Koni 2812s and the Atom

[Matt F]

Could someone please share some information on how to best adjust the 2-way Konis?  I've read Koni's 2812 PDF, but I'd like to hear some real wold experience with how it would apply to the Brammo Atom.  What settings have you tried, and what do you usually use?

Also, I have assister springs.  Does this change the approach to setting the suspension?

Thanks in advance,

Matt

[bolus]

My post from another thread:



Here is the adjustment guide from Engineering to Win by Carroll Smith who has a great set of race car engineering books.

BUMP DAMPING
Bump damping controls the unsprung weight of the vehicle. It controls the upward the suspension as when hitting a bump on the track.  It should not be used to control the downward movement of the vehicle when it encounters dips. Also it should not be used to control either roll or bottoming. Depending on the the vehicle, the ideal bump setting can occur at any point within the adjustment range.

This setting will be reached when "side hop" or "walking" in bumpy turns is minimal and the ride is not unduly harsh.  At any point other than this ideal setting, EITHER the "side hopping" will be more pronounced OR the ride will be unduly harsh. [In the racing car the penalty of a too harsh a reduction in the ability of the tire to put its tractive effort to the road and is evidenced in the tire spinning, sliding or locking at an earlier value of acceleration than necessary]

ADJUSTING THE BUMP CONTROL
STEP 1 - Set all minimum bump and rebound settings.

STEP 2 - Drive one or more laps to get the feel of the car. NOTE: When driving the car during the bump adjustment phase, disregard body lean or roll and concentrate solely on how the car feels over bumps.  Also, try to notice if the car "walks" or "side hops" on a rough turn.

STEP 3 - Increase bump adjustment 3 clicks on all four dampers. Drive the car one or two laps.  Repeat step three until a point is reached where the car starts to feel hard over bumpy surfaces.

STEP 4 - Back off bump adjustment two clicks. The bump control is now set. NOTE: The back off point will probably be reached sooner at one end of the vehicle than the other. If this occurs, keep increasing the bump control at the soft end until it, too feels hard. Then back it off 2 clicks. The bump control is now set for this racetrack


REBOUND DAMPING
Once you have found what you feel to be the best bump setting on all four wheels, you are ready to proceed with adjusting the rebound. The rebound damping controls the transitional roll (lean) as when entering a turn. It does NOT limit the total amount of roll;  it does limit how fast the total roll angle is achieved. How much the vehicle leans is determined by other things such as spring rate, sway bars, roll center heights, etc.

It should be noted that too much rebound on either end ofthe vehicle will cause an INITIAL loss of lateral adhesion (cornering power) at that end which will cause the vehicle to oversteer or understeer excessively when entering a turn. Too much rebound in relation to bump will cause a condition known as "jacking down."  This is a condition where, after hitting a bump and compressing the spring, the damper does not allow the spring to return to a neutral position (ride height) before the next bump is encountered. This repeats with each subsequent bump until the car is actually lowered on to the bump stops.


ADJUSTING REBOUND CONTROL

STEP 1- With rebound set on full soft and the bump set from your testing , drive the car one or two laps , paying attention to how the car rolls WHEN ENTERING A TURN.

STEP 2 - Increase rebound damping three sweeps (¼ turns) on all four corners and drive the car one or two laps.

STEP 3 - Repeat step 2 until the car enters the turns smoothly (no drastic attitude changes) and without leaning excessively. Any increase in rebound stiffness beyond this point is un-necessary and may in fact be detrimental. EXCEPTION- -It may be desirable to have a car that assumes an oversteering or understeering attitude when entering a turn.  This preference will vary from on driver to another depending on individual driving style...

[Matt F]

Thank you very much, bolus.  That's a great place to start.

I love Carroll Smith's books.  I also remember clearly how much Bruce Fielding hates him from http://forum.atomclub.com/index.php/topic,660.0.html.

Do you have the 2812 Konis?  Or, how have you tailored Smith's advice to your Atom's suspension?

[Bruce Fielding]

[quote="Matt F"]
I also remember clearly how much Bruce Fielding hates him from http://forum.atomclub.com/index.php/topic,660.0.html.

