Best springs for performance?
 

Hey everyone, I know we have mulitple threads about springs, but I've yet to see any that compare all the different spring options to one another.

I don't want to start asking questions in the individual threads because I don't want to start pitting sponsors against each other, etc..

So I thought I would ask the question here in my own thread.


I'm interested in hearing what everyone thinks is the best spring option for performance and a mild to medium drop.

Here are my priorities: Keeping in mind that I don't want to spend $1k to $2k for coilovers at this point.
1.) Performance. I want to retain the stock balance of the car. I don't want a set that increases understeer or oversteer and changes the stock balance of the BRZ. I want an improvement of pitch and dive characteristics, but don't want it to be squirley or overly harsh.
2.) I'm pleased with the ride smoothness of the BRZ in stock form. I can handle some trade-off for a little firmer ride if I get better handling. But I don't want it to be extremely harsh.
3.) I do want a drop in height for the asthetics as well. About an inch would be nice I think.. I can handle a little more or a little less.. but I think anything in the 20 to 25mm range should be good.
4.) price is an issue, but not a huge one. I think the springs I've seen so far range between $200 and $350 or so.. Anything in that range is ok for me.


The car is a weekend cruiser.. a play car. I'll drive it to work sometimes, but not always. I plan to autocross at some point, but I'm not hardcore.. i don't need to win.. i don't really care what class they put me in.. it's more for my own education, training, and fun.


So what's the best choice?

-RCE Yellows
-Eibach ProKit
-Mach V Awesome
-Tein
-Subaru STI just came out..


What am I missing?

I have to say i'm leaning toward the RCE's based on their extensive R&D thread here as well as Moto-P's positive comments. But, that doesn't mean the others haven't done just as much work to perfect their products.

Anyone have a good recommendation?


Thanks!

Hey eikond,

Hotchkis just released their springs. These have been designed to match the balance of the stock BRZ. They have been testing at the track and autocross. It's taken them a little longer than the other companies, but they wanted to perfect this platform.

Here's my car with them on:
http://www.ft86club.com/forums/attac...1&d=1343390708
http://www.hotchkis.net/_uploaded_fi...rodimage_2.jpg

http://www.hotchkis.net/2013-scion-f...l-springs.html

These springs seem to fit your priority list perfectly. Good luck with your search!

Cheers!:thumbsup:

Thanks! I'm going to read up on the Hotchkis springs right now.

Swift are releasing their springs soon, and I just got an email from Tanabe that their GF210 is going to be available mid-september. These two are usually top performers as well.

Tanabe GF210 - Minimum advertised price - $280
Drop - Front .6 inches / Rear .9 inches
Spring rates - Front 2.7kg / Rear 4.5kg

I bet you will be very happy with any of the brands that you listed too, they are all top notch stuff.

This thread might help in terms of comparing various spring rates.
http://www.ft86club.com/forums/showthread.php?t=8739

According to the chart, the Hotchkis springs should be slighly less aggressive than the Eibach Pro Kit springs, with a similar drop.

Driving impressions?

I've looked at the sticky thread with all the statistics.. that's why I didn't post numbers or drops in my list above.

The problem is.. Those numbers don't always tell the whole story. Just having drop and spring rate doesn't necessarily mean you can understand how they will handle.

It's also important to know if they springs were developed using FRS or BRZ in mind. The two cars had different settings stock.. FRS is more tail happy. BRZ is more balanced. If someone (Hotchkis) made a set of spring that are 45% more stiff in front and 25% more stiff in back for an FRS.. those %'s wouldn't translate the same way to the BRZ because our springs started differently..

It's all a bit confusing to me.

Why is the drop more in the rear than the front? Wouldn't that mess up the rake? Thanks.

Everything you described sounds like you want Swift Springs. They should be available within a month they told me.

Swift makes springs for HANDLING, not lowering springs, though they end up dropping around an inch usually.

I'm waiting for DG-spec springs! Dan Gardner has already tested his custom spec rims with his springs and told me he loaded them up at a 100mph on turns so yeah I'm good. DG-spec will be everyones best bet. He is making all suspension parts so you all know

Yeah, sorry about that. It is not the same percentage increase for the BRZ. It's more like 21% stiffer in front and 38% stiffer in the rear. Increasing the front rate more versus the rear for the FR-S will improve stability (less oversteer) which was what Hotchkis was aiming for. This strategy was geared toward getting it closer to how the BRZ is balanced while still allowing for rear rotation when needed.

Thanks!

