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      08-07-2021, 01:36 PM   #1
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Racing Harness

Anyone put a 5 or 6 point harness in M4GTS with stock seats
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      08-07-2021, 03:07 PM   #2
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Where would you put the sub belts into? Cut the stock seat?
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      08-08-2021, 05:14 PM   #3
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Stock seats cannot accept 5/6 point belts. You need Euro seats or racing seat.
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      08-08-2021, 06:10 PM   #4
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Quote:
Originally Posted by 4play View Post
Stock seats cannot accept 5/6 point belts. You need Euro seats or racing seat.
Once the car has a racing seat, how do you attach the lap belts?
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      08-09-2021, 10:32 AM   #5
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Quote:
Originally Posted by SYT_Shadow View Post
Once the car has a racing seat, how do you attach the lap belts?
Brey-Krause makes a kit that attaches the 6 point lap belts to the sliders via the race seat brackets. They also make a sub bar kit that bolts in to the seat brackets.

The OEM Euro solution is brackets welded to the chassis, but that is significantly more complex than the Brey-Kruse solution because the US cars didn't have the brackets welded in the factory.

It takes some fiddling to get right depending on the race seat you pick (I had OMP WRC-R), but if you have an extra set of manual sliders, you could probably change the seats out in <30 mins.

The nice part about the WRC-R is the lap belt holes are large enough that you can still use the factory 3-point belt on the road. Once on track, you can take the passenger belt and buckle it in to the stock seat belt receptacle to prevent the seat belt warning chime from going off the entire session (or buy a seat belt stub from Amazon).
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      08-09-2021, 10:38 AM   #6
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I have utilized the Brey Krause solution and been given pushback by tech with NASA. Consider that if you are running any of the factory seat adaptations I believe are being suggested in here.
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      08-09-2021, 10:56 AM   #7
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Quote:
Originally Posted by 4play View Post
Brey-Krause makes a kit that attaches the 6 point lap belts to the sliders via the race seat brackets. They also make a sub bar kit that bolts in to the seat brackets.

The OEM Euro solution is brackets welded to the chassis, but that is significantly more complex than the Brey-Kruse solution because the US cars didn't have the brackets welded in the factory.

It takes some fiddling to get right depending on the race seat you pick (I had OMP WRC-R), but if you have an extra set of manual sliders, you could probably change the seats out in <30 mins.

The nice part about the WRC-R is the lap belt holes are large enough that you can still use the factory 3-point belt on the road. Once on track, you can take the passenger belt and buckle it in to the stock seat belt receptacle to prevent the seat belt warning chime from going off the entire session (or buy a seat belt stub from Amazon).
I have the BK bar and side mounts.
For the sub belts, it's clear, they attach to the BK sub bar
For the shoulder belts, it's also clear as they can wrap around the GTS roll bar
What I don't understand is how to attack the lap belts. In the BK setup, one side (towards the center tunnel) attaches to the seat mount, but the other one attaches to the BK harness bar. That's the one I'm worried about
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      08-09-2021, 11:21 AM   #8
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Quote:
Originally Posted by SYT_Shadow View Post
I have the BK bar and side mounts.
For the sub belts, it's clear, they attach to the BK sub bar
For the shoulder belts, it's also clear as they can wrap around the GTS roll bar
What I don't understand is how to attack the lap belts. In the BK setup, one side (towards the center tunnel) attaches to the seat mount, but the other one attaches to the BK harness bar. That's the one I'm worried about
I pulled my BK setup out of my GTS, but I thought the outside lap belt used an eye bolt + a bracket to pop into the back of the seat slider. You can slide the seat back and forth and just have to adjust the shoulder straps, the sub and lap belts move with the seat.

Curious why NASA would have issues with the BK setup. It's not as rigid as hard-mounting the seat to the chassis, but sliders are used in factory race cars
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      08-09-2021, 11:31 AM   #9
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Quote:
Originally Posted by Gomeler View Post
I pulled my BK setup out of my GTS, but I thought the outside lap belt used an eye bolt + a bracket to pop into the back of the seat slider. You can slide the seat back and forth and just have to adjust the shoulder straps, the sub and lap belts move with the seat.

Curious why NASA would have issues with the BK setup. It's not as rigid as hard-mounting the seat to the chassis, but sliders are used in factory race cars
What setup are you using now, and how are you attaching the lap belts?

I heard there's an OEM GTS solution for the lap belts but seems to require welding?
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      08-09-2021, 11:40 AM   #10
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Quote:
Originally Posted by SYT_Shadow View Post
I have the BK bar and side mounts.
For the sub belts, it's clear, they attach to the BK sub bar
For the shoulder belts, it's also clear as they can wrap around the GTS roll bar
What I don't understand is how to attack the lap belts. In the BK setup, one side (towards the center tunnel) attaches to the seat mount, but the other one attaches to the BK harness bar. That's the one I'm worried about
Both sides attach to the seat rails. The inner lap belt bracket bolts to the seatbelt receptacle (shown here: https://www.bkauto.com/R_9288_Passen...s_p/r-9288.htm)

The outer lap belt bracket attaches to the seat rail via a special bolt on accessory that BK includes in the R-9288 package. You can sorta see it in the photo below.



