Crumple Zones

[hsr2.6]

How many have you have welded up the crumple zones on your cars, i ask this coz after this weekends crash, every crumple zone on the car has done it's job. If these were welded up would i have been worse or better off.....

[compact119]

I am of the opinion that they should remain as intended, bmw spent £££££££ putting them in to take energy from the impact and not transfer it to you

[Daishag]

Can you tell me what you mean by the crumble zones Steve as Sierra's have a huge bit of the front floor pans that are like a huge perferated cheese grater etc to crumble etc BUT i havent seen anything like this on my shell when prepping it ???????

I have how ever seam welded it ...... Purely for the fact if any one comes to buy it should i decide to sell it i really think would say well you have gone to the trouble of stripping to a bare shell and welding in a full cage so why did'nt you seam weld it etc ?????? I think personnaly the BMW shell is more than strong enough without it but for the above reason did it any way etc

Cheers Dave aka Daishag Rallying 07805835655

[hsr2.6]

Hi dave , there's a crumple zone in the A post behind the wing, and then the contours of the floor and bulkhead are all designed to take the energy of the impact away from the driver. The force of my impact was around 20G and the the tunnel has bent by 6"......

[Daishag]

AHHHH right i know what you are refering to behind the wing just in front of the a post and i havent done anything to that at all and have left the contours of the floors as is mate.

the only thing ive done is plated over the holes for the plastic jack points in the sills, seam welded all the seams inside and underneath on the floor pan / tunnel, chassis rails and suspension turrets front and rear but havent touched the box sections behind the wings and up the a posts etc

Cheers Dave aka Daishag Rallying 07805835655

[mike]

I dont think full seam welding is needed on modern cars for the clubman competitor if the car is being used on tarmac. Especially on the BM's, The only area's worth doing are the highly stressed area's like suspension mountings, diff pickups etc. A decent cage will be more than enough to give the shell the rigidity it needs.

Chassis manufacturing has come along way since the 70's/80's where seam welding was neccessary to stop the car tearing itself apart when used in competition. And in reality no amount of seam welding is going to stop and crumple zone from caving in an accident, you might get away with a few mph more in an impact before it goes but it was designed to crumple at the end of the day, no amount of welds will stop this properly.

Id rather have a standard shell with a decent bolt in that will crumple and i can throw away then invest 1000's into a shell with a weld in cage that is solid as a rock and will detatch my head from shoulders in the even of an accident. But then again i can buy a brandew shell from renault for £900 so its not to expensive for me to do that.

For forest use, well thats a different story..