Best roll cage for GT3 991.2 - Page 3 - Rennlist - Porsche Discussion Forums

Notices
991 GT3 GT3RS and 911R
Sponsored by:

Best roll cage for GT3 991.2

Old 09-15-2018, 10:42 AM
  #31  
kyrocks
Addict
Rennlist Member
 
kyrocks's Avatar
 
Join Date: Oct 2010
Location: DFW, TX, USA
Posts: 3,848
Default

Originally Posted by bigs View Post
If you want to be critical of a sponsor, that's fine - but do it with verifiable hard data or personal experience.
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.
kyrocks is offline  
Old 09-15-2018, 10:49 AM
  #32  
Buteo
Addict
Rennlist Member
 
Buteo's Avatar
 
Join Date: May 2015
Location: Colorado
Posts: 1,525
Default

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.

Last edited by Buteo; 09-15-2018 at 11:17 AM.
Buteo is offline  
Old 09-15-2018, 01:43 PM
  #33  
Mech33
Super User
 
Mech33's Avatar
 
Join Date: Oct 2014
Posts: 3,984
Default

Originally Posted by SANDIEGO View Post
Suggestions for the best roll cage for GT3 991.2? Looking for one that fits well, and maintains as much rear view as possible.
Some things for the OP to consider when looking at shoulder belt attachments on potential roll bars:

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.
Mech33 is offline  
Old 09-15-2018, 01:51 PM
  #34  
911therapy
Addict
Rennlist Member
 
Join Date: Sep 2015
Location: Little Rock, Arkansas
Posts: 537
Default

Originally Posted by kyrocks View Post


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.
Agree Kyrocks, I had the CMS roll bar in my 2015 GT3 and it was great. Fit and finish were excellent, very solid product, perfectly color matched. The rear view was slightly obstructed, but it was more the wing that obstructs the view than the top of the roll bar. I would have gone with CMS again in my 991.2 GT3, but I bought used car with a GMG roll cage in it. It is a good one as well. But, there is no real difference in the rear view with the GMG vs. CMS. The one downside to the GMG is mounting my camera. Due to the angle of the bars, and the center plate that connects the cross bars, it is difficult to get my camera mount set properly. But, a different camera mount will solve that.
911therapy is offline  
Old 09-15-2018, 02:44 PM
  #35  
Mech33
Super User
 
Mech33's Avatar
 
Join Date: Oct 2014
Posts: 3,984
Default

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.

Last edited by Mech33; 09-15-2018 at 03:28 PM.
Mech33 is offline  
Old 09-15-2018, 05:00 PM
  #36  
awew911
Addict
Rennlist Member
 
awew911's Avatar
 
Join Date: Apr 2011
Location: Florida
Posts: 1,023
Default

Originally Posted by Mech33 View Post
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.
Agree with all the above. I've installed the Cantrell in 3 of my GT3s and installed the BBI in 2 others (Not Mine). I also like that the Cantrell is 1.75" vs 1.65" in most others.

A Lizard Green Cantrell bar will go in my .2 GT3 RS (when that happens).
awew911 is offline  
Old 09-15-2018, 07:40 PM
  #37  
Hams955
Addict
Rennlist Member
 
Hams955's Avatar
 
Join Date: Feb 2011
Location: Plano, TX / Pagosa Springs, CO
Posts: 544
Default

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.
Hams955 is offline  
Old 09-15-2018, 07:51 PM
  #38  
RENN GTS
Platinum Dealership
Rennlist
Site Sponsor

 
RENN GTS's Avatar
 
Join Date: Jun 2015
Posts: 838
Default

Originally Posted by SupremePower View Post
We have a factory OEM 991.2 cage available if you are interested PM for info
Doesn't get any better than OEM.

__________________
Arya Omidvar - Marketing Director
Porsche Fresno -www.porschefresno.com
Audi Fresno -www.audifresno.com
McLaren Scottsdale-www.mclarenscottsdale.com
Mobile: 949.545.3933
E-mail: [email protected]
IG: @aryadrives

Current:
991.2 Carrera
328d X-Drive

Gone But Not Forgotten:
GT4, 981 GTS, 964 C4,
F10 M5 ZCP, F82 M4, E36 M3, 76' 2002
W211 E55 AMG, W124 E500
16' Audi S3
RENN GTS is offline  
Old 09-15-2018, 07:51 PM
  #39  
Hams955
Addict
Rennlist Member
 
Hams955's Avatar
 
Join Date: Feb 2011
Location: Plano, TX / Pagosa Springs, CO
Posts: 544
Default

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.
Hams955 is offline  
Old 09-16-2018, 09:26 AM
  #40  
CMS
Basic Sponsor
Rennlist
Site Sponsor

 
CMS's Avatar
 
Join Date: Dec 2014
Posts: 610
Default

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.
CMS is offline  
Old 09-16-2018, 01:05 PM
  #41  
Mech33
Super User
 
Mech33's Avatar
 
Join Date: Oct 2014
Posts: 3,984
Default

Originally Posted by CMS View Post
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.
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?
Mech33 is offline  
Old 09-16-2018, 01:23 PM
  #42  
CMS
Basic Sponsor
Rennlist
Site Sponsor

 
CMS's Avatar
 
Join Date: Dec 2014
Posts: 610
Default

Originally Posted by Mech33 View Post


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?
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.
CMS is offline  
Old 09-16-2018, 01:48 PM
  #43  
CMS
Basic Sponsor
Rennlist
Site Sponsor

 
CMS's Avatar
 
Join Date: Dec 2014
Posts: 610
Default

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.

CMS is offline  
Old 09-16-2018, 02:36 PM
  #44  
Mech33
Super User
 
Mech33's Avatar
 
Join Date: Oct 2014
Posts: 3,984
Default

Originally Posted by CMS View Post
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.
I don’t understand why the Schroth “GT3” belts (which Porsche supplies for their OEM Clubsport package cars) come with shoulder belts so long and able to reach rear mounting points if they are not designed to do so safely.

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 03:29 PM.
Mech33 is offline  
Old 09-17-2018, 01:51 PM
  #45  
RyanDDWPartners
User
 
RyanDDWPartners's Avatar
 
Join Date: Oct 2017
Location: AZ
Posts: 168
Default

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.
RyanDDWPartners is offline  

Thread Tools
Search this Thread

Contact Us About Us Advertising Cookie Policy Privacy Statement Terms of Service

© 2018 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: