the thing is the ride isn't stiff in the evo, the bumps are. you can tell the ride isn't stiff because you can pitch the car into MASSIVE body roll. but hte bumps feel like **** and half. this is because the high speed damping is over damped and the spring rate is low. it's almost hte worst of both worlds. but it's cheaper to produce an oem damper like this because you can get a semi soft ride and you don't have to get fancy with damping, you just make it hard.

the swift and espelir gt springs are matched to stock dampers. that said NOTHING will help the stock dampers and lowerin will only decrease the lifespan.

now that i go bak and read your question, let me go into it a bit more. basically a stiff spring will amke a stiff ride no matter what. you hit a bump, the stiffer the spring the harder the hit, if you had a rod in there instead of a spring then it'd hit REAL hard right? that's cuz the spring rate of a solid rod is REALLY REALLY high, as in it gives 0" per 1000+ pounds of force.

now when things oscilate there's three ways they can oscillate. free oscillation, damped oscillation and driven oscillation. now we have dampers on our cars so let's talk about hte damped kind of oscillation.

you want the damping force to be critical. that means you don't get ONE revolution, the whole oscillation is squashed before it can complete one revolution. btw i use the word revolution loosely. but what the stock dampers do is OVER damp (the only other case is underdamp and that happens when you blow your shock and you float up and down almost endlessly). overdamp means one very crucial thing in automotive applications and that that the shock absorber goes hydraulic when overdamping or over driving occurs and you basically go to ROD mode... means it HITS HARD! so that's the little difference there.

 

I too am surprised by the number of people running stiffer rears than fronts. In truth, there's isn't really anything magical about the front:rear ratio in general - to all depends where the springs are etc. However, if we limit our conversation here on the evo it looks rather strange. There appears to be two schools of thoughts around. 1.)run as stiff as you can bear 2.)run only as hard as it is necessary. I tend to go with (2.) There is a point where the responsiveness from a harder setup does not overcome the shortcomings of running that hard - namely the inability to track the surface, terrible wet performance, and even skipping rears.

Trinydex is correct to point out that you can't just throw in any spring you like and 'dial-in' the dampers to sort it out. There are 4 types of damping that go on - bound, rebound both in high and low speed. You can play around with all these but any valve design will either have a limited range or a limited resolution. In any case, if you're looking to really get it right, it's best to get professional assistance and every time you change springs, you should change/adjust your valving appropriately (obviously if you're going from 10kg/mm to 10.5 then perhaps it's not so necessary.) If you have very stiff springs and too little (soft) damping you're going to end up with the dampers not being able to control the motion of your tyre. The other way around is even worse with very strange and unpredictable results. Both extremes will damamge the dampers, so they've got to match. As for the limits of the stock dampers (as to how stiff a spring you can put on them) I don't know since I haven't tried, but you can always have your stockers re-valved to suit.

As for what is too stiff really depends on the surface you're on. If you only track your car and it's a smooth track, there's no reason why you can't run very very stiff setups, but if you drive on normal (or $hitty roads like we have here) then it's best IMO to use the stock or somthing not drastically harder and live with it.

Coming back to the front:rear thing, most Japanese coilover kits lower the car by quite drastic amounts, and virtually all of them will lower the front more than the back. Some lower the front by up to 2". It is clear that this will limit suspension travel and this is one reason why they put such harsh springs in the front (and say "for race use only"). With the evo's weight being front biased this makes an even more difference in the spring rates. The reason people I think can go very stiff with the rears is that if you believe that you should run as hard a set up as you can then a rear that is too hard will affect you less. [Anyhow, if your rears are skipping, perhaps it would be better to go with a softer set of rear springs.]

IMO, anything that gives a harsh ride is too hard. I don't mean that I want my evo to ride like a luxury car, but I drive my car on the fairly crappy roads and so I don't miss the advantages of a hard set up so much.

 

in the end it's all about wheel rate. they tend to like to run solid bars in japan. and also their tracks don't tend to have as many elevation changes and also something VERY important is that japanese production style race cars don't use the massive rubber we do in the states. they don't run hoosier class rubber, they don't run anything over 265 usually. so the level of grip they're driving around is VERY much less and hence it's easier to circumvent the threewheeling action.

 

Just thouht I should remind people that when talking about the stock setup, the MR bilsteins are very different from the non-MR.

 

Perhaps Asian people (of whom I am one) tend to be lighter so it would be easier to 3-wheel the car

 

i don't get this comment. lighter driver would only make it easier to stay planted as the driver is probaby the single largest weight above the center of gravity in the car.

i seriously believe it's mostly about the high overall stiffness of jdm suspensions and the fact that they do not run anything more than an a048 in 265.

once again tripodding is all about grip, how much grip you can muster and how much your suspension can resist that shearing. any suspension no matter how stiff can be three wheeled with enough traction.

 

i also don't get this. all the race evos in america are also very aggressively lowered.

maintaining suspension travel is more about have the right dimensions built into the hardware for a certain geometry spring and then having everything well sorted so that the adjustments are not at their ends when everything is put together and you want to lower or raise or preload your spring etc. (once again why a well sorted setup to begin with helps you out that much more)

i mostly don't understand why anyone would think they can go stiffer in the rear nad have it affect handling less. i'd say that the rear suspension affects overall handling the most.

also... and overly stiff front is bad, hopping rear is surely bad, hopping front is possible too and at that point it's REALLY bad because you don't get your steering inputs.

