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Rear collision analysis help please

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I'm trying to loosly analyze the effects of getting rear-ended in the NSX. Any pro body folks or others that have been hit care to share? Like how hard was the hit, how much was damaged, and how much can reasonably be fixed? I have looked at the body manual. I'm a weight fanatic and rushed to buy one of Procars CF bumper beams without really thinking it out to well. Now that I am thinking about it, I'm having major heartburn. I knew all along the CF beam will absorb mush less energy, and as the beam a good 3/8" thick, it may well transfer too much energy to the frame even before it crushes. That said, it kind of looks like the rear frame sections are so light that no matter what the bumper is, any decent hit will treak both back frame sections and total the car anyways. Any first hand experience greatly appreciated.
 

MvM

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Maybe I can shed some light on this.

I have not been rear-ended in my NSX, but I did manage (unfortunately) to crash my car rear end first on the Spa-Franchorchamps track in Belgium.
My car hit the tire-wall at a pretty high speed with the rear first, but I don't know exactly at what speed. I was travelling at around 90 mph when my car spun out coming out of a uphill turn.
The trunk bottom was heavily folded inward as was the rear vertical trunk wall and the two U-shaped rear chassis bars were both bent and the right one slightly twisted a well.
However, the damage (luckily) did not extend any further than that and the rest of the chassis was not damaged at all. Even the side-walls of the trunk where still straight and ok, all wheels lined up perfectly in all directions, which was the reason why I decided to have the car repaired.

As for the rear bumper beam, apart from being bent on the left mounting point, the beam was still intact. It seems it was the beam that pushed in the lower end of the trunk, but the beam itself survived the crash very good in my opinion.
As a matter of fact, that very same beam is still on my car today :smile: I had to hammer that dent at the mounting point back into shape and that took a lot of hard work. That beam is a very strong beam.
Apart from the outside body panels, I had the rear chassis bars set back into their original position and had the trunk bottom and rear end replaced with new parts to make sure everything was ok again. Took a long time and lots of $$, but I have been driving that same NSX again for another 21K miles since and the car is even better than before.
 

goldNSX

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If you worry about being rear-ended don't mount it. There has been no crash-test as far as I remember with the modified beam.
 
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It all depends on how much contact area there is... I am thinking that there is a good chance that a rear end collision could be caused by someone driving a vehicle with a bumper much higher than the NSX so they would possibly plow into the tail lights anyway.:frown: Not many cars on the road as low as the NSX.
 
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Thanks MyM, exactly the input I was hoping for. It's almost futile trying to guess what the designers were looking at, but I are one so I can't help it. Like you said that back beam is SUPER stiff, in fact it looks way stiffer than the steel one I originally had, and maybe 10 times stronger than the front. I'm thinking they were looking most at keeping the engine out of the cockpit, and the heck with the entire back of the car. They don't look to minimize crash damage, the whole back is a crush zone. With the back beam super stiff all the way accross, when you are hit, you not only crush the frame members(if you can call them that-they are not very stiff IMO), but you also can figure the inner and outer quarter panels into the mix. No matter what, you are going to bend the frame members with just about any substantial hit. Detlef mailed me that Honda R&D was involved in the beam design. With that assumption I feel a little better. My conclusion on the CF beam is that it will make little difference unless you are hit very hard at say a 50 mph differential, so I'm taking that chance. If I drove daily in heavy traffic, I would probably pass, mines a Toy car however.
 
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I agree that the contact point would be higher than the bumper area. I was rear ended recently by a full size pick up truck. a C2500 chevy to be exact. Luckily I wasnt driving the NSX. I was in my ML55. The damage contact point was so high up that it shattered the upper half of the bumper cover and caved in the rear gate. If it was the NSX the rear wing would be the initial contact point and crush the top of the NSX back half. Lucky me, for driving the SUV that day. Bumper would have been useless
 
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