Harnesses bolt-in or clip-on?

[///Manuel]

Looks like Schrotz is the only one to make DOT approved harnesses. I'm looking to get either a Simpson or a Schrotz harness.
For track and street use, what would be the best setup? Should I even wear it on the street?
I'm looking for a camlock 5-point (can delete the sub-belt) one.

[M3RACER]

I spoke to Joe from HMS about this. Basically for a daily driver/driving school car the best set up is the schroth clip in unit. The 5 point belt is very dangerous when used with the stock seat, its intended to be use with a race seat. The clip in out belts are street legal, but I think its much easier to use the stock belt for everyday use. with the harness you can't reach for stuff or if you forget to close the door before you strap in, its a pain. The scroth clip in belt also takes advantage of the factory belt tensioners.

[///Manuel]

Is it very dangerous with the stock seat without a roll bar? I'll have a roll bar in by the time I have my harness so no problem here. I know the reclining seat mechanism can break backwards in case of a rear impact and hit the bar. That's the only problem that could happen with a roll bar I'm aware of.
Also, the Schrotz harnesses give a little bit of slack that allow your body to move a little bit during a high impact to minimize the forces.

[M3RACER]

The roll bar is not the problem. The problem is the stock seat does not have a hole for the anti-sub strap. The ASM feature the Schroth harnesses is not to reduce the forces but but to prevent you from sliding under the lap belt. Which is a great feature to have when you cannot run a 5 or 6 point harness. If your getting a rollbar and have stock seats you should run a 4 point harness, some belts allow for a future upgrade where you can just buy the anti sub strap if you ever get a race seat.

[///Mracer]

I have the Schroth clip in/out harness for my 95 M3 and Love it. Install and remove in 30 sec.

However, I have only used it for auto-x events. I have not used it for track yet. I have heard of horror stories of harnesses w/o rollbars and what can happen if you crush the roof. I have meet many instructors that do however run on track with a harness and no roll bars. There seems to be many different schools of thought here.

Any input???

[///Manuel]

In my opinion, harness w/o a roll bar is a no-no. I would even say harness w/ roll bar but w/o a race seat is not ideal either.
I would definitely use only 4 points out of the harness.
One other problem is insurance-wise, what if something would happen to me while I wasn't wearing my seatbelt? Since only Schrotz is DOT approved, is it the way to go?

[M3RACER]

I also spoke to Joe about the use of of harnesses without roll bars. The stock seats are designed to collapse 6-8 inches or completly collapse in a severe rollover. In most cases you will be safer with a 4point harness that the stock belt, but there is a small chance that you would have been better off with the stock belt. If you call HMS and ask them they can tell you about stories of people who have rolled with harnesses and no rollbar. I think you should understand all the risks involved and do whatever makes you more confortable. But then again it would be safer to just stay home or you can just stand outside and get killed by a sniper, there is a risk in every thing we do. Some people have been saved by air-bags, others would still be alive if the airbags would have never gone off. As far as I know the none of the cam-lock belts is street legal, scroth will be releasing a 4-point single button release belt in about a month that is street legal. another thing to consider a 3inch lap belt is very difficult to adjust with a stock belt, can be a problem if you share a car or have different passengers riding with you.

[///Manuel]

The only advantage of the eye bolts is to clip and unclip the harness easily or is there some adjustability advantage as well?

[M3RACER]

Yea the eye bolts allow for easy removal. If you have a roll bar then the cross brace would be the best place to attach the harness to.

[frayed]

with the harness if you forget to close the door before you strap in, its a pain

LOL. I have a tendency to do just that.

[MAB Badgerbimmer]

I have the regular Schroth harness system in my E36 M3 and the clip-in clip-out in my E46 M3. The clip-in/out works just as well and is significantely easier to live wth and install. The clip-in/out option is the way to go. Also the Schroth harness is DOT approved because of the patented designed which gives way in a roll over allowing the person to move as in a normal seatbelt.

[frayed]

Hmmm, it was the ASM that gave it DOT approval?

My understanding that it was (i) use of DOT approved anchor points (ie, the factory rear belts) and (ii) use of DOT approved buckles (ie, the buckles with the read push buttons).

