I am going to go with Stack on this one. Why use 4-points when 5-points are available and in the same price range? Remember, all it takes is one incident to make you wish you hadn't taken any shortcuts.

 

The 4pt schroth belt that I'm looking at is the profi II with the antisubmarining (ASM) feature.

http://www.on-trackperformance.com/s...technology.htm

The compromises I'm making by using a 4pt system is retaining the stock seat. IMO, there is a higher probability of my getting T-boned at an intersection than going head on into a wall at the track. Yes, compromising sucks. Ideally we all want a dedicated track car with the proper safety equipment, but most of us are dealing with a daily driver too.

As for problems with the schroth harnesses, I'd be very interested in knowing more. It sounds like user install problems vs. defective material or design...but please elaborate, as I'll be making wild *** assumptions otherwise.

 

Yes... what we've seen mostly (and not just with Schroth) is improper install, which can be deadly. I am sure that quality, fit, finish are all up to par with other belts. I did not mean to imply otherwise.

This is a very good point, and you'll notice I think two threads regarding people giving up track events in their 350Z in order to go to a dedicated race car, or in order to keep themselves in check until they can devote the car to track use only. I think they have much stronger will power than I ever could and I applaud them... I hate to see fewer 350Zs on track, but I applaud them anyway.

You are probably correct about the probability of an accident on the street. IMO, you are much safer on track at a well organized event than you are driving to the local store... but in order to be safe on the street, you really need a free-er range of movement in order to extend your field of vision to see those cars trying to t-bone you. Generally speaking, everything happening on track is going to happen in front of you, you can be strapped in, with limited movement of your head and neck, and still be comfortable with your field of vision in that situation. So, most people are not willing to spend 5 minutes every time they get in the car to 'strap-down' before heading off to work.

IF you are going to use a 4-pt system, street or track, and IF your car has an airbag... then that system might be something to look at. But I have my reservations. If its the one I'm thinking of, it has a section of strap that will accordian out, or stretch, a few inches in the event of a hard frontal impact. The theory being that it will allow the torso to move forward and rotate slightly, thus reducing the amount of 'neck snap' and allowing the lap belt to 'grab' before the body has a chance to submarine.... essentially the same effect of a stock 3-point belt system.

Honestly, it sounds like a gimmick to unnecessarily sell belts to replace a perfectly good stock system. Again... you have to weigh your improvements vs the increased risks. I would love to see some testing data on these belts.

 

So Stack, is there any 5 or 6 point harnesses that I can use with the factory seat and not have to cut holes?

 

Any six-point system 'should' work. The sub straps should be long enough that they can mount to the sides of the seat, in a similar position to the stock mounting points (I'm not sure how far back relative to the seat they are in the 350Z.) Then you would sit on those straps, with the latch (point of the 'v') coming up between your legs.

Check this link out from Simpson Race Products:
6-PT restraint diagram

You'll notice (as I just noticed) that they indicate using a seat with only a 5-pt sub strap hole may diminish the effectiveness of the six-point. Most newer seats have a slot as opppsed to a single hole... but for stock seats, depending on your seating position, I would think you could actually mount then directly behind the seat, and run the straps through the 'joint' of the seat, under your butt. I haven't seen this done, but it would be something to check out.

 

What do you think of this system? Looks desinged well, but I dont know how good Impact Racing is.
http://www.bcrltd.net/html/harness_belts.html

 

Looks great to me... thats what I was talking about with the straps coming from behid the seat... and the belts are gonna be high quality coming from Bill Simpson. Price looks good as it includes all mounting hardware.

 

Impact is quality stuff. Bill Simpson is very respected in motorsports. Impact stuff is usually marketed towards muscle car/drag racing guys which is probably why you haven't heard of it.

 

There's also that faction of NASCAR fans blaming him for the death of Big E.

 

I haven't heard that yet, but then again I have never followed NASCAR. I think if I were to blame anyone it would be the wall...

 

In the design I showed you it has all the belts going into that circle mechanism. I have also seen other designed that are different. Is there any real difference?

 

1st, I need to mention that BCRLtd is my company. The Impact belts have been specifically configured for use with an OEM 350Z seat. (A single sub strap is available for a 5 point installation for race seats.) After much consultation time with PCA & Impact, this is a very safe system, following the guidelines of SCCA regulations. The anti-sub straps are longer than Schrothe subs, which allow drivers of different sizes to adjust lengths to their needs. They are also long enough to run outside the seats.

