Re: Coil-over shocks LONG REPLY

[STEADIRIC@aol.com]

rudack@ucsub.Colorado.EDU said:

>> compresses and extends, put a damper in the middle of that and you get a 
>> sideload on the piston.  Sideload=Bind.  Your answer assume's mechnical 
>
>Are you talking about serious binding that will effect the damping rate
>of the shock or just premature wear of the components from the extra
>friction?    

Both.

>> Incorrect again, and the answer shows a lack of understanding of the 
>> terms "low speed damping" and "high speed damping".  A damper controls 
>> ocilations by converting the movment into heat, it's their job.  Add 
>> friction from the coil over design and you creating problems that can be 
>> avoided.  
>
>I am interpreting "low and high speed damping" as a function of piston
>velocity within the damper.  Are you saying that this extra friction
>from the coil-over will
>cause the dampers to "fade",  what other problems might arise?  Is the
>problem too much heat? My inquiring mind wants to know...

Yes that is part of the problem

>> Incorrect you don't have to run coil overs to get flexibility, if that 
>> was true how come Stock Car, Supermodified and other sedan based racing 
>> can get it right.
>
>That may be true but with my resources and especially my rather "shallow"
>pockets, the coil-over setup was the way to go in order to gain what I
>wanted out of my car. 

Incorrect.  Everything that you gained could have been achived without 
resorting to coil overs, and for less money.

>I am no suspension "Engineer" or "Tech" but I have
>driven and ridden in many Q's with MANY different suspension setups and I
>feel that I have achieved what *I* wanted with this coil-over kit.  Some
>may say it is too harsh but frankly I thought H & R equipped cars felt too
>soft.  The beaty of the coil-over is that one has the ability to make the
>car as firm or as soft as they wish for a rather minimal cost.  Another
>plus is that these cars can be kept at stock ride height and still perform
>extremely well.  No loss of city drivability, what-so-ever.  

Some folks think that there is some sort of magic to keeping the car at 
stock ride height while increasing the spring rate, they are wrong.  The 
only thing keeping them from putting the ride height where they want it 
is a lack of understanding of how to do it.

>Personally, I
>have my car lowered quite a bit (No, I don't have a bump-steer problem)
>and if I wish I can raise it up for the snow season with minimal effort.

Yes you are. You just don't know it. It's Geometery and it can't be 
changed inexpensivly.

>QSHIPQ> >expensive, try buying just the springs from any of the "kits".
>> Eibach's ERS
>> >springs are off the shelf, linear rate springs available in a universal
>> 2.5in
>> >dia, and you can spec the effective length in 2" increments and the
spring
>> >rate in 25lb increments, and relative to ANY kit available elsewhere,
they
>> >are price competitive for audis.  

Ahh, but this is where QshipQ is showing a lack of understanding.  Those 
"Linear" rates are actually Falling rates.....

>You forgot to mention that there is a progressive rate ERS setup
>consisting of 2 seperate springs, Anyone BTDT?  Might this be a"better"
>approach for someone building a coil-over for street use?  I am not the
>one to say, I would like to try it and see if it will help soak up those
>little bumps that don't get absorbed by the "stiff" springs I am running.

Now your getting into SERIOUS tuning and with that comes expense, just 
where do you set the cross-over?  Test, test, test.  But yes it would 
work better, that's why I chose it.

>STEADIRIC> Personally in large street car I'd be running larger springs
>> than a 2.5" 
>> Formula car spring.... If you don't understand the reason's go hit the 
>> books.
>
>I don't understand the reasons, would you be so kind as to throw a few
>titles my way???

Tell me what you've got and I'll let you know if your in the ballpark.

>QSHIPQ> >Corner balancing a car for the track, changing ride height,
>> >linear rates, and
>> >phenomenal handling make coil-overs a serious improvement for the audi 
cars.
>
>STEADIRIC > NONE of that requires coil-overs.......
> 
>From my limited experience I don't see an easier way to adjust corner
>weights than to very the ride heights.  Why don't you put a little
>substance behind your statement so we all know what you mean and where
>your coming from?

I'm just varying rideheight's just doing it differently than using a 
threaded coller.  Besides on a street car you'd be lucky to feel 100lbs 
cross weight.

>QSHIPQ> >others.  Not at the expense of ride control, height, or comfort
>> >or longevity
>> >either.  The street ride is not choppy, hardly unacceptable for the
>
>STEADIRIC> Again none of that requires coil-overs.
>
>What does it require?  Is the alternative cost-effective???  

Yes there is but once again it's experience and knowing WHAT the problem 
is not just throwing parts at it.

>QSHIPQ> >The rewards are worth it, the decrease in the
>> >tail wagging antics of the 44 chassis alone brings smiles.  
>
>STEADIRIC> Since understeer is the prevailing condition the "Tail Wagging"
>> >comment makes no sense.....
>
>Agreed. Scott, care to explain that one a bit better, I didn't quite
>follow.  However, driving a highly modded 44 on the track with a coil-over
>brought smiles to my face all day.  Especially since I am not familiar
>with the 44 chassis and I was able to have a respectable "battle" with a
>nicely prepped sticky tire equipped M6.....  The car became so easy to
>steer with the throttle and so predictable with the addition of the ERS
>"kit". 

Just because the car had coilovers on it does not make it superior.

> I can speak just as highly for my car.  It was running
>consistently 3 seconds quicker around Stapleton than a H & R equipped
>"chipped" 90Q 20v. I
>have a 90Q 10v with a 2.5 inch exhaust. No other motor mods. Both cars had
>the same tires,
>same brakes and most importantly the same driver.

And without coilovers you would have the SAME results.........

>STEADIRIC> Which is the problem.  Most people want their cars to "Handle
>> Better" 
>> what does that exactly mean?  Better transient response?  More mechnical 
>> grip at the front? At the rear? etc etc......  What's it going to be? 
>> Enter experience.
>
>That is exactly why the coil-over mod is so nice.  It is easy to tune and
>inexpensive.  It doesn't have to be a compromise for ride height or other
>factors.

Neither does anything else.  Once again you just have to know what your 
doing.




Later!


Eric Fletcher S.O.C.
'87 5KCSTQ WAY too many toys
Trans-am/Sportscar Chassis Engineer
St. Louis, MO

STEADIRIC@aol.com