Originally Posted by gmgracing

We actually have good news!!!

A client of ours delivered his brand new Porsche 991 GT3 with Lightweight Bucket Seats for us to install our GMG roll bar and Schroth 6 point harnesses for both the driver and passenger seat.





After removing the seats from the vehicle, here are a few facts that we discovered and confirmed:


1. The floor pan and seat bracket of the sport bucket seat is in the 991 is different compared to the 997. This means that despite the 997 seats being able to bolt directy into the 991, the Brey Krause sub-strap mount for the 997 sport bucket seats is incompatible with the 991.

The electronics are located beneath the seat and right in between the rails so space is very tight for a conventional substrap mount, and there is no substrap mount available on the market yet for the 991 sport bucket seat.


2. As for the passenger side, we do have better news. Fortunately the air bag sensor is not built into the seat cushion as some have suspected nor does it interfere with the location where we are suppose to cut through the carbon if we decide to do so. In fact, the passenger side uses the same fabric as the driver side and has the same cut out pattern to show us where to cut.

Driver Side:





Passenger Side:




Whoever does the cutting must be extremely careful and use proper tools to ensure that the carbon shell is not damaged in the process. The upholstery will need to be professionally cut and stitched and the will function and appear the same as the driver side. Not ideal, but for all practical considerations, we believe that using a 4 point harness on the passenger seat should suffice for weekend and recreational track events and racing.

For those who are planning on (1) Installing aftermarket racing seats (2) Installing 6 point harnesses on the driver side (3) Installing 6 point harnesses on the passenger side, we are currently in the final stages of developement and waiting for our manufacturer to start production.

We will be releasing 2 products shortly:

(a) GMG Substrap Mounts for 991 GT3 Sport Bucket Seats
(b) GMG 997/991 Seat Base with Built-In Sub Strap Mounts for Aftermarket Racing Seats

To give an idea of what the final production pieces will look like, here is what we developed for the Audi R8:





- Jerry@GMGRacing.com

Originally Posted by Mech33

Now we're talking! But if the only thing preventing 6-point harnesses on the passenger side is a hole in the carbon bucket, why the heck didn't Porsche just cut it?? They really dropped the ball on that one.

Originally Posted by orthojoe

I wonder if the manufacturer screwed up the specs and that is why some cars with LWB got delayed. Maybe the next and final batch of cars coming in the next 2 months will have passthroughs on the passenger side....?

Originally Posted by orthojoe

I wonder if the manufacturer screwed up the specs and that is why some cars with LWB got delayed. Maybe the next and final batch of cars coming in the next 2 months will have passthroughs on the passenger side....?

Originally Posted by Mech33

That would be a sweet reward for the delays.

Originally Posted by Manifold

Please explain the basis of that statement.

Originally Posted by Rovman

That is extremely good news Jerry. I like what I see in your proposed product. So when do you think this product (sub strap bar) will be ready for market?

Also thanks again for sharing your findings with us, very much appreciated.

Originally Posted by YOCOHO

Hi Jerry,

I have a set of GT2 seats with 2 sets of Schroth Harnesses/Hans that I took out of my 2010 GT3 which worked great. Have you installed any in 2015 GT3?
Any suggestions?

Thanks,
Jerry

Originally Posted by gmgracing

Hey guys, thank you for the interest and questions!



This is purely our opinion but everyone should equip their vehicles with the proper safety equipment that corresponds to their skill level, the type of events that they are participating, and ultimately the risks that they are willing to accept. At the extreme end, if safety is of utmost concern, a factory Cup car with a full factory cage, fire supression system, and proper racing suit will be the way to go. For this particular case, there as been questions about compromising the carbon fiber seat's structural integrity if it is cut of modified.




Rovman,

You are welcome and thank you for the kind words. We try our best to help provide the community with useful information.

We have already designed it and we are just waiting for our manufacturer to produce them.



Yocoho,

The seats do bolt in as confirmed in this forum thread: https://rennlist.com/forums/991-gt3/...-gt3-fact.html

However, you will have issues with the airbag light.

- Jerry@GMGRacing.com

Originally Posted by gmgracing

We actually have good news!!!

A client of ours delivered his brand new Porsche 991 GT3 with Lightweight Bucket Seats for us to install our GMG roll bar and Schroth 6 point harnesses for both the driver and passenger seat.





After removing the seats from the vehicle, here are a few facts that we discovered and confirmed:


1. The floor pan and seat bracket of the sport bucket seat is in the 991 is different compared to the 997. This means that despite the 997 seats being able to bolt directy into the 991, the Brey Krause sub-strap mount for the 997 sport bucket seats is incompatible with the 991.

The electronics are located beneath the seat and right in between the rails so space is very tight for a conventional substrap mount, and there is no substrap mount available on the market yet for the 991 sport bucket seat.


2. As for the passenger side, we do have better news. Fortunately the air bag sensor is not built into the seat cushion as some have suspected nor does it interfere with the location where we are suppose to cut through the carbon if we decide to do so. In fact, the passenger side uses the same fabric as the driver side and has the same cut out pattern to show us where to cut.

Driver Side:





Passenger Side:




Whoever does the cutting must be extremely careful and use proper tools to ensure that the carbon shell is not damaged in the process. The upholstery will need to be professionally cut and stitched and the will function and appear the same as the driver side. Not ideal, but for all practical considerations, we believe that using a 4 point harness on the passenger seat should suffice for weekend and recreational track events and racing.

For those who are planning on (1) Installing aftermarket racing seats (2) Installing 6 point harnesses on the driver side (3) Installing 6 point harnesses on the passenger side, we are currently in the final stages of developement and waiting for our manufacturer to start production.

We will be releasing 2 products shortly:

(a) GMG Substrap Mounts for 991 GT3 Sport Bucket Seats
(b) GMG 997/991 Seat Base with Built-In Sub Strap Mounts for Aftermarket Racing Seats

To give an idea of what the final production pieces will look like, here is what we developed for the Audi R8:





- Jerry@GMGRacing.com

Originally Posted by Mech33

Hi GMG, do you have any updates on the passenger seat mods for the 6-point? Curious if you have attempted to cut the CF or not.

Perhaps a second driver side cushion that already has the past rough sewn in would be a good option rather than modifying the passenger cushion?

Originally Posted by gmgracing

Mech33,

Unfortunately, we did not have enough time to install the harnesses as the sub strap mounts are still still in production and our client had to drive back to Northern California.

We have not cut into the carbon shell nor have we confirmed with the dealership selling that cushion separately.