Brey Krause R-1046 Harness Mount Truss
08-30-2016, 11:20 AM
#31
Drifting
08-30-2016, 11:48 AM
#33
Rennlist Member
Thanks for the installation photos and tips. Nicely done.
08-30-2016, 03:37 PM
#34
Very nice! I'll have to call them for tips on the carpet cutting.
By the way, I spoke with Schroth about the whole adjuster length thing after receiving some feedback that my 3-bar adjusters were too far from the B24 bracket.
Schroth confirmed that the adjusters should be as close to the bracket loop as possible, but not for the reason many think. They said having long sections of double belt does not cause an increased risk of "belt stretch" (in fact, double belt sections stretch *less* than single belt since the forces are halved over the same lengths, think about two rubber band in parallel vs. single band with the same total force). They said the issue is with "micro-slippage" of the adjuster when there is longer lengths of belt between the adjuster and the brackets in the "shock" event of an impact, and that having the adjusters right up against the brackets (which changes the angle of the belts as they leave the adjusters and go up and around the brackets, or the bars in other installations) helps prevent the belts from working any length out of the adjusters.
So that being said, their recommendation for a compact installation was to either:
1) use a B63 bracket (built-in 3-bar), which gives the thinnest solution but sticks out slightly further in the plane of the belt, or
2) use a B24 in combination with an LV4 2-bar adjuster, which is a thicker total solution once wrapped, but sticks out the least along the plane of the belt
Here is the LV4:
You can see an example of the LV4 in use here:
And here's a quick solution size comparison:
I think I'll be swapping over to the B63 bracket to keep things simple and thin behind the carpet. Either way the belt and/or bracket tips will will extend through the carpet cut. I suspect the B63 is still short enough to stay hidden with only the belt exiting.
By the way, I spoke with Schroth about the whole adjuster length thing after receiving some feedback that my 3-bar adjusters were too far from the B24 bracket.
Schroth confirmed that the adjusters should be as close to the bracket loop as possible, but not for the reason many think. They said having long sections of double belt does not cause an increased risk of "belt stretch" (in fact, double belt sections stretch *less* than single belt since the forces are halved over the same lengths, think about two rubber band in parallel vs. single band with the same total force). They said the issue is with "micro-slippage" of the adjuster when there is longer lengths of belt between the adjuster and the brackets in the "shock" event of an impact, and that having the adjusters right up against the brackets (which changes the angle of the belts as they leave the adjusters and go up and around the brackets, or the bars in other installations) helps prevent the belts from working any length out of the adjusters.
So that being said, their recommendation for a compact installation was to either:
1) use a B63 bracket (built-in 3-bar), which gives the thinnest solution but sticks out slightly further in the plane of the belt, or
2) use a B24 in combination with an LV4 2-bar adjuster, which is a thicker total solution once wrapped, but sticks out the least along the plane of the belt
Here is the LV4:
You can see an example of the LV4 in use here:
And here's a quick solution size comparison:
I think I'll be swapping over to the B63 bracket to keep things simple and thin behind the carpet. Either way the belt and/or bracket tips will will extend through the carpet cut. I suspect the B63 is still short enough to stay hidden with only the belt exiting.
Last edited by Mech33; 08-30-2016 at 05:20 PM.
The following users liked this post:
clib (03-13-2021)
08-31-2016, 11:43 AM
#36
Rennlist Member
At the annual BMW instructors clinic sponsored by the Genesee Valley Chapter we had a long seminar about head and neck restraints and how to mount them. The forces that can arise in a head-on collision are stunning. The upshot was that bracing the harness bar to the rear shock towers was highly desirable. That leaves this solution out.
On a related topic, even the best head restraint seats (which the LWBs in my GT4 are not) need a good window and right side net to keep the driver's head contained in an offset frontal collision. That's what I'm doing with my race car.
08-31-2016, 12:31 PM
#37
Rennlist Member
I could see the aluminum cross member deforming under multi G deceleration with body attached, but maybe good enough for DE.
