Picking spring rates

[Coletrane]

I'm trying to decide what spring rates I should get for the swifts.
Most coilovers for the EP3/RSX have less stiff springs in the front. I cannot figure out why since the weight ratio is 61/39 and total weight is around 2700lbs, not to mention the power is all going to the front.
My instincts say:
F: Current: 10k 160mm --> 16k 120mm
R: Current: 12k 140mm--> 14k 120mm
The only reason I can work out that a less stiff spring in the front would be so the tires conform to uneven road surfaces better, is this true?

[Thins]

In for an answer as well, as i still don't understand why softer front springs is standard practice.

I'm no expert but FWD cars still "squat" in the rear under acceleration, so a stiffer rear spring makes sense to me with that in mind, more-so on a drag car but maybe a street car as well? :shrug:


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[Oh Damn, it's Sam]

What are the motion ratios of the front and the rear? Oftentimes you'll see stiff springs in the rear on cars that have low rear motion ratios compared to the front, since the mechanical advantage of the motion of the wheel against the resistance of the spring changes with the motion ratio. The E9X chassis is a good example of this.

[KyleAnderson]

As usual, Sam beat me to the answer. I was just going to look up the motion ratio on your car, but this link also gives a very good explanation and recommendations specific to your platform:

http://forums.clubep3.com/showthread.php?t=565676

[Coletrane]

I had come across some motion ratio talk and that cleared it up. Idk how I didnt find the clubep3 post. Thank you so much! BTW Stancenation sells 326 power swift springs that are 100mm, or 120mm, which is shorter than the regular swifts, and thats what I think imma go with.

[Jesus Christ]

I had come across some motion ratio talk and that cleared it up. Idk how I didnt find the clubep3 post. Thank you so much! BTW Stancenation sells 326 power swift springs that are 100mm, or 120mm, which is shorter than the regular swifts, and thats what I think imma go with.

Broadway static has 100mm springs in stock and half the price. You also do not need 4" springs for an ep3 civic, a regular 120mm swift is more than enough.

[Coletrane]

Well damn, already ordered the swifts got the 120mm ones since the 100mm are only 20k and up Heres all the way down on 140mm springs compared to stock
#DestroyedFenderGang

[Jesus Christ]

Well damn, already ordered the swifts got the 120mm ones since the 100mm are only 20k and up Heres all the way down on 140mm springs compared to stock
#DestroyedFenderGang

No worries, a swift spring is a swift spring. We carry a full line of 4" springs from 8k up to 68k because they are popular in the rear of older 3 series BMWs.

I usually use 120mm to get ep3s low, so you should be good if your shocks are short enough. Your new springs will definitely help with the rubbing, and the ep3 takes higher spring rates well.

[Coletrane]

Yeah I got 16k and I'm running the 12k 140mm Megan springs up front. Racelands slam, but damn, car drops an inch if i put a paperweight in the back haha. Do you know if the revised Fortune 500 coils have reverse mount tie rod ends?

[Jesus Christ]

Yeah I got 16k and I'm running the 12k 140mm Megan springs up front. Racelands slam, but damn, car drops an inch if i put a paperweight in the back haha. Do you know if the revised Fortune 500 coils have reverse mount tie rod ends?

Yep, they are revised.