Harness bar instead of a rollbar???
 

I’ve been a long time track junkie and I’m looking to make my c8 track worthy. I’m a firm believer that a seat and harness takes a second off of your lap :)

That being said, I’m kinda shocked at the amount of people that run harness bars instead of roll bars…. I always thought that running a harness where your body, head and neck are in a fixed position could potentially be a fatal situation if the car rolls over. Is there something about vettes where they are much better reinforced and this isn’t a problem or what’s the deal?

Just trying to understand.

your logic us sound, but roll-overs are extremely rare in track-days. I've only seen 1 or 2 in 30 years of driving/instructing/racing . Nothing is going to make driving 170mph around a race track "safe", it's a choice to make driving more pleasant. I consider harness bars a comfort feature, not a safety feature.

I will be putting one in this winter to hold me in place while driving. I agree that a harness bar isn't safety, it is more "retention while driving"

Again I totally understand it’s about comfort and holding you in the seat but if you roll the car with just a harness bar the roof will crumple and your head and neck are held in place and you will likely die. I was just at VIR earlier this year and someone dropped fluid and my friend rolled her Clubsport. She is a de4 driver but a very very non aggressive de4 driver.

I just feel like for a couple hundred more the juice is worth the squeeze. Or lack of squeeze when the car is no longer shiny side up.

First off, is your C8 going to be a track only car or a double-duty hobby machine? Roll bars are a great safety addition BUT in a street driven vehicle with no helmet being worn a minor accident can turn into a life altering catastrophe if your skull makes contact with it. Track safety items can be a slippery slope. Containment seat? Air bag delete? Hans device? Fire suit? Fire suppression? The gm factory stuff is pretty good for hobbyist HPDE. Get above that level and you really need a well coordinated comprehensive safety ensemble. Keep in mind if you get a harness bar and belts those belts might not be DOT approved. Try explaining that to the other drivers insurance company in the event of an injury accident.
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Very fair. Mine is going to be nearly 100% track I guess I didn’t think about the non dedicated side.

this wasn't an issue in the Steel framed corvettes. The OEM hoops were nearly as strong as 1.75" cage tubing. If I had a C8 and tracked it, I might indeed add a roll-over hoop, it would be pretty easy to do in the engine bay (behind the glass).

You aren't getting a competition style roll bar for a "couple hundred more" dollars

I haven't yet made the commitment to cut my C8Z up and add a roll cage to make it a track-only car, but I do run track events and I use a Paragon harness bar to secure the shoulder harness - better than the single shoulder strap. In a roll-over I am more concerned about the strength of the A-pillar than the B-pillar, and the only way to fix that is a full cage - not a roll bar. Attaching a quality steel roll cage to an aluminum chassis is not for the faint of heart. If you look at the cut-aways of the C6, C7, and C8 below, it appears the C8 may have a little beefier B-pillar construction. Still not roll cage quality, but strong enough that I am not overly concerned about it collapsing other than a hard impact against something solid on the roof rather than a simple road course roll-over. I have been considering trying to fabricate a "back brace" to the factory aluminum hoop, similar to the way the C8R braces the roll bar hoop portion of the cage. That would add a lot of strength but would be a little complicated ($$$) and would require a different shaped rear glass.

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C6 Z06
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C7
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C8
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I would not place a lot of stock in 4pt bolt in 1/2 cages. 99% of those bolt-in to existing anchors never designed for that purpose. A 4pt rollover 1/2 cage supported and welded with proper pintle boxed in to the unibody or frame is a very different animal hence Farmer's statement of comfort statement. There is nothing harder to build than a "safe"dual use car.

No one has asked for my reasoning and because its the internet I'll give it freely.

I have a '07 z51. It is street and HPDE use (honestly driven to/on/from the track more miles than street). The stock seat is trash on track, I think everyone can agree there My left hinge on the factor seat broke at VIR in T5a. It scared the poop out of me and had the catch the car. I have the plan to drive the car with stock seat while doing street driving and toss the bucket in when going to the track. Harness bar will help hold me in place for what I'm doing. I have tons of work to do in my development path as a driver before I really care too much about speed/times. I look at lap times to measure progress (I love data). I would love for this to become a full blown track car (cage, fire supression, spherical bushings, gutted, etc) but that isn't a realistic opportunity. I also don't have a truck/trailer and don't want the hassle of renting both any time I want to drive to the track. It is much cheaper to buy a track prepped C5 than prep my C6.

Well you can... Here is a harness bar for 1k:
https://competitionmotorsport.com/pr...hoC6BcQAvD_BwE

Here is a full SCCA legal roll bar for 1500.
https://www.rpmrollbar.com/products/...-coupe-rollbar

Yes you can go cheaper or more expensive on both.

That’s pretty interesting how inexpensive the 4-pt bar is.

I wonder what it attaches to? I believe there are some rollbars for the c6z at least (by rpm?) that are nhra certified but don’t actually attach to the frame.

also, if you get the roll bar pictured, you’d still need the harness bar because the roll bar doesn’t have anything low enough to use as a proper mount for the shoulder straps of a harness.

It actually has an option to add the harness bar.

You don't just bolt a cage to an aluminum frame, and NASA and SCCA require very specific mounting provisions. Here is a quote from Trackspec regarding their cage for a C6Z Corvette, which had a hydroformed aluminum frame. The C8 will probably be even more complicated to develop a properly engineered solution due to its construction. The trick will be design of adequate mounting plates that have sufficient contact area and are fastened in a way that does not compromise the structural integrity of the factory frame structure. You don't just start drilling holes in a fabricated frame rail or other structural component without an analysis of the "unintended consequences".

From Trackspec: "ALUMINUM FRAME C6 Z06 Corvette Cage Kit The most comprehensive and installer friendly kit on the market. This cage kit is a collaboration of SPEC Corvette series drivers, engineers, and fabricators to produce not only the best fitting kit on the market, but one that can be easily installed as a DIY kit. The aluminum frame of the C6 Z06 Corvette makes caging these cars extremely expensive and labor intensive. We have seen many different shops cage these cars with most being questionable mounting methods at best. At Trackspec, we took an engineering and driver point of view and combined it with the latest in 3D scanning technology. By scanning the frame, we were able to engineer THE BEST SOLUTION ON THE MARKET. Our billet aluminum landing plates have the exact contours of the C6 Z frame and allow for a 100% contact patch for bonding and thru bolting to the frame as per NASA and SCCA specs. The billet plates then create a flat surface for you to land the cage on. This is an industry first and patent pending process."

I don't understand why people remark about a roll cage being lethal in a street car. I mean, I do understand what you are saying - but you can "pad" the bar in areas of concern. It's not like the hard plastic panels, which are mounted to sheetmetal, are going to be very forgiving on your noggin'. No, I do understand if the side curtain airbags are now ineffective because of that. BUT - you can wrap and pad/protect the bar above and beside your head.

All of the plastic pieces inside the car have been tested and developed with the passengers safety in mind. They are designed to give to soften the deceleration of the body part that hits it. They have been crash tested and passed DOT/NHSTA standards.

Rollbars add a solid surface to hit. A little bit of padding will help very little in a crash.

Agree. Have you ever ridden in a 1984 C4 Corvette with Z-51 suspension? It was known for bashing the driver's head against the roof frame just above the side window. I think I still have lumps on my head from those days.

boys that's a nice piece of ballast (in an already 3700lb car) that doubles as a steel head-rest. All of this is false sense of security.

If a car lands on its roof hard enough to crush the B-pillar, the occupants aren't going to magically bend their way to safety. That line of thinking might be intuitive but it doesn't seem realistic. The same forces that drove the chassis into the ground hard enough to crush the B-pillars are driving the occupants' bodies into the ground as well.

I have the dubious credentials of going upside down in a C7 at WGI. It was a slow speed roll over the car did not fly and “land” on its roof. One of the A pillars collapsed but the halo bar B pillar structure did not move one millimeter. I have a lot of faith in the B pillar structure at least on the C7. We repaired the car and I drive it today five years later. I had stock touring seats and belts. No injuries including my instructor passenger.

I have a harness bar in my C6 Z06. Is it a proper roll bar / cage? No. Do I run a HANS device with it? Yes. What's my logic? ANY crash that results in a rollover LIKELY initiated with a pretty hard HIT somewhere. Certainly at Mosport, where I usually run (not a lot of run-off, but certainly plenty of concrete walls within close proximity to the track surface).

