TomCat39

Hi All,

When it comes to the spring rates I have the utmost basic understanding. Basically, I understand the concepts, lbs per inch and progressive and linear. But that pretty much covers it.

Also when trying to research what the stock spring rates are for the 5th gen anything, let alone hatchback, I came up empty time and time again. Seems the 6th gen is a little better documented. I did find speculation that the stock springs are progressive with 180 lbs per inch in front and 100 lbs per inch in the rear.

When I hit up Ground Control's website and looking at the Honda Tech special for my car I have 3 options for the front and 3 for the back as far as rates go.

340/380/430 lbs/in front and 250/350/430 lbs/in rear.

I also am aware that the weight balance of the car seriously favors the front with the engine and all. The back is really light in comparison.

Can anyone clue me in what the different combinations of the 3 options of each above will do for the cars handling? As far as I know, the car supposedly under-steers with the stock suspension. I also do not plan on dropping the car to the ground. The most I would like is to have just a smidgeon of gap between the tire and fender on visual appearance. I'm pretty much stock wheels currently and will be for quite some time if that makes any difference.

Currently it allegedly has a 1.8:1 ratio front to back with stock springs and shocks. Can someone educate me on what changing the spring rate ratios on the 5th gen hatchback will do?

B serious

iTrader: (1)

If the stock rates are 180F and 100R, then, yes...mathematically, you have a 1.8:1 ratio, front rate:rear rate.

The car will understeer like crazy from the factory. The more you bias the springs to the rear, the more the car will move to neutrality...and if you keep increasing the bias... it will transition into a tendency for oversteer.

The point where you hit neutral handling and/or oversteer is dependent on a million other things. Swaybar size, alignment, tires, wheels, driving style, LSD/open diff, type of LSD....etc etc etc etc.

The more you change your "spring ratio" to the rear, the car will generally be less comfortable.

For off the shelf Koni yellows to work well for a street car and offer comfort...you'll need to stick with mild spring rates and keep the car at a higher height.

Drop it about 1.5" max and use something like 300/200 or 350/250. It will understeer, but for the street....understeer is fine. If you're not tracking it, it won't matter. The car will ride well, and handle better/sharper than it did from the factory.

If you do plan to track it, you'll need to take penalty in how the car rides in order to achieve a more balanced setup by starting to stiffen up the rear springs unproportionally to the front.

Koni/GC setups don't transition from street to track nearly as well as people say on the internet. "I have 400/600 rates and my car rides great". Yeah right. Maybe if a mollusk were to drive it.

Tyson

ignore all that about ratios.

in terms of comfort, the more you increase the rear rates the car will feel more stiff. it ends up having little to do with the spring rate up front since its much closer to the center of gravity. so therefore front to rear spring rates have little to do with each other so a ratio is not a consistent factor to judge anything.

start with the standard 350/280 rates. go from there.

B serious

iTrader: (1)

I think that the ratio of front and rear bias does matter.

A 400/350 is more comfortable than a 300/350, for example. The more rear bias, the more you're going to feel it.

The rear spring has the most effect on ride either way.

OTS rates ride OK. Rear biased rates ride badly. If we're being honest...

Tyson

no, i dont think youll feel it any different really if the rear spring is the same.

i've put my 900's up front for *****, you barely feel the difference. it doesnt drive any stiffer in terms of ride comfort/bounciness.

going by a ratio is irrelevant. its just a matter of the rear spring.

does changing the front spring affect actual handling and performance? yes. but honestly i really dont think the OP honestly cares about that. if he did, he wouldnt consider road comfort.

and every tuned suspension is different, for each track, car setup, driver, etc. so useless to compare.

bottom line, just going by some kind of ratio is misleading.

TomCat39

The bolded statement above assumes the OP understands more than they do about suspensions and spring rates.

The only reason I brought up ratio is I know the weight is also biased so I was throwing the guess out that that they might be related. I was thinking even with the stiffer eibach springs, if you kept fairly close to the same ratio as stock (430F/250R being the closest) the handling would be similiar even though the ride should be in theory, stiffer overall.

Another part of the mix which is not even as clear as mud is what affect progressive rates play in all of this.

From what you are saying, out of the options available with the coil overs being offered, there isn't going to be any notable handling or ride differences between the 340F/430R and the 430F/430R?

