Best springs to go with stock dampers
 

Hi all! So I'm slowly modifying my FR-S to be more competent on the track and plan on joining in on some of the 86 time attach challenges. I want to do modifications that are allowed without adding any points and risk being bumped up from "stock" classes. I believe Speed Ventures' 86 Challenge has the most stringent rules, so I will be going by those rules.

Rules here: http://svc.speedventures.com/content...6rules2013.pdf

I've already done some minor modifications and have tested them on Buttonwillow this past weekend. Aside from my tire pressure mix up in the morning I was very happy with the results.

Track mods:
RPF1 17x8 -45offset
Hankook R-S3 225/45/17
Stoptech Street Performance Pads
ATE Racing Blue Brake Fluid
SPC front camber bolts set to max (-1.4 deg camber)
JDM under paneling (if that can be considered performance enhancement)
Factory Scion spoiler

The tail still likes to come out more than I'd like, but the turn in from the added front camber was on point. The brakes were sufficient, as it was my firs time on a racetrack in over a decade with a car on a track I've never been to. I wasn't about to bin my brand new car with on track heroics on the brakes (6/10ths driving). I was only able to muster a 2:23.8xx lap that day, but I'm confident with the current set up it would be worth a much faster time. Closer to 2:15.

Next thing I'm looking into is to change out the factory springs to lower it a bit and to gain some camber all around that way and to keep it a bit flatter and less tail happy around the corners. I've looked into the spring rates on several of the offerings out on the market and they seem to be all over the place. From the equal rates and modest drop of the RCE @ 250lb/in all around to the progressive rates of eibach/tein/H&R and their +1" drop. The Hotchkis spring looks pretty promising at 185f/265r, but seem like they would retain some of the tail happiness of the factory setup. The RCE yellows look pretty good as well but seem like it would be prone to understeer and the 20mm drop is not going to gain all that much camber for me.

What would be a good setup for absolute cornering grip with neutral handling on the track while still using the stock dampers? I may also look into swaybars as well later on if I feel they will compliment or enhance my setup. Input and suggestions appreciated! :)

If you want less oversteer I would go with the RCEs.

If you want less oversteer, I would focus on smoothing out your inputs. The rear is coming out from large lateral weight transfers.

Your current setup is actually good for closer to 2:05 (in conditions similar to this weekend)

That's good to know. I was not abrupt with any steering, throttle, or brake inputs and taking it relatively easy. The thing was that I was not able to apply much throttle mid corner without the rear wanting to come loose. Were you there at buttonwillow as well? I saw one other BRZ/FR-S.

I was there Saturday doing some testing with a client's car.

https://fbcdn-sphotos-g-a.akamaihd.n...74338755_n.jpg


This may help a bit too. Really old (read:slower) lap from when we just got our car.

[ame="http://www.youtube.com/watch?v=VZpWlSp2Hvc"]Buttonwillow 13CW Subaru BRZ 2:07 - YouTube[/ame]

And then the current incarnation of our car

[ame="http://www.youtube.com/watch?v=nGBZWkoQO-s"]CSG BRZ Buttonwillow 2:00 lap - YouTube[/ame]

I was there on Sunday only. I think it's widely excepted that the BRZ has a more neutral/understeering tendency vs. the FR-S. I'm sure I can use some 'software' (driving technique) upgrades lol, but in terms of hardware upgrades, which springs would you add to my current setup to get it to corner neutral or to get the rear to hold more G's before wanting to come loose without having to change tires?

Don't believe everything you read. It's *easier* to swing the FR-S's rear around via weight transfer, but at static cornering, it's still an understeering car.

If you're trying to settle the rear by making it difficult to swing out, what you're really doing is reducing the front grip until the front always gives out first. You can get springs/sways now as a band-aid fix, but my recommendation is more seat time. If you're dead set, just get a front sway (and front only) first. Also, get camber bolts for the front, and install them.

