<VV> Corvair braking

[Bryan Blackwell]

Let me be clear - I am *not* talking about wet or snowy conditions.   
I am interested in what happens on a good traction surface on a  
clear, sunny day.  You can pull nearly a G, maybe more, on street  
tires with a Corvair under braking (I intend to measure it).  If  
you've never tried it, it can be quite an adventure to have the rear  
end sliding first at speed (not 30).  The various road racers, BTW,  
all bias their brakes towards the front - this is fairly well known -  
compared to stock on a late model Corvair.  It has nothing to do with  
making it stop like a front engine car.  I am considering what  
happens with maximum braking force from decent speed (say 60 or 70),  
to then negotiate a corner at half that speed.

One other point - the brake bias moves toward the front as traction  
decreases since the weight shifts less.  Under poor traction braking,  
a Corvair is indeed nearly perfect, but under good conditions the  
weight transfer is dramatically higher.  Why is it different now than  
in '64?  In a word - tires.  Street tires then generated about 70% of  
what they do today (assuming decent quality in both periods).

In any case, I'll stand by Puhn's comments - he is directing this at  
the race car builder, many of whom are dealing with mid or rear  
engine cars.  High speed stability under braking is important no  
matter which end the engine is in and rear wheel lockup at speed is  
considered a bad idea (see also Carroll Smith, _Tune to Win_).   
Fortunately for us, the platform allows us to actually *use* the rear  
brakes, and that's a big benefit.

--Bryan

On Oct 28, 2008, at 10:23 PM, Hester, Randy wrote:

> On Corvairs the braking effort is almost balanced just favoring the  
> rear
> a bit, this is NOT a "problem" as in wet or snowy conditions you can
> brake and steer simultaneously.