I had the eibachs, HR's, Ground Controls, JIC's and Espelirs. WE've tested nearly all reputable suspension manufacturer's on Protege5 and sedans.
Toucci, hit it right on the money. The Eibach is progressive on all four corners so in lamen's terms your steering response is slightly delayed because the Eibach spring must compress slightly before yielding the higher spring rate and that superb turn in that most of us are looking for.
For all intensive purposes the HR's were too bouncy, the Eibachs were too slow in turn in, and the Espelirs basically produced a perfect hybrid. They made the front springs linear so as to acheive the quick turn in we so desire, understeer sucks major ballzz when barrelling into a corner. Because the majority of the weight is in the front of the vehicle there is no "bounciness" by use of a linear spring. However because there is not much weight in the rear, when running a linear spring rate there you will yield some bounce. Espelir used a progressive spring rate in the rear to alleviate this problem.
Therefore we got much better turn in without losing any ride quality. The lowering yielded the same as the eibachs even tho the specs show to be different. Eibach is kinda funny with our car.
We have since stopped carrying the HR and Eibach setup for stocking due to the great balance we found with the Espelirs. We do have Espelirs in stock and can also mate them with struts if you so desire. Throw in some camber/caster plates and OMG it's the perfect daily driver, weekend warrior.
I was not aware that Eibach produced a sportline kit for our vehicles. If they had i'm sure it would still be progressive on all fours, i could be wrong. I have never heard of this application for our cars.
If you're interested and want to decide quickly please send me an email and i will give you the price. That should make it easier.
sales@autornd.com
I am flying back to cali tomorrow, as we were in Atlantic City for the SEMA/IAS booth. We are importing a new wheel line from Japan that we debut'd here and looks like the market has taken very well to it. I will be showing the P community some new dope stuff we have been asked to bring to North America. Anyways i'm rambling cause it's late and am glad to return home. Atlantic City is soooo ghetttoooo. Can't walk around alone, scared i might get mugged by some drug dealer or prostitute. lolz....
Well talk to you soon and hope this slightly more detailed explanation helps you to understand the differences. In case you came down we were at the AME booth 1535 right in front of Mazdaspeed as usual. We had a S2K all Mugen'd and a VIP GS430 supercharged, Dumped to the ground. Both running Endless Brakes and Zeal coils of course. hehe.
I will post pics when i get them.
Thanks, Rishie