818 Accident Report--Update

[john g]

Some of you have asked for pictures of the car and a description of how it was set up.

Pictures are at: http://s1368.photobucket.com/user/CRBasin/library/

As for the car, it is based on a stock 2006 WRX. It is also a stock 818, with the exception of a Boyd tank and new seats. I assembled it using the instruction manual and guidance from this forum. In terms of setup, I the rear bars are parallel (per Wayne's measurement method I think); I used strings to set the front and rear toe, and an electronic level for camber and caster. Tires: new 215/40/17 Nexen in the front and 245/40/17 in the rear. The rear tires are used.

The accident occurred early in the morning on a street that was paved about a year ago. After the accident, I noticed a dark spot on the pavement that could have been water or ice. The car was less than 1/2 way up the block before it spun, so it couldn't have been going very fast. Frankly, I am at a loss to explain what happened, and I don't think there is enough information to know.

As you can see from the pictures, the front right corner collapsed. I assume that this is what the engineers intended. Also, the engine shifted forward temporarily and crushed one of the aluminum coolant tubes. Of course the fiberglass in front is toast, and fasteners pulled out of panels elsewhere (eg right sail panel).

For me to fix the car I would need to replace the body panels and the frame since I do not have welding skills and I think I would make a mess of fiberglass repairs. I am undecided whether to invest in new parts and the time needed to complete the project or sell the car.

And thanks again for your support.

John

[wleehendrick]

Hi John,

Thanks for sharing the details and pictures, and sorry again. Were those Nexens summer tires? Since you mentioned the possibility of ice, I assume it was below, or close to, freezing temps. It seems like the 'perfect storm' of cold temps, performance tires (which start to get really slippery below 40F), RWD, high power/weight ratio and no traction control. They fact that they were used could also contribute to the loss of grip.

I run summer performance tires year round on my Z (but I'm in SoCal where it rarely gets cold enough to worry about). Last winter we actually had a couple days with frost at the coast, and I had a major pucker moment just starting my drive to work in the morning when my rear broke loose unexpectedly shifting to 2nd; luckily I caught it, but probably would not have with weight distribution of the 818. Yeah, performance tires can be really scary on a cold day in a sports car.

[Quiny]

John very sorry about your predicament, but like everyone said thankfully everyone is ok.

Just out of curiosity were you running a sway bar?

[michael everson]

Wow. That's quite a bit of damage. Probably would need to start with a new kit. Hope you can get it back to whole at some point.
Mike

[2FAST4U]

Very sorry for the bad luck. Hopefully it can be fixed without too much investment. Best of luck

[thall818]

I would be interested to know the DOT date code on the rear tires. Tires have several problems as they age. Some you can see, others not so much. One you can't see is the rubber getting hard, which doesn't help traction. Of course, soft compound, cold morning & second gear may also indicate tires weren't warmed up. Small patch of moisture and problems.

Sucks any way you slice it.

[Mechie3]

:( So sad to see all of that hard work sitting there in a pile now. :( Crazy how much damage translated to the back of the car.

[JeromeS13]

I'm not sure if anyone has asked or if you're already stated, did you have an insurance policy in place?

[metalmaker12]

Now that we know your ok.

From the pics, how fast were you going when you hit whatever you hit. Looks like a 20mph crash. How did you loose control at such lower speed, sand, ailment way off, brakes did not work right??

[Hindsight]

Maybe a really bad corner balance issue??

[Santiago]

I know it can be really hard to relive/reflect on the incident, but we sure could use a few more details. Speed has been requested, and I'll second it. I'm having a hard time seeing this as a 20mph hit. I could be wrong, it just sounds like a very low number for such extensive frame damage.

Interestingly, the spindles/adapter & control arms (except the rear bushing) look to be stronger than the surrounding frame...not sure that's such a good thing. Even the tires/wheels are in decent shape. Shock looks bent, tie rod & rack bent/damaged, and damn near every panel has damage.

That last part has me scratching my head. Even the engine cover cracked. So this suggests either secondary impacts (engine moved enough to whack it?) or our mounting strategies are intolerably flexible. The engine moving that much also reiterates the importance of an intrusion panel on the engine-side and/or better bushings to hold the engine in place. I mean, you didn't spin around and hit the rear did you? This level of rear frame damage happened because of movement of the engine/trans assembly...from a 20mph hit to the front-right corner?

Speaking of the hit - what was it that you hit? Tree, curbing, wall, parked car? EDIT: Ooops! Re-read your original post. A tree did this. Ok, that might make some sense out of the lack of damage to the tire/control arms if they were offset of the tree's center...

