Choosing coilover spring rates for your EVO
I do believe that there are times when spring rates can be significantly higher than 10K even for street tires - for some people. On my '04 daily driver (25000 miles per year) I ran somewhere around 13k/15K and they were awesome. BUT - I had a perfectly valved set of Ohlins and was on 285/30/18 Advan Neovas . . . .
If you throw that high of spring rate on your average cheap set of coilovers it would probably destroy them before too long. . . so it is definitely NOT for everyone. But with a good set of coilovers and proper dampening . . . I don't think spring rates in the teens are out of the question. . .
EVOlutionary
If you throw that high of spring rate on your average cheap set of coilovers it would probably destroy them before too long. . . so it is definitely NOT for everyone. But with a good set of coilovers and proper dampening . . . I don't think spring rates in the teens are out of the question. . .
EVOlutionary
Not in the rear as long as you don't change ride height. . . . but front - yes. . .
Although this is taking things off topic - I just want to touch on it real quick. Maybe we'll start a new thread. Personally I don't think there is anything wrong with lifting the inside rear wheel off the ground, as long as your car handles fine. All autocross EVOs I know do it at some point. And there have been a lot of EVOs that have won a lot of championships. . . . heck my old silver daily driver did it to the point where even turning a tight corner while decellerating it would do it. . . . and it handled beautifully on the streets as well as the track. . .
Although this is taking things off topic - I just want to touch on it real quick. Maybe we'll start a new thread. Personally I don't think there is anything wrong with lifting the inside rear wheel off the ground, as long as your car handles fine. All autocross EVOs I know do it at some point. And there have been a lot of EVOs that have won a lot of championships. . . . heck my old silver daily driver did it to the point where even turning a tight corner while decellerating it would do it. . . . and it handled beautifully on the streets as well as the track. . .
Great thread!!, anyone have any feed back to my questions above^^
Not in the rear as long as you don't change ride height. . . . but front - yes. . .
Although this is taking things off topic - I just want to touch on it real quick. Maybe we'll start a new thread. Personally I don't think there is anything wrong with lifting the inside rear wheel off the ground, as long as your car handles fine. All autocross EVOs I know do it at some point. And there have been a lot of EVOs that have won a lot of championships. . . . heck my old silver daily driver did it to the point where even turning a tight corner while decellerating it would do it. . . . and it handled beautifully on the streets as well as the track. . .
Although this is taking things off topic - I just want to touch on it real quick. Maybe we'll start a new thread. Personally I don't think there is anything wrong with lifting the inside rear wheel off the ground, as long as your car handles fine. All autocross EVOs I know do it at some point. And there have been a lot of EVOs that have won a lot of championships. . . . heck my old silver daily driver did it to the point where even turning a tight corner while decellerating it would do it. . . . and it handled beautifully on the streets as well as the track. . .
As for having rear lift and it being a problem, you are correct. It's extremely difficult to completely tune it out and not worth jacking front rates to elleventy billion to do so. How much of it you get and where it occurs in the corner will have a big effect on how detrimental it really is. A bit on entry or mid corner is fine, if it's present on corner exit that is not good. At that point you want both tires on the ground to get in the throttle nice and early, otherwise you give away the AWD advantage and effectively shorten the upcoming straight.
There are some decent discussions floating around right now, cool stuff.
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From: Columbia, Maryland
As for having rear lift and it being a problem, you are correct. It's extremely difficult to completely tune it out and not worth jacking front rates to elleventy billion to do so. How much of it you get and where it occurs in the corner will have a big effect on how detrimental it really is. A bit on entry or mid corner is fine, if it's present on corner exit that is not good. At that point you want both tires on the ground to get in the throttle nice and early, otherwise you give away the AWD advantage and effectively shorten the upcoming straight.
There are some decent discussions floating around right now, cool stuff.
There are some decent discussions floating around right now, cool stuff.
- Andrew
After a closer inspection, I realized that the front springs were actually 12K (T120) and the backs were 10K (T100). Luckily, I haven’t had the time to install them yet. So I decided to listen to Andrew and swapped the springs around.
After the swap:
Front
Frontspring.jpg?t=1236042743
Back
IMG_0197.jpg?t=1236042825
Last edited by 18bora; Mar 9, 2009 at 04:47 PM.
I currently have the HKS Hipermax RS and I am looking to upgrade the springs to some swift. The current spring rate is Front Spring rate 6kg Rear Spring rate 5kg. I mainly drive this car on the street with the occasional track appearance but I noticed the rear spring rate is softer than stock. I was thinking of going with 7 up front and 9 in the rear? What do you suspension gurus suggest?
That says it all right there ... As always good job Drew.
I have to agree with this statement, jack up the rates on the front too much and you just end up with a car that understeers even worse and looses total grip. Suspension system is all about balance, sometime you have to compromise in one area to gain in another.
As for having rear lift and it being a problem, you are correct. It's extremely difficult to completely tune it out and not worth jacking front rates to elleventy billion to do so. How much of it you get and where it occurs in the corner will have a big effect on how detrimental it really is. A bit on entry or mid corner is fine, if it's present on corner exit that is not good. At that point you want both tires on the ground to get in the throttle nice and early, otherwise you give away the AWD advantage and effectively shorten the upcoming straight.
Most manufacturer coilovers can be revalved (eg: Ohlins, KW V3, Bilsteins, Konis, AST), I think the exception are Cusco that use Showa shocks. Whether your coilover will need a revalve or not will totally depend on the range of the shock and the change in spring rate you are seeking. Cost usually ranges from $100 - $150 depending on the shock manufacturer and the shop that does the revalve.