AdrianM: I'd like to respectfuly disagree with you there. Cars don't have to have flex to be fast. I consider myself an average racer, and I assure you that no one who has seen me run my Corally C4.1 would consider it's handling poor.
I don't use the split upper deck you mentioned(all though most people do), I do all the traction tuning on the car with the suspension, like I consider it was meant to be done. In fact I am doing better with this stiff car than I ever did with my MR4tcpro or Corally C4 AGLE which both had a good amount of flex in them. I also have a friend of mine on this board, CIVIC91, who runs a very stiff chassis car. The Kawada SV-10. His car is also one of the best at the track. I have run the car on all kinds of tracks. (large and slick)(Large and sticky)(small and slick)(small and sticky) and everything in between. All with the same results, one of the best handling cars on the track.
And I could take my '99pro out on those very same tracks and do well with it. So since people say that car has flex, yet I can run just as well with my C4.1, that would seem to create a new theory. One that says tune with the suspension, no matter what flex characteristics you chassis has.
I mean if the chassis is what we tune for traction with, what are the suspension and tires for
Now will this work for everyone? Probably not. But, you statement seemed to be generalizing about the subject.
What really bugs me about this chassis flex subject is this; Have you noticed that no one really seems sure what they want???
I'm mean think about it. The people with the flexy car are searching for stiffness, while people with stiff cars seem to be searching for flex.
Examples: HPI PRO3- probably the most flexable race purpose car out there. Yet people stick Penguin chassis and HotBodies upper decks on there along with HPI's graphite chassis all in an effort to get it stiff.
......at the same time.......
Corally C4.1: probably one of the stiffest race cars on the market. Yet people are cutting their upper deck in half and replacing it with a turnbuckle in an effort to achieve more flex.
I think this subject is quickly approacing the level of "what do you do to maintain you 3000cells", you know what I mean. Everyone is searching a correct answer when I really don't thing there is one. It probably just comes down to whatever works for that particular driver.
But, I definitely don't think there are any general across the board answers on this issue.
(See thats what I'm saying outload to be diplomatic. But in my head I'm thinking "tune with the suspension NOT the chassis!"
Thanks for listening.....