Anti-Sub belt ? Exige Seats

[ACE51]

Is there a best solution? I have the 4 pt scroth harnesses. I feel pretty insecure without some type of crotch strap. What's so good about the sys6 pack when you can get the harness bar for $30 a piece? Is there some other way to mount the sub belt that doesn't require any extra parts?


I know that someone on here has a really strict opinion about cutting the stock seats, I will admit that the cut top of the elise seats look more worrisome, but I'm looking for just the crotch strap.

Any advice on cutting the seats? what do you guys use a hacksaw?

[apk919]

Originally Posted by ACE51

Is there a best solution? I have the 4 pt scroth harnesses. I feel pretty insecure without some type of crotch strap. What's so good about the sys6 pack when you can get the harness bar for $30 a piece? Is there some other way to mount the sub belt that doesn't require any extra parts?


I know that someone on here has a really strict opinion about cutting the stock seats, I will admit that the cut top of the elise seats look more worrisome, but I'm looking for just the crotch strap.

Any advice on cutting the seats? what do you guys use a hacksaw?

This has been exhaustively covered in another thread... many opinions on this subject.

In any case, here's what I've done... I prefer the sys.6.pack because it anchors the sub strap to the tub, not the seat. I used a Dremel with a cutting wheel to cut the sub slot in the composite section of the stock seat, filed off any sharp corners to minimize stress cracks, and then took the seats to an auto upholsterer to cut the leather and sew in a sleeve.

[ACE51]

i read your posts in the other thread which turned seemed to turn into a safety seminar.

I just want to do the sub belt and I was curious about the sys6 vs the bar. Sounds like the sys6 is the way to go for maximum security but still don't see whats wrong with using just the bar, why else would they sell it?

[apk919]

Originally Posted by ACE51

i read your posts in the other thread which turned into a safety seminar.

I just want to do the sub belt and I was curious about the sys6 vs the bar. Sounds like the sys6 is the way to go for maximum security but still don't see whats wrong with using just the bar, why else would they sell it?

Why else would they sell it? Better put on your flame suit, this ain't gonna be pretty...

[jah29]

I read all the anti-sub belt, 4-6 point harness post here and then went and bought a teamtech jetpilot harness for my exige which already has a harness bar. The jetpilot has a different type of anti-sub strap so you don't need to modify or buy a new seat.

I haven't installed it yet, but it looks really nice in the box

TeamTech Motorsports - Racing Harness - Jet Pilot Harness

[Drmike]

I wonder just how safe most of the aftermarket harness bars actually are


They pivot and swing forward in a crash

I wonder if this could effect a HANs user....

Ive used a couple of bars...Im now going back to OEM style that bolts to the back of the rollbar.

[ACE51]

i forget the user but he brought up a good point that nothing is actually tested. With all of the salvage elises I see here and there and on eBay I wonder what the results were. I suspect most of the salvaged cars are from inexperienced drivers who get in over their head, not that it could happen to anyone.

I think I'm just going to go for it and make my slots and get the seats ready. I read 11 inches from the vertex of the seat back and seat bottom. how wide do you go and how thick do you make the holes (the dimensions of the cut, 6x1 maybe?) I have a momo supercup sitting in my garage for my miata, I guess I could see how the sub belt holes look on that

[Chris Mackey]

Originally Posted by ACE51

i forget the user but he brought up a good point that nothing is actually tested.

fishguy.

I take his advice.

[Drmike]

Originally Posted by ACE51

i forget the user but he brought up a good point that nothing is actually tested. With all of the salvage elises I see here and there and on eBay I wonder what the results were. I suspect most of the salvaged cars are from inexperienced drivers who get in over their head, not that it could happen to anyone.

I think I'm just going to go for it and make my slots and get the seats ready. I read 11 inches from the vertex of the seat back and seat bottom. how wide do you go and how thick do you make the holes (the dimensions of the cut, 6x1 maybe?) I have a momo supercup sitting in my garage for my miata, I guess I could see how the sub belt holes look on that

i was in the same position as you, intending to cut the seats.
fwiw heres my experience setting up harness and seats in exiges.

ive done this on two cars now.

ive learnt the hard way that its a heck of a lot easier, better and safer to not try and cut corners or diy too much when theres off the shelf stuff available. - maybe im just getting old and lazy

anyway fwiw heres what i did;

