Best roll cage for GT3 991.2 - Page 5 - Rennlist - Porsche Discussion Forums

Notices
991 GT3 GT3RS and 911R
Sponsored by:

Best roll cage for GT3 991.2

Old 10-12-2018, 09:07 AM
  #61  
GeoJoe
Addict
Rennlist Member
 
GeoJoe's Avatar
 
Join Date: Feb 2015
Location: Atlanta, GA
Posts: 853
Default

I'm also still in research mode. PM me if anyone is removing one of these and wants to part with it.
GeoJoe is offline  
Old 10-17-2018, 06:32 PM
  #62  
gmgracing
Basic Sponsor
Rennlist
Site Sponsor

 
gmgracing's Avatar
 
Join Date: Dec 2004
Location: So Cal
Posts: 2,382
Default

Originally Posted by Mech33 View Post
If a non-triangulated rear diagonal is good enough for the OEM Porsche GT3 Clubsport and GT2RS Weissach titanium designs, it's good enough for me!

For me personally, it was more important to have the bar hug the headliner so that the bar would start "working" in preventing a roof collapse before too much had crunched down towards my head.

But that's the great thing about having options: each customer can choose what's important to them.
Well put Mech33!

We chose to adopt the guidelines set for roll cages by the FIA for our LMS and WEC models. I think stating it in this thread will be helpful to those who are trying to weigh out their options, and what they like in a roll bar!


__________________


[email protected]
www.gmgracing.com

714.432.1582
facebook | twitter | youtube

Porsche | McLaren | Audi | Ferrari | Lamborghini
Performance Tuning | Motorsport | Factory Service

Pirelli World Challege Race Team GT/GTA/GTS/TC
Pirelli GT3 Cup Trophy USA
Porsche Motorsport - McLaren GT - Audi Sport Customer Racing - Lamborghini Super Trofeo Series
gmgracing is offline  
Old 11-21-2018, 05:53 PM
  #63  
SToronto
Addict
Rennlist Member
 
SToronto's Avatar
 
Join Date: Jan 2012
Posts: 2,427
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 contacted Schroth USA to inquire about the 8" rule as most bars don't allow for that. They said the manual is a bit misleading in wording. You can have more than 8", shorter the better. But if you have more than 8" than you need to bring the belts straight out the seats from your shoulders and cross wrap them, doesn't matter which side is on top or bottom. Also said just don't go crazy with more than 20-24" distance. The greater the distance the bigger exposure to potential web flex/stretch.

Last edited by SToronto; 11-21-2018 at 10:26 PM.
SToronto is offline  
Old 11-21-2018, 06:15 PM
  #64  
kyrocks
Addict
Rennlist Member
 
kyrocks's Avatar
 
Join Date: Oct 2010
Location: DFW, TX, USA
Posts: 3,848
Default

Originally Posted by SToronto View Post
I contacted Schroth USA to inquire about the 8" rule as most bars don't allow for that. They said the manual is a bit misleading in wording. You can have more than 8", shorter the better. But if you have more than 8" than you need to bring the belts straight out the seats from your shoulders and cross wrap them, doesn't matter which side is on top or bottom. Also said just don't go crazy with more than 20-24" distance.
Thank you for this post. It does not seem like GMG or the other manufacturers are doing the cross wrap as their belt to bar length is very long. The shorter, the better on the strap length to the bar makes sense. Appreciate you contacting Schroth.
kyrocks is offline  
Old 11-21-2018, 07:17 PM
  #65  
CMS
Basic Sponsor
Rennlist
Site Sponsor

 
CMS's Avatar
 
Join Date: Dec 2014
Posts: 610
Default Save 15% on CMS Roll bar thru Cyber Monday!

