Hey guys, Im looking into the idea of trying to make me stay in my seat during autocross events a little better. Ive searched and I realize that harness bars have a hot debate around them. Are they infact suitable for autocross use?

Really what I am looking for is a solution for 06+ wrx which officially eliminates Schroth Quick fit solutions from the list. Is there a manufacturer of another belt product similar to the quick fit but for newer cars?.. Im looking for something DOT approved for peace of mind. There hasnt been a lot of reliable information on any thing DOT safe for 06+ cars.

I drive a 2007 sedan NOT the TR model, so I have the better seats to start with... but I am 6'5". Is it possible for the harness straps on such a quick fit type setup to go over my shoulders but NOT through the hole in the backrest, instead stratling the seat upright?

Does a solution exist? What do I need to look into?

Im going to be in street modified, and last year I was having to hold my self in position with my hands and the wheel. Not the best solution.

Have you looked at CG-lock? It only holds your lower body but still better than nothing.

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

Another trick I use, which might not work for you, is to slide the seat back, yank on the shoulder strap causing it to lock then slide the seat forward to keep tension so it would stay locked.

+1 on the CG-Lock. I used one at my last 2 autocross events and it really made a difference. Cheap step before going to a full harness/bar setup, and it is autocross legal. Not as supportive as a full harness, but it was worth the $ for me.

The Quickfit doesn't work with the 06-07?? Weird. There shouldn't be anything majorly different in any parts of the interior from the 05.

Anyway, the basic Schroth Rallye3 or Rallye4 work great. I reccomend the 3, and anchoring the shoulder straps to the rear seatbelt reel (just behind the rear passenger shoulder.. probably accessable from the trunk in the sedan)

When not in use, the harness just stashes underneath the front seat.. with the only part visible being the 10" or so of the shoulder anchor. I've been doing this for 6 years and in 3 different vehicles (still haven't installed it into my STI.. but I will).

The basic one will work, but when they come through the seat, the will contact your shoulders directly, not the seat then your shoulders. This is "ok" for autocross as the likelihood of a crash is remote and won't be a huge castatrophic event. For DD, this would be bad as street accidents are a lot less controlled and your spine would compress.

Belts will not do much to keep you from moving laterally. That is the job of the seat. Stock seats just don't have the side bolsters to get it done. You can either go the way of a fixed back race seat or you can find a reclining 'race' seat. Until you upgrade the seat you'll always be bracing yourself to some level.

I use the stock seat belt. I adjust the seat height lever lower than I want, then pull the belt tight and lock it. Now adjust the seat height to hold you. I usually give it an extra bump up as I am a couple of cars back from the start. I feel very secure that way and actually stopped using my 4-pt harness.

I know some people use a "Turner strap," which is essentially a strip of velcro around the upper torso, holding you to the seat.

I'm not a fan of "no lateral movement," so I haven't used them. I have used the CG-lock (it's in my Camaro) though, to keep my butt planted.

Karen

Belts will not do much to keep you from moving laterally. That is the job of the seat. Stock seats just don't have the side bolsters to get it done. You can either go the way of a fixed back race seat or you can find a reclining 'race' seat. Until you upgrade the seat you'll always be bracing yourself to some level.

I use the schroth rallye 4 and when it's tight, I don't slide sideways at all or need bracing in the stock seats..

+1 more for the CG Lock. I used one in my former '06 WRX and my current RX-8. It's great!

I use the schroth rallye 4 and when it's tight, I don't slide sideways at all or need bracing in the stock seats..

Then you aren't turning hard enough. If you can show me how a traditional 4,5 or 6pt. harness can keep your entire body from moving laterally I'll buy you the harness of your choice.

A harness is really designed to hold you back against the seat. There is nothing that they do to really keep your upper body or legs in place during turns. They 'mostly' keep your hips in place but even then in a factory seat the lap belt still has to go out and down around the seat that the movement isn't entirely negated.

Then you aren't turning hard enough. If you can show me how a traditional 4,5 or 6pt. harness can keep your entire body from moving laterally I'll buy you the harness of your choice.

A harness is really designed to hold you back against the seat. There is nothing that they do to really keep your upper body or legs in place during turns. They 'mostly' keep your hips in place but even then in a factory seat the lap belt still has to go out and down around the seat that the movement isn't entirely negated.

if you're held against the seat tight enough, there will be too much friction to move you side to side. Press a book up against a wall and see if it falls. Its still seeing 1 g of acceleration with nothing stopping from sliding down besides friction. you aren't going to see much (if any) more than 1 g of side accel in a turn, so if you have a harness tight enough it can hold you in the seat restaining lateral acceleration.


now I would like a Black GForce 6-point pull-down camlock please :)

another cg-lock supporter! really helped keep me planted, that way i could concentrate more on driving, than staying put!

and for $25 bucks you cant go wrong! im getting another one for the passenger seat soon!

Then you aren't turning hard enough.

que?! Tell that to my two wheels in the air ;) :D

http://i139.photobucket.com/albums/q291/mechie3/2wheels.jpg

Same deal as the book on the wall. Our bolsters aren't huge, but they're there and, compress yourself against the seat enough so that you can't move and you're fine. Plus, if it's really tight, you can use the shoulder for the direction you're turning (ie, left shoulder if turning left) to push against the harness and hold yourself in.

if you're held against the seat tight enough, there will be too much friction to move you side to side. Press a book up against a wall and see if it falls. Its still seeing 1 g of acceleration with nothing stopping from sliding down besides friction. you aren't going to see much (if any) more than 1 g of side accel in a turn, so if you have a harness tight enough it can hold you in the seat restaining lateral acceleration.


now I would like a Black GForce 6-point pull-down camlock please :)

Too bad you're not right. You may 'think' you aren't moving around in the seat but you are.

The lateral force your body is going under at that 1G is pushing a couple of hundred pounds. Buckle yourself in and have a buddy push you sideways. Your body will move.

Here, watch Leh Keen at Watkins Glen. his car is seeing 1.3-1.5 g's sure but See how much his hard mounted seat is moving? You're body is moving some.

http://www.youtube.com/watch?v=zyM-egecTlw

There are reason people pay me hundreds of dollars to build them custom bead containment seats. Containing lateral movement is right at the top.

and Mechie3, if you are using the harness to brace yourself like that it means that you are moving around.

I use the schroth rallye 4 and when it's tight, I don't slide sideways at all or need bracing in the stock seats..

I use a quickfit Schroth which is like a Rallye 4. It keeps my ass planted.

http://www.racephotolabs.com/gallery/2008/04_12_lvrscca_nellis_auto_x/IMG_4702.jpg

The Quickfit doesn't work with the 06-07?? Weird. There shouldn't be anything majorly different in any parts of the interior from the 05.



thier website says directly not to use with any other year than 04 05.

Ill look into the CG lock and the rallye setups.

So it all comes down to the right seat for safety. I would think that having the right seat with the shoulder holes at a proper height... and the schroth rallye 4 harness I would be much better off. I remember seeing the name of a seat company who made seats for taller people while searching.. Ill have to do some digging.

Having a seat cushion in the back seat is pointless with two 6 footers in my car... lol

Too bad you're not right. You may 'think' you aren't moving around in the seat but you are.

The lateral force your body is going under at that 1G is pushing a couple of hundred pounds. Buckle yourself in and have a buddy push you sideways. Your body will move.


I guess I'm not trying to achieve complete, 100% lack of movement. As long as I don't feel any movement I won't be trying to brace myself and effecting control. Whether I'm actually moving a bit doesn't seem to matter.

With regard to the value of a racing seat, a high speed collision will result in WAY more Gs than cornering and that's where a racing seat really comes into its own. If I was subject to collision forces, I'm sure I'd slide out of the tightest stock belt/stock seat combo.

