Short springs and catching air...

[speeder]

Let's say you've got short springs and stock length struts and shocks and you catch air in a 510. In other words, you're shocks/struts have more travel than the length of the spring as it is set up in the suspension in stock configuration.

 

Do the springs move around loose in their seats?

 

Anyone have experience with this? Problems?

 

Is it advisable to run shorter shocks and strut inserts so that they prevent the top out point from being higher than the length of the spring?

 

I'm about to do a suspension change with Tokico HP's [HZ3038 inserts (for 280zx) in uncut 69' struts, HE2572 rears], and Suspension Techniques springs, T3 camber plates and bump steer spacers. I will be thrashing the car in road rally applications with the potential for air. I don't want springs moving around and getting seated incorrectly.

Edited December 18, 2009 by speeder

[benzo]

I don't do any rally and have no background there but if you don't want springs to move around you can get tendersprings to keep the springs from floating.

[banzai510(hainz)]

I'm about to do a suspension change with Tokico HP's [HZ3038 inserts (for 280zx) in uncut 69' struts, HE2572 rears], and Suspension Techniques springs, T3 camber plates and bump steer spacers. I will be thrashing the car in road rally applications with the potential for air. I don't want springs moving around and getting seated incorrectly.

 

 

I dont see why you need all this on a Rally car

the 280zx cartridge are the shorter one but you can always put them in a longer strut by putting a spacer(some people put steel washers) on the bottom of the strut to move the cartridge higher.

 

Bumpsteer spacers is more for lowered cars. if you rally I think you want close to stock height .

[Skib]

rally? 510?

 

 

HRH its for you...

[ggzilla]

Yep, all you gotta do is wire the the spring to the top and bottom spring seats.

[fo0manchu]

why are you lowering the car if you want to get air? Or is this just a hypothetical question?

[Guest kamakazi620]

You could also extend your tophats for your stock shocks/struts

[speeder]

Thanks for the responses.

 

I don't really want to get air, it just may happen on the type of back roads I like to drive at speed. When I say road rallying, I mean high speeds on tight, twisty, back country two lane roads with undulations, paved with an occasional gravel section. Nothing that would require high clearance, but places where you tend to bottom out hard from bumps and potholes. You would still have plenty of clearance on a car with 1-2" of drop. No offroading capability or high clearance is needed.

 

Ggzilla recommended what another friend of mine with a long racing history recommended. That is to secure the springs to the perches top and bottom. With wire, fat zip ties, strapping, hose clamps, or perhaps small U bolts. This guy also said you can put a cable from the body to the back of the trailing arm in the back to keep the suspension from extending beyond the length of the spring.

 

Speeder

[HRH]

HAHAHAH, Skib, I only just saw this now. I was looking for camber plate info with the search function! :D The big thing with shocks/springs is to make sure you don't run out of spring before you run out of spring. Otherwise the shock takes the load instead of the bumpstop/spring. That's bad. It will either yank the insert past the seals, or push it out the bottom, or at least try to.

 

I wrote about this somewhere just recently, as I decreased the amount of bumper I had to allow for full shock travel. Measure your extended shock insert length, then measure how much compression your spring has before coil bind. Ideally, you want there to be some preload on the spring as if it's too short and the shock too long, it will rattle around on full droop and could even land off the seat, thus totally screwing the suspension, not to mention your landing. Right now I'm using 280zx tubes with 71 510 stock strut inserts (the longer 510 fronts) and an 11" or 12" spring, with about a half inch to 3/4 inch bumpstop. So far it works well.

 

I'd say what you might want to do is run thicker bumpstops and shorter springs, like a 10", or you could run the same setup, but weld the ring lower on the strut tube.

Edited December 28, 2009 by HRH