You give me too much credit and I think B serious was likely on the right track (no pun intended) on breaking down the behaviors into layman terms that should be able to apply to any brand spring evaluations over all.

Which really is what I'm looking for... An understanding for something I don't have an understanding of.

What I got is that I may think about doing the 340F/350R so as to bring the car a little more neutral in handling without affecting the ride overly much. I believe the stiffer springs and the stiffer back end will both reduce the ride "comfort" but I am thinking a compromise of both, not overly improved handling and not overly reduced comfort per say.

Oh and not to say I don't appreciate your feedback, I definitely do thank you for for giving it, I just think you are giving me more credit than I deserve so I am likely to not follow your thoughts very well.

Tyson

when you increase the spring rates, you reduce the travel and increase the response of the suspension.

that doesnt always mean increased grip.

limiting suspension movement can be beneficial because other things like slip angles and camber angles change and dont always follow the same curve of adhesion limits at the tires. so reducing some of that to follow the max amount of available grip is ideal.

response and feel of the car is also another beneficial thing for a driver. i think this sort of speaks for itself.

spring rate, or the front/rear ratio does not make a car oversteer or understeer. the driver makes the car understeer or oversteer with steering inputs as well as throttle and braking by directing the weight transfer over the front or rear or even corner of the car. spring rate changes adjust the response to make the car understeer or oversteer during those weight transfers.

when you break lateral grip in the front, the car will plow, severely understeer. this is a safer response than if the rear were to lose grip first, as the car would spin around.

however, being able to get the rear to actually lose grip and to control that in a turn, while still using all available grip up front, the driver can make the car "dance" into the turn. to get the car to do this (easier), you would actually increase the rear spring rates greatly (also with a increased rear sway bar), which is counter intuitive to what was written above, so that you lose overall adhesion and can rotate the car easier.

take note that none of this is really practiced on the street. if anyone thinks this is applicable to some canyon driving, youre probably not even going fast enough, or youve just crashed. its really only a track type of driving condition.

so how do you know what spring rates to choose?

you dont, until youve tried.

theres no recipe, no ratio, no nothing until you try one setup, change it and see if you like it, and try something else.

TomCat39

Thank you, that is definitely a lot of food for thought.

Under steer and over steer does come into play on the street at times. It's why my front bumper is a bit messed and had I thought it through when the grip let go on the front from the wet road cornering going from a downhill to a lesser grade almost level in the turn, I would have dropped it into second, reefed the wheel a little more and dropped the clutch at WOT. I might have pulled the front out from sliding into the curb and missed just barely clipping the light pole.

My thought is if I could get the car's tendency to under steer to be a bit more neutral it might be helpful in those rare instances. The other times is the wintery icy times, it's very easy to have to deal with under steer or over steer situations.

But from what you've just described, neutral doesn't mean not loosing grip in the under steer, if anything now you may likely loose grip in the front and the back at the same time.

I'm still not sure why the ratio wouldn't be pertinent to the way the weight is pushed around on the four corners of the car though. I would think if it's a 1.8:1 front to back regardless if the spring rates is 180F/100R or 430F/250R, that the inertia weight would tend do do the same things or go in the same directions just with less movement overall.

I do know, trial and error is not really in my pocket book. I can't see buying multiples of springs to find what works for me being that I'm not tracking the car and not sure I really want to get into auto cross at this time.

I'm almost thinking the more expensive setup of air ride might be a more ideal situation for a daily driver. Comfy ride, all the look when desired, all the practicality when needed (speed bumps, driveways etc).

The price difference is pretty significant but it would be one purchase all components used instead of lots of purchases to have spare springs laying around the garage.

B serious

iTrader: (1)

If you're just using the car for street driving, start with 350F/280R OTS rates like Tyson is suggesting.

Build from there. Springs are fairly inexpensive...and the only way to know what you need is to start somewhere and adjust.

Springs aren't so expensive that you can't afford to upgrade/adjust. Stiff rear springs make a big difference in ride comfort. So much so that it may not be worth it for you. Everyone has different ideas of ride comfort...and everyone has different driving styles.

TomCat39

Out of the options provided, the starting point would be 340F/250R.

