Has anybody gotten springrate numbers for popular springs availble for 4th gens?

Jae

 

Eibach prokit progressive rate springs are the following:

166LB/IN thru 266LB/IN for the front as it goes through its full travel.
166LB/IN thru 355LB/IN for the rear as it goes through its full travel.

GXE model OEM springs are 200LB/IN linear rate.
SE model OEM springs are 250LB/IN linear rate.

H&R springs ride a bit softer than Eibachs. So their numbers should be a little less than the above values although I don't know exactly what they are.

Any coilover springs will be linear rate starting around 350LB/IN.
They can't be made softer due to the coil binding that would result.

 

Where did you get these numbers?

 

I got them from some fellow autocross buddies who inturn got them from various performance parts shops.

I do remember asking some shop guys about the Eibach rates as well and they confirmed the same numbers as my contacts in SCCA. I can't remember if it was TireRack or Stillen or Ground Control.

As secret as the spring companies want to keep their info, anybody with a spring tester could figure out the numbers.

Any decent suspension shop should have that hardware and could tell you the rates through the full travel of any spring you give them. Testing a spring is basically measuring displacement vs. a known force.

Testing shocks on the other hand requires much more sophisticated equipment because they have to measure damping force vs. a variety of acceleration rates. A good shock dyno could cost several tens of thousands of dollars.

 

Can you get the rates for progress springs?

 

When searching for part numbers, the SE and GXE/GLE have the same front springs. The only difference is between manual and auto trans.

The rear SE springs are indeed different.

SE shocks/struts are also different.

I would also be interested in valid spring rates. I'm surprised they aren't part of the advertisement, and aren't included with the springs.

 

chris j vurnis: thanx for the insight! I was thinking of getting something more aggressive than the Eibachs. Are there any springs that you know of that are more stiff? I'd go with coilovers, but I don't want to spend so much.

thanx!

Jae

 

May I ask why you want a more aggressive spring than the eibachs? I have maxspeeds on with gr2's and the ride is very stiff. Maybe it's just the crappy roads in nj. From what I've noticed, the max doesn't like stiff springs very much.

Peace.

 

My vision is to create a trackable car. I can live with eibachs, but I've seen and ridden in some eibach cars and it doesn't please me. Like chris j vurnis said, many coilover setups are in the 300-400 range. This should keep the car planted and level. After riding in some coilover setups, I think that's the setup I want.

Jae

 

That's kewl...

Are you planning on getting the AGXs with the coilover springs?

Peace.

 

Thanks Chris for the Eibach rates. Until now I thought progressive's couldn't be rated. Now I understand

 

Front engined cars ALWAYS have stiffer springs in the front since the vast majority of the car's weight is on the front wheels. The difference is usually very significant... Front springs generally have twice the spring rate as rears.

Coilover springs are pretty generic as far as application is concerned. They are available in all sorts of different lengths and rates. I purchased coilovers for the rear of the mustang (tubbing it out and installing a 4-link) and the choices are almost endless. There are even progressive rate springs available. Most front coilover springs are shorter and stiffere than ones marketed for the rear. My rear springs are 14" long, and have a 135lb/in rate. I believe the 'general' outside diameter for these is around 3". I'd have to check to be 100% sure. A set of aluminum, double adjustable (compression and rebound) $400/each Konis takes care of the damping. The rear springs on a rear drive drag oriented car are generally really soft, and the suspension action is controlled by the shocks. All this will get done in the near future when a serious 408 stroker engine finds it's way between the framerails.

Good Luck!

 

sweet!

Yeah, I'll be getting AGX with whatever springs I get (I assume I don't have to modify anything to get the ground controls to fit?). Well, I guess I don't have any choice but to start emailing and calling companies huh? As for gc springs, they don't wind them till you order them, so I can have any springrate I want (diamter remains the same).

Jae