Happy Thanksgiving tomorrow to all of those in the USA! We just wanted to stop in and thank all of our existing customers here on RL for all of the past business. To show our appreciation, lets run a sale and save you some $$$ on a roll bar. Who doesn't like a deal for Black Friday while digesting all of the Turkey and other Thanksgiving goodies? We have been approached by fellow RL members asking about a sale on the CMS roll bars. Ask and you shall receive . Now thru Monday, use RL15 coupon code on our new website to save 15% on your new roll bar for your 991.

__________________
[email protected]
www.competitionmotorsport.com
(844) 438-7244
CMS is offline  
Old 11-21-2018, 07:19 PM
  #66  
Mech33
Super User
 
Mech33's Avatar
 
Join Date: Oct 2014
Posts: 3,984
Default

Just saw this post. Thanks for sharing the FIA rules! It helps confirm that in general most all of these aftermarket roll bars meet this rear diagonal criteria. As it says in the docs:

"The upper end of the diagonal must join the main roll bar no more than 100 mm from its junction with the backstay, or the backstay no more than 100 mm from its junction with the main roll bar."

I measured my BBi bar, and the rear diagonal junction is at the absolute worst case ~83 mm (~3.25") from the backstay junction with the main roll bar. Per the specific measurement spec, in reality it is closer to ~50 mm (2") since you measure the closest distance from the backstay to main hoop contact.






Originally Posted by gmgracing View Post
Well put Mech33!

We chose to adopt the guidelines set for roll cages by the FIA for our LMS and WEC models. I think stating it in this thread will be helpful to those who are trying to weigh out their options, and what they like in a roll bar!


Last edited by Mech33; 11-22-2018 at 06:22 AM.
Mech33 is offline  
Old 11-21-2018, 09:12 PM
  #67  
Buteo
Addict
Rennlist Member
 
Buteo's Avatar
 
Join Date: May 2015
Location: Colorado
Posts: 1,525
Default

Originally Posted by CMS View Post
Happy Thanksgiving tomorrow to all of those in the USA! We just wanted to stop in and thank all of our existing customers here on RL for all of the past business. To show our appreciation, lets run a sale and save you some $$$ on a roll bar. Who doesn't like a deal for Black Friday while digesting all of the Turkey and other Thanksgiving goodies? We have been approached by fellow RL members asking about a sale on the CMS roll bars. Ask and you shall receive . Now thru Monday, use RL15 coupon code on our new website to save 15% on your new roll bar for your 991.
Had your bar in my gt4 and looking forward to putting one in my 991.2 gt3rs.

Just ordered a bar in satin black.

thanks!
tyler
Buteo is offline  
Old 11-22-2018, 02:26 PM
  #68  
SToronto
Addict
Rennlist Member
 
SToronto's Avatar
 
Join Date: Jan 2012
Posts: 2,427
Default

Does anybody know if all harnesses need a sub bracket for 991.2 GT3 w/LWB?

I'm looking at Schroth Flexi 2x2.
SToronto is offline  
Old 11-22-2018, 02:51 PM
  #69  
Buteo
Addict
Rennlist Member
 
Buteo's Avatar
 
Join Date: May 2015
Location: Colorado
Posts: 1,525
Default

Originally Posted by SToronto View Post
Does anybody know if all harnesses need a sub bracket for 991.2 GT3 w/LWB?

I'm looking at Schroth Flexi 2x2.
5 pt and 6 pt yes. 4 pt no.


edit: also- you’d need to cut the carbon on the passenger seat to run a 5/6 pt. The driver side is pre cut from the factory. Many folks run a 6 pt on the drivers and a 4 pt in the passenger because of this...I did the same as I didn’t want to cut the seat.
Buteo is offline  
Old 11-22-2018, 02:59 PM
  #70  
SToronto
Addict
Rennlist Member
 
SToronto's Avatar
 
Join Date: Jan 2012
Posts: 2,427
Default

Originally Posted by Buteo View Post


5 pt and 6 pt yes. 4 pt no.


edit: also- you’d need to cut the carbon on the passenger seat to run a 5/6 pt. The driver side is pre cut from the factory. Many folks run a 6 pt on the drivers and a 4 pt in the passenger because of this...I did the same as I didn’t want to cut the seat.
Ah, I read about cutting. Yes I don't want to cut the seat. So a 4 point will work on passenger with no cutting. Our local PCA seems to have a rule that the passenger (instructor) should have the same safety gear the driver is using available.