In my simpleton opinion, if a crash occurs, the forces of impact are inevitable. And a HANS will help. Basal neck fracture is a real thing. However, despite the countless crashes I've witnessed (in real-time or immediate aftermath), I've yet to see a car on its roof. So I'm rolling the dice, willing to take my chances with the car gods, that in the event of, I'll stay on my feet, and have the (arguably minimal) protection of the harness & HANS. If I'm so unfortunate as to find myself upside down, well, I'll count my lucky stars regardless of cage/bar/nothing.

Also, I only run a 4-pt harness, just to give that one little "hope" of the submarine effect vs. anti-submarine provided by a 5-/6-pt harness. Again, it's maybe un-scientific, but I'm going with it!!

If money were no object, I'd have a dedicated track car and a dedicated street car. But I'm not. So I have a dual-duty car, as many people do. And I'm taking my chances, as many people do ;).

couple things. Containment is everything. It started with harnesses, the nascar bars, full containment seat. When harnesses went from stretchy nylon to no stretch polyester the basilar skull fracture increased…the next weak link. In came the wright device a bunch of straps, issac device a piston damper, R3 straps on a turtle shell, and the HANS the gold standard of head neck restraint.

the 4 pt. Is a poor compromise in any car when a 6pt. Parachute setup can be done if a 4pt can be done. The only 4pt that should be considered is the asm anti submarine schroth 4pt. You can use a Hans with 4pt asm but in a crash the reason it is asm is because a flap of extra webbing that rips open on crash converting the 4 to a de facto 3pt.. with 3 pt there is almost no basilar skull fracture. 3pt has the least containment and lowest protection level. Oem 3pt systems are survivable to around 50g or 45mph delta. Race safety systems are much more capable with pro crashes with data prove with proper construction 100g plus is survivable. I think for those going dual use the goal would be to improve containment within the compromise of street car a difficult task.

Check out what I have written for yourself. It has been a while since I have explored this subject. I would also not right off the rollover. You have yet to see a car on roof. Well, I’ve been on my roof hit by a damn Porsche in a club race. I hate Porsches! That’s why I was #88 for a long time since 88 upside down reads 88. I’ve also been taken out used as brakes twice. That’s why I’m on my second c5z racecar ,#88 RIP. Take the safety gear seriously. It’s not if it’s when. Race long enough your number comes up. It’s part of the sport.

This is a longer watch but so so worth it - it covers all of the stuff that’s been brought up


there are great discussions and points as they pull up different crash videos as well as proper sled crash tests and go frame by frame showing what is happening.


4-point belts are discussed (definitely run a 5- or even better a 6-point!) as well as rollovers in street cars on track, etc.

great video...seen it before. thanks for sharing

Just thought I'd add to the discussion, a couple pics of a C6Z that had a mild rollover at WGI, about 14yrs ago (I was not a Corvette owner back then, but had my eyes on one). Think this happened in T6 laces of the boot, into the guardrail. There was an instructor on board. Not sure, what happened, but think it was brake fade and novice may not have been astute to enough back off as his pedal was getting longer and longer earlier...

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I recall they were both ok...(instructor's right hand crushed) and had their feathers ruffled quite a bit. Understandable!

Anyway, just thought I'd add a couple thoughts, personal experiences to all this...I've been at all this a pretty long time (50 yrs now) and know how difficult it is to configure a dual purpose street car to have all the track orientated safety gear...especially with the speed potential these cars have (just had a student with 4pt in his Viper last summer)

I come from driving a fully caged race car (containment seat, nets, HANS, 6pt belts, fire sys, etc, etc)... multi race/season winning Champcar, WRL, etc etc,
While in the actual race car with all safety stuff, I've had a few pretty high speed crashes into walls over the years (most memorable; tagged in T12 Road Atlanta, T2 Mosport, and lost wheel at 120mph Pitt Race), I never ever felt unsafe or gave any of that a thought whatsoever.

But, I started feeling quite vulnerable in my own old 'project' street car / hopped up 88 MK1 MR2 (2500lb w/350whp turning 2:08s at WGI).
The car had a simple roll hoop, race seats, 6pt belts, HANS, full race suit, hand held extinguisher. That's it. I'd been very lucky with it a long time...one fire extinguished by me hopping out with the 5lb bottle, a few minor offs, failures, but no actual contact in HPDE and T/T...and I was pushing that car pretty hard.
About 10yrs ago, I hit fluid on the front straight at WGI, just as I leaned into brakes for T1 (120mph in that car?). nIt snapped right, facing pit wall! I instinctively locked up brakes (nice, AP all round)...and flat spotted my 4 new Hoosiers as the car went slideways...just just barely short of the pit wall. At that speed, in that old car, I'd have been toast. no frontal protection. No doubt.

