Best roll cage for GT3 991.2
#31
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Look at mech33’s post history, he complains about everything. Nothing new. Let’s move on.
Anyways, if you opt for the eyelets, they rattle. I’ve had them. I’ve also had a straight top bar and partly curved top bar in my cars. The curved may give you and extra 1 cm of view, but really there is no big difference. To say there is a “major” block is hyperbole.
#32
Three Wheelin'
Ive had the CMS in my gt4 and will be going with them again in my 991.2 GT3RS
Stronger bar+view+phenomenal customer service makes me a repeat customer.
Stronger bar+view+phenomenal customer service makes me a repeat customer.
Last edited by Buteo; 09-15-2018 at 10:17 AM.
#33
Eyelets are a trade-off. The belt snap rattles against the eyelet when it is dangling free when not being used, but they also make it easy to unsnap the belts from the bar and slide them through the seat openings to remove the shoulder portions between track days. When the belts aren’t snapped in, there is no rattle from the eyelets (unless the eyelts aren’t installed properly and not torqued down).
With a permanent wrap of the belts around the bar, you have to keep the belts dangling in the back somewhere. If the shoulder belts are permanently wrapped around the far rear horizontal bar (similar to the OEM Porsche Clubsport package setup), then the shoulder belts are long and the metal adjuster portions can rest down on the floor behind the seat when not in use (though they may slide around a bit in turns).
If the permanent belt wrap is sprung a horizontal bar in the closer main hoop section, then the belts are shorter and the metal adjuster brackets may be hanging and not fully on the floor when not in use, so some more care is needed to condigure they in some way so that they don’t whack into the back of the seat when driving / braking on the street.
If you run Schroth HANS belts, getting the 3” section compressed and pushed through the top openings on the LWB seats without scratching the metal adjuster against the plastic is tricky but do-able. If you don’t do that, you are stuck with the belts dangling right off the seat and the belt adjusters bump the carbon seat and door while driving (at least it didn’t on my car).
One nice byproduct of eyelets is when you unclip then from the rear, you can pull the narrower 2” section directly out through the seat quickly (rather than try and force the 3” section through the other direction).
Not everyone would notice and care about details like this when they’re actually using a bar, so keep that in mind.
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#34
Rennlist Member
Totally agree.
Look at mech33’s post history, he complains about everything. Nothing new. Let’s move on.
Anyways, if you opt for the eyelets, they rattle. I’ve had them. I’ve also had a straight top bar and partly curved top bar in my cars. The curved may give you and extra 1 cm of view, but really there is no big difference. To say there is a “major” block is hyperbole.
#35
More data for the OP: for reference, here is the view out the rear window of a 991.1 GT3 with a Cantrell roll bar that I snapped last weekend at the track. (I placed the phone right at my eye position while sitting, and took a photo looking through the rear view mirror).
I do like the Cantrell bar in general. Things I like:
- it has built-in belt loop capture (little wire loops around the bar at the belt positions) which keeps the belts from sliding around along the mounting bar
- they push the bar right up against the headliner (almost touching in the center, and almost touching at the edges), though it just has a single main hoop bar kink in the center, helping with visibility
- the sides of the main hoop are mostly vertical
Things I personally don't like about the Cantrell:
- you have to cut holes in the side panels (because the main hoop sides are more vertical, they intersect the side trim panels rather than clear them)
- the diagonals are pretty visible in the rear view on the left and right sides. I would prefer there to be pushed further out towards the edges to clear the view a bit.
I do like the Cantrell bar in general. Things I like:
- it has built-in belt loop capture (little wire loops around the bar at the belt positions) which keeps the belts from sliding around along the mounting bar
- they push the bar right up against the headliner (almost touching in the center, and almost touching at the edges), though it just has a single main hoop bar kink in the center, helping with visibility
- the sides of the main hoop are mostly vertical
Things I personally don't like about the Cantrell:
- you have to cut holes in the side panels (because the main hoop sides are more vertical, they intersect the side trim panels rather than clear them)
- the diagonals are pretty visible in the rear view on the left and right sides. I would prefer there to be pushed further out towards the edges to clear the view a bit.
