ATTENTION!
Harnesses, Bucket/One-piece seats, and Rollbars/Cages are meant to be used together!
If you are asking about using a harness and/or bucket seat WITHOUT rollover protection, you will be immediately directed here. The short explanation:
-The stock system (3-point seatbelt, reclining seat, no rollbar) is designed to work AS a "system." In the event of a rollover, the 3-point belt allows your body to fold over, and the reclining seat can "break" at the hinge (also allowing your body to move), thus preventing you from getting crushed.
-The "race" system (for lack of a better term; harness, one-piece seat, rollbar/cage) is also designed to work AS a "system." In the event of a rollover, the harness and seat will keep you upright, but the rollbar/cage will be there to keep the roof from crushing you.
-If you use the harness and/or seat without a rollbar, a rollover can result in the roof coming down on you while you are held upright. Think of stepping on a soda can, and relate that to what can happen to your spine. That doesn't mean it WILL happen, but honestly, why take that chance? It's your damn SPINE we're talking about. When I dig them up, I'll post pics of rollovers so everyone has a clear idea of how bad that can be.
-If you use a rollbar/cage with the stock reclining seat, ANY collision CAN result in the seat contacting or going under the harness bar, which could then result in your head contacting that same harness bar. Generally, head-metal tubing contact is bad, whether you're wearing a helmet or not (but especially bad if you're not). Again, that doesn't mean it WILL happen, only that it can.
-The "Correct" or "Smart" way of doing this is to put these things in your car AS a system. Don't have enough money to buy them all at once? No problem. Either set the money aside until you do, or buy them piecemeal and leave them out of the car until you have all the components. Some organizations now require all of these things to be present as a system, or else you have to remain completely stock. For competitive racing, the entire "race" system must be present.
-Helmets
First some good threads
http://www.honda-tech.com/showthread...ghlight=helmet
http://www.norcalcrx.org/tyson/helmet.html
In general, there are few rules about buying a helmet. First and foremost is TRY IT ON! A poorly fitting helmet will be both uncomfortable and dangerous. You're wearing this thing for as little as 1 minute (autox), and as long as 30-90 minutes (HPDE/Racing/Enduros). It is absolutely worth a few-hour drive to the nearest race shop to figure out what works best for your noggin. Sometimes a super cheap helmet fits best, so don't immediately discount them.
After size comes rating. Ratings are discussed in the norcalcrx link above. As of now (Year 2009) SA05 should be the latest helmet you would want to purchase. SA10 should be released soon, and in a few years SA00 helmets will no longer be allowed in many organizations. SA95 helmets are already too old. When making a rating choice, you have two options: M and SA. "M" is for "Motorcycle". These are acceptable for most autocross events, and some HPDE events (depending on organization). "SA" is for "Snell Approval". These pass some slightly different tests, and should all have some type of fire resistant/proof liner. For competitive racing, you will need an SA helmet.
There are also two (sort of three) designs to a helmet: Open Face or Closed Face (with the third being kind of a hybrid between the two).
Open face is seen here:
http://www.bellhelmets.com/index.cfm...roduct_ID=4892
Closed face seen here:
http://www.bellhelmets.com/index.cfm...roduct_ID=4888
This is to some extent personal preference. I know several people who start to feel claustrophobic in a closed face helmet, and so opt for the open face. A lot of autoxers also opt for the open face for whatever reason. I personally am a proponent of closed face helmets, because I've had all kinds of crap hit my visor. Bugs, rocks, melted tire rubber, whatever. The idea of getting ANY of that in my eyes is enough to make me wear some type of eye protection, whether it's a visor or sunglasses.
Quality and unique features are another thing you'll want to pay attention to. The cheaper helmets are cheap for a reason: quality is lower, material used is not as nice. That doesn't mean they won't protect you just as well (the M/SA rating guarantees that), but they might not be as comfy, and things like the liner might shred/fall apart sooner. The unique features would be something like the forced air helmets, where there are inlets for some type of blown air ventilation. This is again personal preference. I'm fine without that, but my brother could really use it. There are also a variety of different visors available, including smoked, mirrored, amber, etc.
-Harnesses
Street legality:
http://www.honda-tech.com/showthread...hlight=harness
Some mounting information:
http://www.honda-tech.com/showthread...hlight=harness
Some more mounting information, Schroth specific but applicable as general guidelines:
http://www.schrothracing.com/sdocs/2...structions.pdf
Mounting how-to:
http://www.sandmracing.com/ssabelt.html
Harnesses are another form of a seatbelt; they keep your ass in the seat where it's supposed to be. They typically do this job "better" than a stock seatbelt, but also differently. See the ATTENTION! bit above for some more information about harnesses.
-There are 3-4 types of harnesses:
3-point (both stock and aftermarket)
4-point (shoulder straps and lap belts)
5- and 6-point (shoulder straps, lap belts, and crotch belts [6-point has two crotch belts])
7-point (shoulder straps, lap belts, and 3 crotch belts)
Which one you use is your choice. 3- and 4-point are generally used by either street drivers or autoxers. Most tracking organizations do not allow these, and require either the stock seatbelt or a 5-7 point harness. The lack of a crotch strap can result in submarining, where your body can slide under the lap belt and squish itself into the footwell. This is possible because the shoulder straps won't allow your body to fold over the lapbelt. Schroth makes a certain type of 3- and 4-point harness with an inertia reel, similar to what is mounted on the B-pillar/door of a stock car. They also make an ASM shoulder belt that sort of allows the same thing. Basically, that design DOES allow your body to fold over the lapbelt, and should keep you from submarining.
There are also various safety ratings for harnesses, with the two US-applicable ones being "FIA" and "SFI". FIA harnesses are legal for 5-years, SFI harnesses are legal for 2-years (for competition). Some HPDE organizations now follow that rule, and some do check the dates on belts (there is a tag on the belt that has a date "stamp"). Regardless of the organization, these things must be kept in good shape. If they are torn or frayed, they're garbage.
Harnesses are also designed to be used ONCE! That means if you get in an accident/hit a wall, they're garbage. The reason for this is that the webbing is designed to stretch a certain amount in an impact. After stretching, they can't stretch again. There are some companies that offer re-webbing services, which can be cheaper than purchasing a complete new harness.
-Seats
There are stock seats, there are aftermarket reclining seats, and there are one-piece seats. Stock seats are...stock. Some are better than others for spirited driving, with higher/tighter bolsters and so on. Popular Honda options are ITR seats (the material is different, and the seat foam is actually different), Del Sol seats, and JDM Recaros. Seats are like helmets; they come in different sizes, and fit people differently. The JDM seats are made for tiny Japanese people, and so won't comfortably fit the average 250lb American. The same applies to one-piece seats. Some are skinny, some are short, some are tall, and some are wide. Also like a helmet, your best bet is to go to a shop and sit in a few to see what fits you best. Things you want to consider are shoulder bolster height, shoulder strap hole height, and width. You'll be sitting in this thing a lot, and so want it to be comfy.
There are also generic eBay reclining seats. While it is always your personal choice, I can't stress enough that these no-name companies typically have no kind of safety testing, and generally are garbage. I have been on track as a passenger in a few of these and the experience was horrendous to say the least. The biggest problem I saw was that the hinge mechanisms are weak and poorly constructed. That allows the seat back to move A LOT. Try putting your faith in something like that in a collision. If you want to go with a reclinable seat, pick a known brand name (Sparco, Recaro, etc.) or stick with an OEM offering.
One piece seats have two mounting options: bottom-mount or side-mount. Sounds pretty self-explanatory, right? The holes for physically mounting the seat are either on the bottom of the seat, or on the side. Side-mounts typically allow the seat to be mounted lower than bottom-mounts. Both are legal. There are also aluminum seats available (Kirkey, Ultrashield), and for these you drill your own holes, and so mount them however you want.
There is really only one type of safety approval for seats, and that is FIA. All others are just classified as "non-FIA". For track use, non-FIA seats usually require a backbrace, which is some type of device that braces the seat back against the harness bar. FIA seats are designed to flex, and if kept within their date (5 years) do not require that brace.
-Rollbar/cage
Some basics:
http://www.norcalcrx.org/tyson/rollcage.html
http://www.honda-tech.com/showthread...light=rollcage
-Track organizations have very specific rules about tubing diameter and wall thickness. You want to figure out what those rules/specifications are, and then get a bar/cage that meets them. As one example, NASA has two different rulesets, one for rollBARS and a different one for rollCAGES. The tubing size is different between the two. Depending on what you intend to do, keep that in mind. Each organization is similar, but might have small differences. Because a bar or cage can be a hassle and expensive, you want to do it right the first time. Pay attention to the details here (DOM tubing, ERW tubing, chromoly, mild steel, vehicle weight, mounting points, footplate sizes, etc.). It can be complicated.
RollBARS are a type of rollover protection that is behind the front seats of a vehicle. It includes a main hoop and rear legs at a minimum. For track use it should also have a diagonal in the main hoop and a harness bar. Additional reinforcements vary.
RollCAGES include the rollbar structure, but add a front structure, that includes front arms and a "halo" design at a minimum, usually also with door bars and a dashbar. Again, further reinforcements vary.
Both bars and cages are available as off-the-shelf bolt-in designs or custom-made weld-in designs. Your purpose will determine what you go with. When properly constructed and mounted in the vehicle, both will offer some degree of increased protection.
For basic bolt-in designs, see Autopower and Kirk Racing. Both companies offer legal products in a wide variety of fitments and for a wide variety of vehicles. There are other options as well.
Do NOT use Cusco bars/cages! There have been numerous discussions here and elsewhere about why. To keep it short and simple, they are not legal according to almost all US organization rules. They might be JDM certified or whatever, but that does not mean it's ok in the US. I could rant on endlessly about these, but won't here. A search for "Cusco" in the RRAX forum will return MANY results, and you can read all about it.
