ZPOST
BMW Garage BMW Meets Register Search Today's Posts Mark Forums Read


Go Back   ZPOST > BMW Z4 Technical Talk > Track / Autocross / Dragstrip / Driving Techniques
  TireRack

SUPPORT ZPOST BY DOING YOUR TIRERACK SHOPPING FROM THIS BANNER, THANKS!
Post Reply
 
Thread Tools Search this Thread
      11-17-2015, 10:14 PM   #1
dfjaws
Lieutenant
dfjaws's Avatar
United_States
57
Rep
535
Posts

Drives: E90 M3 / E86 M Coupe
Join Date: Sep 2011
Location: Des Moines, IA

iTrader: (5)

Harness Bar Pictures

Hey everyone!

I've gotten a few PM's asking for some pictures of my harness bar so I thought I would post a new thread showing it and talking a little more about it.

I had it made by a machine and welding shop. They used 1.5" steel tubing to make it (no fancy chromoly tubing) and 1/8" steel plated for the ends. 1/4" bar was bent into shape and used for the harness guides. It is fairly easy to remove and install and doesn't require any interior disassembly aside from the B pillar covers and the top trim piece in the center of the rear shelf.

To install I drilled out the two existing holes in the B pillar and inserted a 3/8" 'nutsert' in each hole. In the center I just reused the two existing bolts under the center trim piece. It is VERY solid.

I wanted the bar to look nice as this is a street/autocross car so I had the bar powder coated gloss back and added a couple stickers (gopro sticker and a 'BMW Motorsport' sticker from eBay). I also purchased a second trim piece off of the forum from an interior part out and cut a notch so I can have a trim piece installed along with the bar. It doesn't serve a real function besides looking good but it really cleans up the look. The bar looks fantastic and is very solid.

All in, it cost me just under $500 USD. (Bar, powdercoat, and stickers)

I currently don't have pictures of my seat setup or the B pillars with the bar installed but I will get some shortly.

Hopefully this post will help those looking to have a bar built. Let me know what you guys think!

(More installed pictures coming... probably tomorrow)

image by Alex Jacobson, on Flickr

image by Alex Jacobson, on Flickr

image by Alex Jacobson, on Flickr

image by Alex Jacobson, on Flickr

image by Alex Jacobson, on Flickr
__________________

Last edited by dfjaws; 11-17-2015 at 10:22 PM..
Appreciate 1
inTgr8r2415.50
      01-24-2017, 04:00 PM   #2
Jackal
Private First Class
Jackal's Avatar
Canada
33
Rep
142
Posts

Drives: 2006 Z4MC (Bianca)
Join Date: Mar 2015
Location: Calgary Canada

iTrader: (0)

Little late to the party on viewing this, but I dig it. I'd be interested in seeing the two side mounts for the bar while in place. I realize it's a long time ago, but you wouldn't have any dimensions for the setup?

I have been contemplating using harnesses in the Z. I have a set of Schroth quick fits for the 135i that I loved because they were so easy to clip in and go.
__________________
Light a man a fire, you keep him warm for a night. Light a man ON fire,you keep him warm the rest of his life.
Appreciate 0
      01-27-2017, 12:08 PM   #3
3002 tii
Lieutenant General
3002 tii's Avatar
United_States
2199
Rep
12,492
Posts

Drives: Z4 M, 550i, X3
Join Date: Apr 2008
Location: CT

iTrader: (99)

Garage List
Quote:
Originally Posted by Jackal View Post
Little late to the party on viewing this, but I dig it. I'd be interested in seeing the two side mounts for the bar while in place. I realize it's a long time ago, but you wouldn't have any dimensions for the setup?

I have been contemplating using harnesses in the Z. I have a set of Schroth quick fits for the 135i that I loved because they were so easy to clip in and go.
Don't the quick fits get routed under the headrest though? If so seems like you'd have to switch out seats to aftermarket if you want to use harnesses.
__________________
Follow for latest mods
Appreciate 0
      01-27-2017, 01:46 PM   #4
Jackal
Private First Class
Jackal's Avatar
Canada
33
Rep
142
Posts

Drives: 2006 Z4MC (Bianca)
Join Date: Mar 2015
Location: Calgary Canada

iTrader: (0)

I wasn't clear in my last message. I wasn't planning on using the quick fits in the Z. I feel that it could be possible though, by removing the metal crossover that the two shoulder harnesses go through, and wrapping them to a bar, using the appropriate wrap hardware and using the hoops you have to keep them in place on the bar.

I only autocross really (for now), and like the planted in the seat feel of a harness. The plan moving forward is a harness bar and a set of four points wherever I get them from. It also gives me a good place to mount the onboard camera where I should be able to review my control inputs.

I know a full roll bar is the only way to make the setup more safe for all types of incidents, but the four point is still safer for all types of impacts except a rollover.

I'd love to know more about the harness bar and how it's connecting to the B pillar on your setup.
Appreciate 0
      01-27-2017, 05:04 PM   #5
dc_wright
Captain
dc_wright's Avatar
249
Rep
758
Posts

Drives: 2006 Z43.0si Roadster
Join Date: Oct 2014
Location: Orlando, FL

iTrader: (0)

Quote:
Originally Posted by Jackal View Post
Little late to the party on viewing this, but I dig it. I'd be interested in seeing the two side mounts for the bar while in place. I realize it's a long time ago, but you wouldn't have any dimensions for the setup?

I have been contemplating using harnesses in the Z. I have a set of Schroth quick fits for the 135i that I loved because they were so easy to clip in and go.
In the interim until you get an actual harness bar and harness, a CG Lock and torso strap make a huge difference in holding you in place in the seat.

http://www.cg-lock.com/autocross.html

http://www.gforce.com/products/netsanres/4290.php
__________________
Top Down 365
Appreciate 2
inTgr8r2415.50
kaybat125.50
      01-27-2017, 06:04 PM   #6
Jackal
Private First Class
Jackal's Avatar
Canada
33
Rep
142
Posts

Drives: 2006 Z4MC (Bianca)
Join Date: Mar 2015
Location: Calgary Canada

iTrader: (0)

Quote:
Originally Posted by dc_wright View Post
In the interim until you get an actual harness bar and harness, a CG Lock and torso strap make a huge difference in holding you in place in the seat.

http://www.cg-lock.com/autocross.html

http://www.gforce.com/products/netsanres/4290.php
I've used the CG lock before on a couple of my other autocross cars. I prefer using the three point and snap technique to the CG.

I've never used the torso strap though.
Appreciate 0
      01-27-2017, 06:24 PM   #7
inTgr8r
Lieutenant General
inTgr8r's Avatar
Canada
2416
Rep
11,664
Posts

Drives: M2 Comp
Join Date: Mar 2006
Location: Toronto

iTrader: (10)

Quote:
Originally Posted by Jackal View Post
I've used the CG lock before on a couple of my other autocross cars. I prefer using the three point and snap technique to the CG.

I've never used the torso strap though.
+1
The 3 point + snap works quite well.
__________________
'21 M2C Hockenheim Silver
'18 718 Cayman S Lava Orange (sold)
'13 E92 M3 Santorini Blue (sold)
'07 Z4 M Coupe Alpine White (sold)
Appreciate 0
      01-27-2017, 09:02 PM   #8
dc_wright
Captain
dc_wright's Avatar
249
Rep
758
Posts

Drives: 2006 Z43.0si Roadster
Join Date: Oct 2014
Location: Orlando, FL

iTrader: (0)

Quote:
Originally Posted by inTgr8r View Post
+1
The 3 point + snap works quite well.
It does, but it sometimes takes a couple tries to both get the 3 point locked and tight and the seat position where you want it. With the CG Lock and the torso strap you're secured just as well and you don't have to mess around with seat position. For a PDX/HPDE session it's not as much an issue as it is for autocross where you're in and out of the car a lot. You can also independently adjust the tension between the lap and the upper body, which is harder to do with the 3 point snap method. The torso strap also gives more lateral support with less tension than the 3 point does.

Don't get me wrong, I much prefer a 4 or 5 point harness (I had Schroth clip ins for both the E36 and E46), but you don't have much of an option for installing them without serious mods on a Z4R.
__________________
Top Down 365
Appreciate 0
      01-28-2017, 08:57 AM   #9
inTgr8r
Lieutenant General
inTgr8r's Avatar
Canada
2416
Rep
11,664
Posts

Drives: M2 Comp
Join Date: Mar 2006
Location: Toronto

iTrader: (10)

Yeah, the snap method is definitely fiddely.
I have manual seats, so it's even more of a challenge sometimes.
__________________
'21 M2C Hockenheim Silver
'18 718 Cayman S Lava Orange (sold)
'13 E92 M3 Santorini Blue (sold)
'07 Z4 M Coupe Alpine White (sold)
Appreciate 0
      02-01-2017, 12:47 PM   #10
dc_wright
Captain
dc_wright's Avatar
249
Rep
758
Posts

Drives: 2006 Z43.0si Roadster
Join Date: Oct 2014
Location: Orlando, FL

iTrader: (0)

Quote:
Originally Posted by Jackal View Post
I've used the CG lock before on a couple of my other autocross cars. I prefer using the three point and snap technique to the CG.

I've never used the torso strap though.
The torso strap gives a surprising amount of lateral support compared to the cross chest strap from the 3 point. My 3.0si Roadster has the standard seats, which have about as much lateral support as an armless wooden dining room chair, so I cinch the lap belt down to the point of almost forcing out pee, and then light tension on the torso strap so I can still breathe. Same for on track, otherwise I'm having to "butt squirm" back into the center of the seat after every hard corner.

If anyone's spotted a harness bar that could be fitted a Roadster, PM please!
__________________
Top Down 365
Appreciate 0
      02-01-2017, 06:13 PM   #11
inTgr8r
Lieutenant General
inTgr8r's Avatar
Canada
2416
Rep
11,664
Posts

Drives: M2 Comp
Join Date: Mar 2006
Location: Toronto

iTrader: (10)

I would love to have full harness, but the thing that holds me back from a harness bar (or the torso strap?? ),
is the argument that has been put forward several times here regarding roll over w/o out a half cage...
__________________
'21 M2C Hockenheim Silver
'18 718 Cayman S Lava Orange (sold)
'13 E92 M3 Santorini Blue (sold)
'07 Z4 M Coupe Alpine White (sold)
Appreciate 0
      02-01-2017, 06:59 PM   #12
Jackal
Private First Class
Jackal's Avatar
Canada
33
Rep
142
Posts

Drives: 2006 Z4MC (Bianca)
Join Date: Mar 2015
Location: Calgary Canada

iTrader: (0)

Quote:
Originally Posted by inTgr8r View Post
I would love to have full harness, but the thing that holds me back from a harness bar (or the torso strap?? ),
is the argument that has been put forward several times here regarding roll over w/o out a half cage...
Rollover crashes make up less than 30% of all crashes on the road. This includes all the vehicles that are prone to rolling. For passenger cars its somewhere around 22%. The harness will be safer in 70% of the crashes out there, and in 78% of the crashes involving our kind of cars.

Only using the harness for race days further mitigates the chance that the harness will do anything but help in an incident. Meanwhile the benefits to racing are pretty significant.
__________________
Light a man a fire, you keep him warm for a night. Light a man ON fire,you keep him warm the rest of his life.
Appreciate 1
inTgr8r2415.50
      02-02-2017, 08:57 AM   #13
inTgr8r
Lieutenant General
inTgr8r's Avatar
Canada
2416
Rep
11,664
Posts

Drives: M2 Comp
Join Date: Mar 2006
Location: Toronto

iTrader: (10)

Is this insurance industry data?
__________________
'21 M2C Hockenheim Silver
'18 718 Cayman S Lava Orange (sold)
'13 E92 M3 Santorini Blue (sold)
'07 Z4 M Coupe Alpine White (sold)
Appreciate 0
      02-02-2017, 11:35 AM   #14
Jackal
Private First Class
Jackal's Avatar
Canada
33
Rep
142
Posts

Drives: 2006 Z4MC (Bianca)
Join Date: Mar 2015
Location: Calgary Canada

iTrader: (0)

Quote:
Originally Posted by inTgr8r View Post
Is this insurance industry data?
It's slightly older National Highway Traffic Safety Administration (NHTSA) data.

I'm confident that for the minimal amount of use harnesses would get in my specific case, they will provide more benefit than risk.
__________________
Light a man a fire, you keep him warm for a night. Light a man ON fire,you keep him warm the rest of his life.
Appreciate 0
      02-02-2017, 02:46 PM   #15
inTgr8r
Lieutenant General
inTgr8r's Avatar
Canada
2416
Rep
11,664
Posts

Drives: M2 Comp
Join Date: Mar 2006
Location: Toronto

iTrader: (10)

Quote:
Originally Posted by Jackal View Post
It's slightly older National Highway Traffic Safety Administration (NHTSA) data.

I'm confident that for the minimal amount of use harnesses would get in my specific case, they will provide more benefit than risk.
the idea of this is really growing on me......
I'd love to be better planted in the seat, but I'm definitely not going the cage route.


One thing that I wonder about with this bar is the height.
IIRC, aren't the shoulder belts supposed to go straight back, or slightly down.
With this bar it looks like the shoulder harness would angle up from the shoulder?

dfjaws , is there any chance you can provide some input on this?
Now that you've had it for a while, how well has it worked out?
__________________
'21 M2C Hockenheim Silver
'18 718 Cayman S Lava Orange (sold)
'13 E92 M3 Santorini Blue (sold)
'07 Z4 M Coupe Alpine White (sold)
Appreciate 0
      02-03-2017, 11:53 AM   #16
Jackal
Private First Class
Jackal's Avatar
Canada
33
Rep
142
Posts

Drives: 2006 Z4MC (Bianca)
Join Date: Mar 2015
Location: Calgary Canada

iTrader: (0)

Quote:
Originally Posted by inTgr8r View Post
the idea of this is really growing on me......
I'd love to be better planted in the seat, but I'm definitely not going the cage route.


One thing that I wonder about with this bar is the height.
IIRC, aren't the shoulder belts supposed to go straight back, or slightly down.
With this bar it looks like the shoulder harness would angle up from the shoulder?

dfjaws , is there any chance you can provide some input on this?
Now that you've had it for a while, how well has it worked out?
Harnesses that go upward as they gain distance from the shoulders do allow a little movement of the shoulders upward. This is largely mitigated by the tension placed on the main buckle by the side belts, and if you use a 5th point it helps to prevent this upward movement as well.

Still would love to see some detail on the mounting in the B-pillar as well, but I realize this can be a pain once it's all put back together.
__________________
Light a man a fire, you keep him warm for a night. Light a man ON fire,you keep him warm the rest of his life.
Appreciate 0
      02-03-2017, 01:21 PM   #17
dc_wright
Captain
dc_wright's Avatar
249
Rep
758
Posts

Drives: 2006 Z43.0si Roadster
Join Date: Oct 2014
Location: Orlando, FL

iTrader: (0)

Quote:
Originally Posted by Jackal View Post
Harnesses that go upward as they gain distance from the shoulders do allow a little movement of the shoulders upward. This is largely mitigated by the tension placed on the main buckle by the side belts, and if you use a 5th point it helps to prevent this upward movement as well.

Still would love to see some detail on the mounting in the B-pillar as well, but I realize this can be a pain once it's all put back together.
This, plus if you're using a HANS it's not secured as well.
__________________
Top Down 365
Appreciate 0
      04-21-2017, 12:02 PM   #18
dfjaws
Lieutenant
dfjaws's Avatar
United_States
57
Rep
535
Posts

Drives: E90 M3 / E86 M Coupe
Join Date: Sep 2011
Location: Des Moines, IA

iTrader: (5)

Hey guys! Sorry, for some reason I didn't realize this discussion was ongoing. I think it's because my iPad stopped signing me in so I wasn't getting the notifications.

To answer the question regarding shoulder belt angle, yes, from what I understand straighter is better. Somewhere between +10 degrees and -15 degrees from horizontal. Unfortunately, there isn't really a good way to achieve that without cutting or removing significant interior bits and I just am not willing to do that with this car. Maybe one day, but not for now. I think the shoulder belts are pretty much just as functional though due to the size and shape of the harness pass throughs on my (Recaro Pole Position) seat. Because the top of the hole is lower than on say a SPG XL it ends up keeping the belt lower off my shoulder and therefore straighter. I'm sure this could vary significantly with body type and seat model/style. I have a standard sized pole position and I'm 5' 9" and my shoulders fall in just the right spot.

Overall, I am still very happy with my bar and I don't think I would do anything differently. It fits my needs perfectly in terms of having a solid place to mount a barness for autocross driving while at the same time having little impact on the use ability of the car and being totally and easily reversible. Maybe the only other worthwhile note is that you do lose rearward seat movement space with a bar of this style although, it is not an issue with a race seat since the net gain by having a thinner backed seat still ends up increasing room overall. The only time I even think about it is if someone tall rides in my passenger seat (stock seat) and then they try to scoot the seat back and just press it into the bar.
__________________
Appreciate 0
      04-21-2017, 12:38 PM   #19
dfjaws
Lieutenant
dfjaws's Avatar
United_States
57
Rep
535
Posts

Drives: E90 M3 / E86 M Coupe
Join Date: Sep 2011
Location: Des Moines, IA

iTrader: (5)

Here are a couple more pictures if it helps. Let me know if you guys want any more specifics pics of anything. The last picture is me pulling forward on my harness strap to help illustrate the point I was trying to explain about the seat holding the straps more or less straight even though the bar is higher.
Attached Images
   
__________________
Appreciate 1
inTgr8r2415.50
      04-21-2017, 01:30 PM   #20
Jackal
Private First Class
Jackal's Avatar
Canada
33
Rep
142
Posts

Drives: 2006 Z4MC (Bianca)
Join Date: Mar 2015
Location: Calgary Canada

iTrader: (0)

Awesome! Greatly appreciate it!!
__________________
Light a man a fire, you keep him warm for a night. Light a man ON fire,you keep him warm the rest of his life.
Appreciate 0
      04-23-2017, 02:11 AM   #21
Vanne
Down Under!!
Vanne's Avatar
United Arab Emirates
1586
Rep
4,290
Posts

Drives: 2007 Z4MC
Join Date: Mar 2013
Location: Dubai

iTrader: (4)

Just quickly looking at the angel those sabelt straps come into the chair.. thats not the best idea.. thats 45 degrees plus..

__________________
2007 EuroSpec Z4///MC - Building/Developing Z4 GT3
Powered by

Last edited by Vanne; 04-23-2017 at 02:25 AM..
Appreciate 0
      04-24-2017, 03:50 PM   #22
dfjaws
Lieutenant
dfjaws's Avatar
United_States
57
Rep
535
Posts

Drives: E90 M3 / E86 M Coupe
Join Date: Sep 2011
Location: Des Moines, IA

iTrader: (5)

Quote:
Originally Posted by Vanne View Post
Just quickly looking at the angel those sabelt straps come into the chair.. thats not the best idea.. thats 45 degrees plus..

Agreed, it's not ideal, however it works very well for holding me in my seat during autocross runs which was my main goal with this piece. Also, despite the non ideal angle, I get zero upward movement since the belts come off of my shoulders nearly parallel due to the pass-through placement on the seat itself. Overall, I'm still very happy with it.
Appreciate 0
Post Reply

Bookmarks

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -5. The time now is 09:37 AM.




zpost
Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST