Harnesses - SFI vs FIA

Kevin Harvey · **Posted:** Mon Aug 10, 2009 7:50 pm

Yesterday, Dawn and I took our two Cobras to zMAX in Charlotte and participated in True Street in the NMRA/NMCA Drag Racing event. BTW, Dawn won her class... I will post that up later so you can see it on TV.

Anyway, when the inspector was going over my 99 Cobra for the technical class inspection, he kept looking at my belts and flipping them over and looking at each one. I asked if everything was ok and he said he was looking for the SFI rating and expiration date. I pointed out that my two month old Schroth belts are FIA rated and good until 2014 as we examined the rating tag.

He stated that they require SFI and rarely/never see FIA belts.

I pointed out (probably not as politely as I should have) that my belts were good enough for road racing and are some of the best on the market.

We went on to discuss the fact that SFIs expire every two years while FIA expire every five. Common knowledge.

I asked why drag racing would require a belt that expired in two years and he gave me an interesting answer. It is because of the open cockpit cars. The UV rays from the sun break down the belts more quickly and by requiring them to be changed every two years, they were ensuring the drivers had safe belts.

This then brought up the topic of open cockpit cars in road racing and what about them? Surely those belts are exposed to the same UV rays as an open cockpit drag racing car.

The guy works at Heartland Park on occassion and was going to go back to them and ask the same question. He said himself that he was now very curious about it.

So..... what about open cockpit road course cars? Why can they get away with a belt that expires in five years versus and open cockpit drag car that has to change belts every two years due to UV exposure?

And maybe this isn't the entire story?????

steve remchak · **Posted:** Mon Aug 10, 2009 9:58 pm

i would think a sanctioning body has the final say as to the length of time a certification is valid.

look at BMWCCA's theory on front LCAs.

Lemons has a four year limit on harnesses.

Richard Casto · **Posted:** Mon Aug 10, 2009 11:02 pm

steve remchak wrote:

i would think a sanctioning body has the final say as to the length of time a certification is valid.

look at BMWCCA's theory on front LCAs.

Lemons has a four year limit on harnesses.

I don't know if this is true or not, but I wonder how many sanctioning bodies would prefer to just past the buck back to someone else. Either the manufacture or the testing organization.

Replacing every two has to be safer than every five right? Lets go with the organization that says every two.

Frank Catena · **Joined:** Wed Aug 27, 2003 1:08 pm **Posts:** 418

Interesting read:

http://www2.sailrite.com/PDF/Articles/D ... %20Res.pdf

My brother in law sails quite a bit and he sent me this after we had a discussion on harnesses (his son is starting to do HPDEs and ...)

Frank

Richard Casto · **Posted:** Tue Aug 11, 2009 8:04 am

Frank Catena wrote:

Interesting read:

http://www2.sailrite.com/PDF/Articles/D ... %20Res.pdf

My brother in law sails quite a bit and he sent me this after we had a discussion on harnesses (his son is starting to do HPDEs and ...)

Frank

Interesting article. My take... It's hard to determine exactly how much UV exposure you get, so it's better to replace early. My guess is that track cars (even convertables) that see use a handful of weekends a year and are stored inside (garage or trailer) probably get very little UV exposure. I can see how on boats that are probably stored outside would have a serious UV exposure problem.

It would be interesting to test to destruction an aged harnesses after being stored in different conditions. Stored in box; in car that is driven frequently; in car that is driven infrequently (stored inside most of the time).

Kevin Harvey · **Posted:** Tue Aug 11, 2009 8:18 am

This definitely caught my attention in the article:

"It's important to note that the initial
strength of a length of webbing will not
be even close to that of the same piece
one year later. Exposure to sunlight easily
halves the strength of webbing each
year it’s in use."

Going with this, there is something to be said for requiring a change of harnesses every two years on an open cockpit car.

On a somewhat related note, I guess it is a good thing I am in the habit of storing my tow straps for my trailer in their duffle bag under the back seat of my truck or in the garage. I have OFTEN seen people just leave them on their trailer when it is parked for storage.

Mark Vitacco · **Posted:** Thu Aug 13, 2009 11:31 am

Kevin:

To answer your question in SCCA road racing, if your harnesses are SFI
rated only, they too must be replaced in two years. If they are FIA rated, they must be replaced by the date on the tag-which is 5 years. Some harnesses have both tags. In that case, our club uses the higher of the two ratings, which would be the FIA tag. I'm pretty sure the SCCA does the same thing if an FIA tag is present. This has pretty much been the norm since the 2001-2002 seasons. Great to hear the drag racing groups are serious about his and actually checking harnesses.

For our HPDE & TT program use limit 5 years use on harnesses for both
as a minimum.

Mark

Vincent Keene · **Posted:** Thu Aug 13, 2009 11:43 am

Kevin Harvey wrote:

This definitely caught my attention in the article:

"It's important to note that the initial
strength of a length of webbing will not
be even close to that of the same piece
one year later. Exposure to sunlight easily
halves the strength of webbing each
year it’s in use."

Not dispute this claim, but can anyone tell me why they don't make aftermarket harnesses out of the 'magical' material (UV proof?) that stock seat belts are made of? Those have no expiration date, and I've never seen them torn or damaged in a crash. For that matter, has anyone seen a decent aftermarket belt torn or damaged after a crash? The force it would take to snap that 3" wide belt even at half of it's original strength has to be substantial I would think. And yes, I know harnesses stretch in a crash and should be replaced afterwards.

Bernie Baake · **Posted:** Thu Aug 13, 2009 1:26 pm

Kevin Harvey wrote:

This definitely caught my attention in the article:

"It's important to note that the initial
strength of a length of webbing will not
be even close to that of the same piece
one year later. Exposure to sunlight easily
halves the strength of webbing each
year it’s in use."

Remember that was an article on sail boat webbing. Where the expected sun light exposure is considerably more than that of an auto. The sail boat ain't garaged....

Frank Catena · **Joined:** Wed Aug 27, 2003 1:08 pm **Posts:** 418

Good question, but normal car window glass does block over 95% of UV B energy so that probably mitigates things a bit.

Frank

Vincent Keene · **Posted:** Thu Aug 13, 2009 2:06 pm

Frank Catena wrote:

Good question, but normal car window glass does block over 95% of UV B energy so that probably mitigates things a bit.

Frank

My street car also has 35% tint so it's mitigated even more.

Jason Mauldin · **Posted:** Thu Aug 13, 2009 4:28 pm

Do you guys replace tow straps every two years?

steve remchak · **Posted:** Thu Aug 13, 2009 5:44 pm

Jason Mauldin wrote:

Do you guys replace tow straps every two years?

mine are 4 years old, but i have a set of spares stashed in the trailer.

but again, mine don't see direct sunlight.

Marty Howard · **Posted:** Thu Aug 13, 2009 7:08 pm

Vincent Keene wrote:

Kevin Harvey wrote:

This definitely caught my attention in the article:

"It's important to note that the initial
strength of a length of webbing will not
be even close to that of the same piece
one year later. Exposure to sunlight easily
halves the strength of webbing each
year it’s in use."

Not dispute this claim, but can anyone tell me why they don't make aftermarket harnesses out of the 'magical' material (UV proof?) that stock seat belts are made of? Those have no expiration date, and I've never seen them torn or damaged in a crash. For that matter, has anyone seen a decent aftermarket belt torn or damaged after a crash? The force it would take to snap that 3" wide belt even at half of it's original strength has to be substantial I would think. And yes, I know harnesses stretch in a crash and should be replaced afterwards.

Actually as you probably know the stock seat belts are imune themselves. And as I found out recently they are actually the only part on a car that the dealer must replace for life. After X amout of years you can actually take the car to a dealer and they have to replace them, or if there is ANY part of the seatbelt system not working. It's Federal law, or so I was told.

Kevin Harvey · **Posted:** Thu Aug 13, 2009 9:08 pm

All,

Good information, good discussion.

Marty,

Wish I had known that before I threw the ones from my 99 Cobra away a couple of months ago. I don't know what I would have done with a new set though.....

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