I'm in the middle of my 97 civic ex coupe build and have been debating about springs

Car will have a built ls/VTEC based around a gI30r, aiming for 450hp.

Let me preface this by saying a stiff, harsh ride doesn't bother me. I have an s13 that I drift that rides like a steel pole and I daily drove it until I decided to build it further, plus we have a 600hp z06 that does mostly road courses and its sprung very aggressively. I actually enjoy it.

Now the civic is a daily driver foremost, I also do a lot of aggressive mountain runs and will be doing a lot of track days at Atlanta Motorsports Park (due to my dads membership level) nothing wheel ton wheel, just enjoyable aggressive lapping.

Now I bought the car with ground controls already on it (stock shocks though) and am baffled by the rates currently on the car

Front
0800.250.400
8" tall, 2.5" inner diameter, 400lb/in

Rear
0700.250.0300
7" tall, 2.5id, 300lb/in

Spares
CC200.64.58
7.87" tall (8), 2.5id, 325lb/in

The spares are from a previous build. What throws me is the 400/300 combo currently on the car, i would imagine i would want a slightly stiffer rear to compliment the stiff fronts. I think I know why the rears are 7" units, the car is "stanced" so i think/he needed a shorter spring to get the *** end down where it blongs (say what you want but I like it and I'm out to dispell the myth that stanced cars can't be fast)

Now i enjoyed the ride quality, it even felt a little soft compared to what I'm used to.. I would like to get a set of custom valved koni yellows but only because I can't find a decent coil over I like at a price point that won't rape the wallet

Now as for changing spring rates, I used to work at a motorcycle suspension shop where we CNCd everything in house and used primarily Hyperco springs. We were one of the largest stocking and selling dealers for hyperco so we have a massive inventory or can have springs custom made with a phone call

So I can go to the shop and pick out any spring I want at coat basically, so money doesn't matter, plus I can sell the current springs,

I guess my question is this, what spring rates would you recommend? Keeping in mind harsh ride quality is of no issue. Also what should I do about the koni yellows, clearly with high spring rates, the "shelf unit" valving and oil might not be effective.

The car will also be receiving sway bars front and rear, as well as some sort of rear brace like asr, beaks, etc. It will also be getting new bushings, high durometer poly and heim joints/spherical where reasonably applicable.


Now on a little tangent here, where I worked we did a lot of the shocks for penske, including machining most of their components, so i got a set of custom units for basically nothinf



The nice part about these is they are double adjustable (compression/rebound) and each circuit is completely independent of one another so adjusting one will no affect the other. Also since I know how to tear these down, I can go down to the shop, dyno them and then adjust the shim stack/fluid weight/nitrogen pressure, until I reach a combination thats acceptable.

Now these would have to be cantilevered/inboard mounted but that isn't an issue, not at least from a fabrication standpoint, its getting geometry correct and the rocker ratio right. Mounting the rear shocks would be super simple, the fronts would take some serious ingenuity, though still doable

Again, this is if I can't find an acceptable spring/shock combo... although it would be nice to service/revalve my coil overs as I saw fit, as well as experiment. My biggest issue with most of the coil covers today is they won't (or don't know) how the shim stack is arranged, stack height, fluid weight, nitrogen pressure, etc. As well as most don't supply a dyno showing how each setting affects dampener performance.

Opinions/advice? I'm not sure which direction to go at this point, nor can I determine an appropriate spring rate for the car.

Thanks

 

On another note, and something I just thought of, I can take a stock front and rear shock/strut assembly and we can machine adapter sleeves and such to fit my penskes in the stock location and at the correct height.. as my units are modular. I can replace the bottom mount with a threaded sleeve to adapt to the shock (while still having access to adjust) and we can replace the upper mount (heim joint at the moment) to something else to accommodate the upper mounting points, or I can machine a piece that bolts like factory to the strut tower and then bolt the existing upper to that