I'm actually pretty content with what my front end is doing right now, and I already have SPC camber bolts installed in the front. Turn in is good, and I dont want to upset that by adding just a front swaybar. Maybe a little bit more of negative camber in the rear will help it grip more mid corner. Springs will help a bit in that department. I definitely do not want the front to push, which what it was doing with the factory alignment. More track time is definitely on the todo list.

try the swift brz springs

Swift spring rates according to evasive's online store:

http://www.evasivemotorsports.com/mm...R_S-SUSPENSION

Swift $299.25 + free shipping via google search
Front 3 kg/mm or 168 lbs/in
Rear 4.5kg/mm or 252 lbs/in
1in drop f/r

Hotchkis $185 +free shipping via google search
Front 1" (25.4MM) Drop, 185 lbs/in (3.3 kg/mm)
Rear 1" (25.4MM) Drop, 265 lbs/in (4.7 kg/mm)


Hmmmm... I like the look of those rates. Very similar to Hotchkis' rates but slightly lower. And slightly more biased to the front than Hotchkis Springs as well, but I like the bias toward the weight of my wallet of the Hotchkis spring better.. lol

Now I just got to factor in my "being anal about spring rates" vs."wanting to have more more money in my wallet" bias which is about a 2 to 3 ratio towards my wallet. Talk about dilemmas. lol :laughabove:

look up the swift BRZ rates, they have seperate frs and brz applications. The rates are all in the suspension forum sticky. I think you might prefer the BRZ rates

I doubt I will have time to put in springs or rear camber bushings in time for this sunday. thanks Mike! I may try simply unhooking the end links on the rear sway to see how that works out. If I don't like it I can just hook them back up at the track. Easy peazy.

The rates for the Swift BRZ springs looks like they are exactly what I'm looking for right now. Of course I'll still have to run them to know for sure.

Hey we met at a track day a while back. I would go straight to coilovers. Im actually selling my set if you are interested as well. Check the classified!

Thanks! But I'm not going to do coilovers just yet.

I wouldn't do springs simply so you can get more camber...you don't gain much up front from that. You do get some in the rear.

IMO the milder the drop the better for springs on stock struts if performance is the goal. The front of the car is travel challenged and if you lower the car an inch on the SOFT rates that everyone else uses you will be cornering on the bumpstop. The spring rates of the bumpstops make the system progressive in a bad way...spiking the wheel rate and causing sudden understeer in certain situations. Bonus with ours is the replacement shortened bumpstops.

Some of the springs out there are just way way soft up front.

IMO the milder drop with firmer front rates works well to keep the front in a better place geometrically.

Our springs are function first. No, it's not a 4-way hydraulic bumpstop motorsport coilover competitor, but it's a solid improvement to handling that improves front grip AND keeps the rear end stable. Fun, fast, and predicatable. Win-win-win.

- Andrew

So I ran SoW in the morning session with the rear sway unhooked. The result was exactly what I expected. I would mash the throttle mid corner and the tail would stay stuck. Did a 1:43 while learning the track. I thought this wasn't bad for the beginning session and I fully expected to shave at least 10 seconds off of that just as I shaved 12 seconds off my morning session time at BW. Following session I hooked the rear sway back up just to see the difference. Sure enough, I spun off the track on turn 10 applying the throttle like I did when I had the rear sway bar off and did some off road driving.

For whatever reason (probably because of the squishy feeling of the rear with the sway bar detached) I decided not to unhook the rear sway again and had Mike drive the car in a later session. He was carrying way more speed into the turns and pretty much had the throttle pinned through most if not all the turns. I felt the tail did come out a tad, but never it lost traction not even a chirp from the tires. Obviously there is something I'm doing different with the car mid corner than Mike. He decided it was my steering input. While I don't doubt that, I thought I was very deliberate with being smooth with the steering input. Of course I was not as aggressive with the brakes and carrying much less speed into and through the turns compared to Mike. Great driving @CSG Mike BTW and thanks! I was honestly more confused after having ridden with Mike and hearing his feedback about my car. There was no way I was going to duplicate the pace he went at so I was unsure how I was going apply what I saw him do with my car.

It was so hot at the track, hitting 114 degrees at one point, that I had no recorded data from my Harry's lap timer at all to study. iPhone was overheated the entire time on the track. I was only able to hit 1:39.2 as my fastest lap. a good 4-5 seconds off from my goal for today. I was fully expecting to go under 1:35.... rather disappointing day at the track today, plus the heat felt like shit, really hot shit. :thumbdown: Plus side, I met some fellow 86ers at the track. Bunch of cool cats. :happy0180: