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-   -   Best springs to go with stock dampers (https://www.ft86club.com/forums/showthread.php?t=40076)

solidONE 06-26-2013 12:52 AM

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! :)

qoncept 06-26-2013 11:44 AM

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

CSG Mike 06-26-2013 12:12 PM

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)

solidONE 06-26-2013 01:31 PM

Quote:

Originally Posted by CSG Mike (Post 1026677)
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.

CSG Mike 06-26-2013 01:39 PM

Quote:

Originally Posted by solidONE (Post 1026856)
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]

solidONE 06-26-2013 02:00 PM

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?

CSG Mike 06-26-2013 02:24 PM

Quote:

Originally Posted by solidONE (Post 1026918)
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.

solidONE 06-26-2013 03:05 PM

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.

soodxn 06-26-2013 11:31 PM

try the swift brz springs

solidONE 06-27-2013 04:02 AM

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:

soodxn 06-27-2013 04:57 AM

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

solidONE 06-27-2013 06:33 PM

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.

kvnchu 06-27-2013 08:08 PM

Quote:

Originally Posted by solidONE (Post 1030569)
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!

solidONE 06-28-2013 02:18 AM

Quote:

Originally Posted by kvnchu (Post 1030799)
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.


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