1st time i did it i fitted a v-force bar, it was a good height for me and couldnt pivot as much. i used it on stock seats. it was useless as the harness straps were held far too wide by the headrest. the stock seats were also useless with a hans. even my helmet was annoyingly touching the headrest all the time. i ended up using a rs rather than a hans and that helped keep my helmet off the rest. the other thing with stock seats was that they have no side support so i was literally falling out the seat on corners. all in all the stock seats were useless and quite unsafe. in the end i didnt bother cutting harness holes in the seatback or for an anti sub belt because of these problems with the stock seats i knew i wouldnt keep using them.

so i then decided to get an fia seat and after much searching and reasurance that the sparco revo Sparco Rev Seat would fit. i bought 2 and figured id make the rails and sub harness bracket. what a nightmare. i had to bugger around cutting a few inches off the front of each seat then fabricate up the rails - the seats are a tight fit and dont go in easily at all. making the raiils and sub belt mounting was a pain in the ass. the seats looked great but are narrow. i have a 32 inch waist but after a short while the pressure from the sides of the seat becomes distracting. all in all quite uncomfortable.
with the v force harness bar and the revos it was a good set up for circuit providing reasonable side support and correct harness routing. also the rs worked well with the seats. never tried the hans.


ive just set up my current exige and this time it was a walk in the park! no buggering around cutting fiberglass, measuring and making fancy seat brackets. everything was plug and play and went in in about an hour. i learnt that sometimes it pays to spend the money and do it right rather than try to diy and bodge something to save some cash. yes i paid a tad more but man compared to the buggering around trying to make a silk purse from a sows ear it was money well spent.

for the last car i simply ordered a lotus sports seat and fitting kit from bell and colvin. Bell & Colvill About Us - Lotus Catalogue Detail it went straight in it fits like a glove gives better side support than the revs yet is wider so i dont get my ass squeezed uncomfortably. its a far more comfortable seat than stock too

if i was to do it a 3rd time id do it this way again. ive got a safer more comfortable seat with good harness routing and safe anchors. a lot better than a less safe uncomfortable stock seat with poor harness routing and unsafe anchors which is what you could end up get with on a stock seat.

something i didnt appreciate the importance of before was side support. stock seats suck. its day and night compared to a good racing seat even if it wasnt for a harness id swap seats just to gain better side support i also figured that when i sell the car id just throw the stock seat back in and put the car back to stock so as not to put off some buyers

hope this helps - ymmv

[jcs]

Originally Posted by ACE51

Is there some other way to mount the sub belt that doesn't require any extra parts?

get 6-point belts, mount the two sub straps at the same anchor as the lap belts. you sit on the belts as they come up through your lap.

[300hpMR2]

^I was just going to post that my friend just installed 6 pt belts this way (not in a Lotus). I was wondering if this is an acceptable safe setup. I don't see why not.

[Lotus-Position]

Originally Posted by jcs

get 6-point belts, mount the two sub straps at the same anchor as the lap belts. you sit on the belts as they come up through your lap.

Here is what I did (post #84): Safety Equipment Thread

But I've seen a few done with the sub straps anchored with the lap belts and it looks very slick to me. I would love to see test results for that setup if anyone runs across them. I've seen this in a number of purpose built race cars and it saves drilling holes in the tub for subs. As long as the belts hit you at the right spot on your pelvis, seems like it sould work great. Only things I can think of that might be "sub optimal" (pun intended) would be the extra stretch distance you get in a crash from the much longer subs, and the fact that (depending on the seat), the sub straps would tend to lift you out of the seat as they are stretched forward, rather than holding you down like the straps that go straight down do.

Would be worth asking Joe at HMS for his opinion.

[ACE51]

Originally Posted by jcs

get 6-point belts, mount the two sub straps at the same anchor as the lap belts. you sit on the belts as they come up through your lap.

Thats what I was wondering. So did you still have to cut the seat? I don't see where the belts are coming from.

['Nova]

Originally Posted by jcs

get 6-point belts, mount the two sub straps at the same anchor as the lap belts. you sit on the belts as they come up through your lap.

That's not the right way to do it. If you're going to get 6pt belts, at least run them correctly. Don't be lazy then think you're safer because you have 6pt belts mounted like that. You're worse off with that configuration than with 4 points.

From Schroth:

PROFI 6-POINT AND HYBRIDTM MODELS
• Anti-submarining strap routing shall be vertical down from the groin, preferably approximately 20° back.

