Kg = 2.2lbs
1 inch = 25.4mm

Therefore, for example. a 10kg/mm springs = 10*2.2*25.4 = 558lbs/in

This, I believe, is the correct conversion from kg/mm to lb/in.

Does anyone know if Zeal makes suspension kits for the Evo 8? I ran a set of S6's on my previous car and they handled like a DREAM (12k/8k rates). They were also VERY streetable.

 

Erioshi - I use my Evo for open tracking also. I'm planning to get coilovers to increase the overall body roll stiffness and get more camber adjustability at the front.

Did you consider the Cusco coilovers as well? Why did you decide on the JICs? Also, have you seen pictures of your car in a hard mid-corner? How much has your roll actually been reduced? I've been really surprised how much body roll there actually is with the stock suspension. It really doesn't seem to roll much from my driver's perspective. E.g. this is my car with a stock suspension:

http://www.rennercars.com/rallypics/more/MVC-056F.JPG

But people driving on the track with me have commented on how little body roll there is with the car. Obviously that's not true.

 

e8 - I used a kgm (kilogram-meters) to foot pounds conversion at a rate of 7.233 kgm = 1 foot pound. I may be using the wrong units; thanks for the info. I figured a "work" unit conversion would be the most appropriate. Guess I need to dig a bit more

tsi90awd - my car is amazingly flat on the track - we took some video at my last track day, and I was as flat as the fully caged and gutted race only cars I was grouped with. As a static test I've had 2 beefy 200 pound guys (one each in the front and rear - both on the same side) stand in the open car doors and try to rock the car. It squirmed a bit, but it didn't rock.

I didn't really check out the other options too closely; the JICs were offered to me at about 65% of the going internet price. They come with pillowballs and front adjustable camber, so I was happy. One other nice feature is that the ride height is fully adjustable without affecting travel or pre-load. The dampers are adjustable also, but I have yet to use them in ay setting other than full-soft, even for the track. If I hadn't bought these, my ideal set-up would have been something that relied more on (adjustable) damping than spring rate - less track grip, but better overall roadability.

For 98% of my driving, the spring rates and damping are fine. the only times the set-up gets me is on old, wavy concrete freeways (small boat; rough lake syndrome) and on ocassionally on some rough roads with large pot holes and/or badly chopped up pavement. However, even on uneven pavement the tires seem to stay planted pretty well; not too much "float".

 

e8's calculation is correct (just multiply kg/mm by 55.8 and that is lbs/in.) Hence 9 kg/mm is about 502 lbs.
It is quite difficult to answer your question without knowing the objectives. Also, keep in mind that someone's ideal setup may be too harsh or too soft for someone else.

Generally speaking, the Evo actually has very little understeer. If you are comming rear-wheel driven vehicles it may seem as if it requires more work to make it "tail-happy" and that may be true. However, the Evo is actually easier to drive, say, compared to a BMW in my opinion. However, driving style has to be adjusted for sure.

Less body roll is usually a good thing and coilovers help reduce body roll as well as anti-roll bars. The Evo's rear A/R bar is already quite stiff in my observations as it lifts its inside rear wheel on moderate to higher speed corners; even though its wheelbase would not be considered "short". At the same time, the benefit of an adjustable A/R bar, it makes it easier to change front/rear balance of the vehicle, which may be useful for you.
So, IMHO, upgrading A/R bars may be a one the last items you think about depending on your objectives.

Coilovers come with various rate springs as its been discussed here, so you need to first determine what is it that you want to accomplish based on mostly street driving, seldom or frequent autocrosses, certain number of track days, etc; and what features you are looking for (bump/rebound/height adjustments, etc.). Then it is easier to determine which coilovers with which spring sets you should be using.

 

Here's pics of the roll we have w/JICs, but it handles great!

 

 

what rims are those SS RX7 r2?

they look AWESOME.

 

I've been trying to find some useful Pics or Video of my car with the JICs on while on the track. Only thing that's close enough to be usefull are sweepers and such; nothing with extreme loading. The Pics posted by SS RX7 r2 are a pretty good match for my car's behavior. It's not completely flat; but it's way above stock.

One measure I used to cpmare my JICs to stock was lateral Gs. I used my G-Tech Pro Comp to measure my maximum "squeal free" cornering load on a level concrete pad. The test involved driving a constant circle both directions - same tires, ambient and pad tempratures, etc.. With a stock suspension (on this pad) I was able to maintain .9g squeal free; and peak at about .95. With the JICs I was able to maintain about .96g "squeal free" and peak at about 1.1g. Again, this was my pad, tires tires, G-Tech, car, driver, etc. You results may vary.

One thing worth mentioning is that I ended up lowering my tire presures after installing the JICs. Testing showed my car was happiest with 37(F)/35(R) presures with the stock suspension and me driving. After I put in the JICs I got my best results at 33(F)/31(R). I believe that to be mostly the result of having all four tires share the cornering loads more evenly than stock.

 

e8,

They-re Volk ce28n in bronze.