As for cause, cold summer tires can be very slick. Old, cold summer tires are horrible. The fact that there was a split in the condition of the tires (new/old) is a major suspect as well. When you say the car spun, you mean the rear came around on you, yes? So you lost traction on the part of the car that had the old tires, not surprising there. My worst incident on track was largely due to old summer tires that just had no grip left. It was also raining lightly and I wasn't going terribly fast either. I was, however, going around a slight corner at the time that had a gradual loss of camber in it and the rear end came out on me violently. Was this recently repaved street straight or were you going around a bend? What's the camber/crown on it look like?

Replaying what your outputs were might also help. Specifically, were you accelerating just before the spin or carrying constant speed? Had you just shifted into 2nd or the car was already in gear for a second or so? After the spin began, did you stay in the gas or lift off? EDIT: Ooops! Man, I really need to re-read your posts... Ok, so sounds like you just shifted into 2nd. That makes it likely, esp. if you let off the clutch quickly, that those old/cold/summer tires did you in. Here's how I'm replaying it:
1. Let off throttle to engage clutch, nose goes down, weight comes off rear tires
2. Pop-clutch, power goes quickly into rear tires (now lightened)
3. Rear tires haven't had weight transferred onto them yet, they're very cold (early morning + fall weather), they're old, they don't grip
4. Car spins (to the right side?)
5. Driver's output response is...?

Throw in possible crown in the road (most public roads are crowned for water drainage) and you have your perfect storm. I'd appreciate the feedback of others on this replay of events.

Thank you very much John for sharing the information and pictures with us.

Best,
-j

[thall818]

First, I've never driven an 818, but can't wait until I do. Back in the early nineties I had a modified 6 cyl Pontiac Fiero. (Go ahead, make jokes, I deserve it). I used to autocross it and what I found was that due to the weight bias being in the rear it definitely behaved differently than other cars. The back end absolutely loved to come around. I used to compare it to a dart (not Dodge).

Take a throwing dart and pretend you don't know how to throw it. Throw it any way you like. No matter what you do, the weight wants to be out front. Same with that damn Fiero. Once it started to spin, you were a spectator. It would understeer going into a corner, and if you charged it too hard and then let off the gas it would dig the front and then give you the dreaded drop throttle oversteer. I would guess that an 818 has some quirks of a rear/mid engine performance car, but with a higher level of refinement and potential. Nonetheless you can't argue with physics.

It looks and sounds to me like maybe the back end came out, hit something on the passenger side, then caused a spin that took off the front end.

[D Clary]

Sorry to see the mess and glad youre ok. It really doesn't look repairable without a chassis jig . It look like a lot of it is going to have to be cut off. I don't know if FFR will sell portions of the frame or not. Hope you were insured as it looks like it could be a loss.

[john g]

Answers to a few questions:


1. Nexen NFERA suummer tires. It was cold, so this could be a contributing factor.
2. I think the rear tires are relatively new, date code 1713. The tire shop "lent" them to me to test the fit.
3. Yes, I have a front sway bar. It is the WRX stock rear with new bushings.

[Jeff Kleiner]

Happy to hear that you personally came out of it relatively unscathed John.

Maybe you've answered these questions elsewhere and I missed it but if you can recall (sometimes in these sort of incidents you can't be sure) can you tell us what you were doing when the incident occured:
---Straight line or turning?
---Steady state speed, braking or accelerating?
---If braking or accelerating were you doing so gently, moderately or briskly?
---Did the car actually spin around and if so how much; i.e., 180, 360, etc.?
---Were you able to get the car slowed before impact?

You mentioned the possibility of wet conditions or even ice so I presume the temperature was in the mid 30s or lower. I guess it is safe to conclude that after inspecting the damage you do not see an obvious indication that a component may have failed prior to impact causing the loss of control. If you are able to answer some of these questions it might help to understand &/or determine why the accident occured. I'm truly sorry to learn of this but again, very happy that you are OK.