I've always heard good things about Swift.. though i'll admit I haven't owned any of their product in the past.

I can wait a month to see what else comes out.


Hopefully other people will find this thread interesting and helpful as well.

With the Hotchkis coils:
- Ride comfort is great with a slight increase in harshness.
- Noise and vibration have not increased.
- Steering response and transitions are noticeable quicker.
- Steady state cornering shows neutral handling.
- Steady state cornering leading into decreasing turning radius (sudden increase in steering input while in a corner with same amount of throttle input) shows slight understeer.
- Steady state cornering leading into off throttle deceleration shows neutral handling
- Steady state cornering leading into braking deceleration shows neutral handling
- Sudden steering input while mashing on the throttle shows controllable power oversteer.
- Sudden steering input with sudden off-throttle shows slight oversteer

Driving on a road course is great since the balance is so neutral. I prefer neutral handling on the road course and an oversteer setup for autocross. That's where sway bars come into play.

seem like Eibach spring got problems from the other thread, so try and stay away from that

I'm going with the RCE Yellow Starter Kit Lite, you get springs, bumpstops, front camber bolts, and Whiteline rear camber bushings for under $500 not to mention the alignment specs are included...

We run swift springs on almost all of our cars that have springs. They will be out shortly, one member here already has the prototypes.

Yes, I am quite happy with them. Awaiting final technical specs for the production version.

Check that thread again. It seems like the damage to the dampers was caused during installation. The installer used an impact gun on the top nut without using a tool to keep the rod from rotating in the body of the damper.

-Justin

Negative. That OP had a lot of info wrong which he's admitted to. He and the owner of that car agree that it was an installation problem, not a problem with the springs.

I'm not sure what thread you're thinking of. If it was this thread:

Eibach Thread Here

...then I'm not sure it's fair to say Eibach springs have problems. It sounds like it was an installation problem (possible shaft spinning).


Edit: Oops...looks like a few others said the same thing :)

I'm going with RCE Yellow springs. RCE does their homework and I've been very happy with their springs on my STI. 20mm drop F/R, and they will preserve the balance of the car.

Under $500... where?

Direct from RaceComp Engineering!:thumbsup:

Glad I came across this thread. STi pinks only give 15mm drop. Hotchkis Springs 1 inch springs with stock like handling which is exactly what I'm after.

Honestly....I don't remember quoting anyone that or posting it. :lol: But I've been on some meds due to a knee injury so anything could have happened.

And what the hell, 499 sounds good to me. I'll put it up in the for sale thread. :)

I have a lot to say on the topic of what springs are best but in reality it depends and it's still early. I've always liked Swifts and we do sell them but we'd like to see final specs. We got our start selling STI Pink springs so we'll always have a thing for them. Eibach Pro-kits seem like a fine choice too.

- Andrew

I hear some Eibach Sportline reviews will be coming soon...

I think I'm just going to wait for the STI springs.

http://www.sti.jp/news/2012/12024.html

I've got the Whiteline Com-Cs, camber bolts and rear camber bushings plus some Eibach Pro Kit springs lying around in my storage room right now, and some RCE Yellows on the way to complete the Starter Kit setup.

I'm planning on driving the car stock (on summer tires) as much as I can until my trusted mechanic/alignment guy gets back in mid-September so I'll post up a review on the RCE Yellows then.

Will probably skip installing the Eibachs altogether and just sell them on in favour of the RCE Yellows + starter kit since the RCE starter kit was developed as a package. Unless somebody can bribe me to go through the additional effort and $$$ of two spring installs and two alignkents for the sake of a true back to back comparison.

Also, I suspect that an alignment will influence handling in addition to just springs, which gives people another variable to consider.

:)

Doesn't make sense to not try it out IMO.

The RCE is a equal rate setup, who knows you might like the stiffer rears more. :shrug: If you have them, I'd try them out. :shrug:

I'd have loved to but it's all down to my alignment guy not being in town at the moment. Only so many folks here I can trust to do a good job.

:)

this happens to work well with the wl rear crossmember bolts, my h&r are the same way


h&r bias is for brz
grab a calculator and do your arithmatic

im waiting for hitchkis springs and sways to come in, i read up on the forum and i thought hotchkis was the way to go at this point

I know its primitive, but do you guys even calculate bias? It a may be helpful to build a chart, off of that chart that lists all the spring rates. Easy way to tell a drift from a race setup. STuff with Bias like 1:1 like the RCE and many coil overs are not for drift. When you see a front to rear bias of say 0.63, that is more likely to be drifty. fwfw. the oe bias of the brz is like .77. iirc, the FRS is in the 0.60's

while this isnt always the case as everything can be changed with dampers and bars, still..just saying, idiot guide

im interested in the SWIFT as well - someone let us know when they become available.

