Happy New Year
Daniel Heineck
Well, I already wrote this message once, so lets hope this actually
makes it through.
My goal for this message is to put to words my general philosophy for
this car to hopefully justify my design decisions. This is a open
discussion that we never closed previously. I think we need to nail
this down and then we can look at seperating the different parts of the
project and actually get to work.
Vision, Philosophy and general Info:
I really like Formula Atlantic cars. I'll let Rennie rattle off all
kinds of info about them, but I'd like to summarize what I think is
beneficial about FA cars for a "general" driver:
1.) The cars have way too much grip
2.) The cars have a top speed no higher than a DSR
3.) Well set up cars seem very tractable and linear in their grip as
speeds increase
4.) The "aero" grip and the "mechanical" grip regimes overlap,
elimination the need for a driver to take a leap of faith in a corner
as their skills and confidence increase.
If these aren't true about FA's, that's fine, because those
characteristics listed above are my goals for this DSR as far as
performance. I would have no qualms about being over-dragged in early
forms of the vehicle if it means more downforce. My ultimate goal is
an inspiring car that rewards a good driver, but does not require one.
It might end up being an amazing CSR with a Hayabusa or ZX?? motor
also. To meet this end, here are a few the things I have decided to
meet this goal.
Long lower A-Arms have a very conservative camber loss per degree roll.
A larger bonus is the lack of camber gain under bump/dive which should
ensure a large contact patch under braking. This characteristic
brought about having a raised footbox/single keel as opposed to the
other way around.
Long wheelbase/ Wide Track obviously help with load transfer and
roll/pitch stiffness. I want to build in a lot of stiffness before
adding bars and the like. High roll/pitch stiffness will greatly
assist in aerodynamic stability without negatively affecting ride rates
greatly. The large geometric area of the bottom will allow for either
tremendous amounts of downforce from tunnels (We have the most liberal
aero rules of anyone, we would be foolish to not take advantage of
them) or a more conservative set, which should have low pitch/roll
sensitivity with lower drag to boot.
Higher aspect tires (22" all around instead of 20"s) were chosen
because of the superior braking performance and simplicity of packaging
the suspension. Certainly there is a cost in the tire spring rate, but
I believe that may allow for higher spring rates without skipping
across the surface. Hoosier, unfortunately, does not make a 22x7"
tire, so either running 4 22x9's or developing a package around 20"
tire will be necessary if that is part of the action.
That's what I've got for now. I hope this opens lanes of communication
once again.
Daniel Heineck
David Davidson
Maybe by this time next year the first car will be on track.
Dave
David Davidson
Daniel Heineck
partly to blame. I just don't have time to work on this project and do
my work until this summer.
I've made a spreadsheet to do bearing calcs on the uprights, but
evidently my statics skills have failed me because I'm getting some
"big" numbers. Trying to find an intelligent bearing spacing. I've
chosen 2x INA/FAG 6010 Deep Ball Bearings.
Link is here:
http://medias.ina.de/medias/en!hp.ec.br.pr/60_FAG*6010_FAG;ahoO_duxK_yg
By all appearances several cars already use them. They fit the bill as
far as loads are concerned (I think) and replacements should be pretty
easy.
So that's what I've done... fiddling around a bit with uprights.