http://cgi.ebay.com/ebaymotors/ws/eB...926556930&rd=1

can someone explain the purpose of have shocks integrated with a roll cage???

i dont get it, maybe just cuz im a NOOB lol

mike

 

Those are actually hooked to the rear suspension via the triangle-shaped piece above the shock towers. Someone else can fill you in on the benefit - the auction page claims a reduction in unsprung weight (since the regular shocks and springs have been replaced with a solid bar that connects up through the shock tower to the little triangular piece).

-bill

 

Formula cars use suspension similar to this, the purpose is to move the shocks and springs to a more advantageous location. As mentioned, the amount of weight on the 'unsprung' side of the suspension is less now, which improves handling. I'm no Mechanical Engineer, so I'll just leave it at that, reducing unsprung weight is a proven way to improve the handling characteristics of a vehicle, it has something to do with the suspension components having to perform less extraneous work. The other advantage of having shocks mounted like this is that it relocates weight towards the center of the car (again, better handling), many race cars also move the shocks further down to lower the center of gravity as well. It also makes it a lot easier to swap springs / adjust shocks.

Personally, I would be pretty wary of a custom fabricated system that someone's trying to get rid of, maybe he just needs a bit of extra money, but maybe it didn't work either. Maybe it worked, but not as well as he hoped and he's planning on building a better iteration.

-s-

 

Anything connected to the suspension end of the shock/spring is considered unsprung weight (i.e. controlled by, not supported by the shock/spring). In this mounting configuration, you're adding the weight of the actuator rod which takes the place of the spring/shock to what the shock has to control when the suspension moves, so you're actually adding to unsprung weight, as I see it. Furthermore, you're adding sprung or supported weight also, because you've added the brace/cage, brackets, and other parts.

It looks cool, and when you're frequently changing your spring rates for varying conditions and/or using shocks with remote reservoirs, something like this makes it far easier to mount and service the suspension components. However, as far as reducing unsprung weight, I don't think so.

 

Agreed. It also allows cars with a very low ride height to run a shock/spring combination with longer travel/greater fluid capacity, which keeps the shock cooler so that damping is more consistent.

 

Rally cars use it for that reason too, longer suspension travel on a chassis that normally wouldnt allow it (i.e. Focus rally cars).

 

oo now i get thanx fellas

mike

 

This is called a pull rod suspension. It moves the shock and spring to a more advantagious location to reduce unsprung weight. Common practice int the design of most open wheel formula cars, Indy car, Champ Car as well as GT type race cars where active suspension is not allowed.

Joe Geiman
Linder Technical Services
Speedway, In

 

Does anyone have any info on how well this specific kit actually works? I mean, it's a great idea and has some obvious advantages, but how well does really work compared to normal type FD suspension setups?

 

That looks similar to my dirtbike's rear suspension. The shock is connected to a link which can change the amount of movement on the shock. You can use longer or shorter stroke shocks with a system like this. It allows another variable when tuning your suspension.

As for this application. I don't believe it is a worthwhile setup. If I was trying to use a 8 in stroke shock for 20" travel on a baja vehicle maybe. Here I wouldn't buy it. Just buy the adjustable shocks or whatever you need and leave it at that.