Long time Lurker seeking advice on a budget suspension setup
 

I'm a moderately experienced driver and have some autocrosses under my belt, but the FRS is a whole new world. I have now had the FRS in southern California for 6 months, here are my thoughts on the suspension:

-Obviously, the car needs to be lower, but the struts seem to be woefully inadequate in compression dampening with the stock springs to begin with. Kicking up the spring rate I imagine will make it handle like Mercedes. Yuck Are these struts really that bad? Am I wasting my time by thinking someone makes a spring that will lower and stiffen the car and still pair fairly well with the stock struts?

-The car is balanced brilliantly most of the time, but in VERY tight turns (Malibu canyons) you can feel the lack of front camber just ruin front grip. I know the common answer is to simply add camber plates to the front, but I’m not sure that’s the best route.

So my theory is as follows... If I can find a set of springs that match well enough with the stock struts, the key will be the following:


Front Lower control Arms:party0030::party0030::party0030::party0030:

Theoretically, a great set of LCA’s should be able to accomplish 4 VERY important things, all in one easy modification:

1. Add front camber adjustment by pushing the bottom of the wheel outward (widening the track) Added benefit- wheels are a bit more flush with the fender
2. Add a bit of caster which should add negative camber in the very very tight corners.
3. Correct the front suspension geometry for the lower ride height, maintaining negative camber when the suspension is compressed
4. Replace the stock bushings up front to poly, which should really sharpen up the steering feel.

I'm really surprised that I can't find much written about doing the LCA mod? On my Cayman, it was the single best modification I did on the car... and it was cheap: I bought some used GT3 arms for $400 that bolted right on and did everything I mentioned above.

The Racer X LCA's seem to be the best option- does anyone have any experience with them?

The RacerX front lower control arms look interesting, but I've never tried them. We ran a custom front LCA on our car and the difference was dramatic.

An alternative would be camber bolts, the Whiteline roll center kit, Whiteline ALK (the rear bushing, adds caster), and the WL front control arm bushing. I think that comes in a little cheaper, plus the WL roll center kit includes replacement tie rods to correct for bumpsteer after the roll center correction. The RacerX arm will have more adjustability.

The stock springs (especially on the FRS) are very soft up front so the lack of compression damping is noticeable. The shocks aren't THAT bad, but IMO the springs are too soft. We have our RCE Yellow springs which are a popular option with the function first crowd. Mild drop of 20mm plus we include replacement shortened bumpstops. Spring rates are 250 lbs/in front and rear. Some worry that increases understeer...that's not the case since we designed our springs to be much less bumpstop active than stock (there's more than just suspension frequencies going on).

Good springs + some camber and bushings makes a large difference. I'd add a few parts to the rear as well to get everything dialed in nicely.

- Andy

For front lca you might like to get in contact with http://racefab.co.nz/
Their website is pretty ordinary but the quality of their work seems well regarded.

What ever happened to your front lca? I remember you
were working on them and had shown 1 or 2 pics of them.
I was quite interested in them at the time.

After nearly 25,000 miles of dd/autox/track driving on stock dampers and RCE Yellow springs, I can assure you they are well matched. In fact, everyone who has driven my car has praised the neutral and balanced handling. With little more than tires, springs, a front bar and some negative front camber, I finished the LVRSCCA season 1st in STX and 2nd overall in PAX. A true testament to how well this chassis performs with minimal modification. I also commute 50 miles per day with an 8 year old in the back seat so relative comfort is also important in my car's suspension setup.

They were just a little too expensive. Seriously awesome but we couldn't get the price to where they would be competitive.

- Andy

You said you were on a budget? Since you're driving an FR-S, you're going to want stiffer front springs and more over-steer. How about getting some KW V3's and adjustable top hats. They are sprung stiffer than OEM, 60 N/mm front, 70 N/mm rear versus the FR-S 23 N/mm front, 37 N/mm rear, they are 2 way adjustable, and they can be lowered from 1-2.5" without touching the preload. Top hats usually get you at least 2 degrees of negative camber, combine those with camber bolts if you need even more.

Awesome- this is the feedback I was looking for on the springs. I'm going to pick myself up a set.

So rather than my idea, you are suggesting I spend twice as much only to get a car that has a ruined suspension geometry?

My experience with the RCE yellow springs is similar. I found them to be an excellent match to the stock dampers and tires. Very predictable and easy to drive fast. I found the ride was actually more composed compared to the stock FRS setup. A few people have postulated as to why most find this. I don't know why, but that was my experience.

I did find that when I upgraded the tires significantly I was back on the bump stops in a hard turn which brought back the factory unpredictability when going over mid turn bumps. But I was sufficiently impressed with such a simple product as a set of springs that I kept with RCE for a set of their tarmac 0 coilovers. Those are waiting to go on in the spring.

If you have the free time to peruse the other tales of the finely tuned derriere dyno KoolBRZ has, ... Well, it's a valid and common approach to suspension tuning which actually surprises me given the source. Does it yield the best results? I have no idea. I'm building to classing spec (STX) so front LCA is probably out anyway... But then, the alleyway I must use to get to my garage also limits drop... Lovely speedhills. Anyway, no useful info from me here, but this is an interesting topic. Not the usual approach.

C

.....you'll be torn between laughing and crying.