Superforgiata OZ's..weight load rating
#46
Race Director
Discussion on wheels aside, I wanted to be sure to mention Damon at Tirerack is AWESOME to deal with. And I had plenty of dealings with him over the past couple of years. If you buy from TR be sure to let Damon assist you, he knows Porsches and and is an all around good man.
#48
I sell enterprise software so I actually like to buy from the big brands so in this case OZ and BBS.
I'm curious what the smaller businesses do in terms of testing. HRE, CCW, Champion, et al... to what strict standards do they receive certification, if any? They do charge a pretty penny.
We know the lengths to which BBS and OZ go to ensure reliability and strength... very interested to learn more while at the same time cut out as much of the anecdotal, knows enough to sound dangerous mumbo jumbo so prevalent in keyboard jockey arenas.
Thanks!
I'm curious what the smaller businesses do in terms of testing. HRE, CCW, Champion, et al... to what strict standards do they receive certification, if any? They do charge a pretty penny.
We know the lengths to which BBS and OZ go to ensure reliability and strength... very interested to learn more while at the same time cut out as much of the anecdotal, knows enough to sound dangerous mumbo jumbo so prevalent in keyboard jockey arenas.
Thanks!
#49
TUV load ratings for the GT3 are under 400 kg in front and about 640 kg in the rear.
During the TUV "rotary bending test", the wheels are subjected to loads far higher for more than 100,000 cycles. I recall the bending loads are some 50% higher than the SAE J2530 test.
This is the real "acid test" for wheel fatigue.
In my view, if the wheel receives the TUV "gutachten" for load strength and then the "teile gutachten" as being suitable for a specific vehicle, then you can safely assume the wheels are fit for track use on that vehicle.
It really is a wicked test with vehicle and driver safety in mind.
Remember that a wheel optimized for the GT3 would not be suitable for a Turbo, because the load requirements are higher for the heavier car. The TUV calls them out differently on their requirement data sheets.
During the TUV "rotary bending test", the wheels are subjected to loads far higher for more than 100,000 cycles. I recall the bending loads are some 50% higher than the SAE J2530 test.
This is the real "acid test" for wheel fatigue.
In my view, if the wheel receives the TUV "gutachten" for load strength and then the "teile gutachten" as being suitable for a specific vehicle, then you can safely assume the wheels are fit for track use on that vehicle.
It really is a wicked test with vehicle and driver safety in mind.
Remember that a wheel optimized for the GT3 would not be suitable for a Turbo, because the load requirements are higher for the heavier car. The TUV calls them out differently on their requirement data sheets.
#50
The load rating specified is only what the manufacturer chose to have the wheel tested to....
When we did our CFT testing on our private label wheels (fuchs replicas in 17 inch) a few years back at STL we tested them to over 2200lbs. We wanted to go overboard on the testing. There are limits in the test for deflection and failure. Two wheels with the same rating may have defections that are very different, but both would not have failed.
Generally, IIRC when a street wheel is tested it is tested to 1.3-1.5 times the actual corner weight it sees at static rest. A race wheel is tested to 2.0-2.2 times the actual static corner weight, minimum of 100,000 cycles. A wheel producer can choose the rating they wish to be tested to. For the different ratings (JIL, TUV etc) there are min specs based on bolt circle/diameter/width but not specific to the type of vehicle....
The folks at STL where very helpful in explaining all of our testing options etc to us and were great to deal with. They provide a very detailed report as well. STLLabs.com
When we did our CFT testing on our private label wheels (fuchs replicas in 17 inch) a few years back at STL we tested them to over 2200lbs. We wanted to go overboard on the testing. There are limits in the test for deflection and failure. Two wheels with the same rating may have defections that are very different, but both would not have failed.
Generally, IIRC when a street wheel is tested it is tested to 1.3-1.5 times the actual corner weight it sees at static rest. A race wheel is tested to 2.0-2.2 times the actual static corner weight, minimum of 100,000 cycles. A wheel producer can choose the rating they wish to be tested to. For the different ratings (JIL, TUV etc) there are min specs based on bolt circle/diameter/width but not specific to the type of vehicle....
The folks at STL where very helpful in explaining all of our testing options etc to us and were great to deal with. They provide a very detailed report as well. STLLabs.com
#51
The load rating specified is only what the manufacturer chose to have the wheel tested to....
When we did our CFT testing on our private label wheels (fuchs replicas in 17 inch) a few years back at STL we tested them to over 2200lbs. We wanted to go overboard on the testing. There are limits in the test for deflection and failure. Two wheels with the same rating may have defections that are very different, but both would not have failed.
