This Side Up - Car Prep

Must be catching.

nospam@example.com (Richard Welty) — Sun, 06 Jan 2008 21:01:00 -0500

another one, courtesy of Dave Theen:

Lesson of the day

nospam@example.com (Richard Welty) — Sun, 06 Jan 2008 12:37:18 -0500

Always remember to torque your lug nuts (thanks to Paul Foster for the link).

Spec Miata Engine prices

nospam@example.com (Richard Welty) — Thu, 04 Oct 2007 13:33:48 -0400

Some drivers in Spec Miata have complained quite a bit about the cost of engines now that SM has been a national class for a couple of years; they seem quite sure that the expensive motors (ca. $8K I hear) must be illegal or something.
As for my thoughts, well, some Showroom Stock drivers have been paying those kinds of prices for nationals motors for years.
"I am shocked to discover that there is parts bin based balancing going on in a Showroom Stock based class." -- Claude Rains, Casablanca

Harnesses and aging

nospam@example.com (Richard Welty) — Tue, 02 Oct 2007 13:40:07 -0400

The SCCA currently accepts two standards families for harnesses: SFI 16.1 and FIA (one of 8853/1895, 8853/98, or 8854/98). Belt expiration is determined differently for the two families.
For SFI belts, we take the date punched into the SFI label (which is approximately the date of sale in most cases, more on that in a minute), add 2 years, and then round out to the following December. For FIA belts, we just use the expiration date on the belt label. If a belt carries both certifications, we use the later date (giving longer usage). This invariably ends up being the FIA expiration date, which is commonly 5-6 years away for new FIA belts.
So what's the difference? It's pretty simple. Harness webbing is typically Nylon or Polyester; SFI standards permit either. FIA only permits Polyester, which has better aging characteristics, which mostly have to do with the response of the belt to UV exposure (FIA belts also only have cam-lock style latches, but this isn't really an aging related issue.)
So since FIA belts usually last nearly twice as long, I tend to advise drivers that the $30-$40 premium for FIA belts is well worth it.
As for the date on the SFI label, some belt vendors aren't careful. Sometimes this means that you open a box of belts and the date is still two months away. Sometimes it means that you open a box of belts and discover that they are 3 years old and have already expired. I recommend that when you receive a set of belts, check the date immediately. If you just put them in the car and show up, the Tech Inspector isn't likely to have mercy on you.

SRF Seats updated

nospam@example.com (Richard Welty) — Mon, 01 Oct 2007 16:19:51 -0400

I added an update to SRF Seats below and am just posting this to bring it to everyone's attention.

Harnesses & HANS devices

nospam@example.com (Richard Welty) — Mon, 01 Oct 2007 14:10:26 -0400

(Updated below in Bold Face).
Yes, I am reusing some of the SRF pics from earlier for this discussion.

Here is the shoulder harness and the fiberglass seat from the earlier blog entry. It happens to be an SRF, but it could be one of any number of types of formula car or sports racer; I've seen similar problematic harness mounts in a number of different types of cars.
Now what is the issue here? It's the spacing of the shoulder harness mount points behind the seat. The standard mount points in an SRF are 8" center-to-center; in some Formula Cars and Sports Racers it's even larger (I've measured 10" in some.) The General Competition Rules have for many years called for 4" to 6" center-to-center (see figure 1, page 80, 2007 GCR).
On top of this, for drivers using a HANS device, the HANS Owners Manual
explicitly calls for no more than 3" inside-to-inside. There is a small amount of math that's good to do here; if we are using 3" wide belts (the conventional type) with a HANS then 3"+1.5"+1.5" yields 6" center-to-center which matches exactly the widest spacing permitted by the GCR. If we're using 2" wide belts (permitted only with a HANS), then we get 3"+1"+1", so we have 5" max center-to-center when using 2" wide belts with a HANS.
If we go back up to the picture and look at it, we see that the car is equipped with the 2" HANS only belts, but is using the 8" mount points the SRF came with. This leads to 6" spacing inside-to-inside, 3" more than the HANS owners manual calls for. The driver may have problems with the belts slipping off in this set up; it is not in conformance with the GCR or with the HANS owners manual, although it is in conformance with the car shipped by SCCA Enterprises.