[/quote]

'Hate' is a very strong word...

I don't 'hate' very much at all... exceptions include racism, vindictiveness, cheese...

And in Mr Smith's case...

No, I don't 'hate' him either.

Oh, why do you keep reminding me that I once wasted hours of my life reading that tosh?

[bolus]

Hey Bruce, if you dont think his stuff is good do you have an alternative recommendation?  I asked a while back if anyone had other books to recommend  (I'm assuming tosh is the antonym to posh?) but did not get any replies

[nickpoore]

[quote="bolus"]
Hey Bruce, if you dont think his stuff is good do you have an alternative recommendation?  I asked a while back if anyone had other books to recommend  (I'm assuming tosh is the antonym to posh?) but did not get any replies
[/quote]
tosh = rubbish = BS

[Matt F]

[quote="bolus"]
Hey Bruce, if you dont think his stuff is good do you have an alternative recommendation?  I asked a while back if anyone had other books to recommend  (I'm assuming tosh is the antonym to posh?) but did not get any replies
[/quote]

Bolus, I think that the Carroll Smith stuff is the best out there.

Other books, like Compeition Car Suspension or Chassis Engineering are more focused on the actual design and construction of the suspension, including geometry, mounting points, and so on.  Smith covers that also, but his books are the only ones I've found that go into detail of adjusting the important details once the fundamentals are in place.  If there are others out there, I'd love to hear about them too.  And, of course, about how to set up 2812 Konis on an Atom.

[1965Cobra427]

I just replaced my 30 SP8's with 2812's and race springs. Test & tune planned on the track later this month. Also installed these for easy adjustment.





http://www.pegasusautoracing.com/produc ... ct=5179-04

They work fantastic, allowing ride height adjustments and corner weighting without the need to unload the chassis (lift the car).

[Matt F]

[quote="1965Cobra427"]They work fantastic, allowing ride height adjustments and corner weighting without the need to unload the chassis (lift the car).
[/quote]

And they're gorgeous!
Please post a follow-up after testing.

[bolus]

[quote="Matt F"]
[quote="bolus"]
Hey Bruce, if you dont think his stuff is good do you have an alternative recommendation?  I asked a while back if anyone had other books to recommend  (I'm assuming tosh is the antonym to posh?) but did not get any replies
[/quote]

Bolus, I think that the Carroll Smith stuff is the best out there.

Other books, like Compeition Car Suspension or Chassis Engineering are more focused on the actual design and construction of the suspension, including geometry, mounting points, and so on.  Smith covers that also, but his books are the only ones I've found that go into detail of adjusting the important details once the fundamentals are in place.  If there are others out there, I'd love to hear about them too.  And, of course, about how to set up 2812 Konis on an Atom.
[/quote]

Thanks, 

Darth has the same dampers and he had a Porsche instructor on his first track day help fine tune them

[RyanD]

All of my 2812's are set on 8 (firmest) right now.  3 of them came that way from the factory, so I set the other one to match.  I'm sure that isn't optimal, but I really don't find it to be overly harsh either.  I'm really curious to hear how other people have them set.

[1965Cobra427]

Mine were set at max when i got them, a little harsh on rough roads. I set mine 3 clicks from firm for street use. Once we get to the track, we'll fine tune them.
I got a shot of them with the upgraded platform adjusters -

[img width=800 height=533]http://i66.photobucket.com/albums/h269/ ... GP2406.jpg[/img]

[DarthChicken]

I had my full had all the way around (bump and rebound) and after spinning my car, the instructor said drop the rebound down at least one all the way around, and 2 on the back.  I was hopping a bit and it was causing the back of the car to get light (one of the reasons for my spin, the other being cold tires).  It made a huge difference!

So now I'm driving the car on the street that way, but its a pretty rough ride.  I was driving on the streets yesterday, and at one point I saw my front tires actually leave the ground    Thats a VERY strange feeling having no steering input, even if it was only for a split second.

[bolus]

Like this right?

[DarthChicken]

yeah, exactly!