Jeff

[mrmustang]

I see some here questioning the speed of the 818 at time of impact, but seeing the right lower control arm and proceeding frame shot, I can conclude that he at or around that 20-25mph speed at time of impact. I say this as someone who was in the business, and who have seen more than his fair share of Cobra replica bent chassis (over 25 FFR roadster chassis personally inspected since 1995). What I am seeing is the energy absorption of the main rail, and the transfer of that energy through to the rear main frame area. The secondary (smaller tubing) body and inner structure supports also show that transfer of energy (ie: speed + momentum) and the twist that I have come to expect in a sudden and dramatic stop in motion (contact with the tree in this case). This is not a modern day unibody car, so the absorption that many of you are expecting to see from a low impact collision is in fact there, just magnified because of the FFR designed birdcage. It, along with the main rail did it's job quite well. Given the angle of impact. of course at the same time, and I have made mention of this many times before (not just on FFR's), the mounting points for the engine and the suspension points failed due to their design, and lack of torsional bracing (IE: gussets). Not always a bad thing at low speeds, but if this was at a higher speed, I suspect the engine and transaxle would have broken away completely and invaded the fuel cell on it's way through the rear bulkhead and subsequent passenger compartment.

Again just my observations on this first ever 818 low impact pictures I have seen to date. I do suggest perhaps that someone from FFR do a hands on inspection of this frame and measure the cross torsional twist of the frame, all in the science of making their next version bigger and better as they have each time they have produced a new version of their Roadster.

Bill S.

[Blitzkrieg]

I think it was the temperature if it was 30F it could have have been icy. Even on summer tires at 20mph it would be hard to lose that much traction on dry roads. When I first run I was on pretty ****ty tires, miss match brands, slight size difference. I went around the sub a couple of times at low speeds and made sure the engine wasn't over heating and all was good. Then I started doing some more "HOT" runs I would say.

Not really cornering fast but on straights. I did some rolling to 40mph in 2 gear and never lost traction or felt out of control. I even did a 0-60 launch there was a little bit of wheel spin of the line not bad. Now on my car I have the same tire as John G but in bigger sizes. I also have 17 front 18 rear which might make a difference being a rear engine car in cold conditions. The Nexen are definitely high performance summer tires after putting them on in the right car felt amazing, the handling was improved a lot. Once I got seat belts/racing harness it was much better also...( I know doing what I did was not recommended and possibly stupid)

My point is I think the car was set up right and I think it was sorta a freak accident that maybe could have been avoided but I know how bad you want to drive when you just get it running. It is a bummer but you might be able to work something out with factory five where they make you a new frame and body panels and you just take off and put on. That's was I would do mostly because my donor cost about the same as the kit. But on the other hand I am sure you and your boys had fun and learned a lot building the kit. My brother and I are 17 & 16 and we have had a blast building the 818.

[longislandwrx]

glad you are ok.

[Larry J W]

Thank you for sharing your misfortune. It really helps the community.

Based on your damage and Mr Mustang’s comments I am definitely going away from the 3 point seat belts to ones that are SFI rated. I remember in about 2002 a person hit a tree in a Cobra at 30 MPH and his passenger cracked some ribs with the Simpson seat belts! The frames are very strong. Once you get passed the soft stuff it will transfer a lot of shock!

I hope factory five is looking into the engine movement.

Thanks again
Larry

[Jester]

Thanks for posting. Very unfortunate but these things can be replaced. Glad you are ok.

Matt

[Santiago]

I hope factory five is looking into the engine movement.


Agreed. MrMustang's comments have reinforced my concern with the degree of engine movement this incident involved, esp. given the fact it well may have been under 30mph. I can accept that some of the tubular members might deform at these speeds, but not the engine movement. I hope we don't have to test an "engine break-away" incident.

Thanks once again to John, our community really does benefit from sharing this.

Best,
-j

[Mechie3]

In the factory application, I think the dogbone is the only solid drivetrain to chassis connection. Even if the bushings completely rip (which they are unlikely to as they're loaded in compression) the mounting bolts are still captured. The engine and trans mounts (stock ones) are two steel plates connected by rubber loaded in shear. In a high G stop they're also loaded in tension as the CG is above the mounts so the engine leads forward and tips downwards pivoting about the engine mounts.If the rubber rips or hyper extends there is no backup. I don't know if the cross brace is strong enough to support a dogbone so, as others have mentioned, maybe a front mounted one is necessary (at least if you use OEM mounts).

[longislandwrx]

I may consider adding an additional mount point as well after seeing this. thank you for sharing so others can learn.

[129st]

I have a theory on the motor movement. The motor mounts are plenty strong in shear and did their job. However, the motor mounts will not prevent motor pivot (i.e. top of motor moving toward passenger area.) The motor pivot should have been resisted by the transmission mount. It appears that the frame in the area of the transmission mount does not have sufficient cross section or bracing in this area to resist this pivot force.

Probably the best way to resist this pivot force is to add two frame braces from the transmission rear (or frame rear) to the top of the shock towers. Just tossing a theory out to the community in hopes of making a safer car.