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Forgestar F14 Failure on track

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Old May 22, 2016 | 04:46 AM
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Exclamation Forgestar F14 Failure on track


WTF?!
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Old May 22, 2016 | 07:39 AM
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I saw this awhile back on Jalopnik. Gnarly!
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Old May 22, 2016 | 10:07 AM
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That is a cast wheel, no wonder it failed.
I went to the website and looked at the 'forging' process and frankly, it's a joke. They even say on the 'rotary forged forming process' text that it's a cast wheel.


And if you notice on the video, at about the .44 mark, it looks like he curbs it. Possible he damaged it then, you know?
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Old May 22, 2016 | 03:21 PM
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The wheels are cast and then the hoop is hot drawn out- that is what the rotary forging or "flow formed" (tm Enkei) process for wheel manufacturing is.

It leaves the wheel center cast and the hoop is rotary forged as the drawing out process aligns the grain in the hoop to strengthen it.

A die forged wheel center could be stronger for the same shape (though the cast center is just made thicker to compensate) and importantly more tolerant to embrittlement from bending, brake heat and powdercoating, but it drives production costs up.

Racing, it breaks stuff. Check your wheels for cracks.

Running over curbs at speed breaks stuff- check your entire car for cracks and straightness.

Spending four times as much for Volks will make wheels last longer (but four times longer?).

--------
I had an off where my FD hit the bank ~70mph. All the force went through the front Forgestar 18x11 wheel.
It bent the forged lower control arm, the front spindle and pushed both frame rails ~ 5 degrees out at the firewall. The bumper/bodywork was all fine with just the far back corner of the hood getting bent up.

The Forgestar was still straight and true.

This video does not show a strength failure so much as a fatigue failure (as noted at the end of the video) which will happen to any wheel though certainly forging or different materials will prolong the wheel service life.
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Old May 22, 2016 | 10:21 PM
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From: https://www2.mazda.com/en/100th/
Originally Posted by BLUE TII
Racing, it breaks stuff. .
shortened for brevity...

we go through about 3-4 wheels a season. we've never had one fail, its always been collateral damage for contact, or we once had the lug nuts loosen up, and the wobbling wheel ate the lug nut seats
Attached Thumbnails Forgestar F14 Failure on track-img_3458.jpg  
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Old May 22, 2016 | 11:25 PM
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Originally Posted by bajaman
That is a cast wheel, no wonder it failed.
Eh, I dunno. That's a little too general for me. There's lots of wheels that are cast and don't fail. Most Enkeis (RF01s, NT03s), most (all?) Gram Lights, Works (Emotions), most (all?) Advans, virtually every OEM... the list goes on. The flip side of that of course, is that I've seen OZ, Volks and BBS wheels all fail in the same fashion even though they are forged.

**** happens - and for all different reasons. No need to jump on the bandwagon because one brand / process / whatever had it happen.


...and of course yes, racing breaks stuff. Guy admits he never checked the backside of the wheels for cracks after a dozen events. There's the REAL lesson from this video. Be safe guys.

Last edited by MattGold; May 23, 2016 at 09:04 AM.
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Old May 23, 2016 | 09:09 AM
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while the event that triggered this thread, wheel failure, is unfortunate it is important that wheel safety should be discussed.

coming from a racing background i know that wheel strength is consideration ONE when selecting.

contrast this concept w what has been written w re to wheels. it is 100% on how they look and fit.

besides safety being a factor in choice, the other consideration is maintenance. how many of us have looked at the backside of our wheels for cracks?

bigger stickier tires, aggressive driving and a chassis that can load in higher lateral G rates all works to stress the wheel. add in a bunch of positive offset that levers/challenges the structural integrity and i suggest that wheel strength should be at or near the top of the list of considerations.

while there are numerous wheel options i have always liked Enkei as offering a combo of strength and value.

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Old May 23, 2016 | 09:52 AM
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Originally Posted by howard coleman cpr
while there are numerous wheel options i have always liked enkei as offering a combo of strength and value.
But those are c-c-c-c-cast!


Last edited by MattGold; May 23, 2016 at 10:00 AM.
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Old May 23, 2016 | 11:18 AM
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Mistake no. 1, not going with these


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Old May 23, 2016 | 12:05 PM
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Those wheels kind of reminds me of the Mazdaspeed MS02 that was developed in conjunction with the FD and offered as an accessory.




The difference is I love the MS02 funky mix of roulette wheel and clutch pressure plate because it didn't take it too far....
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Old May 23, 2016 | 05:50 PM
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Originally Posted by Howard Coleman
besides safety being a factor in choice, the other consideration is maintenance. how many of us have looked at the backside of our wheels for cracks?
In my experience, only the worst cases have visible cracks. Zyglo seems the cheapest way to go there. Wouldn't say just look at the back either, if anything, more usual in the front face I've found - ones radiating out from the mounting holes in both centrelock and lug style mounting isn't totally unheard of either.
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Old May 23, 2016 | 08:11 PM
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"OMG that's awesome"???!!!

WTF...
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