Im currently in the middle of a complete suspension overhaul w/ the exception of the bilstein HDs/swifts and Im pretty close to saying F it and getting some coilovers.


Car is 80% autocross and not daily driven, but is driven driven on the street. Street comfort is not a huge priority. Im slowly building the car up to SM prep and currently running with a street tire handicap locally. Planning to have dedicated wheels and sticky tires by 2015.


All bushings in the front are being replaced, PSRS, RCK, tanabe fsb, hotchkis rsb. Tires are Dunlop ZIIs for at least another year before hitting the R comp crack pipe. Im estimating race weight will be around 3050 (hopefully less) without driver. ACD pump is getting relocated to the trunk, small battery is in trunk.


Coilovers Im looking at getting are the FA 510s. And my initial spring rate selection was 10k/12k. I am not going to get the swift upgrade right now and thinking I might want to do 8k/10k or similar for the ZIIs and bump it up with the swift springs later when I get R comps/wheels. But Id rather not have to get them revalved later.


thoughts? 10/12 too much for street tires?

 

I run the 510's w/the Swift 10/12 setup & almost wish I had listened to Terry at FA & did the 12/14. I run Nitto NT01's

Call Terry at FA

 

thanks! I sent them an email this morning. Just looking for more opinions.

what sway bars are you running?

<edit: Im also assuming your experience is on the track?>

 

Whiteline 24mm. Softened the setting to the middle hole after adding the 510's / EVO is 98% track only duty

 

This is covered extensively in other threads on this board; nothing will be said in this thread that hasn't already been said so I'd suggest starting here: https://www.evolutionm.net/forums/ev...ead-links.html

Still, I'd do stiffer springs and a bigger delta from front to back-- like 11/14 or 12/15-- based on motion ratios. My coilovers were setup by Works and came from an Evo which took second place (by less than 0.10 sec) in STU at SCCA Nationals, and they have a delta of 150lbs/in from front to back.

 

Charlie, If you reviewed this suggestion to FA, Im sure Terry will tell you this is a recipe for some severe oversteer if youre running a higher rate RSB

 

FWIW I too run ZII's and just switched to 10k /12k on my Ohlins DFVs. I was previously running 8k/10k and found them to be too soft. These findings were the result of only a couple autoxrosses last season since I picked them up so late in the year.. While I didnt have them on for too long I choose to pick up a set of stiffer springs and 650#(~11.7K) Hypercoil which I put in the rear and put my 10k back on the front.

I just went to this new setup yesterday and ahve put probably 30 street miles on the car so far. The car feels perfectly fine on the road. It really does not feel stiff at all but maybe that is more a function of how good the Ohlins really are.

My first autox is on the 29th so I will have more feedback then. As to my sway bar setup I have a Perrin RSB on the softest setting and I have modified my FSB to make it a little stiffer.

Net net I dont believe 10k/12k will be too stiff for street tires.

 

Do you have any weight reduction or know what your corner weights are?

Easiest weight to take out of an evo is in the rear, once you start dropping weight spring balance changes also. My suggestion is 12k/12k with a really big rear and med big front bar. I can give more specifics (actual numbers, not hearsay bs...) in PM if youd like.

 

Brik, Ive read through most of those threads and have a decent idea of what should work. The main thing I question is whether I can get springs that will be "okay" with street tires and then work well with r comps later, without sacrificing too much later.

From the responses here, it appears that I should be okay with 10/12 rates for now. Then when I jump to R comps, maybe jump to a 12/14 setup. Along with my original question, I also asked FA whether they thought the 10/12 valving would not be enough for 12/14 later.


I have been offered the use of a local's scales, but wont be able to use them until I get the car on the road. Likely AFTER coilovers...

As I said in my original post, Im thinking it will be around 3050 or less. Its basically a RS with power windows/locks, a radio and 2 speakers. Ive done alll of the free weight reduction I can in SM except removing air bags. ACD pump is relocated to the trunk, 7lb battery also in the trunk. CF trunk and a few power mods that are likely lighter than stock. Hoping to have a sub-3000lb car soon.

and FWIW, Ive got the hotchkis rear and tanabe front w/ cusco plates.


any input is greatly appreciated.

 

My car when it was 3080 lbs had 1980lbs front and 1100lb rear. Even given our low rear motion ratios, the massive weight difference means heavier rear springs aren't needed. I wont go through all the easy math but my square setup is 2.65hz front and 2.82hz rear. No reason to higher in the rear, and a little less rear spring means I can run more rear bar for the same roll resistance. More rear bar is a good thing!

 

thanks for the suggestions guys.

Terry @ FA got back to me and said my original plan of 10/12k now and going up to 12/14 on Rcomps was spot on. And the valving would be fine for the 12/14s. We'll see it how it goes.