 

Just my opinion, but I would tend to favour the setup of the front being more important that the rear. With the front end almost entirely being responsible for your steering and also the majority of your braking, its setup is going to have a far greater effect on overall performance.

Granted, a poorly setup rear end that is taily or loose can rattle your confidence and slow you down but I thing this is secondary to have a good resposive front end with grip when you need it.

What good is a super sweet rear end setup if the car wont stop or turn.??

 

They might not go quite as wide as you guys but do have access (as we do in Aust.) to some fairly serious R comp rubber like the Bridgestone RE-55s. This tyre has proven over here to offer far superior grip to anything from Toyo, kuhmo, Falken etc. Unfortunately we dont have the Hoosier to compare to. But the RE-55 offers significantly more grip than any of the offerings from the other tyre companies other than the Dunlop DZ02G which it is on par with.

 

I have found tripodding to be more about roll differences fron to rear than grip itself. For exaple if the front right corner dives under braking and cornering, you are likely to lift the left rear. Reduce the dive on the front right, less likely to lift the rear.... Again just my opinion and experience.

To get on topic, spring rate is a very personal choice. What someone can tolerate could be unbearable to another. A bit like exhaust notes. You really need to consider the road surfaces you drive on and your intended use. If possible, test drive a car with the setup you are considering....

 

Chris,
I think you are on the right track with springs. At 12k/14k (670 lb/in, 780 lb/in) I am still experiencing some body roll, but from pictures I am not seeing any inside rear lift anymore. This is with 285 710's and stock ARB's. Balance feels great with the 100 lb/in spread frt to rr too.

John

 

i was just going one step under the spring rate, you mention dive, but what ends up making the dive happen? which direction is the dive in, and that would be the direction of the wheel providing the most grip, and the grip level of that wheel is what's causing the dive. you can circumvent the diving by going stiffer, but if you have more traction somehow you'd still dive. that's why i said for any given stiffness there is a grip level that will make it dive.

 

i see the arguement with the front being more important... i guess i was visualizing something different.

i guess what i'm trying to say is you can go "crazy" with the front and the overall handling would not have catastrophically changed, you'd still likely be facing the right direction. you might not be happy with the steering, the braking or the maximmum level of grip but you'd be facing the same direction, unless of course you detuned the front somehow.

but going too crazy in the rear will get you backwards, a twitchy back end, if there's too much toe you'd get less predictability and all kinds of bad stuff. so i guess i was trying to go off that note.

 

well the other thing is that i'm basing this off of the many episodes of best motoring that i've seen. i know best motoring isn't a measure at all of the ultimate potentials of cars in japan and we all know the more exciting professional series wear the same slicks that are used all around the world in other forms of wheel to wheel.

best motoring is however a great measure of automotive popular culture in japan and with that said they don't run wide, they don't run threadless, it doesn't even ever seem like they shave tires. but once again this is a limited view of what we've been able to see.

and on that note i think that the japanese aren't missing out on anything, when they came here for american touge they didn't necessarily muse about the increased grip of the hooser class rubber they'd seen. actually it was probably an embarassment to them to see a "slick" type tire not provide the 2-3 seconds of faster performance than a typical hoosier. did they notice how much stickier the hoosiers are compared to other dot rs? probably not.

i find it extremely peculiar though, that japanese time attackers and such choose to widen track so much more than widen tire.

 

Perhaps I did not make it clear. I am mainly talking more about cars that are driven on normal roads most of the time and track some time. Race setups are a totally different kettle of fish as you are free to make adjustments and alterations that one would not normally do to road cars. In race cases, the parameters for being 'too hard' or 'too soft' are different. Besides, the surface and things you come across are more predictable.

The packages that come from Japan tend to come with quite stiff springs and are sold to mainstream drivers who put them on to road cars and so provisions have to be made for stock suspension geometry. There appers to be a trend in Japan to lower the front a lot more than the back- this therefore means that they've reduced the available compression stroke in the front more so in order to make it safe from hitting bump stop, the front _may_ have to be stiffened up somewhat more than necessary (compared to the rear).

It is entirely possible, however, to have a setup where the car is significantly lowered, but have sufficient damper stroke/spring travel for the track, but it is rarely achievable on 'real' roads.

One manufacturer (Japanese) actually prduce a suspensoion kit which basically does not match the evo's geometry at all. As a result, they are lousy and will hit end stop surprisingly early with anything less than a 10kg/mm at the fronts.

As regards to the rear and so on, what I am talking about here is mainly about the ride quality, that it would not be so terrible by going extremely hard at the rear, cos you don't feel it so much. As you said, the rear affects the handling significantly (not least because it is attached to the same car as the fronts!) and it beats me as to why anyone would put up with a hopping rear, but if it only happens in one corner and they believe it's getting them advantage everywhere else, then it would probably be more acceptable ride-wise. Also, a harder rear tends to reduce understeer, so I guess that's why people do it on the evo.

I agree that a hopping front is a thing that should never happen (but can be induced) and if it does, then something is seriously wrong. I don't think however, that any of these kits out there are so terrible as to be as mismatched as that.

p.s. as for the lighter driver, most of the time a tripod is induced (or made more likely) by the car cutting, say, an apex of a chicane with the saw-tooth red and white profile. In such an event a heavier car will be less likely to leave the ground, I suppose. In reality, it probably doesn't make any difference unless you've got a fat man sitting over the rear wheel arch. Anyway, it was a joke!!! And yes, I know it can happen without the bumps...