Generally, IIRC when a street wheel is tested it is tested to 1.3-1.5 times the actual corner weight it sees at static rest. A race wheel is tested to 2.0-2.2 times the actual static corner weight, minimum of 100,000 cycles. A wheel producer can choose the rating they wish to be tested to. For the different ratings (JIL, TUV etc) there are min specs based on bolt circle/diameter/width but not specific to the type of vehicle....
The folks at STL where very helpful in explaining all of our testing options etc to us and were great to deal with. They provide a very detailed report as well. STLLabs.com
When we did our CFT testing on our private label wheels (fuchs replicas in 17 inch) a few years back at STL we tested them to over 2200lbs. We wanted to go overboard on the testing. There are limits in the test for deflection and failure. Two wheels with the same rating may have defections that are very different, but both would not have failed.
Generally, IIRC when a street wheel is tested it is tested to 1.3-1.5 times the actual corner weight it sees at static rest. A race wheel is tested to 2.0-2.2 times the actual static corner weight, minimum of 100,000 cycles. A wheel producer can choose the rating they wish to be tested to. For the different ratings (JIL, TUV etc) there are min specs based on bolt circle/diameter/width but not specific to the type of vehicle....
The folks at STL where very helpful in explaining all of our testing options etc to us and were great to deal with. They provide a very detailed report as well. STLLabs.com
But no vehicle-specific "Teile Gutachten" will be issued unless the wheel meets the TUV load requirements for that SPECIFIC vehicle.
It is the Teile Gutachten that must be carried in the vehicle in Germany and Austria if you have aftermarket wheels.
#52
Race Director
for those simple people like me that are reading this...I had to google and translate "teile Gutachten" from Forgedwheelers post...LOL
It means share expertise.. gutachen means act as an expert witness and teile means share.
It means share expertise.. gutachen means act as an expert witness and teile means share.
#53
TUV certification procedure
Since my business is wheel engineering, I decided to explain the TUV approval process to the members.
1.First, all the suppliers of a given product that is to be submitted for approval must have their quality system verified by TUV. No exceptions. This can either be an ISO 9000 certificate, TS/QS certificate like the OEMS use, or an actual TUV verification by an in-person TUV auditor.
In the case of wheels, this means the forging facility or foundry, heat treat facility, machining facility, etc. All must submit their documentation to the TUV prior to testing. The reason for this is obvious.
2. Next, test wheels must be submitted in sufficient quantity for the test at hand. If you are getting wheels certified for just one vehicle, this is usually 3 to 6 pieces.
If you are well known to the TUV, it is possible to get a "family" of wheels approved in a given style and diameter with a variety of bolt circles. This is complicated, but worth the effort.
3. Next, the TUV will test the wheels at whatever load that you state. This includes a variety of tests including radial fatigue, drop test, rotary bending, etc.
These tests are brutal and the test loads are 1.5 to 2 times higher than the stated load, just to be sure.
4. If the wheels pass, you will receive a "Gutachten" certificate from the TUV which states that the approved wheel is good up to a specific load rating. This certificate is "Wheel specific", not vehicle specific. At this point, the wheel would not be legal to sell for any vehicle. This certificate costs 3000 to 5000 Euros because of all the testing involved.
5. If the wheel fails the first test, you have big problems. You will then have to submit twice as many wheels for the next test and the tests will be even more carefully scrutinized. Very expensive.
6. Once you have a "Gutachten", you can apply to the TUV for a "Teile Gutachten". This certificate will state that the wheel is approved for a specific vehicle. The TUV sets their own load requirements for each vehicle, based upon input from the original vehicle manufacturer. The teile gutachten certificate costs about 200 to 300 euros, because it is just a paperwork process.
To be very specific, a teile gutachten is a TUV approval for a specific vehicle or vehicles, and is rarely transferrable to another vehicle. For example, if the wheel manufacturer "weight optimizes" the wheel for a Porsche GT3, they cannot receive a teile gutachten for a heavier Turbo. Conversely, if the teile gutachten covers the Turbo, it will usually cover a lighter GT3.
You will receive a teile gutachten certification number and this number must be permanently inscribed on the wheel. The certificate in the car must match the number on the wheels. If you are stopped by the German police, everything must match or they will tow your vehicle.
7. If the manufacturer changes any vendors in the supply chain, new paperwork must be submitted to the TUV for approval. They will then decide if they want to re-test the wheels and issue new certificates.
This whole process is identical for every wheel manufacturer, large or small.
The vehicle OEMs are not required to do this because they certify the whole vehicle.
So, if you are shopping for a wheel and the wheel manufacturer has a TUV teile gutachten for your vehicle, you can be reasonably confident that the wheels are safe for your vehicle. They could also supply you with test data from a testing company (Like STL) that states the wheels were tested at a specific TUV load. This is not a TUV certificate, but it does mean the manufacturer cares enough about safety to verify their engineering.
It is my professional opinion that more than half of all wheels sold in the USA are not subjected to third-party testing of any kind. So be careful.
The USA standards as set forth by the DOT are self-policing. You can probably imagine how well that works.
1.First, all the suppliers of a given product that is to be submitted for approval must have their quality system verified by TUV. No exceptions. This can either be an ISO 9000 certificate, TS/QS certificate like the OEMS use, or an actual TUV verification by an in-person TUV auditor.
In the case of wheels, this means the forging facility or foundry, heat treat facility, machining facility, etc. All must submit their documentation to the TUV prior to testing. The reason for this is obvious.
2. Next, test wheels must be submitted in sufficient quantity for the test at hand. If you are getting wheels certified for just one vehicle, this is usually 3 to 6 pieces.
If you are well known to the TUV, it is possible to get a "family" of wheels approved in a given style and diameter with a variety of bolt circles. This is complicated, but worth the effort.
3. Next, the TUV will test the wheels at whatever load that you state. This includes a variety of tests including radial fatigue, drop test, rotary bending, etc.
These tests are brutal and the test loads are 1.5 to 2 times higher than the stated load, just to be sure.
4. If the wheels pass, you will receive a "Gutachten" certificate from the TUV which states that the approved wheel is good up to a specific load rating. This certificate is "Wheel specific", not vehicle specific. At this point, the wheel would not be legal to sell for any vehicle. This certificate costs 3000 to 5000 Euros because of all the testing involved.
5. If the wheel fails the first test, you have big problems. You will then have to submit twice as many wheels for the next test and the tests will be even more carefully scrutinized. Very expensive.
6. Once you have a "Gutachten", you can apply to the TUV for a "Teile Gutachten". This certificate will state that the wheel is approved for a specific vehicle. The TUV sets their own load requirements for each vehicle, based upon input from the original vehicle manufacturer. The teile gutachten certificate costs about 200 to 300 euros, because it is just a paperwork process.
To be very specific, a teile gutachten is a TUV approval for a specific vehicle or vehicles, and is rarely transferrable to another vehicle. For example, if the wheel manufacturer "weight optimizes" the wheel for a Porsche GT3, they cannot receive a teile gutachten for a heavier Turbo. Conversely, if the teile gutachten covers the Turbo, it will usually cover a lighter GT3.
You will receive a teile gutachten certification number and this number must be permanently inscribed on the wheel. The certificate in the car must match the number on the wheels. If you are stopped by the German police, everything must match or they will tow your vehicle.
7. If the manufacturer changes any vendors in the supply chain, new paperwork must be submitted to the TUV for approval. They will then decide if they want to re-test the wheels and issue new certificates.
This whole process is identical for every wheel manufacturer, large or small.
The vehicle OEMs are not required to do this because they certify the whole vehicle.
So, if you are shopping for a wheel and the wheel manufacturer has a TUV teile gutachten for your vehicle, you can be reasonably confident that the wheels are safe for your vehicle. They could also supply you with test data from a testing company (Like STL) that states the wheels were tested at a specific TUV load. This is not a TUV certificate, but it does mean the manufacturer cares enough about safety to verify their engineering.
It is my professional opinion that more than half of all wheels sold in the USA are not subjected to third-party testing of any kind. So be careful.
The USA standards as set forth by the DOT are self-policing. You can probably imagine how well that works.
Last edited by Forgedwheeler; 11-19-2012 at 10:52 AM.
#54
Teile Gutachten
You can download a genuine BBS teile gutachten here:
http://217.160.41.106/gutachten/lm/l...1_997-turbo.pd
http://217.160.41.106/gutachten/lm/l...1_997-turbo.pd
Last edited by Forgedwheeler; 11-17-2012 at 12:46 PM.
#55
Further clarification. The TUV does NOT CERTIFY any manufacturers. They only VERIFY that the manufacturer has an acceptable quality system for a given type of product.
And if you already have ISO 9000 or QS/TS, that is evidence enough.
And if you already have ISO 9000 or QS/TS, that is evidence enough.
#56
Race Director
Forgedwheeler, what company are your wheels?
#57
#59
All is well my friend. Just hard at work helping the world make better wheels.
Happy to say that there are lots of good wheel companies out there who really care about quality and safety.
Not all, mind you, but enough to help me keep the wolf from the door.
Happy to say that there are lots of good wheel companies out there who really care about quality and safety.
Not all, mind you, but enough to help me keep the wolf from the door.
#60
PM or email me any info on what's the latest.
Ranger (Sua Sponte)