Well, I havent made my thoughts completely clear here either. I plan to run a few auto x events, and I want go to atleast one track day this year. I dont want to be the example of "you see this here folks, this is what is bad ".. So Im looking in to the schroth harness like Mechie has set up, and later on I will be upgrading my seats... if necessary.

Before I put in a Schroth rallye-3 harness, I used to just do the ol':
1) slide seat back
2) cinch up lap belt
3) spin seat-belt latch a couple of times, insert into anchor (you're turning it like a wind-up peg in a wind-up toy)
4) 'lock' the shoulder belt with a firm tug, lean into it to keep tension.
5) scoot seat up to driving position, shoulder belt should stay locked if you did it right.

Number 3 was a tip a guy showed me on my 1st or 2nd autox. It may not work 100% as well as a cg-lock, but it costs -zero- and worked pretty well. A couple or three 'spins' keeps the belt from sliding back through the slot in the latch... especially when under tension from when you slide the seat forward into driving position.

meh... 'worked for me'... ymmv... worked better than doing nothing, that's for sure.

The harness works much better of course.

Press a book up against a wall and see if it falls. Its still seeing 1 g of acceleration with nothing stopping from sliding down besides friction.

If the book isn't moving, there's no acceleration...

Quickfits won't work with 06/07 because the size of the seatbelt receptacle changed. You could always buy seatbelts from an 04/05 and swap them if you really wanted to.

Well, Im gonna go with the Rallye 4. It will work nicely if and when I decide to upgrade to some better buckets.. or atleast a taller drivers seat. :)

Belts will not do much to keep you from moving laterally. That is the job of the seat...


Ding ding ding.

Forget the gimmicks. Spend the money on a nice seat.

If the book isn't moving, there's no acceleration...

gravity doesnt stop trying just because it isnt moving. there are just two accelerations on it. the friction accelerating it upwards, and an equal and opposite gravity accelerating it downwards. you put a force on the book, therefore you put an acceleration. It just ends at a net of zero.

but thats besides the point. All I was saying is that there is a way to successfully restrain yourself with just a harness. I never said it was easy or probable, but physically possible.

Okay if you want to put the book example to scrutiny.

How much does the book weigh?

How much force are you pressing against the book?

Once you figure out those numbers how do they compare to the forces and weights of you and the harness.

Just a quick guess but the ratio of force to weight on the book is much much much higher than it is on you the driver.

I just did a quick test. I held my 2 pound scale against the wall and with a straight arm leaned against it. 28 pounds was the reading. With that ratio 28:2 ---> 14:1 what would that equate to in a belt system and your body.

Lets say the person weights 180 pounds. That would mean the belts are exerting a force towards the seat of 2520 pounds. I don't know of a person who could handle a constant force of that much through their belts. So no I don't think it is physically possible as you say.

of course it's physically possible, you just proved it with the numbers. Highly improbable, but possible nonetheless :p

its just semantics, but was that 28 lbs the least amount needed to keep the scale from sliding down? Plus theres also the fact that your seat will give and you will sink a little, which will create some bolstering itself and give you a normal force to keep you from moving laterally as well. Just more stuff to throw into the equation.

the whole thing was a joke anyway, I just wanted to see if you'd give me a free harness :lol:

gravity doesnt stop trying just because it isnt moving. there are just two accelerations on it. the friction accelerating it upwards, and an equal and opposite gravity accelerating it downwards. you put a force on the book, therefore you put an acceleration. It just ends at a net of zero.

but thats besides the point. All I was saying is that there is a way to successfully restrain yourself with just a harness. I never said it was easy or probable, but physically possible.

you are confusing 1 g of force with acceleration.

acceleration is the delta of velocity. if speed remains 0, there is no acceleration.

I just did a quick test. I held my 2 pound scale against the wall and with a straight arm leaned against it. 28 pounds was the reading....

You need to modify your analogy a little. A 200 lbs driver has the seat bottom pushing up on his ass with 200 lbs of force.

On a skidpad a 200 lbs driver and his car make 1 lateral g while cornering. How much force does the drivers body experience total during a 1 g corner? Remember vector addition; Answer: ~282.8 lbs.

