For HPDE and street car - 4pt rollbar or harness bar?
11-18-2011, 08:52 PM
#1
Racer
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For HPDE and street car - 4pt rollbar or harness bar?
Car needs to stay street legal and street drivable and I usually do 10-15 HPDE days per year - should I install 4pt Pfadt/Autopower rollbar or harness bar will be enough?
I am planning to put Corbeau A4 as well.....
I am planning to put Corbeau A4 as well.....
11-19-2011, 05:02 AM
#5
that depends, of course, on your desire for additional roll protection. harness bar + harness gives you a benefit of being more likely to stay inside the car if it rolls, but not much beyond that in that particular scenario.
factory roof is certified for holding 1.5 times the weight of the car, the federal standard only requires a "static" test (no movement, the weight is simply placed on the roof, then measurements are taken).
maybe GM built extra protection into the roof structure. we hope they did. I believe that GM claims that C5/C6 convertibles were tested to hold the weight of the car on the A-pillar. As tested at 30mph.
in the end, pretty personal decision.
The only impact to daily use is losing ability to keep large objects in the back behind the seats. I could still get 2 large toolboxes and a jack in there, but my dog could not get in there anymore, and I could not fit 3 tires into the car. I had a second car at that point so it was not a big deal.
I honestly don't know if I would do a rollbar just for DEs if I had to do it again. I had an incident once, where the car "could have" rolled at 100+ mph but I got lucky and kept it going mostly straight with the correct side up. Who knows if I would have put the car where I did, at the speed I did, if I knew I do not have a roll bar in the car. Funny how that works sometimes.
factory roof is certified for holding 1.5 times the weight of the car, the federal standard only requires a "static" test (no movement, the weight is simply placed on the roof, then measurements are taken).
maybe GM built extra protection into the roof structure. we hope they did. I believe that GM claims that C5/C6 convertibles were tested to hold the weight of the car on the A-pillar. As tested at 30mph.
in the end, pretty personal decision.
The only impact to daily use is losing ability to keep large objects in the back behind the seats. I could still get 2 large toolboxes and a jack in there, but my dog could not get in there anymore, and I could not fit 3 tires into the car. I had a second car at that point so it was not a big deal.
I honestly don't know if I would do a rollbar just for DEs if I had to do it again. I had an incident once, where the car "could have" rolled at 100+ mph but I got lucky and kept it going mostly straight with the correct side up. Who knows if I would have put the car where I did, at the speed I did, if I knew I do not have a roll bar in the car. Funny how that works sometimes.
11-19-2011, 07:02 AM
#6
Racer
I have struggled with this decision for a year now on my ZR1, I have the 4 point where the bars dont have to go to the floor and reduce seat travel on my C5z. However with the C6 frame not being steel my shop told me I have to go to the floor.
I do about 20 HPDE's/TT's per year, Id much prefer the roll over protection however because Im a fairly big guy I can't comfortably drive the car without the leg room so I have decided to go with the Harness bar on the Zr1.
I feel the choice I made for my C5z was the best compromise for me as I'd MUCH prefer to have roll over protection.
I do about 20 HPDE's/TT's per year, Id much prefer the roll over protection however because Im a fairly big guy I can't comfortably drive the car without the leg room so I have decided to go with the Harness bar on the Zr1.
I feel the choice I made for my C5z was the best compromise for me as I'd MUCH prefer to have roll over protection.
11-20-2011, 12:38 AM
#7
Burning Brakes
my wife voted for the roll bar
Last winter was the time for a few safety add-ons that included a roll bar. It really fit well. Now my wife is sleeping better
Pfadt roll bar installation can be seen by going to the following site:
http://s1111.photobucket.com/albums/...with%20hithch/
11-20-2011, 05:53 AM
#8
Le Mans Master
C5/6 crash very well. Other then to meet SCCA or THSCC rules no need for a 4 pt. They look good though.