[///Mracer]

"Also the Schroth harness is DOT approved because of the patented designed which gives way in a roll over allowing the person to move as in a normal seatbelt."

I do not think it will give way in a roll over and allow the person to move like in a reg. seat belt. :

[Jim O.]

Originally posted by MAB Badgerbimmer
Also the Schroth harness is DOT approved because of the patented designed which gives way in a roll over allowing the person to move as in a normal seatbelt.

Sorry, but this is wrong. The ASM feature does NOT allow you to move in a roll over. ASM works by allowing the inside shoulder harness to lengthen approx 1.5" in a frontal collision. There's a little extra webbing sewn into a loop - the stitches tear out in a collision, making the harness longer. This allows the torso to rotate a slight amount towards the outside of the car. The rotation does two things. One, it makes the hips snag on the waist belt, which prevents sliding under the waist belt (Submarining, hence the acronym "ASM" for "Anti-SubMarine"). Two, it makes the driver's head go towards the outside of the car so that it doesn't collide with the passenger's head.

This feature has nothing at all to do with roll over safety. In a roll over, you may not even have enough force on the harness to rip out the stitches in the ASM feature. And, 1.5" is definitely not enough slack to allow your body to be pushed over out of the way if the roof collapses in a roll over.

Jim

[M3RACER]

Originally posted by frayed


LOL. I have a tendency to do just that.

I have done this to many times, I have even tried launching quickly to close the door but it doesn't work.

[///Manuel]

No, but backing up and slamming on your brakes will

[Pinecone]

For interest, I have the Schroth Rallye 4 normal ones in the M3. The rear mounting points are already in the car. Apparently they are a dealer installed option in Europe.

The are not usable on the street as they do not allow enough movement. But on the track they are wonderful.

In between track events, I unclip the shoulder part and flip it over the headrest and tuck the whole thing under the back of the seat. Out of the way, but still installed.

[///Manuel]

Looks like their 5-point camlock harness has ASM technology so you could probably use it as a 4-pt as well. I have seen that they have a new push button camlock system that is DOT approved. It seems that Schroth makes the best harnesses for street and track hands down as none of their competitors include these technologies.

[Jim O.]

I wouldn't recommend it. Yes, the Profi series of belts has ASM technology. However, the shoulder harnesses still attach to the camlock close to the middle of the lap belt - what that does is pull up the lap belt as you tighten the shoulder harnesses. You really need to have a sub strap to keep the lap belt in place, down on your hip bones.

The harnesses designed to be 4-points, like the Schroth Rallyes, have the shoulder harness attachment points on the lap belt moved over, away from the center of the belt. That way, when you tighten the shoulder harnesses, it pulls more against the lap belt mounting points, and doesn't pull the belt up onto the soft bits of your abdomen. So, if you're in a crash, the lap belt distributes its forces against your hip bones like it's supposed to, instead of riding up onto your abdomen and causing internal injuries.

Jim

[///Manuel]

ok makes sense. I think I will be looking at 5-pt harnesses then and cut up the vaders if I have to so I can slide thru the sub belt.

[Jim O.]

It isn't that easy. To be effective, the sub strap must be in the same plane (or behind) as the shoulder harnesses. If the sub strap is forward of that plane, it will pull the lap belt away from your body when the shoulder belts are tightened. That lets your torso slide forward in a collision, which is not a good thing.

Problem is, there's no good place on a stock seat to cut through for the sub strap. The easiest place is between the thigh bolster and the rest of the seat. Unfortunately, that's way too far forward. If you cut through the bottom of the seat, you run into the height and tilt mechanisms.

I'd say that you have two choices. One, if you really want to use the stock seats, use the Schroth Rallyes which are designed to be used without a sub strap. Two, if you really want to use a 5-point, get a seat that's designed to be used with a 5-point harness. Either a shell, or a sport seat like the Recaro SRD, the Sparco Torino or Milano, etc.

