Topic: Common Tech Failures. UPDATED W/PIX
I figured I'd post some of the most common tech failures we've seen, nationwide. Please read the below information and look at your car, let's get through tech quickly....
1. 360 degree welds on the cage. Often on the main hoop to halo or down bars and the door bars to the main hoop, two very difficult places to get a complete weld. One car at Phoenix had only tack welds on the door bars. We've also seen some really poor welds: cold, lumpy and weak. You have to be a good welder to build a cage correctly. A cage built with a 110 V flux core welder is likely to fail.
1a. Please read the roll cage rules- We are seeing a bunch of cars without backstays and main hoop diagonals. At Pointless there was quite a few teams struggling to get their cages fixed before the race started. Also, two of the recent rollovers were cages that were found lacking and were fixed the night before the race. Re-read the cage rules and get it right. Your backstays should be as close as possible to 45 degrees and have NO BENDS..
1b. Mandrel Bends. Some of the cages we've seen have crush bends. Not acceptable! If your cage is bent on an exhaust bender it is going to fail.. No question.
2. Poorly installed harnesses. Mostly the belts aren't wrapped correctly, look at a diagram, when finished the loose end of the belt should be pointed away from the driver and only one bar of the 3 bar clip should be visible, again, look at a diagram online or the one that comes with your harness set. On clip-in belts, you need to install a locking cotter-pin or safety wire. All bolts/eyebolts must have strong mounting points, either the stock,welded in and reinforced seatbelt mounts or backed up with washers as per the rules. Lap belts must be at the right angle to restrain the driver, we've seen quite a few belts that were mounted too far forward to do any good, the belts must lay on the drivers hip-bones and pull both down and back to be effective. Same with sub-belts, the belt must pull down and back, we will fail a sub-belt that runs over the front of the bottom seat cushion and back to the lap belts. All parts of the harness should be away from sharp protrusions that will fray the belt and cannot be mounted so that the webbing of the harness is clamped between the metal of the car and the belt bracket, that will also cause fraying. If you have HANS-specific belts then everybody on your team MUST use a HANS, these belts are not safe without the use of a HANS. The BEST way to install shoulder harnesses it to wrap them around a harness bar at the right height. You want to sail through tech? Have wrapped shoulder harnesses at the right height with the belts threaded through the clip correctly. Just do it, or we are likely to make you fix it at the track.
3. Poorly installed seats. Loose, sloppy seats will fail tech. The seat must not be able to fail in a rear-end impact. That means that there has to be something structural within 6" of the back of the seat, that includes your shortest driver. A back brace is highly recommended. This rule also includes in-date FIA seats, there is no difference in the rules by type of seat, all must not be able to fail rearward.
4. Disconnect Switch. The switch must cut off all power to the engine, that usually means that the alternator circuit has to be cut as well as battery power. The switch also has to be reachable and marked.
5. Electrical clean up. Most of you have managed to cover the + terminal on your battery, but not on the back of your disconnect switch or elsewhere there is 12 volt power. If I see an uncovered terminal or bare wire, I will make you cover it.
6. Loose stuff. Zip-ties are you friends, get everything tied down. This falls under the de-scuzzification part of the rules.
7. Fire extinguisher, geez, you'd think that the rules are written in Sanskrit. Metal brackets that are through-bolted, done. Why do we still see so many plastic brackets held on with one screw?
8. Windshields: We've seen a bunch of totally spider-webbed broken windshields lately. We failed them and the teams had to scramble for a windshield Friday night. A few small cracks/ chips are ok, beyond that, get it fixed.
9. Oil leaks- we cannot let the track get oiled down and a car that leaves a trail of oil through tech is going to be told to fix it.
10. roll cage padding. There must be padding any where the driver can contact the cage while strapped into the seat. Add padding!
11. Fuel cells. If the cell is not an FIA certified rubber bladder cell (Fuel Safe or ATL) then it must have a sealed metal barrier between it and the driver, even if it is in a metal can. NO EXCEPTIONS! This means most cells from Jazz, RCI, Summit, Etc. They all need a metal bulk head between the cell and the driver. A fuel cell install is always judged by its quality of install and is looked at by the race manager, The bar is high, do a good job.
These are what I've seen most often: there are, of course, many others, read the rules and ask questions.
Here's are some photos of some of the common failures we see--in no particular order:
Scary-looking cage spreader plates are REALLY common. Make sure they are appropriately sized, attached with good welds, and affixed to a part of the car that is structurally sound. Air space, missing or crappy welds, and undersized plates will ALWAYS catch the eye of the tech inspector.
Bent rear stays are really common--they significantly compromise cage integrity and result in an essentially automatic tech failure. Make sure your cage builder knows to run them in a straight line.
The rear stays of can't terminate in the strut bar, as they do here. They need to extend to appropriate spreader plates in the floor or frame.
The diagonal does not continue across the entire plane of the main hoop--it is required to.
Cage positioned too low in car--you don't want your head poking up over the top of it.
Crimped bends are a no-no. Basically, if you can see any deformation in the bend, that won't fly.
The rear stays should be as close to 45 degrees as possible--too steep or too shallow (seen here) puts you at risk of failure.
This one is actually in somewhat of a gray area--what the cage builder SHOULD have done here is run the rear stays to the shock towers with the appropriate mounting plates. Running the rear stays toward the center is a much less sturdy layout--and puts you at risk of failing tech.
We get a lot of questions about what constitutes an unacceptable windshield crack--it's hard to say, but if you have to ask, you're probably screwed. These two didn't fly.
FIA-certified fuel cells can be used without a metal firewall between it and the cockpit. That means we'll be looking for the FIA stamp--this cell didn't have one, so it needs a firewall.
Seat belts must be mounted between zero degrees and 15 degrees below the seat entry point. Anything that comes downward like these do will fail.
Incorrect lap/sub belt placement--the anchor points need to pull back and downward on the driver's waist--so the lap/sub belts must be anchored in spots that pull the driver TOWARD the seatback.
Anti-submarine belt coming over the top of the seat squab is pretty much an automatic failure. The anti-sub belt should be anchored at a point behind the center of the driver.
Hooptie-ass fire extinguisher mount. The rules specify a bolted-in metal quick-release mount--this ain't it.