And just for fun: a 200 lbs driver in a kart on skidpad in a 3 lateral g corner experiences ~632.5 lbs of force. No wonder those guys wear thick pads around their lower torsos.

you are confusing 1 g of force with acceleration.

acceleration is the delta of velocity over time. if speed remains 0, there is no NET acceleration.

fixed

a g is not a force, its an acceleration. and you can't have a force without an acceleration. Your net acceleration and your net force are zero, but you still have two components of both force and acceleration. The friction accelerating upwards and gravity accelerating downwards. You can't have a friction force without a friction acceleration. I can draw you a free-body diagram if I need to. The only thing I seem to be confusing is you.

either way, the thread seems to be over

I have use the scroth rallye 4 in my DSM, WRX, STI, and now the EVO with great success.

I have similar issues with installing the belts on the EVO with seat design.. you have to disassemble the belt and it will fit with enough persuation

fixed

a g is not a force, its an acceleration. and you can't have a force without an acceleration. Your net acceleration and your net force are zero, but you still have two components of both force and acceleration. The friction accelerating upwards and gravity accelerating downwards. You can't have a friction force without a friction acceleration. I can draw you a free-body diagram if I need to. The only thing I seem to be confusing is you.

either way, the thread seems to be over

i will beg to differ on the g is not a force but an acceleration.

like you corrected my statement, change in velocity over time is acceleration.
http://en.wikipedia.org/wiki/Acceleration

gravity is a force, and a g is measured by acceleration, but it does not mean that a g IS acceleration.
http://en.wikipedia.org/wiki/Gravity
http://en.wikipedia.org/wiki/G-force

force will acellerate an object, however when net force is 0 there is no acceleration because there is no change in velocity over time. acelleration can not exist without a change in velocity over time.

force is not dependent on velocity. in this case, the force of gravity is normalized by the shear friction force (mu) x normal force (force pushing against the wall). the force of pushing against the wall is normalized by the normal force exerted by the wall pushing back.
http://en.wikipedia.org/wiki/Normal_force

with no change in velocity over time, there is 0 acceleration.

my physics maybe a bit rusty; but i'm confident of my interpretation of this issue.

edit:

and for this issue, it seems the consensus is that using belts to exert force through tension to create a friction force against the seat is the disfavored approach to controling lateral movement.

your interpretation of the gravitational force is correct. but a g is not a representation of a force. If you put two people of different masses into a centrifuge and make them experience 9.8 m/s^2 of lateral (centrifugal/centripetal) acceleration, they will both be experiencing 1 g. However, they will not be experiencing the same overall force, because their masses are different. A g-force and a g are different things. Though a lot of times people consider them the same. If you're dealing with the same object (or same masses) then they are.

One of your wikipedia articles is wrong (g-force). They call it a g-force, but define it as an acceleration. They are two different things. Theres case #1 for why you shouldn't always trust wikipedia.

and again, the delta velocity/time gives you a net acceleration. the book analogy can be shown with force/acceleration components, which end up with a net acceleration of 0. again, a free body diagram will prove it. so here it is:


F = Human force applied pushing against wall
N = Normal force of the wall pushing back
f = Frictional force (f=mu*N)
W = Weight of book
http://img413.imageshack.us/img413/2568/fbd.png

The overall force equals zero, so your acceleration is zero. But you still have 4 force components, therefore you have 4 acceleration components

I like clipper ships.







:unamused:
And now back to the OP's question.

I just tried out a CG lock at our first AutoX this season. It holds the seat belt tight against the lap, but it would NOT stay clipped to my stock belt clip. A fellow racer let me borrow it and noted that the shape of my seat-belt clip did not fit well with the CG lock, consequently the CG lock could be pulled off of the belt clip with minimal force.

I too am looking for a superior solution that will fit with my '06. I am NOT interested in new seats, because this is my daily driver and I want to keep full function of the stock airbags.

what if the book is on a treadmill?