And yeah, the whole "comfort" aspect is subjective. None the less, I get both of you on how the harshness of bumps, train tracks, etc, translates into the car more with the stiffer springs especially stiffer rear springs.

Being the plan isn't to track the car but to look nice and be a quality daily driver sort of car my thoughts were looking in this direction after the discussion here:

AirPlus Air Struts

End price with the digital management system, leveling sensors etc is about 3 grand USD.

GC/Koni setup to start is 1100.

Pros and Cons to each. The extra expense gives you the comfort and practical aspects.

B serious

iTrader: (1)

Tein street flex would be a much better option than Koni/GC....especially for what your planned useage is. They're around $900 from thmotorsports.com.

Trust me. I'm right.

TomCat39

I'll have to look into that.

I remember stumbling across one brand that checked every spring as they noted the Eibach springs were not consistent, so when you bought a set of their struts, you got exactly what was advertised.

For the life of me, I don't remember what the company was.

B serious

iTrader: (1)

You're too worried. 99.9% of people and applications won't notice a slight difference in spring rates/inconsistencies. Its nice to be consistent....but your stock springs probably have some inconsistency from the factory.

Your goals are street car that looks better and handles better than stock. Not difficult at all.

I won't claim to be a suspension expert. But I do know what to look for and how to discern my fair share, as well as fairly effectively analyze suspension feel. I will even go as far as to say that I know how to pick rates and damper settings.

I'll try to be helpful subjectively instead of absolutely technically.

I will first say that I've never really been fully satisfied with any of my Koni/GC setups when it comes to street use. I've tried OTS, and several types of custom spring rate setups. I like the versatility of Koni yellows for a track setup that's cost effective and bearable on the street. Bearable is as far as I'd go, though. I would recommend them for someone looking to track the car on a budget...who was planning on tuning the suspension via uncommonly available spring rates...and didn't mind taking a bit of a beating on the street.

Cons that I've found for Koni yellows if we're considering a street suspension:

-The finish is wack. Even looking at it funny makes the paint peel off.

-Lowering them more than 1.5" from stock (5-6th gen civic, 3rd gen integra) poses an issue with stock hats and "streetable" rates.

-Only the rebound damping is adjustable. While this theoretically makes them more versatile for use with lots of different spring rates....it kinda makes for more "wrong" settings than "right" ones. You're stuck with the bump damping that you're given. Sure, you could use a stiffer spring to help with roll...but that adds more harshness than just being able to add bump damping. And who the f#&k is jacking around with spring rates on their DD to simply make it RIDE a certain way? Its counterproductive AF.

I was satisfied with Koni yellows using my stock ITR springs. They did better than the stock shocks in terms of ride AND performance with those tall, soft springs. I currently have 440/513 on my ITR...lowered about 0.75 - 1"....and it rides like dogshit on the street.

I have also had 360/380 on my ITR and it rode OK. Not great. Not bad. But not good either lol. I used them because they worked pretty well on TRACK due to my preference for rear biased spring rates that weren't commonly available on matched spring/shock coilovers. **Though I think PIC and AMR will make them that way if you want.

You don't plan to go to the track, though. I had OTS (~380/250 IIRC) rates on my EM1. It was slightly better than OK.

I also used Tein SS's on another EM1...and it rode fantastic in comparison. I would never be able to tell the handling difference between the two. Nor did I care. It was a DD that I lowered for the same purpose as you're lowering yours for.

Street Flexes are a giant leap upward from SS's.

I am currently riding on a set of street ADVANCE that I've had for over 40k miles now on my DD TSX.

I wanted a suspension to enhance my commute, make the car more fun to drive, ride BETTER than stock, and lower it for looks. It does all that. The powdercoat is seriously tough (mine are on their 3rd Chicago winter with no signs of rust) and they have a derlin washer under the spring to make it easier to adjust ride heights. I look forward to driving the car every day. I like that the bump damping and rebound damping change with each click. Tuning the ride via damping is easier and better (IMO) than with spring rates.

The advantage of a matched spring and shock system, besides simplicity, is that you can adjust so much of the car's ride characteristics by adjusting damping. I really like what Tein has done with their new street systems in terms of damping curve. The settings make sense, and you can easily dial in how you want the car to feel. My SA's ride feel is very european. The damping range is also HUGE. I will admit that the way soft side settings are useless and will make the car feel like an old Grand Marquis. The damping range, for the very large majority of settings, is well suited to the springs, however.

