F500 Suspension dampening guideline

[TDI PILOT]

Guys,

I put together a guideline on setting up F500 suspension dampening to share with the group. I would guess most of you crusty old timers already know the procedure, but it may be helpful for some of the newer guys.

-Eric F5 Suspension dampening guideline.pdf

[yoitsmatt]

Guys,

I put together a guideline on setting up F500 suspension dampening to share with the group. I would guess most of you crusty old timers already know the procedure, but it may be helpful for some of the newer guys.

-Eric F5 Suspension dampening guideline.pdf

Thanks new to this game and i figured it was close to something like that but that will give me a nice place to start!

[cory mcleod]

Great write-up Eric!

[Frank06]

I would love to have a look at this but it's not showing up for me. Any chance you could repost? Thanks!

[TDI PILOT]

Setting the correct suspension dampening on your F500

-Tools needed: Stopwatch, Torque wrench, sockets, and open end wrench to work on suspension pieces. A second crew member to run the stopwatch is very handy for this procedure.

-Make sure the car has the correct ride height set on all 4 corners and the suspension rocker pivots are clean and grease free.1. Put the car up on a lift or a stand that raises all 4 wheels completely off the ground. Raising the car up to a height that allows you to comfortably work on the suspension components while standing will make this task less painful.

2. Unbolt and disconnect the upper pushrods from the suspension rockers on all 4 corners of the car so you can lift an individual wheel all the way through its range of motion. Leave the tires on the car and all the other suspension components connected.

3. Find the pivot point of the suspension rockers, it will be a bolt that goes through the frame and the rocker. This bolt with varying torque settings will provide the specific amount of dampening you desire. Loosen the nut on this bolt until it’s just barely putting any “pinching” pressure on the rocker from pivoting. Loosen this bolt on all 4 corners of the car.

4. Start on the rear of the car at one side, it doesn’t matter which side is first. Lift up on one of the rear tires by hand until it is at the very top of its suspension swing or travel. Next, let go of the tire and observe how much time it takes to fall from the top of the travel to the bottom.Typically with the correct torque set, the time it takes to fall should be about 3-4 seconds depending on car and driver preference for a particular track.

5. With loose pivots the suspension will fall very fast (less than half a second). Start raising the torque values on the pivot bolt or nut so it’s slowing down the fall of the suspension on that corner. Continue to raise the torque value slowly and repeat the drop test until you get the drop time you desire. I recommend starting with 3.5 seconds on the rear and 2.5 seconds on the front. Once the desired drop time is achieved, redo the drop test a few times to make sure the drop time stays consistent.

6. After the desired drop time is reached, note the torque value as read on your torque wrench and use a sharpie marker to write down that value on the rocker arm for that suspension corner.Remember if you use nyloc nuts for your pivot bolts that is ok, but over time the resistance of nyloc nuts to tighten or loosen will be reduced so you will need to perform this drop test every few race weekends. If you use regular nuts then this will not be an issue, but the regular nuts can loosen during a race so I recommend using nyloc ones…Just check them often to make sure you can’t tighten or loosen the nut with your bare hands. If you can, replace them and repeat this test.

7. Continue on to the other side of the rear axle, the idea here is to have the EXACT same drop time on the LR and RR. Don’t be alarmed if the torque values from left to right differ by a few pounds when the drop times are the same this is normal, however if the values vary significantly, you will want to check out the pivot area to make sure everything is clean and the Friction washers are in good condition. Never use any kind of lube or grease on the friction washers themselves. Clean them with Acetone or Electrical contact cleaner to remove any unwanted lube or grime.

8. Move on to the front of the car, perform the procedure on each of the front corners to make the Left and Right side drop times EXACTLY the same. A good drop time to start with on the front is about 2.5 seconds. Remember, the torque values on the L and R may differ a little, just make sure the drop time is the same.

9. Make sure to first loosen, then set the torque value written on each of your suspension rocker pivot bolts each time you go out for a session. Don’t be afraid to play with the Drop times to better suit a specific track, your car, or your driving style.

How can you tell if you have the correct amount of dampening? Try this test: While driving the car with hot tires and while cornering below the limit of lateral grip purposely drive over a single very small bump near the apex of the corner. If you notice when hitting the bump the cars balance is affected or it becomes unsettled in the front or rear, you need to consider more dampening or a slower drop time for that area of the car. If the car is observed by your crew to bounce at one end or both while cornering you most likely also need more dampening. Make small changes until the desired handling effects are reached. Also remember, the more dampening you have set, the wheel rates for that corner will get higher or the suspension will be stiffer and less compliant. Sometimes you may need to soften the suspension by moving the pushrod pickup points on the rocker then try the on-track dampening test again.

[Frank06]

Thanks very much and happy New Year.

[TDI PILOT]

No problem, in an effort to help tighten up the competitive levels within the class I will be posting some more of these F500 tech guidelines for all to see. I think having this information out there could help newer guys with getting up to speed faster. I believe there is value in trying to make more people competitive within the class.... stay tuned

-Eric

[Frank06]

I just wanted to add that I used this process recently and it was very interesting. One corner was too tight and it was definitely affecting corner weights. Thanks again for posting.