Spring Rates - Track / Autocross

[Dave-ROR]

Originally Posted by CSG Mike

I wish there were a way to do an apples to apples comparison. The tracks in socal tend to bring out understeer in cars, so a lot of setups here are slightly biased toward oversteer.

It probably doesn't help that I prefer a looser car.

Coming from my FWD experience, a loose car was a fast car in my opinion. I've been more consistant and fast in a car with stiffer rear springs/sway bar, that but's FWD. I can imagine with RWD I'd have a different opinion, the car stock is pretty neutral IMO so I'd be fine with keeping that balance, but that seems to include higher rear rates. I could see that being a bad thing too on some tracks, Perhaps I just need to switch it around to a heavier front setup and learn to drive again

My RWD experience is more limited to stock, or lightly modified setups (coilovers/swaybars) and I've never had to spend the time really sorting it out.

[Sam Strano]

FWD and RWD are not the same. You can drive a loose FWD fast because it turns in better, but you can literally pull is straight with throttle (especially if you have a limited slip).

If the rear of a RWD moves around too much, that option is not there. Now I'll happily admit that you can get away with one of these cars looser than say a Corvette. Not as much power to get you in trouble. However by the same token that lack of power means if you get sideways it's speed scrubbed you can never get back. What you want is balance, pure balance. This is something that has been a problem getting the "subaru" guys to understand. While the car is a Subaru mostly, it's not like a WRX or an STi, or what have you. It's not super nose heavy, it's not AWD.. no front wheel drive to help fix things.

[CSG Mike]

We successfully tested 10/12 springs this weekend. We're going to test 12/14 next weekend, but we're worried that it may overload our skinny street tires...

Car was very neutral after the dampers were dialed in; I can cause under/oversteer with purely steering and/or throttle input, with zero power adders.

[Kido1986]

What do you guys feel the limit of the stock dampers, performance wise, is with springrates? Most aggressive I've found is 250/250 from RCE. Debating between that Swift's springs but they have stiffer rear and softer front than the RCEs...

[Sam Strano]

Originally Posted by CSG Mike

We successfully tested 10/12 springs this weekend. We're going to test 12/14 next weekend, but we're worried that it may overload our skinny street tires...

Car was very neutral after the dampers were dialed in; I can cause under/oversteer with purely steering and/or throttle input, with zero power adders.

Obviously there is a lot of personal preference in this stuff. I'm not saying you are wrong, if that's what you like best then ok.

I am a pretty firm believer in not making the springs any stiffer than necessary. The best mechanical grip comes from having the car softer... until you run into issues with a poor contact patch, etc. Once I get where I've got a really good loaded contact patch that spreads the load across the entire tire, I don't want the car any stiffer in spring rate.

I'm sure what I find tolerable is different here in Western PA than what you might in SoCal given the climate and the roads.

To each his own. I know that I've run against cars with double my rates and sometimes more, and came out the winner. They clearly thought they needed more rate, I didn't. YMMV.

[Sam Strano]

Originally Posted by Kido1986

What do you guys feel the limit of the stock dampers, performance wise, is with springrates? Most aggressive I've found is 250/250 from RCE. Debating between that Swift's springs but they have stiffer rear and softer front than the RCEs...

Considering that the car rides better and is much more planted with upgraded dampers and much higher rates, I'd say that the stock dampers aren't great for anything, and more and more less so when you ask them to do more work via a higher rate and shorter spring.

Nobody will have a for sure answer. Lots will tell you that the stock stuff is fine to X, but not have anything to back that up other than "it drives fine". And being honest, that's the trouble here. I think a lot of stock cars had dampers that were severely lacking too, even brand new (this isn't *that* bad mind you), but the OE thought they were fine.

What a shock can "handle" is largely a matter of when you the owner considers it to be out of whack. Trouble is most folks don't know a lack of damping when they feel it... until they feel what something better is, then it's very clear.

[CSG Mike]

Originally Posted by Sam Strano

Obviously there is a lot of personal preference in this stuff. I'm not saying you are wrong, if that's what you like best then ok.

I am a pretty firm believer in not making the springs any stiffer than necessary. The best mechanical grip comes from having the car softer... until you run into issues with a poor contact patch, etc. Once I get where I've got a really good loaded contact patch that spreads the load across the entire tire, I don't want the car any stiffer in spring rate.

I'm sure what I find tolerable is different here in Western PA than what you might in SoCal given the climate and the roads.

