I'm assembling a coilover on my Civic EG and I have a couple of questions regarding shock body length and spring lengths. I'll be running revalved Showa shocks with 2.5" ID and 8" coilover springs front and 7" rear. This seems to be the same dimensions as the Ground Control springs used with the Koni Yellows and Tokico Illuminas Are Koni Yellows or Illuminas shorter than an OEM shock? If so, by how much? I could only find information about the Koni Race, which indeed are shorter. I'm assuming there is no problem in running a 8" spring at the rear so I can swap the spring rates if needed to get a different setup at the track.

 

no.

theres a trick you can do by removing the brake line bracket by cutting the weld off, and dropping it into the fork more.

you get this for free with off the shelf koni yellows by simply not reusing the brake line bracket since they dont provide one for you.

depends on how low you want to go, 8" may be too long in the rear.

 

Thank you! So, there's no need to worry about cutting the shock body to get more travel when using proper springs? I'll be using 350/300lb or maybe 300/300lb springs and I don't plan to go lower than a 1.5" drop. A guy from a shop told me that I need to make the shock body smaller to prevent bottoming out, but I really don't think that's needed on our Hondas.

 

you can always use more shock travel.

keep your bump stops.

see how it travels with it in the air.

 

Will do! Do you think it is a must though? I plan to assemble it with the OEM shocks and run it for a short while before getting the shocks revalved/rebuilt. Seeing that the Illuminas and Yellows are OEM sized and people use this setup a lot with 8"/7" springs, I don't think it will be a problem, will it?

 

Length of the spring doesn't determine shock travel directly.

Ride height does.

With a 1.5" drop, and virtually ANY streetable or reasonable spring rate, you would still engage the cut bumpstops every single time you drove the car. If you didn't cut the bumpstop, you would be riding on it 100% of the time.

Its a small car...so there's not miles of shock travel...and the bumpstops are part of the rate.

A 1.5" drop is fairly agressive for your desired rates. But with yellows, it will probably work anyway.

Like Tyson said...just measure what travel you have.

But...its better to bumpstop at the shock than it is to hit the UCA into the shock tower. So don't go nuts with adding shock travel.

 

Thank you for the response. I don't mind having the car sit higher if it means a better working suspension. I've seen that something like S-Tech lowering springs provide a 1.8/1.7" drop with very mild rates (213F/140R) on OEM shocks. With 350F/300R I figured I could get decent travel and would not bottom out at 1.5". I'm assembling a "custom" coilover setup because it's easier to get and more reasonable financially than importing any off the shelf setup due to where I live. So, I'm trying to understand all of this so I can get the best of my car and avoid any "suspension tuner shop" mistakes/workarounds which are common here.

 

The suspension is designed to use the bumpstops a lot.

A stock ITR uses the bumpstops almost 100% of the time, for example.

A 1.5" drop should probably be accompanied by like 450-600LB rates and cut in half bumpstops. But each civic model starts out a different height because their weights vary...so...

Just lower it how you want. Drive it, measure travel, and maybe cut the bumpstop a small amount.

With soft springs like the ones you want...DON'T add shock travel with extended hats, short bodies, etc. Bumpstops are better than UCA hitting shock tower. You can gain some travel by trimming the bumpstop. But when you engage the bumpstop, it will be more harsh than a non-cut one.

The car came at a certain height for a reason. The suspension doesn't have a lot of travel. Youre lowering/modifying it...so just make the best of your setup.

You'll be fine. Don't over think this. Get the parts and a measuring tape first.

Make a post second.

Also...

Tein S techs aren't really performance parts. And almost any lowering spring for any Honda uses the same philosophy; soft, low spring that uses the bumpstop as a helper.

 

For reference, here is what I measured...

A 1.5" drop on an Integra leaves you with ~1.5" of TOTAL front shock shaft travel on unmodified length shocks.

Meaning if you cut your bumpstop so that it is 1" long, you will have 0.5" of shock shaft travel before touching the bumpstop.

Civics start out higher. So yours will be different. Just measure.

Rear shocks have quite a bit of travel...so I wouldn't worry that much there.

 

Thank you, I'll get the parts and get to work on it. I'm also helping a friend dial his suspension, we ran on some spare unknown springs (99% certain that is actually the OEM ones cut something like 3 coils) and coilover sleeves so we could do some testing. The car would hit the bumpstops on almost any elevation change even at minimal to low speeds, and it was a harsh bang, it felt like the car would break apart. My take on it is that the spring rate was too low for the ride height and it would engage the bumpstop abruptly. The bumpstop was trimmed to get more travel, but it didn't help in that specific case. I just don't want that to ever happen with my new setup.