing to accept. How many miles do you plan to put on the car on the street? 1k a year? 20k a year? How much head-to-roll bar clearance do you have when sitting in your seats with no helmet on? Would your head come anywhere near the bar during transition following a bracket or seat-back failure (fully pushed back and fully reclined)? In a crash that causes the car to move vertically, all bets are off anyway. You'd be better off getting into a wreck in something modern with side curtain airbags and modern crumple zones then you are a 20+ year old sports car, roll bar notwithstanding :P

SA3R

Here in Australia it is an offence (get the car confiscated from you, in my particular state) if they pull you over and you have any sort of roll cage or bars inside the car. Its entirely illegal.

The last time I had an issue with this, the officer who pulled me over, tried to tell me that the rear factory shock tower brace was a roll bar, and have the car defected and taken away. I had to prove to him that the rear strut tower brace was factory fitted. I was let off with a caution.

It never ceases to amaze me how much you guys are allowed to get away with running on the street legally in the USA. Rollcages legal on the street.... Well I never....! :p

elwood

iTrader: (1)

Most cars from the '90s and earlier don't perform very well when dropped on their roof. I did work in crash development for a few years at a major OEM, and the results of rollovers in older cars were pretty sobering. For that reason, I have a rollbar in my car. My seats are SFI race buckets that are directly mounted to the floor without sliders, with under-car reinforcement so they will stay attached (hopefully). I also use a 5-point harness.

As for a rear impact -- it's an interesting problem. As one poster indicated, an OEM seatback will go flat with a hard enough crash. I'm sure this is true. We didn't honestly do much development on seatback integrity during rear crashes. We were primarily concerned with making sure the fuel tank didn't leak (FMVSS requirement).

If you have an OEM bucket and the seatback does go flat, it can't be good. I picture the occupant no longer restrained, shooting out of the seat like a projectile, through the rear hatch, into the thing that made the car decelerate. Very bad.

The horizontal and diagonal bars in the main hoop of a properly made rollbar will stop the seat from going flat and keep the occupant in the passenger compartment. If there's a concern with the headform hitting the rollbar in some combination of upward and sideways motion, I say pad the rollbar and you'll be better off with it than without it.

If you want another example of a vehicle with bars inside the pass compartment besides Porsche, look at a Jeep Wrangler. Major OEM; significant volume.

Just because OEMs don't do it doesn't make it a bad idea: Vehicle OEMs are creatures of habit who want to avoid risk and make money. A rollbar isn't common, it's potentially risky because everybody else doesn't do it (Wrangler gets a pass because it's an icon that has had one for decades), and it would cost a vehicle OEM extra money to put one in a production car (not conducive to the typical stamped and spot-welded assembly process).

gracer7-rx7

iTrader: (16)

Back when my friends and i are were younger dumber and full of **** n vinegar circa 1990, we were screwing around on the street. A fully done, big turbo 87 FC Turbo II against another fully prepped big turbo car. Doing about 110-120 on a 4 lane road with a long curve. My friend in front of me in the FC broke something on the fully loaded rear suspension in the middle of the curve. FC started spinning, broke a telephone post in half moving it over 6' started rolling, first end over end and then barrel rolling. We were feet away from his car the whole time he was rolling and spinning trying not to get taken out. 1/4 later, it came to a stop. B pillars were fine. A pillars slightly flattened. He walked away.

Lucky ******.

The FC is pretty well built. I've never seen an FD roll but I hope it is as robust.

On track, it is nice to have that extra safety net. Never know what's going to happen but you need to think about it as a safety 'system' including roll bar, seat, harnesses, helmet, HNR.

Sgtblue

iTrader: (16)

Hoping to get back into autocross in the future and wanted to use a harness for better retention in the seat. Reading through the thread I'm feeling good about picking up an old M2 rear tower brace for it, rather than a rollbar I had a line on. I honestly hadn't considered the dangers of a rollbar for a street car with stock seats. Mind you, I only autocross.... no track.

turbodrx7

iTrader: (43)

Isnt there an issue having that much length between the mounting point for the harness and the seat? Because its so long to the back harness bar, it can leave slack in the harness and lead to submarining I believe? Someone with more knowledge should chime in on that. Ive always been curious but never asked.


-Austin

Mahjik

iTrader: (1)

Submarining is more from improperly mounted front straps. The longer the shoulder straps to the harness bar, the more tension the straps need to support, but IMO that's the least of the worries. You simply cannot properly hook-up a 5 or 6 point harness with the stock seats. For AutoX, it's not so much of an issue since you are mainly just looking for additional support being held in the seat. For the track (which I have done), it can be dangerous as the straps will not work properly in an accident.


Food for thought. Most track organizations require convertibles to have rollover protection. Only the upper end convertibles (like the Boxster) come with pop-up bars which are allowed to be used. With that, a lot of Miata's and S2000's have rollbars installed so they can track their cars. They all drive them all over the town without issues. While I won't say I've heard every story, but I haven't heard/read stories about accidents where a driver got injured from having a rollbar installed. I'm sure we all sat in front of our computers/tablets long enough, we can come up with all sorts of possible scenarios.....

Tem120

iTrader: (5)

its very common for people who have those weak aesthetic looking roll bars get hurt , and in a miata is pretty much a given that when you have a rollbar you pad it .

Mahjik

iTrader: (1)

Are assuming or are you going to provide some data?

To be honest, for track day cars, padding isn't required and I rarely see the track day Miatas with it. For competition cars, padding is required and those drivers will have it (as it's enforced). All rollbars should have it regardless if it's enforced or not....

Tem120

iTrader: (5)

When I get home i'll put some data up , This is the cheap half assed style bars that people put on for looks rather then actual safety .

Tem120

iTrader: (5)

hey there's a bar where your head used to be! .

there are just asmany crappy half assed bars that make things worse these are much cheaper , and quite common .

Tem120

iTrader: (5)

When you're in a track day you have a helmet helmet is supposed to protect your head from the bar .

for a street car where your head is prettymuch bare the soft foamy stuff comes in handy specially if you are a taller person whos head goes over the OEM seats which isn't a hard thing to do .

RENESISFD

iTrader: (13)

Lol at the miata a pic,

Are you seriously implying that the driver would be better off without that bar in place?

An impact like that to bend the bar would surely snap your neck anyway.

Imo, roll bar is better than no bar.

Mahjik

iTrader: (1)

No sh*t... You are saying exactly what others are saying, that padding should be used. Again, I'm talking about real rollover bars (like the photo above), not the crap that "looks like" protection... And Goodfellas is referring to his Raceshop Rollbar which is about as real as it gets.


However, SFI rated padding is not soft. It's still designed to be used with a helmet.

Tem120

iTrader: (5)

Yes , that is not a true rollbar its a stylebar alot of miata owners put on their car

point is do it right

otherwise its more of a danger then a safety .

Tem120

iTrader: (5)

LoL , I'm with the Roll bars are good crowd , but I'm also for the using the foam stuff .

And i only said that because most miatas with what are sold as roll bars , are cheap crappy style bars that dont do anything but make things worse LOL

if I were goodfella I'd definitely use it the raceshop bar.