Last edited by d00d; 10-29-2017 at 09:44 AM.
08-31-2016, 01:19 PM
#38
I really like the way this manner of securing shoulder harnesses works--low cost, clean install and little or no cutting.
At the annual BMW instructors clinic sponsored by the Genesee Valley Chapter we had a long seminar about head and neck restraints and how to mount them. The forces that can arise in a head-on collision are stunning. The upshot was that bracing the harness bar to the rear shock towers was highly desirable. That leaves this solution out.
On a related topic, even the best head restraint seats (which the LWBs in my GT4 are not) need a good window and right side net to keep the driver's head contained in an offset frontal collision. That's what I'm doing with my race car.
At the annual BMW instructors clinic sponsored by the Genesee Valley Chapter we had a long seminar about head and neck restraints and how to mount them. The forces that can arise in a head-on collision are stunning. The upshot was that bracing the harness bar to the rear shock towers was highly desirable. That leaves this solution out.
On a related topic, even the best head restraint seats (which the LWBs in my GT4 are not) need a good window and right side net to keep the driver's head contained in an offset frontal collision. That's what I'm doing with my race car.
Last edited by Mech33; 08-31-2016 at 11:37 PM.
09-01-2016, 12:01 PM
#39
If anyone has questions regarding the R-1046 or parts involved, I can answer them. I was asked to share some of the testing information we gathered while engineering this product. Last time I talked about our products on here I got flagged, so if I am crossing any forum lines here please let me know.
Just a little background on this product. We explored several options for mounting shoulder belts; all required a lot of cutting panels or locating harnesses at incorrect angles. When we came up with this design, we knew it would meet all of our requirements. However, our number one concern was the strength of the factory aluminum cross member. Something that we burn into our engineers heads is a product is only as good as what it is attached too. This is something I hope everyone thinks about when purchasing safety products.
As many of you may know, we are the only company in the industry (that I know of) that has all production harness mounts and load bearing mounts tensile tested (by an independent lab). The reason we test our products is not to see if they work-- If we were unsure of our engineering and production methods we wouldn’t be making safety products. We test our products to show you guys that, after over 100 years experience in metal fabrication and 26 years in the automotive industry, we make a product you can always trust to be the best.
(The important stuff)
Being that the load of our harness mount is placed on the aluminum cross member we decided it was crucial to test the cross member assembly as well as our mounts. We tested the whole R-1046 assembly with the factory cross member. Without getting too much into DOT, NHTSA, and SAE testing standards, the tensile test performed by/for DOT, SAE NHTSA for motor vehicle seat belt anchorages requires occupant restraints be tensile tested to 3,000lbs.. We tensile tested the assembly (incl. 2-R-1046 and Porsche cross member) to 6,700lbs. with less than about 5% deflection or deformation. If we tested to failure, I am sure that number would be much higher. If you would like see how it held up, the pictures we used on our website are actually the pieces that we pull tested.
To put these numbers in perspective, Fernando Alonso last big crash recorded forces as high as 46G’s at 193mph. Let's say you weight 160lbs. That would mean in a 41.875G impact you would weight 6,700lbs. Keep in mind that 6,700lbs should be distributed evenly to each point of you harnesses.
Someone mentioned that deforming after multiple uses was a concern. I am assuming implying that the aluminum will work harden resulting in cracking or failure. While this a issue with aluminum, I am certain that the repeated movement from putting on belts and vibration from being strapped in is nowhere near enough to work harden the cross member. The cross member job is to stiffen the chassis, so by design it was made to withstand these types of forces. I can not speak for Porsche's part. However, if I know Porsche like I think I do, it’s well engineered and exceeds the strength requirements for that task.
Just a little background on this product. We explored several options for mounting shoulder belts; all required a lot of cutting panels or locating harnesses at incorrect angles. When we came up with this design, we knew it would meet all of our requirements. However, our number one concern was the strength of the factory aluminum cross member. Something that we burn into our engineers heads is a product is only as good as what it is attached too. This is something I hope everyone thinks about when purchasing safety products.
As many of you may know, we are the only company in the industry (that I know of) that has all production harness mounts and load bearing mounts tensile tested (by an independent lab). The reason we test our products is not to see if they work-- If we were unsure of our engineering and production methods we wouldn’t be making safety products. We test our products to show you guys that, after over 100 years experience in metal fabrication and 26 years in the automotive industry, we make a product you can always trust to be the best.
(The important stuff)
Being that the load of our harness mount is placed on the aluminum cross member we decided it was crucial to test the cross member assembly as well as our mounts. We tested the whole R-1046 assembly with the factory cross member. Without getting too much into DOT, NHTSA, and SAE testing standards, the tensile test performed by/for DOT, SAE NHTSA for motor vehicle seat belt anchorages requires occupant restraints be tensile tested to 3,000lbs.. We tensile tested the assembly (incl. 2-R-1046 and Porsche cross member) to 6,700lbs. with less than about 5% deflection or deformation. If we tested to failure, I am sure that number would be much higher. If you would like see how it held up, the pictures we used on our website are actually the pieces that we pull tested.
To put these numbers in perspective, Fernando Alonso last big crash recorded forces as high as 46G’s at 193mph. Let's say you weight 160lbs. That would mean in a 41.875G impact you would weight 6,700lbs. Keep in mind that 6,700lbs should be distributed evenly to each point of you harnesses.
Someone mentioned that deforming after multiple uses was a concern. I am assuming implying that the aluminum will work harden resulting in cracking or failure. While this a issue with aluminum, I am certain that the repeated movement from putting on belts and vibration from being strapped in is nowhere near enough to work harden the cross member. The cross member job is to stiffen the chassis, so by design it was made to withstand these types of forces. I can not speak for Porsche's part. However, if I know Porsche like I think I do, it’s well engineered and exceeds the strength requirements for that task.
The following 3 users liked this post by lmw:
09-01-2016, 12:15 PM
#40
Rennlist Member
Thanks lmw, good to see these were tested.
The 6,700lb load was distributed over two R-1046, so 3,350lb each?
The 6,700lb load was distributed over two R-1046, so 3,350lb each?
Last edited by d00d; 10-29-2017 at 09:42 AM.
09-01-2016, 12:26 PM
#41
Thanks lmw, good to see these were tested.
The 6,700lb load was distributed over two R-1046, so 3,350lb each?
__________________
2016 white/black GT4;
https://rennlist.com/forums/gt4/9321...e-journal.html
2008 white/amaretto S8
The 6,700lb load was distributed over two R-1046, so 3,350lb each?
__________________
2016 white/black GT4;
https://rennlist.com/forums/gt4/9321...e-journal.html
2008 white/amaretto S8
Yep, that is correct.
09-02-2016, 04:55 AM
#43
Thank you for sharing! It's nice to know these parts have been load tested to some standards.
This product is such a simple concept. Love it!
This product is such a simple concept. Love it!
If anyone has questions regarding the R-1046 or parts involved, I can answer them. I was asked to share some of the testing information we gathered while engineering this product. Last time I talked about our products on here I got flagged, so if I am crossing any forum lines here please let me know.
Just a little background on this product. We explored several options for mounting shoulder belts; all required a lot of cutting panels or locating harnesses at incorrect angles. When we came up with this design, we knew it would meet all of our requirements. However, our number one concern was the strength of the factory aluminum cross member. Something that we burn into our engineers heads is a product is only as good as what it is attached too. This is something I hope everyone thinks about when purchasing safety products.
As many of you may know, we are the only company in the industry (that I know of) that has all production harness mounts and load bearing mounts tensile tested (by an independent lab). The reason we test our products is not to see if they work-- If we were unsure of our engineering and production methods we wouldn’t be making safety products. We test our products to show you guys that, after over 100 years experience in metal fabrication and 26 years in the automotive industry, we make a product you can always trust to be the best.