What you're describing is an acceptable configuration in a formula car, but the seat bottom angle is raised so you are wedged in there. Our cars are obviously not a formula car and thus the sub strap needs to be between vertical or 20 degrees backwards.

More from Schroth:

Anti-sub straps must not be redirected. Redirected straps, e.g. using an OE stock seat for a formula type racing harness and running the straps over the seat edges down to an anchor point, will provide extra slack during a crash and the expected performance will not result.
Slack from such anti-sub strap routing will allow a buckle ride up during an accident which results in higher upper torso and head movement. This increases the risk of head impact, head and neck injuries and internal injury.

http://www.schrothracing.com/sdocs/2...structions.pdf

[fishguy]

Originally Posted by 'Nova S4

That's not the right way to do it. If you're going to get 6pt belts, at least run them correctly. Don't be lazy then think you're safer because you have 6pt belts mounted like that. You're worse off with that configuration than with 4 points.

From Schroth:


What you're describing is an acceptable configuration in a formula car, but the seat bottom angle is raised so you are wedged in there. Our cars are obviously not a formula car and thus the sub strap needs to be between vertical or 20 degrees backwards.

More from Schroth:



http://www.schrothracing.com/sdocs/2...structions.pdf

Nova S4 is spot on correct.

guys, use the right equipment for the right application.

[luxige]

Absolutely, the rig shown in post #10 is UNsafe.

There are harnesses designed to work this way. Schroth makes one; post #5 links to another.

One point that a lot of people miss is that the function of the anti-sub belt is not to restrain the driver as much as to hold the lap belt DOWN as low as possible so that an impact is absorbed by the 'hardpoints' of the crests of your hipbones. (The only hardpoints are the hips and clavicles, unless limb restraints are used). If the lap belt is allowed to ride up over the hipbones, the impact is taken by the soft tissues of the lower abdomen, drastically increasing the risk of fatal injuries. The purpose of the anti-sub strap is to hold the lap belt down; it also prevents your hip section from 'squirting' under the lap belt.

With that in mind, look again at the makeshift rig in post #10. Note that nothing is really holding the lap belt down, because the tension in the substraps is applied to the tissues of the back of the thighs. In an impact, several hundred pounds of force will crush those muscles nearly to the bone. If the substraps have been run over a cushioned seat edge, that will be compressed as well. Suddenly several inches of slack appear in the substraps, when the margin of safety is only a couple of inches. There is no way to be sure that the lapbelt will not slip up over the hips, so this is not at all safe.

(Note: this is my very strong opinion. I am not an expert in race safety or ergonomics. I do wear a five-point harness in my work.)

[Lotus-Position]

FYI: I heard back from Joe Marko at HMS. He confirmed that as long as the subs are routed directly to the anchors, and not up and over the seat edge or over/around anything else, sharing the lap anchors can be effective.

So the setup shown above does NOT qualify because it has to go up and over the edge of the seat. Plus there will be more stretch.

So, per the last few posts, going with the schroth fitment, with the right angles and anchors through the floor is the safest approach.

Personally, I don't think anchoring to the seat is solid enough for any of the straps.

[ACE51]

not quite sure how the $30 bar from Sector works, mounts between the seat rails?

opinions? anyone using this set up?

[ACE51]

I'm not all out racing, just feel a little insecure without a 5th or 6th point to hold me in in case I slam against something.

I really like the racing seats built for this stuff, but I do street my lotus and I'm not sure I want to drop almost 2 grand on a set of seats. But then I start to think about how I could sell my stock seats for a grand........

but for my application of occasional track days I think I'd be best just slotting what I got to hold my boys in place.

[fishguy]

Originally Posted by ACE51

I'm not all out racing, just feel a little insecure without a 5th or 6th point to hold me in in case I slam against something.

I really like the racing seats built for this stuff, but I do street my lotus and I'm not sure I want to drop almost 2 grand on a set of seats. But then I start to think about how I could sell my stock seats for a grand........

but for my application of occasional track days I think I'd be best just slotting what I got to hold my boys in place.

$2k for seats, you say you can sell your stock seats for $1K, so your new seats will only cost you one grand.
what is the deductable on your health insurance policy, how much does a missed day/week of work cost you?

above i am just pointing out the numbers side of it.

you already know that there is no difference with the physics in accident that happens during an "occasional track day" or a racing event. it all works the same.
dont rationalize saving money on this one.
its a false economy when you look at the big picture.
if you are going to do the safety mods, do the correctly, or dont do them at all.