CMS says the Flexi 2x2 has a special bolt in attachment to use factory mounting points for the sub. I would think they know, but is that not correct?
SToronto is offline  
Old 11-23-2018, 12:36 AM
  #71  
Buteo
Addict
Rennlist Member
 
Buteo's Avatar
 
Join Date: May 2015
Location: Colorado
Posts: 1,525
Default

Originally Posted by SToronto View Post
Ah, I read about cutting. Yes I don't want to cut the seat. So a 4 point will work on passenger with no cutting. Our local PCA seems to have a rule that the passenger (instructor) should have the same safety gear the driver is using available.

CMS says the Flexi 2x2 has a special bolt in attachment to use factory mounting points for the sub. I would think they know, but is that not correct?
Our PCA has the same rule and our local track has a ban on 4 pt. I took the harness out for PCA events.

I found it a bit silly...but PCA has always been a bit silly. When testing to run solo in the past my chief instructor WANTED me to take more risks in the run group, not later braking, early power exit ect. But running up on cars in front, corner diving, ect. Things I later learned through actual track driving schools as poor form. So I take PCA in general with a grain a salt and I recommend my friends do the same.

Cant help you on the flexi 2x2, no experience with that.
Buteo is offline  
Old 11-23-2018, 02:36 AM
  #72  
Mech33
Super User
 
Mech33's Avatar
 
Join Date: Oct 2014
Posts: 3,984
Default

Originally Posted by SToronto View Post
Ah, I read about cutting. Yes I don't want to cut the seat. So a 4 point will work on passenger with no cutting. Our local PCA seems to have a rule that the passenger (instructor) should have the same safety gear the driver is using available.

CMS says the Flexi 2x2 has a special bolt in attachment to use factory mounting points for the sub. I would think they know, but is that not correct?
They must mean factory attachment points for the lap belt. All of the "GT3" series Schroth belts have a special lap belt bracket that attaches easily to the OEM LWB seats, but you'll need a sub strap bar to run 6-point on the drivers side.

Personally, I prefer the Cantrell sub strap bar design.
Mech33 is offline  
Old 11-23-2018, 07:46 AM
  #73  
SToronto
Addict
Rennlist Member
 
SToronto's Avatar
 
Join Date: Jan 2012
Posts: 2,427
Default

Originally Posted by Mech33
They must mean factory attachment points for the lap belt. All of the "GT3" series Schroth belts have a special lap belt bracket that attaches easily to the OEM LWB seats, but you'll need a sub strap bar to run 6-point on the drivers side.

Personally, I prefer the Cantrell sub strap bar design.
Yeah after a bunch of reading I think CMS is thinking lap belt. I did ask about sub brackets though.

Do you know if the passenger seat cut is a notched section of the seat? As in factory marked for cutting.
SToronto is offline  
Old 11-23-2018, 03:22 PM
  #74  
Mech33
Super User
 
Mech33's Avatar
 
Join Date: Oct 2014
Posts: 3,984
Default

Originally Posted by SToronto View Post
Yeah after a bunch of reading I think CMS is thinking lap belt. I did ask about sub brackets though.

Do you know if the passenger seat cut is a notched section of the seat? As in factory marked for cutting.
No, it’s flat carbon where it needs to be cut. Though the felt cover stuck to the carbon does have an opening in it like the drivers side roughly outlining where the cut would go.
Mech33 is offline  
Old 01-10-2019, 11:00 PM
  #75  
Eddie Gou
New User
 
Join Date: Jan 2019
Posts: 1
Default

Originally Posted by SupremePower View Post
We have a factory OEM 991.2 cage available if you are interested PM for info
I was wondering if it was still available?
Eddie Gou 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: