5 point harness - Mazda3 Forums : The #1 Mazda 3 Forum
Reply
 
LinkBack Thread Tools
post #1 of 17 (permalink) Old 09-26-2013, 12:03 PM Thread Starter
Grand Am Series
 
arsprod's Avatar
 
Join Date: Feb 2009
Location: Indianapolis, IN
Posts: 423
5 point harness

Anyone ever tried putting 5-point harness in mz3 using stock seats? Yeah I know it sounds bizarre but I saw a Civic at the track last weekend that had done it with a harness bar and it looked like it worked well.

I am the Stig... Corksport SRI, Sure Torq R3, Sure BSD, JBR short shift plate, Eibach Pros, Koni yellows, Hotchkiss rear sway, EBC Yellow Stuff, Hankook Ventus RS-3 (track)
arsprod is offline  
Sponsored Links
Advertisement
 
post #2 of 17 (permalink) Old 09-26-2013, 12:19 PM
F1 Driver
 
philrab's Avatar
 
Join Date: Apr 2010
Location: Louisiana
Posts: 8,599
Why you should never use five point harnesses without a race seat and a rollbar/cage

Quote:
Originally Posted by arsprod View Post
Anyone ever tried putting 5-point harness in mz3 using stock seats? Yeah I know it sounds bizarre but I saw a Civic at the track last weekend that had done it with a harness bar and it looked like it worked well.
It's not recommended for one really good reason; the stock seat is not properly designed to support 5 point harnesses. Without the slots in the seat to locate the harness, there is a possibility that in a severe impact the harness could slip off your shoulders and off the top of the seat, and your face now becomes a crumple zone with the steering wheel. Also bare in mind that the airbag's discharge is calibrated assuming you are suspended by the seatbelt. If you slip free of the belt, your head is going to be moving a whole lot faster and further.

Beyond the belt not holding you, there is also the fact that three point belts are angled into the centerline of the vehicle in case of a roof collapsing during a rollover. In this scenario, your body will be displaced laterally towards the center of the vehicle. You'll still be injured, but more survivable than if the harness held you upright and your forehead has to support the sheetmetal roof as it collapses down on top of you.

Now with modern crash structures, the latter roof collapse if fairly unlikely, but the belts slipping off during impact because no part of the seat is making sure they are properly located is a definite possibility, and I've personally witnessed it.

2007 Phantom Purple hatch; JBR RMM/busihgs/shifter plate, Koni STR.t's, Michelin Pilot AS3's, Spin on oil filter conversion, stubby antenna, Kenwood KDC-X997 hu + Sundown Audio SA12 + Infinity speakers + JL 320.4 amp, debadged and door edge guards removed, Lamin-X + indy fog mod, aluminum AC knobs, DIY SRI, TRS 5000K HIDs, more coming.
Build Thread:
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


Newb Thread: please read this!!!
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
philrab is offline  
post #3 of 17 (permalink) Old 09-26-2013, 12:25 PM Thread Starter
Grand Am Series
 
arsprod's Avatar
 
Join Date: Feb 2009
Location: Indianapolis, IN
Posts: 423
Quote:
Originally Posted by philrab View Post
It's not recommended for one really good reason; the stock seat is not properly designed to support 5 point harnesses. Without the slots in the seat to locate the harness, there is a possibility that in a severe impact the harness could slip off your shoulders and off the top of the seat, and your face now becomes a crumple zone with the steering wheel. Also bare in mind that the airbag's discharge is calibrated assuming you are suspended by the seatbelt. If you slip free of the belt, your head is going to be moving a whole lot faster and further.

Beyond the belt not holding you, there is also the fact that three point belts are angled into the centerline of the vehicle in case of a roof collapsing during a rollover. In this scenario, your body will be displaced laterally towards the center of the vehicle. You'll still be injured, but more survivable than if the harness held you upright and your forehead has to support the sheetmetal roof as it collapses down on top of you.

Now with modern crash structures, the latter roof collapse if fairly unlikely, but the belts slipping off during impact because no part of the seat is making sure they are properly located is a definite possibility, and I've personally witnessed it.
That might be the most thorough and complete answer I've ever gotten! Thanks, 'nuf said!!

I am the Stig... Corksport SRI, Sure Torq R3, Sure BSD, JBR short shift plate, Eibach Pros, Koni yellows, Hotchkiss rear sway, EBC Yellow Stuff, Hankook Ventus RS-3 (track)
arsprod is offline  
Sponsored Links
Advertisement
 
post #4 of 17 (permalink) Old 09-26-2013, 12:28 PM
Senior Member
 
Join Date: Feb 2012
Location: Dayton, OH
Posts: 722
Here's a great tech article with diagrams and reasoning showing why a stock seat cannot safely run a 4 or 5 point harness.
http://www.pirate4x4.com/tech/billav...rness_install/


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

2009 Mazda 3i Touring /// Hawk HPS front pads /// Goodyear Eagle GT 205/50R17 on stock wheels /// Ghetto fabulous filled motor mount

Guinea pig for Dynotronics tuning.
flatlander937 is offline  
post #5 of 17 (permalink) Old 09-26-2013, 12:36 PM Thread Starter
Grand Am Series
 
arsprod's Avatar
 
Join Date: Feb 2009
Location: Indianapolis, IN
Posts: 423
Quote:
Originally Posted by flatlander937 View Post
Here's a great tech article with diagrams and reasoning showing why a stock seat cannot safely run a 4 or 5 point harness.
http://www.pirate4x4.com/tech/billav...rness_install/
Excellent - should be a sticky somewhere on the forum! I'll stick with stock belts and CG lock

I am the Stig... Corksport SRI, Sure Torq R3, Sure BSD, JBR short shift plate, Eibach Pros, Koni yellows, Hotchkiss rear sway, EBC Yellow Stuff, Hankook Ventus RS-3 (track)
arsprod is offline  
post #6 of 17 (permalink) Old 09-26-2013, 12:37 PM
F1 Driver
 
philrab's Avatar
 
Join Date: Apr 2010
Location: Louisiana
Posts: 8,599
Actually THISis the most complete answer.

If someone's looking for some of the benefits of a harness (holding you in the seat better) with a stock seat, google CGLock. Autocrossers in stock class use it all the time to prevent the stock seat belt from loosening, which helps pin your butt in the seat better.

2007 Phantom Purple hatch; JBR RMM/busihgs/shifter plate, Koni STR.t's, Michelin Pilot AS3's, Spin on oil filter conversion, stubby antenna, Kenwood KDC-X997 hu + Sundown Audio SA12 + Infinity speakers + JL 320.4 amp, debadged and door edge guards removed, Lamin-X + indy fog mod, aluminum AC knobs, DIY SRI, TRS 5000K HIDs, more coming.
Build Thread:
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


Newb Thread: please read this!!!
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
philrab is offline  
post #7 of 17 (permalink) Old 09-26-2013, 12:47 PM Thread Starter
Grand Am Series
 
arsprod's Avatar
 
Join Date: Feb 2009
Location: Indianapolis, IN
Posts: 423
Quote:
Originally Posted by philrab View Post
Actually THISis the most complete answer.

If someone's looking for some of the benefits of a harness (holding you in the seat better) with a stock seat, google CGLock. Autocrossers in stock class use it all the time to prevent the stock seat belt from loosening, which helps pin your butt in the seat better.
Guess you didn't see my response to flatlander first - already using CG Lock, love it! What it doesn't do is hold my upper body flat against the seat which is really nice when running long track stints

I am the Stig... Corksport SRI, Sure Torq R3, Sure BSD, JBR short shift plate, Eibach Pros, Koni yellows, Hotchkiss rear sway, EBC Yellow Stuff, Hankook Ventus RS-3 (track)
arsprod is offline  
post #8 of 17 (permalink) Old 09-26-2013, 01:06 PM
F1 Driver
 
XCNuse's Avatar
 
Join Date: Jun 2009
Location: Atlanta, GA
Posts: 14,003
Don't do it, you'll compress your back.. (because I've done it before, and it hurts.. bad).
Nor can the stock seat really hold the harness in place meaning it can't work properly.

For your stock seat belt, whenever doing runs or whatever I would suck it in (my chest), pull the seatbelt tight, and then pull hard out so it locks itself in place, and that always worked great for me.

'06 Whitewater Pearl build |
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
XCNuse is offline  
post #9 of 17 (permalink) Old 09-26-2013, 02:03 PM
Grand Am Series
 
Join Date: Jul 2012
Location: Rochester, NY
Posts: 496
I'm very happy with my CGlock for autocrossing. In fact, I feel so much more secure in the seat with it that I don't feel right without it anymore. I'm glad you've given up on the idea of a 5-point with a stock seat. It's a shitty way to get hurt or die.

That said, for autocross, I know people who have 4-point harnesses that use the rear seat buckle attachment points. This gives great support to your upper body. It would be a death trap in a track situation or a traffic incident, but if you use it ONLY for autocross it's not bad. It's still smart to have the variety with the breakaway stitching that lets the shoulder straps lengthen under high loads.

But again, just to be clear because this is sort of a life-or-death point: That's ONLY for use in an autocross situation where you're not at risk of high speed collisions with solid objects or other vehicles. This type of harness allows you to leave your stock seatbelts in place, and those are what should be used for regular driving.
ckingsley is offline  
post #10 of 17 (permalink) Old 09-26-2013, 03:08 PM
F1 Driver
 
philrab's Avatar
 
Join Date: Apr 2010
Location: Louisiana
Posts: 8,599
Quote:
Originally Posted by arsprod View Post
Guess you didn't see my response to flatlander first - already using CG Lock, love it! What it doesn't do is hold my upper body flat against the seat which is really nice when running long track stints
You posted before I could click the button. Brilliant minds think alike.

2007 Phantom Purple hatch; JBR RMM/busihgs/shifter plate, Koni STR.t's, Michelin Pilot AS3's, Spin on oil filter conversion, stubby antenna, Kenwood KDC-X997 hu + Sundown Audio SA12 + Infinity speakers + JL 320.4 amp, debadged and door edge guards removed, Lamin-X + indy fog mod, aluminum AC knobs, DIY SRI, TRS 5000K HIDs, more coming.
Build Thread:
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


Newb Thread: please read this!!!
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
philrab is offline  
Sponsored Links
Advertisement
 
Reply

  Mazda3 Forums : The #1 Mazda 3 Forum > Technical / Model / Performance > Autocross, Track, and Dyno Results

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Mazda3 Forums : The #1 Mazda 3 Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



  LinkBacks (?)
LinkBack to this Thread: http://www.mazda3forums.com/90-autocross-track-dyno-results/553490-5-point-harness.html
Posted By For Type Date
Autocross, Track, and Dyno Results [Archive] - Mazda3 Forums : The #1 Mazda 3 Forum This thread Refback 09-06-2015 01:13 PM

Similar Threads
Thread Thread Starter Forum Replies Last Post
4 point harness Adam3s Autocross, Track, and Dyno Results 78 05-31-2013 08:09 AM
FS: Speedware harness bar + Sparco 4 point harness for C4 Corvette tigermack General Buy/Sell 5 04-04-2008 06:25 PM
5 point harness in MS3 Ryz Autocross, Track, and Dyno Results 23 01-13-2008 11:30 PM
MOVED: 5 point harness CosmicBlueMS3 MazdaSpeed 0 11-10-2007 11:30 PM
3 point harness? Jebus Interior Modifications 6 03-09-2004 10:28 AM

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
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome
8