ProCoach

On the former, yes. Anything you can do to control and reduce acceleration and deceleration of your head is good,

On the latter, I've seen some people here disagree, but my opinion and experience indicates that if you build or install a half cage, the car remains streetable (especially with proper seat height rearward) and protects more than stock from lateral unibody intrusion or compression. As well as vertical compression...

Manifold

Agreed on both.

mlct

If you go with a half cage you might want to consider a Sparco Ergo as has removable head protection so you can drive it on the street. Better visibility than a full containment seat on the street. Not sure if it is certified for racing though.

Horus2000

I'll echo everyone's comments here. Thank goodness you're ok. But you're not fully ok, so make sure you get cleared by a good doctor before hitting the track again. And yes, definitely new helmet and re-cert the Hans.

My 2 cents on the GT4. Personally I'd keep it as is and invest in a dedicated track car. Something less expensive like a spec boxster, etc., etc. The GT4 is beautiful and incredibly capable, but given the speeds I'm assuming you're hitting, I wouldn't want anything but a fully caged car. It's not likely, but certainly possible that you could ball up that GT4 at some point and for me personally, I'd rather do that in a 'throw away' race car rather than a collectible. But again, that's just my opinion.

Be safe and get back out there (when doc says it's ok)!

TXE36

Yes, I recall this problem with the E46s. E36s didn't have the subframe problem nearly as often, although you do have to reinforce the shock towers and rear anti-roll bar mounts, likely because the E36s don't support the wider tires of the E46. The picture of the LR tire is pretty catastrophic, as everything is broke, but that is likely due to it being ripped off the car. The shock appears to have height adjust threads on it, so it looks like the car had a rear coil-over conversion - not cheap. In stock form, the rear has springs on perches and separate shocks.

Worn rear trailing arm bushings are an infamous cause of dartiness in these cars, but this comes on very slowly - it sounds like what happened to you developed during the session thus this is unlikely. The failure mode here is the rear trailing arm pocket rips out and the rear trailing arm rotates. If the pocket is still in the car, that didn't happen especially if the front of the trailing arm (the rear is still attached to the wheel) is still there. If it is not, it will be hard to tell with all the post primary failure damage.

With your provided data, I'm inclined to agree with 24Chromium quoted above. Cracks in the subframe are common and relatively difficult to check for. When it got greasy, these cracks were likely opening up and the rear alignment settings started moving around. These cars are very sensitive to rear alignment settings. When it let got, you likely lost the inside connection to the upper or lower control arm and that was it.

I suppose it is also possible that a fastener worked itself loose - I'd look over the rear on a lift and look for backed off bolts or the cracks. If a bolt let got, the rear subframe should still be attached.

Good to hear you are okay and the safety equipment worked. One thing about these cars is if all off a sudden they start feeling squirrely, get off the track, it is not your imagination. A bit greasy is much harder to evaluate.

-Mike

Thundermoose

Mike

I have MCS like in the pic. They can be set up in true coil over or to use the normal configuration. It looks like it was not used in true coil over set up.

I agree most like cause was RTAB pocket failure. A guy at VIR had similar failure a couple of years ago and rolled over once or twice IIRC.

Eric_k

Wow, big hit. I'm glad you are okay and the safety gear worked for the most part. I feel bad for you and the car owner.

Portland is a pretty safe track but there are still lots of walls without tire barriers to find. I've done all my crashing on the back straight at PIR. Hopefully you don't get a bill from the track to straighten the wall. I've had to pay for PIR armco. Not a fun bill to get with an already busted up car.

Manifold

A concrete barrier isn't supposed to move like that, they're generally designed to be "rigid." But in this case, since it appears to be have deformed smoothly without creating offsets which snagged the car, the movement of the barrier may have helped reduce the crash severity. If they tried to send me a bill for straightening the barrier, I'd be telling them "your barrier isn't supposed to move."

pkh

Thundermoose

Here's the RTAB pocket failure I mentioned. Your incident sounds familiar.

mark kibort

Wow, what a nasty crash. i had one at Sonoma that did the same job on the barrier. however, after i was hit by a lapped car, and ended up into the Kwall at near 100mph, they put a couple of rows of tires for even better protection for future impacts in that area of the track. the barrier moving is what could have been part of what saved him. I know it saved me! they do move and it doest take much to reduce the gs at impact, tremendously.

Manifold

My point is that if you want to redirect a car with a shallow angle of impact, you generally want a rigid barrier which doesn't move. If you want the barrier to move and absorb energy, you want something more flexible like guardrail (Armco), tire walls, etc.

ProCoach

Interesting comparison here, it's from the ISS site, there are more out there. http://www.impactsafetybarriers.com/...e-analysis.php

BF951

Glad that you can recover and are able to tell the story.
Sure I'm not the only one but it's caused me to look at what else I can do to add safety.

Manifold

Thanks for the link. They're right about some things, but referring to a concrete barrier as a "cement retaining wall" makes me wonder about what kind of engineering expertise they're drawing on. Their "competitive analysis" is clearly biased in favor of their product, and it's not clear to me that their product has been properly tested for cars.