M3EvoBR

That would be a valuable information to the public, in case you can share with us.

Forgedwheeler

Hey, it's like I've been saying for years. If you ask for the engineering test data, you will have your answer.

You will hear:

1. "No problem, what's your email address and we'll send it right away"
2. "Sorry, that's proprietary and we can't divulge it"
3. "We're working on it" , "It's in process", or some such.
4. "hold on, let me check"
5. "Huh?"

If the answer is anything but #1, you might want to look elsewhere for wheels.

Just my opinion.....

If you have specific questions you can PM me. Anytime. Especially if you need help deciphering the data.

CM991

How did you mathematically calculate this value?

Also, at 415kg per corner for front = 1826lbs load per axle which should be sufficient for a 1g vertical g-force (assuming no elavation/drop) no?

mdrums

^^^CM991, he probably calculated on his Playstation...he's good at that.

Lots of OZ's at the track these days...no issues

TRAKCAR

Here's your math

mdrums

NJ-GT's favorite car sim

Forgedwheeler

As tough as you may think the track is on these wheels, the TUV rotary bending test applies DOUBLE the rated load for 200,000 cycles.
This is the real acid test for any wheel.
Some quick math shows that to be more than a 2g cornering load for 250 CONTINUOUS miles.

I think these wheels will be fine.

CM991

That's what I would like to see, the "quick math".

CRex

There's a fundamental difference between static load bearing (measured in weight) and impact strength (measured in weight per unit area). The former is the 800-something pounds stamped on your wheel, while the latter is not publicized.

Rad's got his point on a lot of things but the facts are not with him on this one. It may take a bit more material science to debunk this myth, but until then, I'm sticking with my empirical observation: that OZ superforgiatas appear to stand up to track duty--have seen three sets put through the ringer (incl. street use) and they handle abuse alright.

CM991

LOL

Forgedwheeler

The TUV load requirement for the 997 GT3 front wheel is 390Kg or 850 Lbs.
The TUV rotary bending test subjects the wheel to roughly a 1700 lb load for 200,000 cycles.

On a wheel/tire setup with a static loaded radius of 12.5 inches (25 inch diameter), those 200,000 cycles equates to about 250 miles.

During this test, the bending force is continuous. It is a brutal test.
It is roughly equivalent to putting a 3400lb load on the front axle of a GT3.

Once the test is complete (if the wheel survives), the wheel is checked for cracks and excessive deformation. Any failure requires twice as many wheels to be checked during the second test.

mdrums

Are you talking about the OZ HLT wheels? They are TUV approved.

CM991

Asked one of my good friends and so here is some math for you...

Taking into consideration the following vehicle:

2010 Porsche GT3
Curb weight with passenger/fuel: 3500lbs
Weight Distribution: 38F/62R

Based on a load of 1g force we obtain the following:

Weight Distribution Front 38%
Weight Distribution Rear 62%
Vehicle Weight (lbs) 3500
Vehicle Weight (kgs) 1591
G-Force (g) 1

Load on Front Axle 5928 N
Load on Rear Axle 9672 N
Total Load 15600 N

Load on Front Wheel 2964 N
Load on Rear Wheel 4836 N
Load on Front Wheel 302 kg
Load on Rear Wheel 493 kg

This is the static load, or the load of the vehicle sitting on the ground.

Based on a force of 1.3g (The new Porsche GT3RS 4.0 stops from 186mph to zero in 6.5s, yielding an acceleration of -12.79 m/s^2 or 1.3g) we obtain the following:

Weight Distribution Front 38%
Weight Distribution Rear 62%
Vehicle Weight (lbs) 3500
Vehicle Weight (kgs) 1591
G-Force (g) 1.3 MAX

Load on Front Axle 7732 N
Load on Rear Axle 12616 N
Total Load 20348 N

Load on Front Wheel 3866 N
Load on Rear Wheel 6308 N
Load on Front Wheel 394 kg
Load on Rear Wheel 643 kg

This is assuming no elevation changes and/or suspension travel changes or many other multiple factors.

On a Porsche GT3 with with Michelin Pilot Sport Cup, the max I've seen is 1.2G of lateral force. Based on the PSC tires we obtain:

Weight Distribution Front 38%
Weight Distribution Rear 62%
Vehicle Weight (lbs) 3500
Vehicle Weight (kgs) 1591
G-Force (g) 1.2 MAX

Load on Front Axle 7114 N
Load on Rear Axle 11607 N
Total Load 18721 N

Load on Front Wheel 3557 N
Load on Rear Wheel 5803 N
Load on Front Wheel 363 kg
Load on Rear Wheel 592 kg

So, the OZ rating of 415kg front and 625kg seems to be within safe margins. During hard cornering or braking most of the force will rest on the front axle and with a rating of 415kg we still have some room for error. The rear, however, is below the MAX 643kg at 1.3g but it is very unlikely the rear will reach 1.3g during braking/acceleration/cornering unless it is on race/slick tires. I would prefer a rating of 420kg-450kg for the front and 640kg-660kg for the rear it it were my vehicle.

Forgedwheeler

Very nice work. Your math is nearly a match to the TUV rated loads for this vehicle (997 GT3RS).
And remember, the TUV TEST loads are MUCH higher than the rated loads.
I feel that unbiased third-party testing is the cornerstone of vehicle and passenger safety.
If we all ask for it, more companies will do it. The wheels will get better. Everybody wins.

mdrums

Thanks guys...glad to know my OZ Challenge HLT wheels I use for the track are actually good wheels...especially for the price.