(The important stuff)
Being that the load of our harness mount is placed on the aluminum cross member we decided it was crucial to test the cross member assembly as well as our mounts. We tested the whole R-1046 assembly with the factory cross member. Without getting too much into DOT, NHTSA, and SAE testing standards, the tensile test performed by/for DOT, SAE NHTSA for motor vehicle seat belt anchorages requires occupant restraints be tensile tested to 3,000lbs.. We tensile tested the assembly (incl. 2-R-1046 and Porsche cross member) to 6,700lbs. with less than about 5% deflection or deformation. If we tested to failure, I am sure that number would be much higher. If you would like see how it held up, the pictures we used on our website are actually the pieces that we pull tested.
To put these numbers in perspective, Fernando Alonso last big crash recorded forces as high as 46G’s at 193mph. Let's say you weight 160lbs. That would mean in a 41.875G impact you would weight 6,700lbs. Keep in mind that 6,700lbs should be distributed evenly to each point of you harnesses.
Someone mentioned that deforming after multiple uses was a concern. I am assuming implying that the aluminum will work harden resulting in cracking or failure. While this a issue with aluminum, I am certain that the repeated movement from putting on belts and vibration from being strapped in is nowhere near enough to work harden the cross member. The cross member job is to stiffen the chassis, so by design it was made to withstand these types of forces. I can not speak for Porsche's part. However, if I know Porsche like I think I do, it’s well engineered and exceeds the strength requirements for that task.
Just a little background on this product. We explored several options for mounting shoulder belts; all required a lot of cutting panels or locating harnesses at incorrect angles. When we came up with this design, we knew it would meet all of our requirements. However, our number one concern was the strength of the factory aluminum cross member. Something that we burn into our engineers heads is a product is only as good as what it is attached too. This is something I hope everyone thinks about when purchasing safety products.
As many of you may know, we are the only company in the industry (that I know of) that has all production harness mounts and load bearing mounts tensile tested (by an independent lab). The reason we test our products is not to see if they work-- If we were unsure of our engineering and production methods we wouldn’t be making safety products. We test our products to show you guys that, after over 100 years experience in metal fabrication and 26 years in the automotive industry, we make a product you can always trust to be the best.
(The important stuff)
Being that the load of our harness mount is placed on the aluminum cross member we decided it was crucial to test the cross member assembly as well as our mounts. We tested the whole R-1046 assembly with the factory cross member. Without getting too much into DOT, NHTSA, and SAE testing standards, the tensile test performed by/for DOT, SAE NHTSA for motor vehicle seat belt anchorages requires occupant restraints be tensile tested to 3,000lbs.. We tensile tested the assembly (incl. 2-R-1046 and Porsche cross member) to 6,700lbs. with less than about 5% deflection or deformation. If we tested to failure, I am sure that number would be much higher. If you would like see how it held up, the pictures we used on our website are actually the pieces that we pull tested.
To put these numbers in perspective, Fernando Alonso last big crash recorded forces as high as 46G’s at 193mph. Let's say you weight 160lbs. That would mean in a 41.875G impact you would weight 6,700lbs. Keep in mind that 6,700lbs should be distributed evenly to each point of you harnesses.
Someone mentioned that deforming after multiple uses was a concern. I am assuming implying that the aluminum will work harden resulting in cracking or failure. While this a issue with aluminum, I am certain that the repeated movement from putting on belts and vibration from being strapped in is nowhere near enough to work harden the cross member. The cross member job is to stiffen the chassis, so by design it was made to withstand these types of forces. I can not speak for Porsche's part. However, if I know Porsche like I think I do, it’s well engineered and exceeds the strength requirements for that task.
09-02-2016, 11:48 PM
#44
Considering these. Wondering - can we us snap in shoulder harnesses, a B14 and B23B combo? I like the idea of being able to remove the harnesses when not in use. Maybe not enough room behind the seats?
09-03-2016, 02:39 AM
#45
Rennlist Member
Hey Guys great info and great pictures !!
Marty great job and picts !
Marty great job and picts !