11-20-2011, 08:23 PM
#9
I totally disagree. You need the rollbar. Full race T1 cars with stock engines are doing laptimes just like HPDE Z06's and ZR1's. We are talking near 160mph going into nascar turn 1 at ACS or 140mph entering T8 at WSIR. You will die at those speeds and anything can happen. No fault of your own you can loose a tire happened to me twice which makes you spin. I just had a clutch blow up yesterday and that could hiccup and unsetle the car into the wall. I have spin on my own radiator hose watering myself. There are so many potential hazzards. If you guys are hpde'ing miata or audi TT's ok I get it. But vettes are just dang fast. There are other advantages to the 4 point. You can add side nets or head/enhanced containment to a race seat and still keep your seat streetable. You got better places to mount your cameras. You can extend a 4pt to include a chassis stiffening truss and mount your harnesses to them more effectively. Oh and a real place to mount your seat back brace.
11-20-2011, 09:41 PM
#10
Safety Car
Most 4-points are marketed as "chassis bars" for leagal reasons. Most all that I've seen for sale mount to relatively weak parts of the car and really kill your interior room and line of sight.
IMO the C5 has a very strong structure and the factory roll hoop is a good piece. The risk with these cars is more side impact which a roll-bar doesn't help vs. a rollover.
IMO the C5 has a very strong structure and the factory roll hoop is a good piece. The risk with these cars is more side impact which a roll-bar doesn't help vs. a rollover.
11-21-2011, 12:10 PM
#12
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that depends, of course, on your desire for additional roll protection. harness bar + harness gives you a benefit of being more likely to stay inside the car if it rolls, but not much beyond that in that particular scenario.
factory roof is certified for holding 1.5 times the weight of the car, the federal standard only requires a "static" test (no movement, the weight is simply placed on the roof, then measurements are taken).
maybe GM built extra protection into the roof structure. we hope they did. I believe that GM claims that C5/C6 convertibles were tested to hold the weight of the car on the A-pillar. As tested at 30mph.
in the end, pretty personal decision.
The only impact to daily use is losing ability to keep large objects in the back behind the seats. I could still get 2 large toolboxes and a jack in there, but my dog could not get in there anymore, and I could not fit 3 tires into the car. I had a second car at that point so it was not a big deal.
I honestly don't know if I would do a rollbar just for DEs if I had to do it again. I had an incident once, where the car "could have" rolled at 100+ mph but I got lucky and kept it going mostly straight with the correct side up. Who knows if I would have put the car where I did, at the speed I did, if I knew I do not have a roll bar in the car. Funny how that works sometimes.
factory roof is certified for holding 1.5 times the weight of the car, the federal standard only requires a "static" test (no movement, the weight is simply placed on the roof, then measurements are taken).
maybe GM built extra protection into the roof structure. we hope they did. I believe that GM claims that C5/C6 convertibles were tested to hold the weight of the car on the A-pillar. As tested at 30mph.
in the end, pretty personal decision.
The only impact to daily use is losing ability to keep large objects in the back behind the seats. I could still get 2 large toolboxes and a jack in there, but my dog could not get in there anymore, and I could not fit 3 tires into the car. I had a second car at that point so it was not a big deal.
I honestly don't know if I would do a rollbar just for DEs if I had to do it again. I had an incident once, where the car "could have" rolled at 100+ mph but I got lucky and kept it going mostly straight with the correct side up. Who knows if I would have put the car where I did, at the speed I did, if I knew I do not have a roll bar in the car. Funny how that works sometimes.
My dog doesn't ride in Vette, so loosing extra space is not a problem. Plus I have another car for winter, etc...
However my car is a coupe, not FRC, and I was under impression that FRC roof is stronger, so having rollbar installed would add protection as well improve stiffness of the body, no?
11-21-2011, 12:59 PM
#13
Safety Car
Here's a picture with the roof off of my Z06. You can see the main OEM roll hoop and the rear cross-piece. The coupe doesn't have that rear part since it's a hatchback.
