Should I Install A Harness Kit?

[AWN] There are a whole lot of good reasons for installing 5-point belts in your car; if you’re involved in a relatively-minor crash, for instance, they’ll hold you in the seat (so you can still reach the steering wheel and pedals) better than the stock belts will. However…

 
5- or 6-point harnesses will keep you securely fastened in your seat, but ONLY IF      THEY'RE USED PROPERLY. To be effective, harnesses must be very tight; if you can only      latch them yourself with difficulty and after exhaling, they're just about tight enough. 

   People used to wonder why I always wore a suit when I drove my harness-equipped Porsche to      work. The reason was simple: I needed a jacket to cover the harness-generated wrinkles in      the shoulders of my shirts. If you are at all concerned with how their clothes look when      you get out of the car, they'll never tighten the harnesses enough, and you'll end up with      LESS security than they have with the stock belts. 

   Related to this is the fact that racing harnesses are uncomfortable or awkward for many      women to wear. Large breasts get in the way, and pregnant women DEFINITELY shouldn't use      them. If they can't tighten the belts without discomfort, they simply WON'T tighten them.      Also, many people can't STAND being tightly strapped into the seat for any length of time.      I've taken cross-country trips in the Porsche and didn't feel very uncomfortable, but I've      had passengers who started to feel claustrophobic after only a few minutes in the car.

 
Even if you properly tighten the belts, they still stretch. Nylon belts can stretch up      to 20% in a severe crash, so your upper body is likely to move forward a few inches      anyway. This is not necessarily a bad thing. The whole idea of crash-survivability      revolves around decelerating your body (relatively) gradually. Kevlar harnesses are      available from Stand 21 (and maybe from other manufacturers, as well), but because they      have no stretch to speak of, they're dangerous in most tube-frame cars or really stiff      single-seat racers. They'd be less dangerous in a street car with crush zones, but you      should still expect a broken collarbone if you crash while wearing a Kevlar belt. 

 
Although nylon belts will stretch a little, your neck will stretch A LOT. Paul Tracy,      who was belted very securely into his Indy car at the time, HIT HIS HEAD ON THE STEERING      WHEEL when he crashed at Indianapolis a couple years ago. With the racing harnesses, as I      mentioned above, the belt-stretching will allow your shoulders to move forward only a few      inches. With the stock belts, you may still bang your nose on the steering wheel, but your      shoulders won't still be held near the seatback at the time. For those of us whose necks      aren't as strong as Paul Tracy's, this is a good thing.

 
In the VERY unlikely event that an object is coming at your windshield with enough      warning for you to get your head out of its way, the stock belts will let you lean over or      duck. Racing harnesses will keep your face right in the line of fire.

Like most vehicle modifications, you need to remember that what’s good for a race car is not necessarily good for a street car.

What Harness Kits Are Available?

Comptech

Comptech’s bolt-in roll cage.

Dali Racing

[WM] I also installed the 5th point of the five point harness from Dali Racing (also highly recommended). While playing, I did a little modification to the harness bar to allow the stock seat belt to work properly (I ground down one of the edges). I will try to post the pictures of the seats with the holes cut in them by this evening for anyone who wants to see them. You can check out http://www.waynemiller.com and go to the NSX section.

[KM] Dali racing harness and bar – a great value for the unit and easy to install.   My wife and I did this job in about 4 1/2 hours, the instructions were very   well written and straightforward. The convenience factor in being able to   access the panels is a tremendous advantage and not having to cut any panels   is a great plus. A non-technical person with a torque wrench and some common   tools can put this together (a helper is a plus)! If you do this, follow the   directions (including putting a towel over the door sills for protection). If   you are planning to do some wiring and want to replace the stock chip for the Dinan box, this is a good time to do that also. Many thanks to Dick Hackman for marketing this at the Southeast NSX Spring Fling and to Mark Johnson for helping out with tips over the phone!