Last edited by Mech33; 09-15-2018 at 02:28 PM.
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Yargk (06-26-2019)
#36
Rennlist Member
More data for the OP: for reference, here is the view out the rear window of a 991.1 GT3 with a Cantrell roll bar that I snapped last weekend at the track. (I placed the phone right at my eye position while sitting, and took a photo looking through the rear view mirror).
[img]https://dl.dropbox.com/s/xyegiy8azjibl0r/Cantrell%20bar%20on%20991.1%20GT3.jpg?
I do like the Cantrell bar in general. Things I like:
- it has built-in belt loop capture (little wire loops around the bar at the belt positions) which keeps the belts from sliding around along the mounting bar
- they push the bar right up against the headliner (almost touching in the center, and almost touching at the edges), though it just has a single main hoop bar kink in the center, helping with visibility
- the sides of the main hoop are mostly vertical
Things I personally don't like about the Cantrell:
- you have to cut holes in the side panels (because the main hoop sides are more vertical, they intersect the side trim panels rather than clear them)
- the diagonals are pretty visible in the rear view on the left and right sides. I would prefer there to be pushed further out towards the edges to clear the view a bit.
[img]https://dl.dropbox.com/s/xyegiy8azjibl0r/Cantrell%20bar%20on%20991.1%20GT3.jpg?
I do like the Cantrell bar in general. Things I like:
- it has built-in belt loop capture (little wire loops around the bar at the belt positions) which keeps the belts from sliding around along the mounting bar
- they push the bar right up against the headliner (almost touching in the center, and almost touching at the edges), though it just has a single main hoop bar kink in the center, helping with visibility
- the sides of the main hoop are mostly vertical
Things I personally don't like about the Cantrell:
- you have to cut holes in the side panels (because the main hoop sides are more vertical, they intersect the side trim panels rather than clear them)
- the diagonals are pretty visible in the rear view on the left and right sides. I would prefer there to be pushed further out towards the edges to clear the view a bit.
A Lizard Green Cantrell bar will go in my .2 GT3 RS (when that happens).
#37
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Location: Plano, TX / Pagosa Springs, CO
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I have had a BBi bar in my RS and a CMS bar in my 991.2 GT3. I am 6'2" with buckets in the lowest position. The CMS bar significantly impacts the upper portion of the view from the rearview mirror; above the wing. The only area you can see clearly is below the wing.
My other two complaints about the CMS bar:
1) the plates for the rear kickers where they mount to the shock towers - the plates could be cut down like BBi's plates to make installation simpler. They are really large and difficult to get into place without complete panel removal.
2) There is a lateral bar across the rear kicker that is too low. It makes it extremely difficult to get the rear shelf carpet back into place.
I would say is a nice bar but if they made the top hoop follow the contour of the roof line visibility would be improved. If they raised the lateral bar on the rear it would make carpet installation easier. Lastly; those plates.... Grr.
Nice bar but definitely could be tweaked to make it better.
- Chris.
My other two complaints about the CMS bar:
1) the plates for the rear kickers where they mount to the shock towers - the plates could be cut down like BBi's plates to make installation simpler. They are really large and difficult to get into place without complete panel removal.
2) There is a lateral bar across the rear kicker that is too low. It makes it extremely difficult to get the rear shelf carpet back into place.
I would say is a nice bar but if they made the top hoop follow the contour of the roof line visibility would be improved. If they raised the lateral bar on the rear it would make carpet installation easier. Lastly; those plates.... Grr.
Nice bar but definitely could be tweaked to make it better.
- Chris.
#38
#39
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Here's pics of the rear cross bar I am talking about along the kickers:
See how close it is to the shelf carpet? It's virtually impossible to get installed again.
Flat top hoop. It obstructs rearward vision badly for me, but I am taller.
This is my BBi bar in my RS for example; notice the top hoop follows the contour of the roof:
- Chris.
See how close it is to the shelf carpet? It's virtually impossible to get installed again.
Flat top hoop. It obstructs rearward vision badly for me, but I am taller.
This is my BBi bar in my RS for example; notice the top hoop follows the contour of the roof:
- Chris.