The price might seem high compared to the prices on their website, but ALL necessary hardware is included for 350Z installations. Impact's hardware didn't work, so I sourced some that does work.

A little history on Impact. Bill Simpson owns Impact. Impact was formed after Bill was sued by NASCAR & the Earnhart family for Dale's death, as Bill's Simpson belts were deemed the cause. In reality, Dale refused to mount his belts correctly as Bill had advised many times. This improper belt mounting is what caused his belts to fail.

BTW, many NASCAR, IMSA, & Grand Am Prototype cars currently use his belts......along with some 350Z owners!

 

My harness installation. A year later I added a roll bar, also by Piper Motorsports. (John: what happened to our thread about the install? I couldn't find it.)

I'm still happy with both, although fortunately, I haven't put them to the acid test, yet.

 

First, let me say that I am new to autox, and began driving just this year. I was hooked after the first fun event, and race with the best bunch of guys you could ever ask for in the Central Kentuck Region (CKR). I have, very unfortunately, put the stock safety systems to the test.

Following the "work on the nut behind the wheel first" theory, I made no changes to my car at all this year. I did add SSRace Dunlops, as I wanted to drive to the sites on them, and perhaps compete in track events as well. These tires are a great compromise, unlike some other dedicate autox tires. Working with 2003 grand touring (yes, it's the automatic), I moved from 86th to 11th in the DOY points race, with a pretty solid shot at BS championship. I may still get rookie of the year.

Now for the relevant part; While racing out of my region to gain more seat time, I had a nasty accident on the last cone of my final lap. At well over 80 (rev limit in second), I slipped sideways in a slalom and the LSD locked up, shooting me off the track between a metal fence and a serious manhole cover. After leaping the crest of the hill, I landed in the street, and into oncomming traffic, but I didn't hit anyone. I was not hurt either (except my pride of course, they still call me Luke Duke). The car sustained nearly 10k in damage, but has been completely repaired. Here is what I've learned;

1) Just like the track guys say, point the car. You DO NOT control anything when your sideways. Doing this saved lives, maybe even mine.
2) What we do IS occasionally dangerous. Yes, we call that fun or adrenialine.
3) Locking the seat belt and the sliding the seat forward keep me securely in place, and allowed me to concentrate on other things. But, a racing harness would have been better.
4) A rollover in autox is entirely possible, even more so in track racing.
5) There is NO completely safe car made, and none can be built. You still have to add the driver, after all.

If you can afford the harness, harness bar, or roll hoop, by all means do so. However, do not think this makes you invincible, your not. And remember, the biggest safety investment you can make is in yourself. Just because you put your brain in a bucket, doesn't mean you shouldn't take it out and use it.

On a positive note: Props to all the CKR guys. They had me back in borrowed cars racing at our final points event the very next week, and a divisional event the week after. I still drive like grandma, but I'm working on it a little slower this time, just to get it right.

 

Yes, the Profi II 4pt. ASM harness is supposed to work as you described. There is a downloadable video of some test crash dummies using the 4 pt. belts w/ ASM (accordian strap on one shoulder belt). I'll provide a link if I can find it again.

I will retain the stock steering wheel with airbag (that's why I elected to use an open faced helmet as I don't really enjoy looking like Marvin the Martian). The ASM belts will keep me secured to the seat while on the track, but will work similarly to a 3pt. belt if a head-on impact occurs. However, I plan to retain the 3 pt. belt for daily driving.

 

As Stack points out, almost any 6 pt. system will work (the 5 pt. ones are the ones that don't work well on a stock seat). I have changed my driver's seat to a dedicated race seat, but my passenger seat is still stock. I was able to fabricate bolt-in mounting points for the passenger side harnesses out of steel angle iron (heavy, but strong) in about one afternoon in my garage using simple tools (drill, saw, grinder). My Kirk roll bar serves to mount the shoulder harnesses no problem. The sub belt comes around the bottom of the seat and up between the passenger's legs - no problems. I will have to take some pix later...

There are also some interesting new harness types on the market... ones that you sort of put on. I'll see if I can dig up some websites. I have seen these during my work as a tech inspector for the Silver State Classic open road races.

By the way, as most replies above imply - no matter how good the harness bar, there is just no substitute for a roll bar. If my Z wasn't also a daily driver, I would have a full cage in it by now. I have been shunted into enough walls and other cars enough times to know first hand how well both harnesses and roll bars/cages work.