Hi guys I'd like to get some input from some folks who know this chassis well and understand how to set it up.

I currently have a 1997 civic DX coupe that I attend track days with.

It is fully gutted with only 2 race seats in the front
SI front brakes ans master
DX rear drums
PIC Select r3 full coilovers F 12K R 14K
4 clicks front 1 click rear for stiffness
15X6.5 wheels with Yoko A032-R rubber 205/50R15
tire pressures around 40 front 36 rear when hot
S2 rear LCAs

The RTA bushings and all other bushings are stock and have at least 260 000kms on them

Camber is 2.5 front with a s2 pro kit
rear is stock from lowering at 1.8 negative
toe and caster are stock.

Car is lowered about 2.5 inches all around

I previously raced the car a full season with this setup and no front or rear bars and found that at the limit the car would snap oversteer and be very hard to catch. I tried playing with lower pressures in the back and lowering stiffness in the coilovers but it made close to no difference.

I then tried a front EX sway bars with ex LCAs and that also did not help the car understeer a bit more.

I would rather the car understeer a bit more at the limit since it's quite scary when it breaks away and crazy in the rain at the moment.

Also to rule this out it's not a throttle input problem or me braking mid curve the car just snaps when it hits dips or it finally loses grip but the limit is not communicated well so it's hard to feel.


Could it be possible that RTA bushings being dry and cracked is causing this issue? Do I have too much spring in the back, should I look at making camber or toe changes?
Could the older tires just be causing this since A032-Rs have been out for a long time?

It reacts the same when the tires are cold and hot and even brand new the tires reacted this way.

 

I would start with swapping the front and rear springs since it is free and should deff help with the oversteer issue.

 

agree on swapping the rates and make sure you have toe in out back. you may experiment with varying levels of front toe out

 

Do you guys think the coils will work as well with a spring swap?

I was actually thinking of doing that for next year anyway but am worried the damping will not match the spring properly anymore.

 

What is the range of damping adjustment on the shocks?

If you feel it is properly damped now, move the softer springs to the rear and stiffer to the front, and have more damping available on the rear shocks and less available on the front (meaning, they aren't maxed out now), why wouldn't you be able to adjust them to correct for the swapped springs?

 

Not sure I understand the question, if we are talking about height, I can still go either up or down without a problem and never ever hit the bumpstops at the current height.

The damping is adequate right now but I am not sure if the coilovers are a once size fits all for let's say springs between 6k and 14k or if they are valved based on the specific spring installed. It is stiffely sprung right now so it's harder to tell if it's properly dampened like a softer setup.

I guess I can adjust the height as needed to compensate for the springs and they are 8 way adjustable so I can play with that too.

It just feels weird that others run stiffer springs and still look for massive bars in the back where as I feel like if I add anything back there it will make the car completely uncontrollable.

That is why I was asking about RTA bushings possibly causing this as they fail?

 

If your RTA bushings are bad enough, that's probably the root of your problem. They could be moving around enough to make some really significant alignment changes under load, and this could certainly cause the behaviour you're experiencing. Change those puppies out for new ones. The dealer sells them as a seperate part now, and they're believed to be the exact same part as the Mugen ones that are sold as harder pieces.

And whoever suggested that you run toe out in the back needs their pee-pee whacked. That would make your issue worse. If your car was understeering more than you liked, then a little toe out in the back (1/16 to 1/8" total at the most) would amke things a little more lively. It most certainly would not calm down a tail happy car.

And I believe that your shocks most assuredly could handle a 2k (about 110 lbs) difference in spring rates.

 

There seems to be some basic misunderstanding here.

Adjusting shock damping has nothing to do with ride height. You'll probably want to adjust ride height if you swap springs, but only because going stiffer up front will allow you to lower the car more without bottoming out.

"8 way adjustable" is, um, not exactly the correct way to refer to shock adjustment. You have a single adjustment (either bump, rebound, or both together, depending on the shock) that can be set to 8 different positions.

The shock damping is what you adjust to compensate for changes in spring rate. Depending on what the shock actually adjusts, and how large of a range of adjustment is there, will determine what spring rates the shocks can still adequately control.

Experience, driver preference, and traction, all play a role in determining what front / rear balance is best for you.

Failing RTA bushings will cause all kinds of handling issues. Toe can change quite a bit if that bushing allows the trailing arm to move longitudinally, for example.

 

no one in this thread has suggest rear toe out

where did you come up with that?

i mentioned toe in for the rear and out up front but that would help his situation

 

I plan on replacing the RTA bushings first and doing some quick testing without changing the spring rates first. Do you guys recommend something like PCI rear spherical bearings or something softer such as the PIC, Hardrace or even the Mugens?

Once the change is made, if it still rotates too much for comfort I will swap out the springs.

Does that sound like a good way of going at it?

 

If the car ever sees rain, snow, or other inclement weather, those PCI sphericals will wear out fairly quickly. If it is track only, then that would be a good option. Otherwise I would go for PIC or HardRace RTA bushings. They appear to have more rubber in them than the OEM/Mugen pieces.

Also, 14 kg/mm wow, that's pushing 800 lb/in and definitely isn't helping the oversteer situation if the RTA bushings are the root cause.