Anyway sold that labor of love project car, and retired from W2W racing right after, at 66 then (still had the speed, but not the focus, or stamina for that grueling stuff)...and so bought my 08 Z06 with the intention of nice road-trip street car, but also few 'easy' track days (I'm not dead yet!)...and kept repeating "not a race car" mantra!
But, as many have discovered, the car disappoints 'out of the box', and this immediately started a seemingly endless series of addressing shortcomings; cooling, brake cooling, reliability, and of course remaining snugly ensconced in the Barcalounger seat.
With these cars, hitting 150mph is not difficult and frankly, short of full blown caged gutted safety equipment, there's also going to be considerable risk factor and nothing will make me feel as comfortable as in that race car. Its just the way it is. The question is, just how far do we go, and take it away from comfy street config....

And all this makes me muse, how if the same thing (hitting fluid while braking for T1 at WGI in my MR2) would happen at WGI now, in my comparatively modern' C6 Z06 (hey! it has crush zones and airbags!), the ABS would prevent me from being able to 'lock' the brakes up and the car would surely smash into the pit wall....and its going faster there than my old MR2 was.

Anyhow, done rambling...but I think everyone needs to assess what their accepted risk factor is

I appreciate your input.

Hitting the wall at T12 at RA sounds like a worse nightmart situation. I think every time I came down that hill it took every piece of me to not look at the wall in t12.

On many similar pages the answer is always "miata."

real fun cars! Had one (99). Even raced two (Ecotec & V6). But, most definitely not the answer for me, nor am i looking for alternatives at this point and that wouldn't be on my list. Thanks

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tommyc6z06, excellent food for thought in your article above. The speed and capability of new cars like the C7/8Z and ZR1s make the possibility of an eventual catastrophic even on track more likely. Like you, I have been tracking for over 50 years, and for the last 7 years have tracked a Viper ACR on slicks with just a six-point harness and a helmet. I just started tracking my C8Z with the same configuration. I have, over the years, had two major head-on impacts with interesting and conflicting results. One was in a 66 Corvette head-on into a concrete wall at fairly high speed. The car was a crush zone. My only injuries were bruises from the seat belt and a cut elbow from the center console being pushed back into me by the engine. The second was taking on the inside retaining wall at the Bull Ring in Las Vegas in a Super Late Model stock car at a recorded 108 mph. The harness (or my neck) stretched far enough I hit my helmet on the roof and the back support of the seat tore loose (bad construction). The front clip folded up pretty good and absorbed a lot of impact. I only got a mild concussion and a retina detached in one eye. In both cases, I feel most fortunate for two things - no sustained fire and no cockpit intrusion. I have a NASA spec-Focus (tall Miata) and I count on the cage for rollover protection. It has a high center of gravity and I have had it on two wheels more than once. I also have a very high-power dedicated track car under construction that is built old school - very substantial, multi-point cage designed for maximum chassis rigidity at the expense of crush zones. Full containment seat with nets on both sides, 7-point harness, and HANS. It has great protection against impact (especially side), but would be brutal in a highspeed front impact. At my age with the ACR and C8Z, I am kind-of in the "pay your dime, take your chances" mode. However, I would encourage younger drivers with more to lose and a longer future ahead of them to consider advanced safety features IF your mindset starts to stray away from HPDE to FTD.

The C5-C8 cars have a strong roof brace that is part of the B pillars and right behind the occupant's head. With the C5-C7 adding a roll bar is iffy. To provide any support it can't be fastened to the top of the crossbar located behind the seats. That bar is basically sheet metal and is strong horizontally but not vertically. If the force on the car is sufficient to collapse the stock roof brace it will push the roll bar down through the panel. To work in those cars the front supports of the roll bar have to be welded to the frame just behind the seats while the rear supports are welded to the frame in the cargo area. Not sure what they can do with the C8. Here is a picture of a C6Z that I watched climb the T6 tire wall and the catch fence at the Glen several years ago. When it finally stopped riding up the fence it hung there for a minute and then dropped straight down onto its roof. Notice the roof brace held up well but the A-pillar on the passenger side didn't.

