Ground Control Coilovers binding on a 2g?

[hsk8te2006]

Background info: My car is a 1996 Spyder Turbo daily driver, that I do not expect to intend to race anytime soon. I want to lower it about 1 inch.

My intended suspension set-up:
-Koni Sport (Yellow) shocks x4
-Ground Control Coilvoers x4 (2.5ID, 400lb/in, 8 in spring front/ 2.5 ID, 325 lb/in, 7 in spring rear)
-RRE Pillowball upper mounts (front only)
-JIC Coaxial Upper Spring hats x2 (front only)

I caled RRE to discuss their opinions on suspension options, and they were concerned that if I paired Ground Control Coilovers with Koni Sport (Yellow) shocks, that they have seen problems wih the springs binding, and recommended that I go with something else.

However, I called Eibach, and their 2.5ID 400 lb/in 8-inch long spring (what I would use on my fronts), has 4.76 inches of travel before it binds. Considering that the front corners on a stock spyder turbo are around 1265 lbs., it should compress 3.16 inches up front at my spring rate due to the cars weight alone, leaving behind only 1.59 inches of travel before the spring would bind up front.

What I need to know is if a one-inch lowered car would even have that much suspension travel, and therefore if I would be in danger of having the spring bind under full suspension travel.

Opinions anyone?

 

[VETTE_50_TH]

Bump stop.

James

 

[hsk8te2006]

Are you saying that 1) I should just set my bumpstop low enough that I'll hit it before my spring binds, or 2) that I'll have less than 1.59 inches of travel on a 2g car lowered by one inch even if I set my bumpstops as high as they will go?

 

[VETTE_50_TH]

Get a bump stop to give the car only 1.25 inch of travel rather than 1.5

James

 

[hsk8te2006]

My concern with that though... is that 400 lb/in probably isn't enough spring for only 1.25 inches of travel, and I'd end up hitting my bumpstops all the time... am I right or wrong?

 

[VETTE_50_TH]

I don't know man, i not the most knowledgeable about suspensions in the first place. But something doesn't seem right. I read about plenty of people using similar equipment and not having problems. I forgot the guys sn, its like jtcider is amazing at suspension geometry of these cars. Hopefully he tells us whats up.

James

 

[VETTE_50_TH]

I think what is messing both of us is that your corners might weigh 1250 pounds, but over how many feet is that force spread over. We are talking about 400lb over 1 inch.

James

 

[hsk8te2006]

A spring rate is a measure of how many lbs of weight it takes to compress a spring by an inch... That's why I expect that the 400lb/in. spring would compress by 3.16 inches just under the 1265 lbs of the corner, leaving only 1.6 inches behind.

I guess I just need to find out if 600lbs (1.5 inches on a 400lb/in. spring) is an acceptable amount of weight transfer limit for a front tire on a street car.

Is there anyone with enough experience care to chime in?

Thanks in advance!

 

[hsk8te2006]

Hey... I figured out why the math wasn't lookign so good for an 8 inch long 400lb/in spring. I had teh wrong corner weight! The corner weight fo rmy car is roughly 885 lbs, not 1265!. Redoing teh math, using 880 lbs, the car should be able to have 100% weight transfer side to side without coil binding, so I think it'll work just fine.