Both are eyelets that you clip the lap belt harnesses into. Other than the sub belts that have to be wrapped, the other 4 belts are easy clip-ins.

Quote:
Originally Posted by SYT_Shadow View Post
What setup are you using now, and how are you attaching the lap belts?

I heard there's an OEM GTS solution for the lap belts but seems to require welding?
Yes, the OEM Euro GTS brackets require you to cut the carpet and weld in brackets.
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      08-09-2021, 11:49 AM   #11
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Quote:
Originally Posted by 4play View Post
The outer lap belt bracket attaches to the seat rail via a special bolt on accessory that BK includes in the R-9288 package. You can sorta see it in the photo below.
Just like that.

Quote:
Originally Posted by SYT_Shadow View Post
What setup are you using now, and how are you attaching the lap belts?

I heard there's an OEM GTS solution for the lap belts but seems to require welding?
I reverted the car for street use, and went true racecar instead. Lasted ~15 months trying to do hybrid duty with the GTS. If I was going to keep tracking it, I'd have gone with the EDM seats + BK mounting hardware. I didn't want to cut the carpet + weld-in the tabs, and I really liked the lap/sub belts sliding with the seat.
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      08-09-2021, 11:55 AM   #12
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Perfect, thanks guys, I appreciate the help!
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      08-09-2021, 12:52 PM   #13
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Quote:
Originally Posted by Gomeler View Post
I pulled my BK setup out of my GTS, but I thought the outside lap belt used an eye bolt + a bracket to pop into the back of the seat slider. You can slide the seat back and forth and just have to adjust the shoulder straps, the sub and lap belts move with the seat.

Curious why NASA would have issues with the BK setup. It's not as rigid as hard-mounting the seat to the chassis, but sliders are used in factory race cars
Tell me about it. Each time I got a “I’ll let you pass this time, but next time it cant mount to the same location as the seat” lecture.
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      08-09-2021, 05:52 PM   #14
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Anyone have pictures of the factory installed euro harness brackets?
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      08-10-2021, 09:28 PM   #15
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Upgrading to seats better suited for the track is on my winter to do list. Thanks to all that have provided some tips here.

I still would like to have sliding adjustment, any tips there?
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      08-11-2021, 08:39 AM   #16
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Quote:
Originally Posted by JimmyS View Post
Upgrading to seats better suited for the track is on my winter to do list. Thanks to all that have provided some tips here.

I still would like to have sliding adjustment, any tips there?
Use the Brey-Krause setup and purchase a 2nd driver's side seatbelt tensioner assembly. Buy a spare set of M4 sliders (believe they are shared with the i3).

Then, all you need to do when you have a track day is remove the 4 seat rail bolts, unplug the stock wiring harness, swap in the entire race seat assembly, and plug in the tensioner wiring harness (so you don't get a seatbelt chime all track day).

You can also skip the seatbelt tensioner step and code it out. Just depends on what is easier for you.
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      08-31-2021, 09:15 PM   #17
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Factory belts

I went with welding in the OE belt mounts. Mis-installed belts are worthless, I would rather use the factory 3 point belts than some hack solution.

It was not cheap. The whole interior (carpeting) had to be removed, brackets welded in place, repaint the floor to prevent rust, reinstalled interior and installed belts. Look at the videos of mis-installed belts to see the dangers.

This is not a subject for the uninformed well intentioned shade tree mechanic.
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      08-31-2021, 10:49 PM   #18
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Quote:
Originally Posted by rcompound View Post
I went with welding in the OE belt mounts. Mis-installed belts are worthless, I would rather use the factory 3 point belts than some hack solution.

It was not cheap. The whole interior (carpeting) had to be removed, brackets welded in place, repaint the floor to prevent rust, reinstalled interior and installed belts. Look at the videos of mis-installed belts to see the dangers.

This is not a subject for the uninformed well intentioned shade tree mechanic.
Not sure what the insinuation is here. The Brey-Krause kit attaches the harnesses in the same way as factory race cars with sliders (911 Cup Cars, Ferrari Challenge, etc). It is perfectly safe and allows for adjustability for different drivers or simply to position the harnesses correctly for maximum effectiveness in a crash.

I would caution against thinking the OEM solution is always superior. If you are above 5'9", the OEM Euro buckets and chassis mounting points are not safe due to the incorrect installation angles they create in the harnesses relative to the driver. As you undoubtedly are aware, the OEM mounting points are not in any way adjustable.