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The instructor riding in the car said when the car roof hit the ground he felt his body going down (belts stretching) and the roof coming up and pushing his head forward and up. As far as I am concerned if you need a rollbar you need to consider a cage as the rollbar won't do any more than the stock roof brace to protect you. My student and I had ringside seats to this incident as we were about 100 ft behind the car when it rode up the fence. It was amazing since when it stopped moving forward it looked for a brief instance that it was gong to be stuck sideways on the fence about 5 ft above the ground.

Over the years I have attended several BMW driving schools and have attended several safety sessions put on by Joe Marko of HMS Motorsports. He has some videos of what happens in rollovers and most of the time the roof doesn't collapse but one of his videos shows what happens when you are in a car with stock belts and a rollover. The belts stretch because of the G forces involved and the occupant's heads come out of the windows and contact the ground. To protect yourself you need a roll cage, a seat that holds you in place, a belt system that holds you in the seat, a window net and an inside net between the driver seat and the dash to protect the driver from that side.

Given that most driving schools rarely have rollovers where is it better to spend your safety dollars?

Bill

As many have already covered, it's a very hard task to really prep a C8 for pro racing, and anything less might compromise safety as well, while providing improvements.

Unless you can go all the way in, I think it's best to utilize car's own safety mechanisms as much as possible. In my case, I picked OEM competition seat for my build, and only added a harness bar (that actually supports the dome ring), and Schroth 4 point Profi II ASM racing harness, which comes with a double-stitched inner shoulder belt that pops open during an accident, letting you crumble down like what would happen with the OEM belts, mitigating that risk of becoming a 'pillar' to support the roof if the car ever flips... This allows you to use a 4 point harness safely along with an OEM seat that's not designed to work with a 6 point.

Agree with your assessment. Here is an observation from the photos you posted. The C6Z is a little different than the C7/8 in that its fairly substantial roof panel is bolted between the A and B pillars with 10 bolts.
Notice that it does not appear the roof structure separated from either pillar. Also notice that the rear hatch glass is shoved rearward an inch or so. This indicates that the A-pillar collapsing probably pushed the roof panel structure rearward and bent the B-pillar. The B-pillar has some strength in the vertical plane by design, protecting the occupants from a "simple" rollover like the one pictured. I would hate to experience a violent rollover that involved a lot of forward velocity that stressed the B-pillar in other than a vertical (downward) manner.
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here's another pic, from a more rearward angle. But, i did not actually witness the crash (re above). It occurred in a student run group.
I'm not sure what there is to learn from all this other than risk/reward must be weighed...

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there was another, quite different crash the following year...in T10...into the inside wall. Very fast, tweaked car. Experienced driver, was ruffled up and sore but fortunately not seriously hurt. I think it had race seats and harness bar. Not sure if he was wearing a HANS, or if the car still had airbags.
I think that back then, track-out was still a kind of alligator type edging, then pea gravel. I don't remember when they changed it.
I recall he mentioned that car started skittering over the track out berm and he ended up rotating counterclockwise almost 180* and hitting the inside. Thats a very fast turn, even if it scrubbed off a lot of speed. I was first car there after the crash, but didn't actually see it happen.
Since then, track out has been updated with a smooth wide berm, and plenty of paved runoff (guess that it had caused more than a few issues, hauling cars out during races).
I was relieved he was ok, but, just thought this was interesting with regards to crashworthiness of the passenger compartment.
That car was brought back in 2 pcs. Sobering for sure...and good reminder that nobody wins a track day (a good reason why at my ripe old boomer age, i no longer use a laptimer...I just don't care, and know that it encourages me to push harder)

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Just for grins, I'll go to an extreme example that goes beyond our road course expectations. When you are doing 280+ and are belly up to the direction of travel, nose down and 40' in the air, you are about to have an appreciation for a well built cage that is about to endure the ultimate test. Driver/owner survived.
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Disagree!

which harness bar did you go with?

I ended up going with the BK bar. The fitment was not perfect, though, and I had to grind quite a bit of stuff on the car to make it fit OK. I've since heard more horror stories about bar fitments on C8s from other manufacturers as well, but I digress.