Thinking about suspension.

On my EF Civic. The good thing is this is such a proven platform that I could copy any of the proven national championship winning setups and have a very competent autocross car.

The problem is I don't want an autocross car.

I will autocross the car but I will also rallyx the car. And I have speed bumps in our neighborhood that scrape the belly at it's current (topped out) ride height and our roads are in terrible condition.

The car currently has Ground Control coil overs with 2.5" I.D. 7" Eibach springs with rates of 350-F and 250-R. It has no sway bars front or rear. It has blown Tokico Blue dampers in the rear and Cheap eBay dampers in the front.

They feel a little on the stiff side to me. I know that they are way soft compared to typical auto cross set up but it's a really light car, about 2100lbs according to the FSM. The best numbers I could find for stock spring rates are somewhere around 150-180 for the front and 80-90 in the rear. The balance feels pretty good and on gravel it's very easy to rotate. But it's very harsh which I'm sure has more to do with the terrible dampers than the spring rate.

I've seen setups with the same spring rate front and back and also I've seen them with stiffer springs in the back.

I've seen setups that use the small 17mm HF front bar and setups with no front bar.

What I'm thinking is this. Get some 9" 250-F and 200-R springs, run the Sedan 19mm front bar, copy Andy Hollis's diy adjustable rear bar. Or get the Suspension Techniques rear bar.

Street- sways connected softest setting on the rear, ride height at the standard height of 25.3 front and 25.8 rear.

Disconnect the sways for dirt and raise the ride height .5" from standard.

Connect the sways for AutoX, stiffest rear sway setting and lower ride height .5" from standard.

For dampers I'm debating between of the shelf Koni yellows or custom valved Bilsteins. I like the idea of a monotube damper considering I'm planning for rough terrain. With no first hand experience my impressions of the Koni's is that while they are adjustable, they adjust from stiff to stiffer. I really just want a damper that will control the springs well.

Anybody like to second guess my thinking or have any wisdom to impart?

I'm curious about what people say. Seems like on asphalt the big concern is controlling body motion, while on dirt it's allowing the wheels to follow bumpy ground.

Whatever happened with the Koni Frequency Selective Damping stuff? Strikes me as being like a lot of the modern motorcycle dampers, which vary damping on velocity with shim stacks adjusting bypasses. Not sure where else that tech is making its way to auto dampers for sub-Fox/Penske/Ohlins money...

They make that for certain vehicles, unfortunately not this one.

I thought Koni explicitly said not to take yellows Rallycrossing. I'd imagine that applies to their other sport dampers as well. May want to check with the shock manufacturer.

In reply to ProDarwin:

When time comes I will talk to them. It may be that I just have to run a cheap replacement damper and consider them an annual wear item. Although I'd prefer something that's closely matched to the spring rate.

Or I could just sell all the aftermarket stuff and put it all back to stock and just run off the shelf Bilstein B6. Which would remove most of the headaches.

Good dampers will make a huge difference. Keep in mind, as long as you don't go super stiff and have the car bouncing off of everything, being a bit stiffer will be good on dirt. It'll mean you need less suspension travel on the rough stuff (to avoid slamming the bumpstops all the time) and it'll also keep the body from smashing down onto things better.

I'd start with seeing if there's anyway at all to get reasonable geometry over the 5 1/2" of ride height you're talking about adjusting the suspension. Personally, I'd set it up for rally cross and just live with it everywhere else. It should ride pretty decent as a daily driver and be fun, and predictable as an autocrosser even though you're unlikely to set FTOD.

In reply to APEowner:

One inch of ride height adjustment. The car has adjustable uppers in front and back. The only thing I need to check is how much the toe changes.

Wouldn't it be better to set the alignment at street height? If there is weird toe action or bump-steer from being rased, you'd notice it less on dirt. Right?

Nick (Bo) Comstock wrote: In reply to APEowner: One inch of ride height adjustment. The car has adjustable uppers in front and back. The only thing I need to check is how much the toe changes.

Sorry, in my mind the decimal point was in a different place for your rallycross setup.

Koni's, Ground controls, done.

Alignment is the easy part. I'm not too worried about that. Camber goes negative as you lower the car, the adjustable arms will let me easily correct it when running higher. Toe is really the only thing I need to keep an eye on through the ride height changes.

I'm more wondering about spring rates. Currently they are around two times stiffer than stock. If I keep them as they are there are really no off the shelf dampers that will control them with the exception of Koni sports. Which may be too stiff. If I drop the rates per my post they'll still be noticably stiffer than stock but the Bilstein's may have half a chance off the shelf or I can get them re valved.

ProDarwin wrote: I thought Koni explicitly said not to take yellows Rallycrossing.

I better stop doing it, then!

Now, they aren't anywhere near GOOD for it, way too much initial damping, but they're what I got, you know?

