Koni Adjustable 3012 : How?

[nickpoore]

So, I have a question regarding how the dampers work on the car, and more importantly, how to easily adjust them.

The UK guys talk about setting ther cars to A, B, C, D, etc.
I don't think the Koni settings are quite as simple.

Does anyone have a simple procedure on how to adjust these dampers.

Also, can somebody explain to a non-technical individual what adjusting these dampers actually does?

Thanks.

[KK]

[quote="nicolas"]
The UK guys talk about setting ther cars to A, B, C, D, etc.
I don't think the Koni settings are quite as simple.
[/quote]
As far as I understand A, B, C, and D are not settings on the dampers but different specifications of dampers. Dampers are revalved to those specifications at the factory (i.e. Bilstein).
An A damper is the softest, a D damper the hardest. Common consensus on here is that B is best for road use with RBBC, with an A damper a car with RBBC would be underdamped. Cars with PBBC use the A damper as standard because there's more friction on the suspension.

I am sure there are better qualified people out there to provide you with the right answers to all your questions.

[bolus]

Are the 3012 the single adjustable or the dual adjustable? 

I have the single adjustable one.  I started with them all to fully soft (turn toward the negative sign until I could not turn it further).  I can get 9 turns until locked in the other direction so I turned them all 6 turns for what I guess is a medium hard setting.  I can definitely tell when driving in the bumps are a lot more painful but the car feels much more firmly planted at higher speeds.

In reality the dampers should be fine tuned by track testing.  another reason the learning curve on this car is so high.

Here is what my race car engineering handbook says on shocks:

Too much shock overall:

• Very sudden car with harsh ride quality, much sliding and wheel patter
• Car will not absorb road surface irregularities but crashes over them

Too much rebound force

• Wheels do not return quickly to road surface after displacement. Inside wheel in a corner may be pulled off the road by the damper while still loaded
• Car may "jack down" over bumps or in long corners causing loss of tire compliance. car does not put power down well at exit of corners when road surface is not extremely smooth

Too much bump force: general

• Harsh reaction to road surface irregularities
• car slides rather than sticking
• Car doesn't put power down well - driving wheels hop

Too little shock: overall

• Car floats a lot and oscillates after bumps
• Car dives and squats a lot
• Car rolls quickly in response to lateral acceleration and may tend to "fall over" onto the outside front tire during corner entry and onto the outside rear tire on corner exit
• Car is generally sloppy and unresponsive

Too Little rebound force: overall

• Car floats - oscillates after bumps

Too little bump force: overall

• Initial turn in reaction soft and sloppy
• Excessive and quick roll, dive and squat

Dead shock on one corner

• A dead shock is surprisingly difficult for the driver to identify and isolate
• At the rear, the car will "fall over" onto the outside tire and oversteer in on direction only
• At the front the car will "fall over" onto the outside tire on corner entry and then understeer

[nickpoore]

Hey Bolus.
Thanks for the reply.
I'm a complete idiot when it comes to some of this stuff, so I really just need to put my learning hat on and start paying attention.

[quote="bolus"]
Are the 3012 the single adjustable or the dual adjustable?  [/quote]

From their website: http://www.koniracing.com/3012.html
Our 3012 Series is a double adjustable Aluminium body shock that is lightweight, consistant and affordable.
These shocks are adjustable for rebound while on the car with a total range of 6-8 sweeps.
Adjusting compression requires that they must be removed and extended this allows for 10 distinct compression settings.

I'm slowly learning about rebound/compression adjustment, and am sure I have quite a lot to learn.

[bolus]

The only adjustment you should really plan on doing is with the small adusters at the top of the damper.  Removing the damper and adjusting it or adjusting the spring would require a lot of re-tuning to be done to the car like resetting corner weights. 

Here is a picture of my single adjuster on my dampers.


You should have 2 adjusters in that space.  One for bump control and one for rebound.  Bump is compression of the shock (when going over a bump) and rebound is return to the resting state.

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 right 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...

