sjdsir

I did some searching and couldn't find a definitive answer. I have a 2000 Civic Si and purchased a recently rebuilt (Truechoice) set of Koni Sports with race valving and was wondering what rates to run. Is there a minimum rate? I have a set of Sportlines on right now and as you can imagine its terrible so I need a set of Ground Controls.

I'm looking to set the car up for occasional STS autocross (don't care about being competitive) since my son will be autocrossing this car in a couple years when he turns 16. Street manners aren't important. I'm new to Civic suspension set-ups as my autocross and track experience is with an STR prepped 2010 MX-5. Thanks!

Xian

The standard "race" or SPSS valving typically has enough rebound control up to ~1000-1100# spring rates on club race cars. I don't know anyone who autocrosses with those sorts of rates so you should be fine with them. There's no minimum rate for them either... you just have additional rebound control and a higher baseline, soft setting.

GC sleeves with Koni's are certainly the easy button... what spring rates/bars are you planning to run?

sjdsir

Spring rates are what I'm trying to figure out. I asked about minimum rates because as I said it sucks right now with the Eibach Sportlines and they are 310/275 I think?

My STR MX-5 has 12K/7K springs on it and my wife and I daily it during the summer so I'm not afraid of higher rates. I just don't know where to start on a FWD car.

Currently I have the stock 26mm bar up front and a 14mm GSR rear bar that I had laying around. I'd like to run the ASR 24mm rear bar. I wasn't planning on changing the front bar.

Xian

The issue with most "lowering" springs like the sportlines is that the rates aren't nearly high enough for the ride height. The result is that you end up on the bumpstops an awful lot and the ride/handling suck. Similar to your MX5, the Honda's have a pretty decent DW setup front/rear so with the motion ratios around 0.65-0.7 (IIRC) the wheel rates end up pretty low for a given spring rate. For instance, your 310# rate is probably more in the ~140# rate at the wheel... silly low given the ride height and shock travel.

Shock choice will play a huge role in how livable it is at given spring rate/ride height. The Koni's are great for the $$ but I've found that their street manners aren't nearly as good as the higher end remote monotubes (Moton/MCS in particular). Granted, for the $$, you wouldn't expect them to be as good so probably no real surprise there.

As far as what rates to run, I can tell you where I landed with my last STX ITR. This may help you as the suspension design/wheelbase/track/etc is very close between the cars. I was at:

650F/550R
25mm Front/25mm Rear
4* front camber/ 1* rear
1/16" toe out front/ zero toe rear
~4" to the jack tabs, zero rake

I'd planned to increase the front spring rate to 750, drop the front bar to 24mm, and add a tender spring setup to the front. This was all in an effort to help the stock Torsen style diff do a little better from corner apex out. Given that your car has an open diff, I'd highly consider going a soft as you can on the front bar. IIRC, there are softer bar options down to maybe 21-22mm? I'd also highly recommend checking into tender springs for the front in an effort to get as much grip on that inside front as possible and thereby reduce wheelspin. Oh, also spend a little time to make sure that whatever bumpstop you choose to cut to the right length. Since you'll be pretty low, you want all the travel possible without the front UCA pounding the chassis too often. Your shocks are shortened already, right?

FWIW, there are a ton of ways to get the car balanced how you want it. Rear toe out, high rear rates, massive rear sway bars, etc. All of these end up with more or less the same balance but how they handle transitional elements as well as uneven/bumpy surfaces is wildly different. I've found (for me, my driving style, my car, etc) that keeping the rear rates fairly sane, the front rates slightly higher than the rears, and the bars "not huge" makes for a more drive-able car. Tossing away rear camber and playing with shock gets me the balance that I'm looking for.

Christian

sjdsir

Thank you for the advice! As I mentioned I don't really care about the ride quality on this car so the Koni/Ground Controls set-up offer the bang for the buck set-up I need. Unfortunately the shocks aren't shortened though and I was planning on purchasing a pair of the Ground Control upper shock mounts in the front. I was also hoping to not run the car so low.

Xian

I'm surprised that they haven't been shortened. Most (but not all) of the time they're shortened at the same time they're revalved. The GC upper hats will get you the travel that you need though. You can also get a little more travel by "sliding" the shock body further into the lower shock fork. Look around online and you'll see some posts/threads on how to DIY that if you need it.

Best of luck with the new car!

Christian

sjdsir

Thanks. I have read about the shock trick in the front.

Oh its not new. I've owned it for a few years and have put 137K (km) on it since I bought it from the original owner with 123K.

scook179351

Some Civic's have hallow front sway bars. The HF EF9 has one but it will probably not fit on your 2000. Some people use no front sway bar at all.
Like Xian said, the springs rates at 650F/550R would probably work well on the civic. I run in SMF class and my camber settings are -3° front and rear. Toe in/out, F/R are about the same.
Top hats are needed for the front shocks but not so much for the rear.
You should go to RedShift Motorsports website. Chris has autocrossed civic's for a long time and can help with shocks and spring rates. Look in the tech page.
RedShift Motorsports Home Page

CW-ITR

iTrader: (11)

Like others already mentioned above, the "650F/550R would probably work well on the civic". Once you and your son find the limit with it and get use to the FWD behavior of the Civic (more under steer), I think you will want to redo your suspension set up to generate more rotation (more over steer).

Xian

My $0.02:

No front bar feels like a bag of smashed ******** without a metric ton of low speed compression up front. Since you're not going to have that with the Koni's, I'd highly suggest not planning on that as your "go to" setup. Try it out for sure but it's horrible in transitions. If you want to make it work, budget for a nice set of custom monotubes IMO.

To my knowledge there are no hollow front bars for the later EG/EK/DC chassis. The HF CRX mentioned earlier had one but it doesn't work on the later chassis.

Don't be too quick to jump onto the "high rear rates" bandwagon for an autoX car. It makes the rear end more skittish over uneven pavement than you may want. If you were doing a dedicated club racing car, I'd suggest substantially higher rear rates but they're just not needed for autoX. You can get the balance you want/need via rear bar and rear camber.