gixxerdrew
DSM Wiseman
- 664
- 21
- Oct 5, 2007
-
Yokohama, Japan,
Asia
Hi everyone, I want to keep this blog going and posting tech. I'd like to keep sharing technical details, but I have almost no free time, so I have to rush through writing. With that said, I cant write it all up from square one to explain all the concepts. So if it's alright with all of you, Id like to try giving you food for thought and get you started on your own research to understand it. That way I can concentrate on trickling down the technology we've developed to help you all go faster sooner.
I recommend a good starter book Carrol Smith, Tune to Win. There is a suspension geometry section that's really good at explaining the basics.
One of the problems we noticed early on with the car was that as we increased grip, the car began to have excessive body roll in the front, this was a big problem and the driver was complaining at our first event, Buttonwillow 2009. The car was rolling over like crazy on the front tires. Nobody likes excessive body roll and it wreaks havoc with camber curves. It was resulting in the car touching onto the bump stops which created big time under steer and handling unpredictably. Driver was unhappy... the car looked bad in the photos (sponsors always love that). But we knew we were taking our first stab at the handling setup we needed some direction and now we had it.
The trouble comes in that both of the two standard methods to address this had big associated problems for our platform.
1) increase the spring rate. Big problem. Buttonwillow, the #1 time attack track is really bumpy and a rough ride isnt just hard on you... it reduces tire grip and driver confidence. Additionally stiffer springs generate more heat in the tires and that was the absolute last thing we need. When you are on street class tires in a 700hp car... trust me those tires get plenty hot.
2) increase sway bar. I had done some testing on this in the past with a custom made piece, the problem was that the front differential didn't like the change the car had less acceleration traction on corner exit and that was costing a lot of time all the way down the straight.
I wasn't sure where to go with it, so I consulted with Robert Fuller at ROBISPEC. His suggestion to build roll resistance into the suspension geometry. ROBISpec modified our front sub frame with the inboard pickup points moved upward. This raised up the front roll center. Robi used precision instruments so that when the change was made it wouldn't upset other important aspects of the cars geometry. This was a huge change, the driver feedback was excellent and the car proceeded to win its biggest victory, willow springs 2009.
In Episode II, exploding steering racks after going wide body and the solution.
I recommend a good starter book Carrol Smith, Tune to Win. There is a suspension geometry section that's really good at explaining the basics.
One of the problems we noticed early on with the car was that as we increased grip, the car began to have excessive body roll in the front, this was a big problem and the driver was complaining at our first event, Buttonwillow 2009. The car was rolling over like crazy on the front tires. Nobody likes excessive body roll and it wreaks havoc with camber curves. It was resulting in the car touching onto the bump stops which created big time under steer and handling unpredictably. Driver was unhappy... the car looked bad in the photos (sponsors always love that). But we knew we were taking our first stab at the handling setup we needed some direction and now we had it.
The trouble comes in that both of the two standard methods to address this had big associated problems for our platform.
1) increase the spring rate. Big problem. Buttonwillow, the #1 time attack track is really bumpy and a rough ride isnt just hard on you... it reduces tire grip and driver confidence. Additionally stiffer springs generate more heat in the tires and that was the absolute last thing we need. When you are on street class tires in a 700hp car... trust me those tires get plenty hot.
2) increase sway bar. I had done some testing on this in the past with a custom made piece, the problem was that the front differential didn't like the change the car had less acceleration traction on corner exit and that was costing a lot of time all the way down the straight.
I wasn't sure where to go with it, so I consulted with Robert Fuller at ROBISPEC. His suggestion to build roll resistance into the suspension geometry. ROBISpec modified our front sub frame with the inboard pickup points moved upward. This raised up the front roll center. Robi used precision instruments so that when the change was made it wouldn't upset other important aspects of the cars geometry. This was a huge change, the driver feedback was excellent and the car proceeded to win its biggest victory, willow springs 2009.
In Episode II, exploding steering racks after going wide body and the solution.