[NM] Dali Harness Bar (approx. $300) / Camera Mount (approx. $75) / Fire Extinguisher & Mount (approx. $25 if you buy the Harness Bar) / 3" Schroth F1 Belts (6 Pt driver / 4 Pt Passenger) (approx. $415): Thanks to Mark Johnson for making such an outstanding set of products. Mark actually installed all this at NSXpo for me, but with just the instructions, a dummy like me could have done it myself. The bar is as attractive as it is functional and you will not have to butcher your beautiful appolstry like another harness bar solution. The video came out great and the fire extinguisher goes over the passenger mat and comes in and out with 2 bolts. As for the belts, for the ultimate in convenience use the 2" Schroth belts that replace the factory belts. I wanted to keep the factory belts so I used the 3" F1. As for the 6 points vs 4 – the lower 2 points can be pushed through the bottom of the seat and stored for track events (it looks a little obscene when wearing them around town!). Again – I can not emphasize enough what an incredible product / value this is.

[BZ – 99/3/10] I highly recommend the DALI RACING harness bar. It is solidly constructed, comes in one of three colors (black, red, gray), uses the stock mounting locations, does not requires ANY cutting of the interior, and has the best installation instructions in the industry*. And best of all, it’s cheaper than the competition! * the last comment is slightly biased…. I wrote the installation instructions.

[FG – 99/3/10] I use the Dali harness bar with Scroth belts (3" for the shoulders and 2" for the laps). The OEM belts stay in place, the seat loses about 1" of rear travel and you get strapped into the seat fine.

[AWL – 99/10/21] If you install a Dali Racing harness bar with the solid/single-piece cross beam, along with a good aftermarket stut tower bar [in an NSX-T], the car becomes nearly as stiff and solid as a coupe. My car is setup this way, and it is great on the track.

[PMI – 2000/2/26] DaliRacing’s harness bar ,which I installed today, is quite good and very well made.

RM Racing

What is the best way to mount that anti-sub belt?

[MJ] 5- or 6-point belts cannot be installed correctly IF you retain the stock seat without modifications. If you mount a 5 point belt and run the belt FORWARD and over the front of ther seat, then around to the back to attach what are you doing ? pulling the lap belt down ? NO, you are pulling it forward and AWAY from you. (believe me we tried it) it also rubs on your seat = noticable front seat cusion wear very quickly.

If you get the 6 point version, then you are forced to:1) sit on the straps and run them up and over the sides of the seat to attach to the rear bar – so what happens in a crash ? you cut the arteries in your legs and/or remove your family jewels. 2) undo the upholstery on the seat back and run them through the back of the seat, good option IF you use them all the time, as it positions them correctly, BUT it involves taking out the seat and unclipping the upholstery etc etc. Not a good choice for occasional use.

There is no "best way" but I’d rather not cut a hole in the floor pan. It is more appealing (IMO of course) to take out the seat bottom and either modify it ala Wayne Miller’s car (see http://www.waynemiller.com) **very sanitary** or just take it out completely on track event days and run the belt up under a piece of foam pad (ala Alan Watkins).

Either way, you WILL have to modify the length of the 5 point belt if you decide to attach it to the rear floor cross member of my harness bar or CTECH’s bar. All the 5 point belts I’ve seen (and that includes the SCHROTH) are ALL made to be either floor mounted, (as you suggested) OR attached to a cross bar (like other one I have in my car with my DALI RACING competition seat (for SPARCO, COBRA, RECARO etc.) mounting kit. (shameless plug) Otherwise, you can extend the belt at an auto upholstery shop to make it long enough to reach back to the crossbar and then wrap it.

There is room between the seat bottom and the seat back to slip the 5 point belt through but you would still have to cut a slice in the aluminum seat frame shell to feed the belt through it. **There are cuts in the shell to feed a 6 point belt through without modification to the aluminum seat shell OR the upholstery.**
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