Street Flexes are rebuildable when they wear out just like Konis are. Tein will also revalve them to your choice of rates if you choose.

The Koni lifetime warranty is nice. But its a DEFECT warranty. I don't believe Koni will rebuild a normally worn damper for free.

Tein has a 1yr warranty. But...I've used Teins for 7-8 years and never had one with a defect. My first ever modded suspension was a set of Flexes on a S13. Primitive in every sense. But with all the abuse...and my shitty knowledge of settings...I never saw a leak, they never made a sound, they never rusted out, and the ***** always worked. And...even if defects existed....not many types of manufacturing defects take over a YEAR to manifest.

Tein has come out with the Flex A recently...which is supposed to be in-line with the street flex. They added a hydraulic bump stopper and used an oil that's supposed to be less temperature sensitive, and thus more consistent over a larger temp range. Cool stuff.

The optional EDFC unit is a little gimmicky...but a nice touch. You can adjust the shocks from the cabin, on the fly...and they also have EDFC units with GPS and active damper adjustments based on cornering loads, etc.

I've been happy with the quality and ride of the different models of Teins that I've used over the last 14 or 15 years: Flex/RA/SS/SA, etc.

TomCat39

That my friend is one of the most solid answers I've seen a quite some time. It is staged with just the right amount of technical and subjective observance to be most useful and covers a wide range of experience and setups to paint a very full picture.

Thank you, that is most appreciated and is point on for my general goals.

B serious

iTrader: (1)

No problem man! Good luck with your decision.

redlinetuning

Spring rates are one thing, and matching them would be ideal, but corner-weight balancing is more important. Everyone talks about spring rates but no one realizes that for spring rates to work effectively, corner balancing plays a huge role.

DJackson1357

Out of curiosity, did you end up deciding on anything or still thinking?

I recently got my car going after two years (93 Civic EX Coupe), during which I installed the Koni / GC setup with 400 lb/in front and 330 lb/in rear rates. Handling was good, but I didn't like the ride so the 330 lb/in rears came out and I swapped in a set of 250 lb/in springs. It's better, but I still don't think I'm a huge fan of it. In most areas it is not bad, but several areas (like my neighborhood) hit pretty harshly. It understeers pretty bad with this setup too, but I'm not overly concerned with that.

My previous car (94 Civic DX Coupe) had OTS GC rates on Tokico Illuminas and I almost think I liked that better.

Based on what has been stated here I think I'm going to look into the Tein Flex Z when they come out for the 92-95 Civic or maybe the H&R Coilovers (less info out there on these) or maybe even just ITR springs on the Konis. The main concern I have with the Teins is that I'm not sure if they will go high enough for me. I'm currently at 13.0" from wheel centerline to fender front and rear and it sounds like the Teins are typically pretty low.

Tyson

koni's have no bump compression.

illuminas adjust compression along with rebound.

illuminas > koni

TomCat39

Do you mind expanding on this?

I can't say I'm versed in anyway on all of this stuff.

I haven't made any decision. I was pocketing this information for safe keeping for the day I'm ready to upgrade the struts.

I currently have other areas that need renewal first before changing out my struts. The struts I have still work fairly effectively so can wait until everything else is up to par.

I'm still personally leaning to bagging the car. Been looking into both the Truhart systems and the Air Lift Performance systems. Would be nice if I could use the Truhart Struts with the Air Lift Performance 3H management system. Either way, it's going to be at least double of coil overs but gives you the comfort, practicality and stance all in one.

However if at the time I'm ready and the budget isn't there, I'm leaning towards the Teins Street Flex by the sounds of things.

B serious

iTrader: (1)

Koni is definitely a reputable company that makes excellent products. Their yellows work exactly as advertised by Koni:
-35mm max drop.
-*reasonable* ride quality.

The biggest issues with Koni/GC setups are:
-People dump their cars like 2.5 or 3" with them.
-Forum folks seem to insist that the ride is like a warm silk air mattress at any ride height.

Not saying you're guilty of either of those things. But for a car you plan to drive on the street, a matched system's comfort and simplicity wins out. I think you'd be happy with the Flex Z if you want a budget system with full height adjustment, and damping adjustment.

