[F500] Even more Newbie questions

[Eric D. Christensen]

On Wed, 2003-05-21 at 18:12, Mike Moench wrote:
> Sorry Eric.........some of your facts are confused. 

That's entirely possible. Too many years of breathing exhaust fumes has
likely killed of a few too many brain cells. :-) Thanks for being polite
Mike... I suspect that I'm due a bit more of a slam than you delivered.

I don't believe that I've been wrong this many times in one message
before...

> Dave Elliot was the one who was DQed for no thermostat.

Humm... I could have sworn it was Arron.... but that was a lot of years
back. Now that you jogged my brain cells, I belive that you are right on
that one. I stand corrected.

> As for the jackshaft brake, it does act directly on the rear wheels.
> The jackshaft brake is standard on the Sidewinder F500 and the DSR.

Yipes! Sorry Mike... I didn't mean to inadvertently slam the Sidewinder.
I hadn't seen that setup. I'm impressed that you've developed a
jackshaft brake systems that works. Judging from the results thus far
this year, it seems to work well too. Of course, you've got some
'ringers' driving sidewinders.... that helps with both development and
results! :-)

> Just look at snowmobiles, the only brake they have is on the
> jackshaft...............As for the loads the front brakes supply 70% of the
> stopping power. The jack shaft brake spins 3 times faster than the rear
> axle......It also has 3 times the leverage...................Just think of
> all the unsprung weight off the rear axle!

Yes, I appreciate the unsprung weight advantage! Though I am a bit
surprised that you're not having belt problems. It's entirely likely
that I am overestimating the brake loading on the belt. Obviously you've
done the engineering work and have a system that works well, so once
again I humbly stand corrected. 

> Sudden loss of rear brake does NOT cause the car to snap spin. Conversly
> loss of the front (too much rear) brakes causes the rear to come around.

We can debate that over a beer at the runoffs. :-) Certainly too much
rear brake (i.e. locking the rears) will snap spin you. Been there, done
that. But I have a bit of personal experience with sudden total loss of
rear brake that makes me believe that under heavy braking, the sudden
weight transfer is sufficient to unload the rear and brake what little
rear grip you have (since most of the weight is already forward under
braking). 

Of course driving style can play a big factor. Since I tend to trail
brake, I'm still on the binders pretty hard when I turn in. That puts
the car in a tenuous state of stability all by itself. Thinking about
it, you're correct if the car is braking in a straight line. 

Anyway... moot point if the belt is up to the loads it's placed under.
And you have all the evidence to suggest that it is. 

> There is no max distance behind the rear wheels that I know of other than
> exaust.

I'll have to go double check my GCR, but I'm relatively certain that the
wording is to the effect of 'no part of the car may extend more than XX"
behind the rear axles. It just happens that the pipe is the thing that
us rear engined guys get tripped up on all the time. Again, I'm working
from a somewhat feeble memory, so I may very well be dead wrong here
too.

> "That can't be done" "That will never work"  "That big diffuser won't work"
> "That big diffuser is rediculous" "Gwad look at the size of those brakes!"
> "alluminum won't work for a brake disc" "That car will never go fast" "What
> the heck is that?"
> 
> JB and I have heard all of the naysayers and we have proved them wrong time
> and again.

That you have Mike. I can't argue with success!

Just for the record, I'm a big diffuser fan myself (as in a fan of big
diffusers). My experience with the diffuser on the Novakar converted me
to a fan very quickly. 

> It does pass tech. It also passes the competition.

I really surprised that tech hasn't been a problem. The lovely thing
about rules is that the can be interpreted so many ways. :-) I actually
had a discussion some years ago with the Chief of Tech out here in SFR
(who was also the COT at the runoffs for many years) about that very
subject. His interpretation was different, and that was the viewpoint I
was basing my comment on.

Now, that was many years ago, and a lot has changed in SCCA since than.
It may be that I'm basing my opinion on outdated information. Or the COT
may have had a much more critical opinion. 

In any case... I stand corrected yet again. Sigh.... can I get a side of
fries with the crow that I'm eating? Maybe a little ketchup...

> 
> Eric...I know your not a naysayer and I thank you for everything you do for
> all of us.........including letting me vent!

I wouldn't call it venting... I'd call it setting the record straight
after I muffed it up so badly. 

I certainly don't mean to sound like a naysayer! Maybe a little bit of a
safety nazi at times... but that's not such a bad thing, is it?

My apologies if my comments about the jackshaft brake caused confusion.
Apparently my brain wasn't running before I tossed my fingers into gear.
Anyone happen to have a good recipe for grilled crow? I could use one
about now! :-)

-- 
Eric D. Christensen <edc at proadmin.com>
Proadmin, Inc.