11-21-2011, 01:11 PM
#14
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The roof itself is not stronger... the Z06/FRC chassis does have more torsional rididity vs. the coupe. This comes from having the b-pillar roll hoop from the coupe and the rear cross-bar from the vert; the piece the trunk lid hinges off of. The coupe only has the b-pillar roll hoop.
Here's a picture with the roof off of my Z06. You can see the main OEM roll hoop and the rear cross-piece. The coupe doesn't have that rear part since it's a hatchback.
Here's a picture with the roof off of my Z06. You can see the main OEM roll hoop and the rear cross-piece. The coupe doesn't have that rear part since it's a hatchback.
11-21-2011, 01:16 PM
#15
good visual aid ^
mind you, I am not trying to dissuade anyone from installing extra roll protection. it's a good thing since there is no evidence that factory-supplied level of protection is designed to work at track speeds.
I have never driven a coupe, but I rode in a few C5/C6 non-FRC cars and they did not feel any less stiff than my C5Z with a 4 point bar.
there are so many rigid connections already between 2 frame rails, that adding one more may have little effect.
mind you, I am not trying to dissuade anyone from installing extra roll protection. it's a good thing since there is no evidence that factory-supplied level of protection is designed to work at track speeds.
I have never driven a coupe, but I rode in a few C5/C6 non-FRC cars and they did not feel any less stiff than my C5Z with a 4 point bar.
there are so many rigid connections already between 2 frame rails, that adding one more may have little effect.
11-21-2011, 01:16 PM
#16
Safety Car
The C5/C6 platform has one of the stiffest chassis in any production street car... IMO there's nothing to "fix". You need something to mount your harnesses on and the harness bar is designed to do that. As an added benefit it will stiffen up the chassis some.
As I've mentioned before... I've yet to see a 4-pt rollbar install in one of these cars I could live with. However, I'm 6'4" 240 and need every bit of space I can get.
As I've mentioned before... I've yet to see a 4-pt rollbar install in one of these cars I could live with. However, I'm 6'4" 240 and need every bit of space I can get.
11-21-2011, 01:22 PM
#17
To answer the question directly - yes, 4+ point roll bar that attaches to frame rails directly in at least 2 points to the rear of the B-pillar will add at least the same level (or more) stiffness to the chassis.
that "extra" stiffness may or may not have practical use, but who knows for sure.
that "extra" stiffness may or may not have practical use, but who knows for sure.
11-21-2011, 02:16 PM
#18
Le Mans Master
I totally disagree. You need the rollbar. Full race T1 cars with stock engines are doing laptimes just like HPDE Z06's and ZR1's. We are talking near 160mph going into nascar turn 1 at ACS or 140mph entering T8 at WSIR. You will die at those speeds and anything can happen. No fault of your own you can loose a tire happened to me twice which makes you spin. I just had a clutch blow up yesterday and that could hiccup and unsetle the car into the wall. I have spin on my own radiator hose watering myself. There are so many potential hazzards. If you guys are hpde'ing miata or audi TT's ok I get it. But vettes are just dang fast. There are other advantages to the 4 point. You can add side nets or head/enhanced containment to a race seat and still keep your seat streetable. You got better places to mount your cameras. You can extend a 4pt to include a chassis stiffening truss and mount your harnesses to them more effectively. Oh and a real place to mount your seat back brace.
I have seen, and been in several, C5/6 severe collisions and we can definitely disagree (I defended that right as a matter of fact). In the end whatever makes you happy is what you need to do. Best option is to not hit walls head on at 100mph on a racetrack but if you do it in at stock C5Z you can walk away from it. Car looks a bit used up though!
11-21-2011, 02:28 PM
#19
Safety Car
I use a harness bar with a low mount (to get the angles to Schroth specs, I use their harnesses), real race seat, super strong steel seat mounts that I welded, and a huge piece of steel channel for the anti-sub belt anchors.
I don't think there is a worthwhile in-between step between the above and a cage. And a cage is a no-go on the street.
I don't think there is a worthwhile in-between step between the above and a cage. And a cage is a no-go on the street.