None of your math, Mook! You take that devil worship elsewhere, where people with braincells appreciate that kind of nonsense

:happy0180:

Honestly...it's much more complicated than that.

If two springs have a front/rear ratio of .7, they still might handle completely different and have a different balance, even if all else is the same.

175/250 and 350/500 will behave very differently and have a very different balance, beyond just less roll for the firmer set-up.

The front and rear do not react exactly the same to changes in spring rate. So if you take the stock spring rates and simply make them 10% stiffer, you're NOT keeping the stock balance. A lot of people (and tuners) still don't understand this.

With our RCE Yellow springs, we went a lot firmer up front than everyone else. Some will think that means we shifted the balance of the car, but in reality...the front with a macstrut needs a lot more help than the rear of the car. Plus it means you can put power down easier coming out of corners (helpful with the torsen rear diff) and have a more stable car that also has excellent turn-in and balance. The front of the car has vastly different geometry and does not have the same camber curve of the rear.

EDIT: and on top of all that, you can throw it all out the window when you drop the car 1.25 inches and are now cornering on the firm bumpstops. Those add spring rate of their own. Or....run RCE Yellows that include shortened bumpstops. ;)

- Andrew

Can anyone confirm the ride comfort of these springs?

i heard a lot of good things about the RCE yellow

Thing 1: Ride comfort is 1000X more a function of dampers than springs! Soft springs with piss-poor dampers will ride harsh. Stiff springs with excellent highly digressive dampers will ride MUCH more smoothly and comfortably, while better controlling pitch and roll. I just went from 9F 7R Tein SS coilovers to 11F/11R Ohlins DFVs on my RX-7, and the Ohlins are UNBELIEVABLY smoother-riding on the street, despite being a LOT (22%/57%) stiffer.

Thing 2: A 5k spring is a 5k spring, no difference between manufacturers other than consistency and accuracy (i.e., is "5k" really "somewhere between 4k and 6k"), susceptibility to corrosion, and fatigue life. I would stick with straight linear-rate springs, not a fan of progressive or multi-rate. For springs, I would pick a *known good-quality supplier* based on what rates I wanted.
One manufacturer's springs aren't going to feel more comfortable than another's of the same rate, and spring rate has WAY less impact on ride quality than damping characteristics.

Thing 3: Wheel rates are what are important. Spring rates are a means to get the appropriate/desired *wheel rates*. Front and rear motion ratios for the FR-S/BRZ are ~0.95 and ~0.75 (as far as I've gathered), and wheel rate is spring rate multiplied by the SQUARE of the motion ratio. If you run same-rate springs all around and you'll have 61.6%/38.4% relative front/rear stiffness at the wheels. In my opinion, that's too much front bias.

Some front-bias will work, but often automakers give a little more rear spring stiffness relative to weight distribution to have slightly higher rear frequency so that at speed, when you hit a bump the two "settle" at close to the same time even though the front hit the bump first. Then they balance the handling toward understeer with sway bars and alignment settings.

Stock FR-S *wheel rates* are right at 50/50 front/rear (spring rates 2.4 kg/mm front, 3.8 kg/mm rear).
Stock BRZ *wheel rates* are ~56/44 (spring rates 2.8kg/mm front, 3.5kg/mm rear)
So their wheel rates bracket the weight distribution, which is ~54/46 - 53/47 with driver and fuel.

I don't think there's anything about MacPherson struts that makes them "need" relatively more spring or wheel rate, and neither did Subaru or Toyota/Scion.

My .02!

Thing 1: I agree that dampers are more important for ride comfort, but with lowering springs we're usually talking about ride comfort problems due to a lack of bump travel and that's still very much a thing. The rates themselves are not as important (and you're on the bumpstops or bottomed out most of the time anyway with the big drop springs.

Thing 2: Agreed....BUT the consistency and accuracy thing is a real concern sometimes.

Thing 3: You should drive a car with our springs. :) On the stiffer end spectrum of spring rates on coilovers on a more dedicated car I would generally go with a firmer rear, but on the soft end with OEM fitment lowering springs you're fighting roll so much that the firm front helps so much. Even with medium rates (the default on our coilovers) we've found that our car is faster with a good bit more front wheel rate, at least for how we have set it up.

- Andy