In any case, 5/6 point belts in this car maybe create false sense of security. They will hold you in more securely and may help to an extent in a frontal collision. However, this is a road car that is not even remotely close to complying with any serious race series regulations with regard to crash protection, be it cage, seat mounting, etc. If you get in an accident at high speeds, you will likely be seriously injured or killed, half-cage and 6-points or not.

Last edited by 4play; 08-31-2021 at 10:54 PM..
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      09-01-2021, 04:59 AM   #19
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Quote:
Originally Posted by 4play View Post
Not sure what the insinuation is here. The Brey-Krause kit attaches the harnesses in the same way as factory race cars with sliders (911 Cup Cars, Ferrari Challenge, etc). It is perfectly safe and allows for adjustability for different drivers or simply to position the harnesses correctly for maximum effectiveness in a crash.

I would caution against thinking the OEM solution is always superior. If you are above 5'9", the OEM Euro buckets and chassis mounting points are not safe due to the incorrect installation angles they create in the harnesses relative to the driver. As you undoubtedly are aware, the OEM mounting points are not in any way adjustable.

In any case, 5/6 point belts in this car maybe create false sense of security. They will hold you in more securely and may help to an extent in a frontal collision. However, this is a road car that is not even remotely close to complying with any serious race series regulations with regard to crash protection, be it cage, seat mounting, etc. If you get in an accident at high speeds, you will likely be seriously injured or killed, half-cage and 6-points or not.
How is the oem mount points unsafe for someone over 5'9"? i have euro buckets and harness so am curious.
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      09-01-2021, 08:43 AM   #20
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Quote:
Originally Posted by 4play View Post
Not sure what the insinuation is here. The Brey-Krause kit attaches the harnesses in the same way as factory race cars with sliders (911 Cup Cars, Ferrari Challenge, etc). It is perfectly safe and allows for adjustability for different drivers or simply to position the harnesses correctly for maximum effectiveness in a crash.

I would caution against thinking the OEM solution is always superior. If you are above 5'9", the OEM Euro buckets and chassis mounting points are not safe due to the incorrect installation angles they create in the harnesses relative to the driver. As you undoubtedly are aware, the OEM mounting points are not in any way adjustable.

In any case, 5/6 point belts in this car maybe create false sense of security. They will hold you in more securely and may help to an extent in a frontal collision. However, this is a road car that is not even remotely close to complying with any serious race series regulations with regard to crash protection, be it cage, seat mounting, etc. If you get in an accident at high speeds, you will likely be seriously injured or killed, half-cage and 6-points or not.
The message is do your homework. OE solutions, as flawed as they can be are tested, warrantied, regulated by governments, associations and industry standards. Aftermarket solutions can be very clever and cost effective but range from straight out copies of OE parts without any quality checks, production standards or industry standard testing to engineered and tested quality products. I worked in the OE and IAM automotive market and you would be stunned by the lack of quality standards.

There are suppliers to the IAM that do adhere to industry certifications/standards that provide tested solutions. That is the first thing to look for in safety items.

Belts/restraints are very technical subjects that require exact installation. I have seen many 5/6 point belts installed with the shoulder belts mounted to rear seat belt attachments and the sub belt over the front of the seat.

Finally safety is an evolving topic. For example lap belts for 5/6 point harnesses have gone from 3" to 2" (Schroth), helmet restraints have evolved into Hybrid devices and finally the BMW NA driving schools are conducted without helmets - Their reasoning is the car is fully secured with retractable belts, airbags and crush zones and not engineered for a driver wearing a 3# helmet.

I would like more information about the following:

"I would caution against thinking the OEM solution is always superior. If you are above 5'9", the OEM Euro buckets and chassis mounting points are not safe due to the incorrect installation angles they create in the harnesses relative to the driver. As you undoubtedly are aware, the OEM mounting points are not in any way adjustable."

Given that the M4 GTS was offered in Germany with the belt/seat combination, I would like more information. Thanks for the comment.

Just as I thought. SILENCE. Don't waste your time, money. Six point belts are the evolution of 5 point belts. Safety systems are tested to perform. Like I said before, Just stay with the factory 3 point before you engineer your own safety system.

Last edited by rcompound; 11-28-2023 at 09:11 PM.. Reason: Added content
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      03-19-2023, 04:38 PM   #21
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Sorry if this is resurrecting an old thread - has anyone seen or used this for harness mounts?

https://burkhart-engineering.com/en/...t-engineering/

It appears like it coukd be a better solution than the Bret Kraus?
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      03-20-2023, 07:08 PM   #22
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Quote:
Originally Posted by mikerunt View Post
Sorry if this is resurrecting an old thread - has anyone seen or used this for harness mounts?

https://burkhart-engineering.com/en/...t-engineering/

It appears like it coukd be a better solution than the Bret Kraus?
Per harness installation instructions I wouldn't consider this product. IIRC sub straps should be mounted 20 degrees behind the attachment point to the other belts, this puts it way further back than that and I've never seen a sub strap mounted this far back
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