Spring Rate Chart for Evo X

[Hiboost]

Added info for Eibach Pro-Street, HKS Hipermax III, and HKS Hipermax III Sport Coilovers.

[goofygrin]

Tanabe springs: OFFICIAL: Tanabe GF210 Springs Available Now!

[BigT]

Why is the rear end lowered more compared to the front on most springs? Its obvious that the front end has more wheel gap.

[Hiboost]

That's a good question, it may have to do with the clearance to the body and greater suspension travel in the front. Considering if you turned the wheel to it's most extreme angle and hit a bump you wouldn't want it to hit your body panels. Might be more of a carryover from the rally days since the last time I saw extremely lowered cars at the road course there were cars with 1/2" of wheel gap and no allowance for hitting a bump with the wheel turned.

[evoluXrichie]

great information!

[Tractionlimit]

Originally Posted by Hiboost

The spring rates are measured the same way on Lowering Springs as well as Coilovers. The biggest difference is that Lowering Springs are limited by what spring rates they can use if they are going to be used properly with the stock OEM shocks. Typically you will only see 10-30% increased spring rates and often progressive rate springs will minimize the impact on how much of that you feel in daily driving. If the spring rates are too high they will wear out the shock faster and could actually hurt the handling of the car if the shocks can't control them properly.

Coilovers can get away with higher spring rates because they also include upgraded adjustable dampers that allow you to tune them to the spring rates depending on what kind of ride you want. Most will adjust for compression and rebound where a softer setting will be a bit easier on the street to a point and stiffer settings are more for smooth race tracks. Going too far in either direction of adjustment in relation to the spring rate will make the car ride as if it's out of balance. If the settings from front to rear are not tuned to each other properly you can also get that porpoise effect where the whole car oscilates out of balance front to rear.

A well setup coilover combo doesn't always have to be harsher on the street, but if the roads are really rough you would definitely feel the increased spring rates and firmer ride. Where Coilovers really shine is on a relatively smooth race track where weight transfer on a good setup is precise and predictable when compared to the OEM springs and shock combo that often lets the car roll too far for crisp handling.

I'm no suspension guru by any means and this is just what I've read over the years. Perhaps we can get someone with first hand knowledge to add to that as I didn't really find any good links that talk about the differences when I did a quick google search.

Chris, are you still liking your Eibachs compared to stock? Any plans on going to a coilover setup? Any loss of performance or bouncing with that initial softer spring rate? Thanks again for the great info.

[wongck]

Stance changed their spring rate on GR+ from 10k/10k to 10k/9k, just FYI

[Hiboost]

Stance changed their spring rate on GR+ from 10k/10k to 10k/9k, just FYI

Cool, I'll update the chart!

Chris, are you still liking your Eibachs compared to stock? Any plans on going to a coilover setup? Any loss of performance or bouncing with that initial softer spring rate? Thanks again for the great info.

For being only lowering springs I've found they are quite good compared to when I installed just lowering springs on my 96 Eclipse GSX. This is likely due to the fact that the stock suspension and shocks are much better than those Eclipse parts back in the day. The Eibachs are predictable on the roadcourse and the slightly more compliant initial spring rate seems fine for street driving. I'm going to upgrade 275/30-19 tires on 19x9.5" wheels and see how the overall package feels before deciding on coilovers, so far for my needs the car already handles quite good and is very forgiving. Getting a stiffer rear antiroll bar in the back also seemed to balance the car to a more neutral state over the slight understear the car had stock.

[timbo299]

Was wondering if anyone has k-sport coilovers on there evo x. I'm looking seriously into purchasing them. Please let me know Thanks

[wenbenten]

[leecavturbo]

why does the eibach's have a range of rates?
does it mean available special order?

[Hiboost]

They have a Progressive Spring Rate so initial spring rate for small bumps is actually less than stock and as it compresses it will feel stiffer.

[kidneythief13]

I believe I found the rear spring rate for the X MR here: http://sccaforums.com/forums/thread/333415.aspx (post 339863?)

Of course we rated the OEM rear springs (some goofy tapered/progressive Eibach spring). It was variable rate 160-215 #/in...

So, that would be ~2.86-3.84 (rear)

Maybe someone wants to double check & add to the OP?

[smgevo]

Hiboost, could you also add to your list the various adjustability levels to each coilover design, ie; Single adjustable (rebond only), Single dual adjustable (compression and rebound adjusted together with one knob), Dual (compression and rebound adjusted independently), Triple (compression high and low and rebound)

[Hiboost]

I'll see if I can sort out the info tomorrow, any missing bits I'll call out and see what others can find. :P