Rep Power: 424

ok, well whats the equation?
Here's my current deal. The front end of my car is TOO STIFF. This is not me whining about the ride, I'm a big boy, I can handle a little bounce, but it chatters coming hard out of corners... its not supposed to do that. If I lower the spring rates, I'm hoping to transfer some more weight around and get the front to dig in a little more. Currently, I'm at 500 lbs, they're OTS JICs for the EP3, which weighs about 180 lbs more. Its also a 70/30 split vs. mine which is 61/39.... maybe 60/40 with the battery in the trunk. But whatever... There's about an extra 381 lbs over the Si front end. so cutting that in half then accounting for the approximate 2 lbs of car for every 1 lb of spring... so say 425 lbs. Thats an easy number, and eibach sells 8", 2.5" diameter springs on 25 lb increments... hmmm funny coincidence.
Is there a more exacting science? I guess I really don't care, springs are cheap as hell and race people will pick them up used for almost the same price as new.
Just try em?
I kinda want to do it before winter... I fear too stiff in the snow.
Oh yeah.... anyone know how to dissassemble JIC struts? Does the pillowball come off or do I need to take them apart from the bottom?

 
Rep Power: 315

I'd say just try it...but then again, they're JIC's..so if you fubar things during the swap...well...let's just say JIC isn't known for their product backing/customer support.

But about the pillow ball mounts. From what I saw on my BC's...you could probably disassemble them from the top. Give it a shot, and take some pics for a DIY (for those of us with Pillow Ball mounts.)

Wish I could help more.

 
Rep Power: 424

Well, theres not much that can be fubared.... As far as I can tell, they can be taken apart by just spinning the bottom bracket off.... that may be the easiest way to do it rather than trying to take the camber plate apart.
On the other hand... I know how to get Konis into them... so even if I fubar it, I've got a back up plan

 
Rep Power: 381

I think it would be a start... My understanding of suspension tuning is that you start with springs and shocks. Shocks to compliment the springs. Springs to give you as close to the handling balance as they can get, then you fine tune it with antiroll bars.


BTW, what front anti-roll bar are you running??

 
Rep Power: 424

The stock 02 one.

 
Rep Power: 381

may be an Idea to Try the OEM 03.

 
Rep Power: 424

^^^ its up for consideration

 
Rep Power: 381

I was just thinking... does it skip through the corners? if it does it may be that you have your dampers set too stiff.

 
Rep Power: 424

Not through them, it'll go right on through without much problem, its exiting them... once you hit the gas, all bets are off. Its fine going through... and I usually run the dampers in the front near full soft. Its not over- or understeering, just generally displeased with doing it. Excessively stiff springs or bad front/back balance of rates seem to be the consensus agreement, but since I'm happy with they way the *** moves, I'm leaving it alone.

 
Rep Power: 381

Well, Just be aware, if you drop the size of the antiroll bar or the spring rate, on the nose the *** end is going to want to come around more... so you may have to adjust your rear Spring rate/antiroll bar, as well as tire preasures, alignment ect ect ect..... Dam it, why cant tuning be easy?

 
Rep Power: 424

Because if it was easy, everyone would be good. I'm gonna talk to a couple of shop guys around the country who do this stuff and get paid for it first... I want to see what they say and if they know what kind of spring rates RSXs and EP3s are racing on.

 
Rep Power: 0

Why not look at the spring rates other suspension companies are using? Both KW and Progress are using 350lb front springs.

 
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For a front corner weight of maybe 780 (includes driver) your 500 spring roughs out to 130 cycles per minute. IIRC, road cars are 60-80, firm/sports cars 80-100, and non-aero race cars 100-175, gravel rally cars can be all the way down to 70-ish. It takes a big spring rate change to get much change in the frequency, a 425 gives 122CPM, 300 is roughly 106CPM. There's not much spring data for the 7gens but I found a bunch of rates for the WRX, for example the DMS rally suspension is approx 92CPM, DMS tarmac 132CPM, STI tarmac/autocross (a factory spring I think) 91. Granted, the WRX is a taller, longer travel beast, but at least it's something to compare with.

 
Rep Power: 315

Yes...I'd like to know.

 
Rep Power: 424

New springs are getting ordered monday. I re-affirmed my stance on this today... I had absolutely no corner exit traction. 375s are on the way... hopefully I can pop them in within the next few weeks.

 
Rep Power: 0

if you realy want to get deep into it there is a computer software or about five pages of math to figure out the ideal spring rate to start with. but you would still have to tune from there.