A year or two ago I purchased a used set of GC coils from a member on here, and I've been rocking them since. Only problem is the shocks, KYB AGX, are pretty crappy and old and the ride is a little mushier than I'd like. I've already purchased Koni Yellows to replace em and I'm waiting on new tubes and nuts from GC to do the swap.

My question is how much of a difference am I gonna notice after swapping to the Konis? My worry is that the springs themselves are really soft, but given the age of the KYBs I'm really hoping that's not the case. I'm looking for a stiff ride so I can go a little lower because right now my tires rub the chassis during hard cornering and braking.

How likely is it that even with stiff springs, blown shocks could make the car roll a lot and dive under braking?

 

A big difference. Koni are so much stronger then KYB agx.

Also if those rates dont suit ur tastes you can buy them from ground control for 55 each..

 

Um. Correct me if I'm wrong but don't the Konis require a specific GC sleeve specifically made to fit them?

 

You're correct, GC sells a conversion kit for $108 that includes new sleeves (or tubes) and adjustment rings (or nuts)

I ordered them a week and a half ago, and they have been terrible with communication. They told me that the last batch they got from the machinist was wrong and I have to wait a few weeks to get mine. However when I email them they never respond. Kinda pissing me off to be honest.

 

Then you're covered as far as that goes. Do you know what spring rates you have now?

 

I don't as I got the coils used. I wonder if I can grab the numbers off the springs I could find out?

 

Post 'em up.

 

Fronts read 48/99 - GC200.64.58

Rears read 32/99 - GC180.64.44

 

I found this.
Numbers on eibach springs
ground control
48/99 front - gc200.64.58
39/99 rear - gc180.64.44

From another thread this looks like the spring rates for those
Front Springs read:GC200.64.58 is a 330 lbs/in
Rear Springs read:GC180.64.44 is a 250 lbs/in

So maybe you want to go up to maybe 450 front and 350 rear.

 

Thanks, did a search on GC's site for those part numbers and came up with 340 for front, but either way it's a little bit on the soft side. I guess I'll look into getting new springs as well.

Hopefully it's $59 a pair and not each, already spent a lot in the past month haha.

 

At this point I might as well just buy a whole new GC kit, I can order them with the spring rates I want and maybe I won't have to wait weeks with no word from GC on conversion sleeves. :/

 

Go 400 front and 300 or 350 rear.

 

each.

 

I was browsing through the spring rates thread and I think I'm gonna go 450 front and 350-380 rear...I daily drive the car but a lot of people were saying even 450 felt a little on the soft side and was too soft for autocross or track work.

My commute is mostly highway so a higher spring rate won't bother me at all. Of course all that is subjective, but personally the stiffer the better imho

 

I currently use 350/350 on my progress setup, and until I got my front swaybar I really thought the front should have been 450.

 

Hmm...I'm running a GSR rear sway and front EX sway bar on my EJ8...this is a tough decision. The 340/250 on my car now feel terrible.

 

Rear rates attribute a lot more to ride comfort than front rates.

When I go AMR for next years AutoX season I'll be running 550/450 with a 24mm rear sway. 22mm front will likely stay.

 

Do you think anything above 500 front will be okay for daily driving? Talking about this stuff over the internet is kinda pointless since this all is personal preference. How frustrating.

The last thing I want is to spend another 250 on springs and have them still be too soft for my liking.

 

350 front I can tell you is still soft. I don't think you'll notice a stiff front as much as you'll notice a stiff rear.

I and several others will tell you that the rear will make up for much of the ride discomfort with stiff suspension.

Remember, the engine/trans/etc are all weighing down the front. Our cars are very front heavy and it thereby necessitates higher rates to get the similar effect from the rear since you're working against gravity by a greater degree thanks to the extra weight.

If my front springs were 100-150lbs stiffer than my current 350 I'm not sure I'd notice a difference in driving comfort. Mostly just the tendency to have too much travel in the front when pulling out of a driveway or something and my oil pan/linkage hitting the curb/pavement. Stiffer front springs would alleviate that.

 

The 450F 350R is not a bad setup. It's a good "middle of the road" setup, and you wont give up that much ride quality.
You will deffinetly feel the increase in spring rates, but, a 350lb spring is still quite soft.

I run 650F 350R and my car rides like complete ****, most of this can be blamed on my shocks, but, none the less it's quite rough/harsh.

I am pretty sure once you get to a certain point in spring rates in the front end, you'll notice the difference. Were the line is, I don't know. The rear does have much more of an affect though.

I am either going to go 450/350 or 550/450/500, still toying with this. But, I am leaning heavily on the 450/350 rates.

 

My main concern is the front tires rubbing the chassis under hard braking and mid-corner dips. So if I have to go 450-500+ in the front to alleviate that I will do so without hesitation. From what I'm reading if I stick with under 400 rear I will retain some sort of ride comfort for daily driving. Thanks for all the help.

 

How low are you looking to go?

 

Yes, at 350 with no tire gap in the front my car does scrub/scrape with the suspension travel on dips/etc.

450-500 would definitely alleviate that to a degree.

350/400 will be tolerable for daily driving. Mine is fine at 350, but again tolerance is subjective. Generally consensus agrees that 350 is in the middle for street driving. I doubt 400lbs would feel much different, but it would still promote turn in if you're looking for that for autocross.

A beefy rear swaybar always fixes that right up

 

This is how the car sits now, I'd like to go slightly lower maybe .25" rear and .5" front. I will decide once I get the konis in, I just want a slight rake, right now the side skirts are parallel to the ground.

 

So just enough to close up the wheel gap?


I would deffinetly reccomend 450/500F