Jim

[Young]

This was my solution. I have an Autopower 5-pt. camlock harness, H-type (Y-type harnesses are uncomfortable). I have a rollbar with a harness bar for the shoulder belts. Since you're getting a rollbar, you should seriously consider the harness bar attachment. I ALSO retained my 3-pt. street belts because it really isn't comfortable to wear a 5-pt. harness on long road trips.

I also have cloth Recaro SRDs. The SRDs, ironically, are more comfortable than the BMW power leatherette seats.

[///Manuel]

You have got to be kidding me. M3 cars are meant to be driven on a track but you can't use harnesses on Vader seats, does that make sense? It doesn't to me. Looks like "Roll bar, Harnesses & Seats" go all together...

[Jim O.]

Nope. It's stuff like this that separates a real track car from a street car. No matter how much we pose or pray, M3's are just another street car. Sure, they're a lot of fun to drive on the track, but they're built for the street. Take, for example, the stock seats. 60+ pounds each! If this was really a car built for the track, they'd be down in the <25 pound range. And they'd have sub strap openings....

Jim

[M3inSC]

Originally posted by Jim O.
Problem is, there's no good place on a stock seat to cut through for the sub strap. The easiest place is between the thigh bolster and the rest of the seat. Unfortunately, that's way too far forward. If you cut through the bottom of the seat, you run into the height and tilt mechanisms.
Jim

Actually, with the help of some other folks, I found an excellent solution for my situation.

I have a 4 door 98 M3 with stock manual seats. These are not the vaders and have the thigh bolster on the front of the seats.

What I did was go with a 6-point harness using dual strap sub-belts attached to the "front" seat mounting bolts under the seat rails. SafeQuip, a harness manufacturer located locally, made the sub-belt and found some threaded stainless mounts that would fit the front studs under the front seat rails and were thin enough to allow the nuts to be fully engaged on the bolts. They are bent a little to allow them to fit in the little valley where the rail attaches.

Then I did have to cut the leather between the front thigh bolster and the seat and used a dremel tool to make two slots in the plastic molding under the thight bolster so that the two sub-belts could come up from either side. There is a metal slider in the middle of the thigh bolster and the sub-belt comes up on either side to a single clip in the middle which attaches to the camlock. When you close the thigh boster, you can't see the cut and you can even put the sub-belt clip out of the way under there!

As it turns out, the sub belts comes up at almost 90 degrees to vertical and the mounting points on the seat rails are on almost exactly the same plane as the camlock. So the alignment is almost perfect.

The sub is not easily adjustable since it is threaded into the connectors under the seat, but by moving the seat slightly forward or backward, the effective length can be changed so that the camlock is located in the proper position for different size drivers.

BTW, my shoulder harnesses are attached to a harness bar. My outside lap belts are clipped into i-bolts mounted in the front outside hole of the rollbar mount. The inside lap belt is clipped into an i-bolt drilled through the floor behind the seat. You have to watch carefully for the brake lines under the car when drilling these holes.

Also, FWIW, I had to get my rear seatback modified at an upholstery shop to fit back in with the Autopower rollbar. And if you have a 4-door, the removeable cross-brace is a waste of money. You can't get anything in the back seat anyway, even with the cross-brace out.

But all-in-all, the harness setup worked great and tested out fine in a BMW drivers school this last weekend at Carolina Motorsports Park. I was instructing and took 5 or 6 people of different sizes for rides and everybody fit the sub-belt just fine.

So, there "is" a decent way to install the harnesses with stock seats that meets almost all the safety rules.

Finally, someone had brought up the point that there could be a problem attaching harnesses to the seat mounting points if the seat came off. With my setup the sub-belt is attached under the seat rail. But even if the seat rail became un-attached, I don't know where the seat would go with me in it and attached by four different mounting points that were not attached to the seat. If I'm attached to the car and the seat is between me and the car, it is not going to be going anywhere!

P.S. Jim O., if you know of a lightweight seat that will fit a 275# driver and also fit in the car, please let me know. At least the seats in the 4-door don't recline and should be less likely to fail. But I just haven't found a seat other than stock that is big enough to be suitable for street and track for a big guy. When you are as big as I am, another 80 pounds in seat weight is a small price to pay for a little comfort!