[nickpoore]

[quote="bolus"]
The only adjustment you should really plan on doing is with the small adusters at the top of the damper.  Removing the damper and adjusting it or adjusting the spring would require a lot of re-tuning to be done to the car like resetting corner weights. 

<<Your dampers look just like mine.>>

You should have 2 adjusters in that space.  One for bump control and one for rebound.  Bump is compression of the shock (when going over a bump) and rebound is return to the resting state.[/quote]

Bolus.
Thanks once again for the reply.

Your dampers look identical to mine, and there is only bump-adjustment available on the outside.

I've now read that the instructions for adjusting the damper are on page 32 of this catalog:
http://www.koni-na.com/pdfcatalogs/KONI ... atalog.pdf

They say:
Note: Do not place shock absorber in a vice (except at the lower eye).
The Rebound adjuster requires a pin with an outside diameter of 3mm or a 2.5mm Allen key.
To increase the rebound force, put the adjuster pin next to the minus sign and turn the pin towards
the plus sign (left to right). This is one sweep of adjustment. From the minimum position there is a
total adjustment range of 6-8 sweeps. There are no specific clicks of adjustment to mark the adjustment
position and the rebound adjuster can be placed at any position in the adjustment range. DO
NOT FORCE ADJUSTER AS BINDING MAY RESULT!
The Compression adjustment is made with the shock fully extended. The compression
adjustment requires tool 1037.74.01.04 or a tool of similar dimension to depress the adjuster
button. Hold the shock body where the piston rod emerges from the cylinder. Depress the button
fully, and hold it down while adjusting. It may require turning the rod slightly to get the button fully
depressed. The adjuster has 10 distinct stops (clicks) each of which marks an adjustment position.
To increase the compression force, turn the piston rod counter-clockwise. When finished, release
the button and make sure the button fully springs back into position. Otherwise, the correct
adjustment will be disturbed.

So, it would appear that I can adjust the rebound setting with the car in place.
However, to adjust the compression setting, I need to remove that end of the damper.

Of course, to say that I can adjust the rebound setting in place is a little misleading.
The front ones are easy, but the rear ones involve the removal of the rear engine cover (which involves little things like disconnecting the gas tank from the gas cap.).

And removing the dampers to adjust the compression settings will involve removing the pressure from the springs, and so having to mark and re-setup the springs when complete.

This is looking like a bigger job than I first thought....

[bolus]

You can adjust the rear without removing the cover.  Just do it from below.  The adjustment is reachable from both sides. 

[nickpoore]

[quote="bolus"]
You can adjust the rear without removing the cover.  Just do it from below.  The adjustment is reachable from both sides. 
[/quote]
SMART MAN!!!

[twebb]

3012's are double adjustables.  Unless you have 2 sweep mechanisms on "top" of the shock you can only adjust the rebound on 3012s by removing the shock.

If your shock looks like the photo above and they are 3012s, then you should see a brass button on top of the shock body (where the piston enters the shock body).  To adjust bump you need to remove the shock from the car, push the button down and turn the shock body.  You will feel the detents when changing the bump setting.

The 2812s are fully adjustable on car. Unlike the photo above, there are two "sweeps" to adjust.  If your shock looks like the one in the above photo, you need to remove the shock to adjust bump.

As Bolus said, you will need to check your weights after reinstalling the shocks.  You can get close by taking very careful notes as to number of turns you move the spring perches.

For a race car, we always look to get bump set correctly first and then worry about rebound.  If you are not familiar with setup techniques buy Carrol Smith's books.  They are a great help.

[4RTR]

Bolus - nice close up picture, but is that a spec of rust on the allen head? Surely not. Maybe just the light reflecting.....



Wish mine looked like that.

[nickpoore]

Hey TWEBB, thanks for the input.

Yes, in hindsight, the 2812's are more adjustable, and make the compression setting much easier to adjust.
Just a shame that they cost $1200 more, and there's probably not an easy "upgrade" option.

Also a shame that we need to do the bump/compression adjustment first, when it's the hardest one to reach.

Oh well, gotta learn sometime.