The H&R's (fixed damping) are great if you don't plan on lowering the car much, like you're thinking. ST (KW) also has a fixed-damping, height adjustable system that's fairly inexpensive, but really well set up. I have ST ST-X's on one of our cars and I really like the way they ride. The downside is the zinc plating if you live somewhere with road salt. But if a damper adjustment **** isn't desirable, and you don't need body length adjustments (they're just single-height adjustable), then they're both really nice.

You could also try pairing your GC's up to Bilstein B8's. I believe they have a digressive curve...which should ride better than Koni yellows. Although, you'd need new sleeves.

Or...try playing with the damper on the Konis some more. See if you can dial them in.

DJackson1357

I don't have many posts, but have been around long enough to figure you'd respond on that. The Illuminas were awesome shocks, put 70,000 miles on them with three different spring setups (Eibach Pro Kits, OTS GCs, stock) and they still worked like new.

Gotcha. My only recommendation on that is be careful and do lots of research on the air suspension before heading down that path. Air springs can work great when properly designed, but there a lot of variables at work there. At work we had an old Praxxis WRX (air suspension setup with adjustable shocks and 3 pre programmed ride heights) and while it had three ride heights available the ride quality didn't change a whole lot between each. A lot of the ride quality is going to come back to shock settings. Then there is the electronics, the reservoir tank, the compressor, plumbing etc and it gets complicated fast.

I wasn't trying to say they were bad shocks. There are a lot of things I like about them, but a few things I don't. The ride height is what I would consider reasonable and within the limit for lowering. Part of the problem may be, as you mentioned, that I had unreasonable expectations as so many people on the forums here run what I would consider high rates for the street then talk about how great the ride quality is. While ride quality is subjective, I'm putting these more at the "bearable" level than the "great" level.

I've been playing with the adjustments and think I have the shocks to about the best setting for me. Any softer on the rears and it seems like I'm getting into an under damped situation. Really didn't like that. It's fine most of the time, my main concern with ride quality comes with large / sharp dips so a lot of that probably comes off of the compression damping which I can't change.

Good point on the ST coilovers also. Those are also on my list as they are several hundred cheaper than the KWs and I don't really need the stainless. This car won't get driven in winter so the zinc coating would be fine.

Do they make the B8 for standard rear lower control arm? I couldn't find any while searching. It looks like I'd have to change over to the ITR rear lower control arms to run the B8s. Could do the B6s though with stock rear arms.

At this point will probably wait until after tax / bonus time and make a decision then. Will put together all of the options, figure out the cost of each then go from there. Thanks for the feedback!

redlinetuning

Once you have installed your suspension and set the ride height to where you want it, you have to take it to someone with scales so they can adjust the corner weights. Most civics will be around 2400 pounds with most of the interior. Depending on your setup, your car could be lighter. You want each corner to be roughly 500 pounds total, with you in driver seat. For someone who knows what they are doing, the corner weight adjustment process will take about an hour or two.

But remember that each time you adjust the ride height, you will have to check/adjust the corner weights again. Adjusting the corner weights is just a matter of adjusting the spring perches slightly, i.e., raising will remove weight from the front driver corner, but will add the most weight to the rear passenger corner.

B serious

iTrader: (1)

I was under the impression that OP knows what corner weighting means. But was wondering why it would be important for a street car...and why it would be more/as important as spring rate choice.

I am also wondering.

redlinetuning

corner weight balancing is like using a level bubble tool. You can cut and assemble a work bench, or table, or shelf. In the end, if you don't use the bubble tool to level your bench top, table top, or shelf, it could be off.

So no matter what spring rates you use, your car might handle well, like a bench top, it might look level, but it would perform a whole lot better if the weights were balanced.

Or better example yet, say you're in boat, your outboard might be in the back, with most of the weight there. If you don't have some counter-weight in the front, you could risk your tail-end of the boat pulling in water. same concept. Balance is key.

B serious

iTrader: (1)

I get what you're saying. But I don't believe it is as impactful as you think....especially for a street driven car. It has more benefits for a track car that you're trying to gain a small advantage with.

EVOs, Corvettes, S2000's, M3's, and NSX's...as well as lots of other fast cars that handle well and ride well are not corner balanced from the factory.