S2k@9K

iTrader: (3)

Hello, I recently put on a set of new Koni Yellows and GC sleeves on to my 99' SI.

The ground control specs are as follows:

F- 7" length - 2.5" ID - 450 lbs
R- 6" length - 2.5" ID - 375 lbs

I am using the soft progressive ground control bumpstops, i believe they are 46mm (1.8 inches) in height and stock top hats.

I played around with the height and visually set it where the front had about a finger gap and an inch or so higher in the rear. While inspecting, i noticed the bumpstops were sandwiched in between the top hats and the strut. The rear has about 1/2" before it touches.

I then adjusted the spring up on the sleeve as high as it will allow and while not completely resting on the bumpstop, it touches it.

Questions:

1. Is this normal to be resting on the bumpstop, when the sleeve is adjusted to maximum height? How much space for travel does there need to be between the bumpstop and strut housing?

2. Where the rear height is currently set, i had to preload the spring a couple of turns. To raise the height to match the front will result in alot of pre-loading.

3. Would a longer spring setup like F-8", R-7" help? My thoughts are no, if I'm trying to achieve a lower ride height anyways.

4. Would cutting the bumpstop help? I know it will visually gain more clearance, but my assumption is the softness of the first ring on the bumpstop would compress to the same clearance without much resistance?

I would like to lower it back down to the original set height. 1 finger gap in the front, 1.5-2 in the rear-ish.

But, before I get extended top hats or lower the strut into the fork. Does riding on bumpstops at max height sound right?

I would also like to mention that I replaced a stock strut, weapon-r sleeve setup with this and went from 17" oversized to 15" wheels, so I don't really know how much lower I am than a stock setup. I didn't really have a good base to start from.

I've had this same setup on my S2000 and don't remember running into this issue. I would appreciate some input on the matter.

Thanks, Matthew

B serious

iTrader: (1)

Cutting the bumstops is needed.

OTS yellows can "handle" about 400-500LB springs up front and up to about 350 in back.

With those rates, you really cannot lower the car more than like 1.38" from stock. You can get extended hats. But then the new bumpstop is your UCA to your shock tower.

You would need astronomically high spring rates to ride low with those shocks and stay off the bumpstops.

The bumpstops are meant to be used...and that's why they are progressive. But you're not allowing the springs to really work if the ride height is too low and the bumpstops are always compressed.

The stock suspension uses the bumpstops quite a bit...but they're not being rested on at all times.

Speaking about your S2000: S2000's have this issue in the rear suspension. On S2000's, Koni yellows actually have a little less travel than stock rear shocks, I believe. The stock rear S2000 shocks have external reservoirs to increase travel. You should really really stick as close to stock height as possible on a S2000 with yellows.

B serious

iTrader: (1)

Idk what 1 finger height translates to. Here is my ITR. At this height, I have about 1.5" of total shock travel left. Not shock to bumpstop. Shock to tower bushing. Even with 600LB springs...the car would smash the shock body into the tower bushings on big bumps.





I now have 400/440 and am using cut-down bumpstops. I'm sure they're not in contact at static height, but are used very often on bumps.

My car is lower than it should be....but its not daily driven, and the increased negative camber from the lower height should help at a track more than the reduced travel hurts.

If I was DD'ing it, it would be higher up and have softer springs if I really wanted to use Koni yellows. I (me) would likely opt for a different suspension for street use, though.

S2k@9K

iTrader: (3)

Thanks for your very informative post!

Looking at your ITR, I had it lowered about the same height, maybe a tad higher in the rear. I also appears that I had the same clearance from shock to tower bushing. (before I raised the front back up)

With the front raised back up to the max height the GC's will allow, it still only appears to have only 2" of clearance between the shock to tower bushing. (assuming the bumpstop is 1.8" in height)

How much bumpstop would you suggest to trim? half? That would leave about 1" of bumpstop and 1" of travel before the bumpstop hits the shock. Will that be adequate for most conditions?

This is not my daily. I only drive it a few times a month and looking to auto-x/track a few times a year. While I never go all out on the street. My concern would be hitting the bumpstops too hard/soon and understeering into a tree during spirited back road driving.

Also, Does the rear sound correct? at full droop the front has about 2" before the spring meets the top hat. The rear is loaded a few turns, but when go to raise it and inch or so to match the fronts, there's going to be a good amount of tension on it? I believe I will have to force it with a spanner wrench at this point.

But, yeah I would rather raise the height to a correct setting, before I go the extended hats route etc...and risk punching holes in my strut tower.

and you bring up a valid point about the S2000, I do remember switching to Eibach Pro-Kit and maybe even running on the lower perch on the Koni's. Which would have only been a 1" to 1.5" drop (10 years ago, don't quite recall) I don't think I ever ran an event with the ground controls though, just the pro-kits. That may have been my saving grace!

Thanks, Matthew

B serious

iTrader: (1)

No problem. The springs you're using are very short for their rates. I was using 6" springs in the back at one point...but they were 513LB rates. So it makes sense that you have them maxed out to get to a reasonable height.

I have about 1" or so of bumpstop total, IIRC. I wouldn't worry about bumpstops making you understeer into a tree. These are progressive bumpstops....and ultimately, you're driving the car...not the bumpstops.

The rear of a civic/integra of your vintage does have more travel than the front...and is also much lighter. You're really just fighting for front travel.

S2k@9K

iTrader: (3)

Hey man, I truly do appreciate the replies. It certainly saves me from a lot of time and headaches of trying to figure this out all on my own. I've been reading for hours and like everything else on the internet, there are a thousand opinions on how to do something and everybody thinks that there way is better than the next.

I should have specified longer springs when I ordered these, but, I didn't even think of it to be honest. I was so focused on getting proper rates.

I think I will just trim the bump stops, raise the rear back up to match the front and call it a day! and then if I run into any issues down the road or when it's time to freshen these up, I will upgrade or re-assess the rates/length etc...

You know, you bring up another valid point. While, I have removed the A/C and Powersteering from the motor. I have stripped everything behind the front seats as well. Which could possibly be causing the front to squat down more than normal? Who knows.

Thanks for giving me proper guidance! -Matthew

B serious

iTrader: (1)

No problem at all bud. Good luck with the setup.

FWIW, my springs are 400LB x 8" up front. And 440LB x 7" in back. From what I remember, I'm somewhere in the middle of my thread travel.