Need Help on Adjusting Shocks

[ViperTony]

I have an '01 RT/10 with stock Koni shocks. I attended Chuck Tator's tech session a while back on how to adjust these shocks. I somehow lost the well organized and detailed instructions Chuck created. I've take off the shock and coil springs but I don't remember the following:

# of Half Turns: Is it 5?
Clockwise = Firmer?
Counter Clockwise = Softer?

Can someone validate the above for me? I checked Koni's website and found adjusting instructions for the 8240 series. After taking all of shocks off I found that each shock was adjusted to a completely different Rebound. The rear shocks were set at 2.5 and 4 half turns. The fronts were set similiar to rears. Helps explain why my car seemed to be bouncing all over the place when hitting bumps.

Thanks.
- Tony

 

[DWR46]

I have no expeerience with Koni's on Vipers, but have worked with and rebuilt Koni's for over 35 years. With the bottom of the shock held in a vise, turning the top of the piston rod clockwise will stiffen the shock. You will also see the rod tightening down into the lower housing. Remember to fully compress the shock and then carefully turn the top section while still pushing down until you feel the rod drop slightly into the slot of the adjuster. Only then can you begin to count the number of turns of existing adjustment. Generally, Konis that are relatively new will be adjusted to similiar settings for a given end of the car. However, sometimes if the shocks are qiute worn, they will require different settings to achieve the same characteristics. We have a shock dyno that we use to set all our adjustable shocks. It is really the only way to verify the shocks are set correctly. Until we got our dyno about 10 years ago, I always used the ARMSTRONG method, ie, with the shock nmounted in a vise, pull up on it with a steady force and set all the shocks to feel the same. This is not very scientific, but usually works fine for regular road usage. I am assuming the Konis you are working with are single adjustable for rebound only.

 

[ViperTony]

Yes, they adjust for rebound only. The car only has 8K miles on them. No previous maintenance was done on the shocks. After further inspection, my driver's side rear Koni was set to 0 and the passenger rear was set to 2.5. I was always wondering why I felt like I was bouncing out of my seat on each bump I drive over. Chuck mentioned that just about every viper he's serviced had each shock set to a different rebound setting. Unbelievable.

 

[Tom F&L GoR]

aperugini,

# of Half Turns: Is it 5? YES
Clockwise = Firmer? YES
Counter Clockwise = Softer? YES

DWR46 has a good comment; the gas pressure will naturally make the rod extend. As you set it stiffer, it will significantly increase the amount of time for the rod to extend by itself. It is not really that inaccurate to pull up and feel the difference, either. I'd say it's like bubble vs spin balancing a tire - you can certainly get in the ballpark.

When you set them, I think most would agree that the fronts should be at least a little stiffer than the rears. And full stiff on the fronts with half stiff on the rears is not intolerable for street use.

 

[GTS Bruce]

I went 1 and 1/2 turns from soft front and 1 turn rear with eibach springs.Car is well manered and comfortable.You may need a good alignment too.Chuck did mine.Also not radical.Stock caster,3/4 deg neg front,1/2 deg neg rear,zero toe front,1/32 toe in each side rear.It handles very nice indeed.Alignment took him around 4 hours because 2 other shops worked on it and it was really screwed up. GTS Bruce

 

[crossram440]

DWR46 is correct in the statement of having your shocks dynoed to see if they are set to match each other exactly, However to determine the actual damping characteristics you CAN NOT tell by pushing or pulling on the shocks by hand. When you adjust the shock you are tightening or loosing the inernal valve (common sense stuff here) The valve is a series of very thin steel discs that cover the holes of the piston. When the shock is moved under high forces by your suspension the metal discs deflect allowing the shock fliud to flow through the openings. The rate and pressure required to deflect this "valving" open gives you your changeable damping values and handling changes on an adjustable shock as ours. When you move a shock by hand (any shock not just Koni's) You are only forcing fluid through what is called a "bleed". This is a small hole in the shock shaft that allows small amounts of fluid to bypass the shock valving so it can be manipulated in a static form. It also has a big affect on the very first split second of movement. It affects the initial "nose" or breakaway forces of the valving. In a vehicle where you can electronically go from a sport or performance setting to a touring or soft setting this is the only adjustment that is made internally on the shock to get this different feel.(there are new high tech magnetic particle wiz bang techniques but for 99% of electronic suspension settings this is whats done) The valving does not change. Only the bleed opening size. So when you manually pull on a shock you are NOT causing the shock Valving to operate you are only moving fluid through the bypass. If you were to build a shock that you could operate the actual damping valves by hand it would be the equivilent of putting marshmellows in between your springs for damping. Not trying to get a big debate going here just wanted to let everyone know when you push or pull on any shock absorber you are not feeling the actual shock work. You can have a shock that you can push or pull somewhat easily and have it dyno with high bump and rebound forces, likewise you could have a shock that is almost impossible to move by hand and it can dyno with relatively low bump and rebound forces. If you do have a significant noticable difference in feel by hand when you pull one of your shocks over the other (same axle pairs), you most likely have a problem with a shock, gas leaked out , small debris in valving which cuases the valve to stick open, leaking seals. Bent rod, Damaged shock body. It is not because one is misadjusted. Have them checked out. Also note that Koni will revalve any of their shocks to a customer specs , don't assume that a used rebuilt set has the same valving it came with it could be changed. ask questions.

 

[DWR46]

I agree with everything that Crossram440 says. However, when you adjust Konis, you will be able to feel the difference. When a Koni is set to full soft, it can be extended by hand fairly easily. When it is set to full hard, it is very difficult to entend by hand.

 

[crossram440]

Yep they do , I guess I was trying to elimate the thought of people judging shocks by hand as to their "stiffness" on the vehicle. If you are only working with the set you have been running you can tell that you have made changes by moving the Koni's by hand, I have seen people turn their shock and not get it engaged and they did not know it. it is a good indication of what direction you have moved the shock too if you can feel a difference, I do need to state that you will feel the difference when moving them, so you know you accomplished something with the adjustment, The feel by hand doesn't necessarily relate on a graph to what you feel. If you have adjusted your shock and it feels twice as stiff by hand than it did before, you will not translate that into twice as much damping forces. Why you feel a difference by the adjustment is there is a slight amount of "leakage" past the valving, It is similar to a nut against a washer. The tighter it is the tighter the disc sits on the piston. Some fluid will seep by when moved by hand but not much. When you tighten it up it helps seal that off by more pressure. Only the movement by a Dyno or the suspension reacting to the road will open those valves fully to create that performance damping our Hotrods crave. Just about all street cars like a little more rebound (what our shocks can adjust) than what the factory provides. A little bit goes a long way. Don't over do it if your car is otherwise stock. Too much dialed in rebound will upset the handling and not allow the suspension to move through it's motion and return to a ride height quick enough to deal with the next movement. Rough roads will limit you to less dialed in rebound, a nice prepped smooth track surface will allow you to dial in more. Unfortunately you have to expirement a little to see what is best for you. Driving style , where you drive , road conditions, all play a part. One persons settings may not be the best for your setup or area.

 

[DWR46]

Absolutely correct Crossram440. You obviously know what you are talking about. Thanks for putting your thoughts out for fellow Viper owners to read.