#40
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Chris, fair points all. As an FYI we raised the rear cross bar to eliminate that issue. Having the rear cross bar low on the kickers allows it to most effectively reinforce the rear strut towers.
Also, be mindful that with a kicker-mounted harness cross bar (further from the driver), you should be using harnesses designed for that application. The shoulder straps will have a different elongation rate than the standard ones you’ll get if you buy “regular” harnesses.
Also, be mindful that with a kicker-mounted harness cross bar (further from the driver), you should be using harnesses designed for that application. The shoulder straps will have a different elongation rate than the standard ones you’ll get if you buy “regular” harnesses.
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#41
Chris, fair points all. As an FYI we raised the rear cross bar to eliminate that issue. Having the rear cross bar low on the kickers allows it to most effectively reinforce the rear strut towers.
Also, be mindful that with a kicker-mounted harness cross bar (further from the driver), you should be using harnesses designed for that application. The shoulder straps will have a different elongation rate than the standard ones you’ll get if you buy “regular” harnesses.
Also, be mindful that with a kicker-mounted harness cross bar (further from the driver), you should be using harnesses designed for that application. The shoulder straps will have a different elongation rate than the standard ones you’ll get if you buy “regular” harnesses.
So then if the Schroth GT3 belts aren’t the right belts for the CMS bar from a safety perspective, what belts do you typically sell with your bar for these shorter belt applications?
#42
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Regarding the rear mounted harnesses, Schroth provides the standard GT3 harness set with shoulder belts long enough reach the rear kicker area, and the OEM Clubsport bar mounts them this way. Based on your comments, you’re suggesting that Schroth GT3 belts must be designed with the stretch appropriate for rear bar mounting (not close mounting like the CMS bar), since Porsche + Schroth together must be doing what’s right for the OEM Clubsport config.
So then if the Schroth GT3 belts aren’t the right belts for the CMS bar from a safety perspective, what belts do you typically sell with your bar for these shorter belt applications?
As for the “GT3” version of Schroth harnesses, that has to do with mounting hardware that attaches to LWB OEM seat belt mounts instead of clip in-clip out. It has nothing to do with the harness material itself. Those are our most popular for the GT3/GT4 because of the hardware.
#43
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Also, make sure if you are using hard shoulder-mounting points to pay attention to how far apart they should be based on the distance of the driver’s shoulders (peak of the HANS) from the harness bar and his/her shoulder width. We don’t typically recommend the clip-in/clip-out shoulder straps. They’re easier to put in/take out for sure, but a roll bar manufacturer needs to be sure to get those measurements right for each driver so they’re in the right place.
#44
You have that backwards. Standard “off the shelf” harnesses, including the Schroth Profi II GT3, are designed for the shoulder straps to be mounted about 8” behind the driver. Its not a question of whether the straps will reach; it has to do with the rate and amount of elongation of the webbing in the event of an impact. Schroth and others do make harnesses with shoulder straps designed for mounting further back, as in Porsche’s race cars, and those are what PMNA uses in their factory race cars. They’re not unavailable to the general public, you just have to ask for them specifically. If you just buy “harnesses”, they’re designed for close mounting because that’s how the vast majority of race cars are designed.
As for the “GT3” version of Schroth harnesses, that has to do with mounting hardware that attaches to LWB OEM seat belt mounts instead of clip in-clip out. It has nothing to do with the harness material itself. Those are our most popular for the GT3/GT4 because of the hardware.
As for the “GT3” version of Schroth harnesses, that has to do with mounting hardware that attaches to LWB OEM seat belt mounts instead of clip in-clip out. It has nothing to do with the harness material itself. Those are our most popular for the GT3/GT4 because of the hardware.
If you have any data to back this up I’d love to red about it. In the Schroth manuals it just recommends certain lengths as ideal but to just cross the belts if you have to go longer.
Last edited by Mech33; 09-16-2018 at 02:29 PM.
#45
I have a brand new in the box BBi roll bar in Guards red that I decided I'm going to sell. I was going to put a bar and belts in my new RS but decided not at at this time. If anyone wants it I'll hook you up. Let me know.