Mark Dutton has detailed how spring limitations led to the right front lower control arm on Shane van Gisbergen’s car bending and later breaking at the Superloop Adelaide 500.
During the second race of the Virgin Australia Supercars Championship, van Gisbergen lost maximum adjustability of his front anti-roll bar.
As a result, that put load through the front control arm. That, coupled with the spring rates the team were running, meant the control damper reached the bump stop limit.
Dutton, team manager of the Red Bull Holden Racing Team, told Speedcafe.com the team are ‘looking at all the various aspects’ of the failure.
“It’s broken because you can run out of travel on the springs,” said Dutton.
“When a spring coil binds it’s like having no spring at all. The suspension goes solid in that point and if the wheel wants to travel any further it has to bend the arm.”
Dutton said the introduction of the control damper didn’t cause the failure but said their understanding of how their spring rates combine and interact with it is an ongoing learning process.
“It’s more so the travel you have in the spring, how and where your bump stops come into effect,” he said.
“Unfortunately this year we’re not allowed to pack the bump stops so that we can’t change their engagement whereas previously you were able to.
“That is also used as a tool to limit the travel of your suspension so that you don’t coil bind. Teams don’t have that ability this year to do that.”
“It’s not so much us pushing the limit, although it is going past the limit, it’s more so just how our particular suspension installation and the size of our springs and the amount of travel we have.
“Your spring lengths and diametres are free, so different teams have different lengths and then also different stiffness as well. You can be susceptible to it just because you run a different spring rate to other people.
“It’s not every spring that needs to change. The stiffer springs will travel less because of the given weight, but they will also compress less.
“You just look at a different range of springs and we double-check with the new bump stop package and see which springs need to either have more travel available or a larger diameter, whatever the case may be.”
Earlier in the weekend Triple Eight Race Engineering customer outfit Team 18 suffered an identical right front lower control arm failure.
However, for driver Scott Pye, the Holden ZB Commodore he was driving ploughed into the outside concrete wall.
Dutton said the team is still working to find out whether the cause of the two failures is related though he said it is likely.
“We’ve got to fully analyse whether it’s for the exact same reasons or if they take such a beating around there, there is a point where it can be too much.
“For sure, on the surface of it, you’d be crazy to say it’s not related. They’re both our suspension. They’re our spring packages and installations.
“So while you don’t want to take the easy option and say ‘yes, that was it, it doesn’t need any investigation’, you still want to investigate to make sure there isn’t some other cause that’s going to catch you out. The initial thinking is that it’s for a similar reason.”
After Adelaide, Dutton said he doesn’t expect to have the failure happen again. However, the team is working to ensure it won’t happen in future.
No drastic changes are expected for the forthcoming Beaurepaires Melbourne 400, which takes place in support of the Formula 1 Rolex Australian Grand Prix on March 12-15.
“It is circuit dependant, but you still want to make sure it can’t happen,” he said.
“We’ve got a little bit of time to make sure that we’ve got some short-term, mid-term and long-term changes to make the car’s suspension as robust as possible.”