One of the most calm, composed, controlled, and FAST Civics that I've seen rallycrossing was using stock Integra Type R springs and shocks.

Knurled wrote:

ProDarwin wrote: I thought Koni explicitly said not to take yellows Rallycrossing.

I better stop doing it, then! Now, they aren't anywhere near GOOD for it, way too much initial damping, but they're what I got, you know? One of the most calm, composed, controlled, and FAST Civics that I've seen rallycrossing was using stock Integra Type R springs and shocks.

If that's the case then I was on the right track with my 250-F and 200-R rates. My research says the type-R stock rates are 246 linear front and 160-246 progressive rear. I guess I need to call Bilstein to see what they can do for me.

My gut feeling says underdamping is better than overdamping. If you're overdamped, the tires stutter over the ground and you got no grip, no grip means no control, control is paramount.

Meanwhile, a friend and I embarrassed Stock AWD in an nonturbo Impreza wagon that had seemingly no oil in the rear shocks at all. But the tires stayed glued to the ground, which is the important thing.

If you go to YouTube, look up "nization" channel, find the videos labeled "OVR SCCA RallyCross 2007 Impreza 2.5i Wagon", posted in late July 2014, that's Miles and I driving his car.

https://www.youtube.com/embed/0-cM1EGcdfs

He posted every dang video, both with him driving and me driving and him riding along. In at least one of the videos the back end was bouncing so hard with him driving that I was involuntarily burping from the abdominal compressions. It was a riot. Then he annihilated his mirror by sliding into a finish cone.

Damping just turns speed into heat, therefore slows you down

I'm waiting to hear back from Ground Control about their recommendations for Bilstein dampers. On the website if you place an order they ask you which dampers you are running. I'm assuming they match spring rates to dampers as they have most of the brands and models listed that fit the car. I'm also wondering if the Bilstein bodies are a different diameter meaning my sleeves wouldn't fit.

I'll agree that slightly under-damped on rebound is better for grip on dirt than over-damped. Being more than a little under-damped on compression is bad though, as it leads to slamming the bumpstops way too often. And that sudden spike in spring rate leads to bad behavior.

If you can't keep it out of the bumpstops (progressive springs can help there), run the most progressive bumpstops you can to avoid a sudden change of behavior when you get deep into your suspension travel.

After some more research I have mostly decided on 225F & 125R 10" springs. I just hope that's enough free length.

Shocks are still up in the air. Budget may dictate something cheaper than Billies.

Thinking about it, what do you have for sway bars on this thing? Especially if the end links are prone to binding towards the ends of the travel range (or if they limit droop significantly), you might be better off with more spring and less bar (or possibly no bar at one or both ends).

As an example, I found a significant increase in predictability (both on and off pavement) and an increase in rear end grip on rough ground when I took the binding-prone rear sway bar out of the Jeep and put stiffer rear springs in to compensate. Overall handling balance stayed about the same (as did body roll) but with better behavior. And surprisingly, it rode better, not worse with the stiffer springs and no bar.

In reply to rslifkin:

Plan is for no sways at rallyx. 225/125 would be around 65℅ stiffer than stock.

19mm front and I'm leaning towards copying and Andy Hollis's diy adjustable rear bar for autocross.

I think I have to sacrifice autocross performance to get a car that will survive on the street and in rallyx. Which I'm completely fine with.

Couple of things- these civics don't like being raised. watch how much you raise it. You still need roll center. No one makes rally style arms for raising these (a damn shame).

The wago-civic of the same gen had longer suspension.

Doubling springs makes lower spring rate. But I also know there isn't a lot of room on this front suspension.

Rotation comes easy enough if the front is compliant and can be compressed under braking (without locking up the tires).

HF transmission for auto cross and rallycross. Only one gear to put it in: 2nd. Run it the whole course after launch and the 1-2 shift.

Get a DA (90-93 Integra) suspension setup. Use the Bilstein HD's and enjoy the benefits of platform sharing. Along with the increased ride height AND proper geometry, the stiffer springs from the Integra will also work wonders out on the stage.

Trackmouse wrote: Doubling springs makes lower spring rate. But I also know there isn't a lot of room on this front suspension.

Are you saying doubling the length?

Here is a shot of how it's currently set up. 7" 350lbs springs with adjusters topped out. This gives me a 24.5" ride height in the front. The FSM says the stock ride height in front should be 25.3".

I'm hoping that 10" 225lbs springs will allow me to set the ride height to the stock 25.3" ride height while having the adjusters in the middle of the sleeve, allowing me to go a half inch up or down depending on dirt or asphalt. So at most I would be running 25.8" and the least would be 24.8"

Those spring rates and Bilsteins are right for what you want to do. You don't want to be too stiff, especially at BCR. Stock height is fine, no reason to go higher. Play with height at those rates for the street and see how it feels. A decent RX car is closer to a decent street car than AX/street.