This installation represents one that will work well with a HANS. The belts are an appropriate distance apart, laying flat as they come forward through the seat, they will not bunch up and will drop naturally over the HANS "horse collar". This particular SRF has had the new kit installed that allows better spaced mounting of the shoulder harnesses.

This seat/harness setup is an intermediate step; this car is still using the 8" spaced mount points, but the Butler seat is pulling the straps closer together. This driver will probably not have problems with his shoulder harness and a HANS, although the bunching of the webbing at the outside ends of the slots is slightly troubling (See the discussion of this installation in the earlier SRF Seats posting.)

Drivers are trying various other things with the HANS. Some are using harnesses with the extra sternum latch up near the top of the chest; unfortunately, these are not actually legal harnesses in the SCCA (2007 GCR 9.3.18.D page 78 requires a SINGLE common release point for the lap and shoulder harnesses.) At the NARRCOffs one driver showed me a friction material applied to the top side of the HANS "horse collar" to assist in keeping the shoulder belt from sliding off. I am uncertain how well this will actually work.

SRF Seats

nospam@example.com (Richard Welty) — Mon, 01 Oct 2007 10:30:47 -0400

Updated below in Bold Face.

This is a shot of the right side mount of the original fiberglass seat which is still commonly seen in SRFs. The metal strap under the three bolt heads is a critical piece of the mount; it was added after failures occurred in crashes. It is sometimes left out during assembly; not all SRF owners understand its purpose.
This spring I saw a couple of SRFs with damage to the fiberglass at the rear end of the valley on driver's right between the seat and the mount; this is something that an SRF owner with one of these seats needs to keep an eye on.

This is a shot of the top of the seat back, where the shoulder harnesses exit the bodywork. This car has the original shoulder harness mount points, which are 8" center to center. The GCR specifies that this dimension should be 4"-6". A kit is available from SCCA Enterprises that allows for more appropriate (and more GCR compliant) mounting. I understand from Shawn Morrison of Motion Dynamics (the NEDiv CSR) that it's a bit of work to install properly; it can be bolted in but is apparently best if welded.
One important point about this type of seat -- we impounded SRFs at the NARRCOffs on Friday afternoon, and two of the cars we inspected had noticeable fraying problems with shoulder harness webbing where the harness came in contact with the rough edge of the fiberglass. It's something an SRF owner needs to keep an eye on.

This is one of the newer style Butler seats. Drivers who have switched definitely like these better. One key point here, though, is that with unmodified shoulder harness mount points, the belts are pulled inwards and the harness tends to bunch up where it passes through the seat. We would very much prefer to see harnesses laying relatively flat where they pass through the seat. In fact, the 2007 GCR 9.3.18.D (page 78) says this:
The seat itself, or anything added only to the seat shall not be considered a suitable guide. Guides must be a part of the roll cage or a part of the car structure.

Here is a Butler seat in a car with the new style shoulder harness mount. Note how the belts now lie flat and run straight from their mount over the shoulders. This is really what's best all around.

SRF Seats

nospam@example.com (Richard Welty) — Fri, 24 Aug 2007 11:03:20 -0400

The original seat in the Sports Renault/Spec Racer/Spec Racer Ford is a fiberglass shell. It doesn't fit anyone particularly well, and long ago an alternative aluminum Butler was approved. The Butler seat is gradually replacing the fiberglass seat, but there are still a lot of the old ones around.
At Lime Rock a couple of weeks ago, and at Pocono this past weekend, I saw a couple of fiberglass seats with cracks in back on the driver's right, down in the well between the seat proper and its mounting to the right side of the car. I don't recall having seen these sorts of cracks before, and they concern me (I wish it had occurred to me to take some pictures; if I see any of these at Lime Rock at the end of September, I'll be sure to take some and post a followup.)
I'm not yet sure how serious this is; I'll probably drop a line to Enterprises to get their take on it. But still, I strongly recommend going with the Butler, it's a much better seat than the old one.

fool cells 101

nospam@example.com (Richard Welty) — Tue, 04 Apr 2006 15:07:34 -0400

There are two common types of fuel cell in road racing. In most SCCA classes, the cell must meet FIA Standard FT-3 or better. Additionally, in tub and production derived tube frame cars (e.g., things that aren't formula cars or sports racers), the cell must be contained in an approved metal container. finally, in all classes, there must be a complete metal bulkhead between the fuel cell compartment and the passenger compartment.
Because of space restrictions, in formula cars and sports racers where the fuel cell is under the driver's seat, one metal bulkhead is sufficient, but the cell must still be FT-3 or better. The FT-3 restriction means that inexpensive plastic cells are generally not permitted (at one point, there was a manufacturer who had gotten a plastic cell through FIA FT-3 certification, but that seems to have been a one-time event; it has not happened again so far as I know.)
The one loop hole where plastic cells are permitted are classes where fuel cells are permitted but not required; in these cases a plastic non FT-3 cell is considered a viable upgrade even if it doesn't meet the spec. Improved Touring is the class where these are likely to be seen.
How do you tell? At a superficial level, look at the filler cap area. An FT-3 cell will have a large oval metal plate with the filler neck and ports for all the various hoses and lines. The hole in the rubber bladder covered by this plate will be the only hole in the cell. By comparison, a plastic cell will have multiple holes drilled in the plastic for the various fittings.
Although the SCCA doesn't currently enforce aging of fuel cells, there are aging rules built into the FT-3 Specification. After 5 years of service, a cell bladder needs to be recertified or replaced, and recertifications are good for 2 years. I have not yet checked to see if recertification is an affordable (or even available) alternative to replacement; there's a good chance it's just not worth it.
Why would a bladder fail? That's easy enough; it's manufactured from petro-chemicals and is exposed to gasoline and whatever is in gasoline more-or-less continuously. In particular, if racers are perhaps using fuel additives that they shouldn't, one can well imagine that premature bladder failure (or disintegration of the foam inside) is a real possibility.
In the next article (Fool cell 102) I'll talk about proper mounting of a cell.

Aging safety equipment

nospam@example.com (Richard Welty) — Tue, 21 Mar 2006 16:10:31 -0500

One of the odder factors about the way the SCCA handles safety equipment specs has to do with aging. We do enforce harness aging per SFI and/or FIA requirements. However, we really don't do much else with aging. If an aging rule is in the main GCR, we enforce it.
The reason this is odd is that most safety equipment standards have recertification rules. A good example is fuel cells; the FIA FT-3 spec calls for recertification of a fuel cell at 5 years, and limits the use of the bladder to 7 years, max. Since the GCR calls for Fuel cells per FIA FT-3, probably we implicitly have this age limit in a strict reading of the GCR -- but I've never enforced it that way, nor have I ever seen anyone seriously attempt to do so.
Window nets are no different; there is a 2 year recertification rule embedded in the current SFI spec.
If you go to the SFI Foundation web site and click on Specification List, there's a table which shows the recert periods in the right hand column. On the FIA Web site, the standards are here and here. The recert info for FIA standards is not broken out conveniently, but is buried in the specs. I didn't know what the aging rules were for FIA FT-3 until I downloaded the pdf and read it. I don't recall ever having been encouraged to do anything like this in the 14 years I've been an active tech inspector.

Tech articles

nospam@example.com (Richard Welty) — Tue, 21 Mar 2006 12:31:06 -0500

I had started an article on tech inspection a few months back. It kept bothering me that I wasn't making progress on it. So all these tech articles constitute an experiment in writing it using blog entries; tonight I'll head over to that article and start cannibalizing it into more blog entries, providing links back to here. It'll likely be come useful faster this way.

harnesses

nospam@example.com (Richard Welty) — Tue, 21 Mar 2006 12:15:29 -0500

There's one question we get a lot; it has to do with belt aging. Specifically, if a belt has an SFI certification label with a manufacture date and an FIA certification label with an expiration date, which takes precedence?
Short answer: the FIA label takes precedence, which is a good thing, because SFI based expirations are now 2 years in most sanctioning bodies, and FIA belts, while more expensive, are generally good for at least twice as long.
Why is this? Because the SFI permits belt webbing to be made from shorter lived materials which the FIA does not accept (I'll post a follow up on this materials question later.)
Here is a helpful hint for anyone who has just bought or is about to buy belts: as soon as they arrive, open the box and check the date on the SFI label. It should be within a month or two (or maybe three) of the day you open the box. Don't be suprised if the date hasn't arrived yet; sometimes vendors post date towards an expected date of sale. If it's more than a couple of months old, though, call the vendor you got them from and give them an earful (and get a newer set of belts out of them). With non-FIA belts, the SFI date of manufacture defines when you will have to toss them and get a new set.

Window nets

nospam@example.com (Richard Welty) — Mon, 20 Mar 2006 16:43:55 -0500

I've long felt that the window net section of the SCCA General Competition rules was very weak, not giving a good description of what is needed in a window net and mount.
Window nets are required in all closed cars in the SCCA, with one exception, which are the closed cockpit sports racers. The only example of such a car that I've seen is the Diasio replica of the Porsche 962; in cars like this you can use arm restraints instead (window net mounting in this car is difficult, so it's a reasonable allowance.)
For the rest, there are some basic principles to consider. First window nets should mount to the roll cage, not to the door. I don't know what IMSA rules look like now, but we used to occasionally have discussions about this with people bringing IMSA firehawk cars over that had door mounted window nets. If the net is on the cage, and the door pops open, you will appreciate having the net stay in place.
Window nets are supposed to keep your arm inside in a heavy hit. You therefore need to consider the strength of the net system when your arm hits it HARD, not when you push on it lightly. I've seen people using elastic cord, and people using hollow aluminum tubing through the top and bottom. Neither approach really cuts it; use steel rod the length of the top and bottom.
Do not make holes in the window net webbing. SFI certified window nets will, to the best of my knowledge, cease to be SFI certified window nets when destructive modifications are made to them, so making a row of holes for a "shower curtain ring" mount is right out (yes, I have seen these types of mounts presented in tech. This is a "you don't race 'til it's fixed" kind of problem.)
Typically, one edge of the net is quasi-permanently mounted and one has a release. I suggest that the top have the release; egress when upside down is rarer than egress when right side up, so having the net fall down when released makes things easier when you're in a hurry.

Shoulder Harnesses and the HANS device

nospam@example.com (Richard Welty) — Mon, 20 Mar 2006 11:30:35 -0500

For a HANS device to work properly, the shoulder harness needs to be properly mounted. The Owner's manual for the device is fairly clear, but some users of the HANS device appear to have not really paid enough attention. (there's a link to the owner's manual on the HANS website, it's a pdf but downloads "funny", you'll probably want to drop it on your desktop and rename it so that your pdf viewer will launch.)
The problem is that the shoulder harness mounting should be about 3" center to center, close behind the driver's shoulders. Additionally, the harness should drop 1" to 2" from the top of the shoulders to the mounting point. This is important because of the need to capture the "horse collar" of the HANS device with the shoulder harness; if the harness is not properly mounted, it may tend to slip off the HANS device and bad things may ensue.
Who should worry about this? Well, everyone with a HANS device, but in particular drivers of purpose built formula cars and sports racers should look long and hard at the factory provided mounting points. A great many of these cars have stock mounting points that are 8" to 10" apart, which are completely inappropriate for the HANS. I wouldn't use a HANS device in these cars until the mounting points got fixed.
This isn't really the fault of the makers of these cars; many (most?) of these designs were done before the HANS device became a big deal. But if you want to use a HANS in one of these cars, you need to mount the shoulder harness correctly.