Hi, this is Shaikh from Fat Cat Motorsports and I'm creating this video to talk about what packers or bump stop spacers are. It's something that I've used for numbers of years to help adjust both the amount of suspension travel on a vehicle and to change its handling behaviors. 

So first of all, here's a Bilstein shock and this is the bump stop that we've got on it right now. It's a 58 millimeter red. A packer would be a spacer or is a spacer that will go underneath, typically underneath the bump stop. So it'll go on the shaft first. This is a nine millimeter packer on here. I can zoom in a little bit so you can see this. three-eighths of an inch thick or so and then the bump stop will go on top of that and in some cases say if it's a Kony or KYB not usually Bilstein's because you can take a Bilstein and compress it all the way down and there's enough room for that to happen without causing internal damage. 

Sometimes with other shocks usually it's a twin tube where there's an additional foot valve in here that shaft can go in and actually bottom out you need to be careful of how much suspension travel and how much shock travel you're allowing before you start to resist that and so the packer is like creating a bump stop that's just high density but this is adjustable you can use another spacer if you need to this is a three millimeter sorry this is a six millimeter spacer here this one is not slotted and this would go also on top underneath the bump stop if needed. So this is the protective function of a bump stop spacer or a packer. 

Most of the kits, all of the kits that need spacers or packers already come with them. We also have them available for sale if you want to tune your bump stops on your car, especially if you want to adjust the handling. That's the second function of the bump stop spacer slash packer is to change the handling balance. So this is what they look like. This is Delrin material. We've used high-density polyethylene. Currently Delrin's our favorite. It's nicely machinable. It's very lubricious. It can slide up and down on the shock shaft, not causing any issues because it's much softer than the chrome. And we actually usually chamfer and round this so that the edges are very smooth on the inside. 

So if you wanted to say already had a bump stop installed and the car is understeering, and you want to reduce the amount of understeer, which is that you turn the wheel and the car keeps going the same direction. It's not responding to the steering as much. You would put a spacer like this, which is slotted. You'd put this on the shock shaft underneath the bump stop. And basically you can do this with the setup already installed. You have to, you know, either use pliers or... your fingers to get in. 

If there's a spring around this, then you would need to be able to take the plier, push it over the shock shaft. Usually there's room between the spring coils to be able to do that. 

So this is, you've just got, you know, a stiffer rear bump stop in the case of a car that's understeering. If it's the opposite, if it's too loose, if it's oversteering and you want to basically stiffen up the front end on the front shock, you would do the same thing. If it's a double wishbone car, say this is for a Miata, it could be a Miata, S2000, a Lotus, Corvette, any number of double wishbone front and rear cars. For a strut, the shaft is usually a larger diameter and we have different size spacers or packers for that. Or you would have to hog it out a little bit more. This is a slightly more widened version compared to the one that I put on the shock shaft. But essentially you would use a packer of some sort with the slot in it to be able to put it on the shock shaft. 

So you don't have to disassemble the suspension to make a change. You don't have to change the whole shock setup. You can just go and make this one simple adjustment. And at a racetrack, at an autocross, even on a back road, if you just want to try to fine tune the car's behavior, Packers are awesome. I've used them many, many times to change the behavior of the car. Even if you don't have adjustable shocks, you're causing the car's behavior to change. It's more of a steady state effect, more of a steady state cornering effect. But it can also come in as like a transitional effect. It's really a very powerful tool. 

It's simple. You can make them yourself. If you get a cutting board from a dollar store, you can use high density polyethylene and cut spacers like this on your own. We sell them for $5 each. You can choose either 3, 6, or 9 millimeters. They're all the same price. Some of them will come slotted if you're getting one of our FCM Elite coilover kits. If you're buying it just off the shelf, then you will have to do the slotting yourself. It'll basically have just a solid profile. That's it for now on bump stops and packers. Please leave your questions and comments, and thanks for watching.