To each his own. I know that I've run against cars with double my rates and sometimes more, and came out the winner. They clearly thought they needed more rate, I didn't. YMMV.

Our application is strictly for track use; I wouldn't recommend our setup for AutoX. Likewise, the majority of our tracks are unbelievebly badly maintained, and as a result, very bumpy.

Different environment, different recommendations. Perhaps we should split the discussion into a AutoX and Track thread, as the setups will diverge more and more as cars are developed.

[Racecomp Engineering]

Originally Posted by Kido1986

What do you guys feel the limit of the stock dampers, performance wise, is with springrates? Most aggressive I've found is 250/250 from RCE. Debating between that Swift's springs but they have stiffer rear and softer front than the RCEs...

I'm frankly surprised that so many other companies went firmer than us in the rear. We thought we'd have one of the stiffer rear rates but that doesn't appear to be the case. From the shock dynos we did for both BRZ and FR-S we weren't comfortable going past 250 in the rear. I guess other companies had other ideas. Also surprised everyone went soooo soft up front compared to us. The 250/250 with mild drop and shortened bumpstops works out very well in controlling body roll, soaking up bumps, and keeping a good balance with good turn-in. I just can't get over why everyone wanted a super soft front (that rides on the bumpstops) on this RWD car with a macstrut front. But hey, a lot of companies just take stock and multiply by 1.15 and call it a day.

For an OE shock they aren't bad. With Subaru we're used to complete crap, so we can tell when they put even a little more effort in which they have done for this car and to a lesser extent the most recent STI.

To be clear there is tons of room for improvement from a Koni or maybe a Bilstein sport later. But with just our springs and shortened bumpstops, it's a good match to the valving. Not bouncy or harsh, and around 65-70% critically damped. A little more low-speed damping would be nice, but with our springs vs. stock on OE dampers you'll come out ahead with our springs.

- Andrew

[Dave-ROR]

RCE: Most tried to stick with the stock softer front/stiffer rear setup would be my guess. I found stiffer than 250lb/in rear springs to work fine, no damper issues at all and the dampers handled the rate well enough (as well as I'd expect them to).

I'll be done with my stock dampers soon

[Racecomp Engineering]

Originally Posted by Dave-ROR

RCE: Most tried to stick with the stock softer front/stiffer rear setup would be my guess.

I know, I just think it could be a lot better than stock. The eibachs you have are one of the other better springs out there right now IMO.

- Andrew

[gmookher]

250/250 is fine with stock tires. What are they 500+ treadwear? Sure stock dampers work.

Even as you go to a 200TW tire, you start to really lean into things with stock coils. Dampers get worked harder. They work fine, tho.

Just by going to a stiffer coil theres lots to be gained, especially if you keep the same exact bias front to rear, as was the case with my BRZ and H&R. Fine for DD.

But in HPDE< you can feel the under dampening with stiffer coils and realize there is more to be gained by modding past the stock point, it means committing to the next class up, but oh well. If you must stay with stock dampers, I see RCE as a no brainer, if coils are what you want for track use. If you want a DD, you may consider the HR option, the supersports are fun, and handle great.

As you add FI power, I think brakes, and stuff like squat and dive need to be addressed a bit differently. Hard to compete with a well designed coilover solution if you ask me, spring versatility is key for me.

Once I go to something like a stickier R-DOT tires, I will take a whirl at 440 front 430 rear for driveable track setup. I am sure there may be benefit stiffer still, but I wanna keep try my fillings in my mouth before going any stiffer, should not really be required at my recreational level.

My earlier post is a great departure point for most folks, 375/430 allows for DD more comfortably, where youre not standing on the brakes just before going into a hairpin corner at full speed all day.

Stiffer front sway bar, rear sway set on softest setting or may even need to redrill a hole..
Welcome feedback from the vendors posting above

[Dave-ROR]

Yeah I think I'm going to test 350/400 on Multi Pro R2's as a first attempt. ERS coils are cheap so I can test more options as needed

[swift996]

Originally Posted by Dave-ROR

Yeah I think I'm going to test 350/400 on Multi Pro R2's as a first attempt. ERS coils are cheap so I can test more options as needed

I know we are both waiting on these. Do you know if they have released info on the default spring rates? I know last I heard they were still determining what that was going to be.

[Dave-ROR]

Originally Posted by swift996

I know we are both waiting on these. Do you know if they have released info on the default spring rates? I know last I heard they were still determining what that was going to be.

I know them and pricing (msrp, not map/street pricing) but I'm not sure if they've been released. I'll check my emails and see if I can post them up.