CSG and RCE tag-team suspension Q&A thread! Ask us anything!

[Racecomp Engineering]

Originally Posted by Spacemane969

I've been running TRD springs for a while now and I want to upgrade to BC coilovers. I want moderately more stiffness but I'm so hesitant to make drastic changes in the overall engineering so I'm thinking 5k front and 8k for the rear to simulate the OEM FR-S 2.3k and 3.8k rates. Anything wrong with this idea of matching the spring rates F/R? Thanks

5k front and 8k rear is a pretty aggressive rear bias. Those that do run that much rear bias in spring rate usually have a clutch LSD that behave differently than the OEM LSD.

For the spring rates, it's important to remember that the OEM suspension is very bumpstop active, so the spring rates are only one part of the equation. And then there's the effects of the dampers. Coilovers are usually a lot less bumpstop active. Another factor, the front and rear suspensions are a completely different design. Increasing the front by 10% will have a different effect than increasing the rear by 10%.

Spring rates are usually chosen after considering tire choice and intended usage. What tires are you using?

- Andrew

[Takumi788]

Thanks for the answer guys. My OCD is going to drive me to purchase the SPL lower control arms to fix this but it is good to know it isn't a huge issue.

[churchx]

Takumi788: what top mounts you have? Raceseng should be able to adjust also caster. Whiteline ALC should change it too. Imho SPL LCAs are expensive overkill unless you go for them for other reasons (eg. changing bushings to pillowballs and insane adjustability of everything) instead of just to even caster. My OCD would have lost the fight against cost of $1.3K for those LCAs, even if they are such quality piece of work

[Takumi788]

Originally Posted by churchx

Takumi788: what top mounts you have? Raceseng should be able to adjust also caster. Whiteline ALC should change it too. Imho SPL LCAs are expensive overkill unless you go for them for other reasons (eg. changing bushings to pillowballs and insane adjustability of everything) instead of just to even caster. My OCD would have lost the fight against cost of $1.3K for those LCAs, even if they are such quality piece of work

I should mention it is a track car. I plan on sticking with the chassis for a while and don't care about street-ability.

I am still on a modified prototype top mount from YCW Engineering.

My OCD leads me into horrible and often costly places. lol. Its an issue and I am aware. On top of that I am also competitive, and if there is a few tenths to be gained by correcting my caster, I'm in. Maybe the raceseng top mounts would be a more cost-efficient solution. Thanks!

[Spacemane969]

Originally Posted by Racecomp Engineering

Spring rates are usually chosen after considering tire choice and intended usage. What tires are you using?

- Andrew

I get a lot of flak but I'm actually a fan of OEM primacies. I haven't found a tire that has a sidewall as stiff and communicates as accurately. I'm considering the new PS4S after the coils if I need the grip. This is for spirited/occasional track.

[Pat]

Originally Posted by Spacemane969

I haven't found a tire that has a sidewall as stiff and communicates as accurately.

I'm surprised. What other tires have you tried?

[Spacemane969]

Originally Posted by Pat

I'm surprised. What other tires have you tried?

Started with hankook v12 Evo 2 and that was a disaster. I was about to pull the trigger on pilot super sport but I read too many remarks about mushy sidewalls to justify the risk of being unhappy. I have more confidence in the PS4S now that it is the OEM option for the brz ts and 86 trd.

[AndreC]

The factory Primacys have a much softer sidewall than the Pilot Sport 4S, which is still on the soft side. Hankooks are a medium stiffness sidewall typically, like the V12 and RS4 and more communicative. Stiffer but not ultra stiff are the Firestone Indy 500 (Bridgestone Re003), and super stiff tend to be the case with "most" BFG's and Dunlop's.

Sent from my SM-G965W using Tapatalk

[Spacemane969]

So for a mild spirited driver setup, what would be wrong with a 5/6k coilover setup? Ft86speedfactory stocks BC coils at 8k/8k, with anything else a special order. I just don't understand why this would be the default if the OEM spring rates are different front and rear. I understand there are tons of variables but surely those OEM numbers mean something right?

[solidONE]

Originally Posted by Spacemane969

So for a mild spirited driver setup, what would be wrong with a 5/6k coilover setup? Ft86speedfactory stocks BC coils at 8k/8k, with anything else a special order. I just don't understand why this would be the default if the OEM spring rates are different front and rear. I understand there are tons of variables but surely those OEM numbers mean something right?

6K in the rear with the right amount of damping pressure can be comfortable and even ride like a boat. 5K~6K range is a good range for spirited street, IMO. 8K is far from mild on this car. The main function for such high spring rates on the BC, i believe, its a sort of bottom out prevention. That should give you an idea on the ride quality on this.

[NoHaveMSG]

Originally Posted by Spacemane969

So for a mild spirited driver setup, what would be wrong with a 5/6k coilover setup? Ft86speedfactory stocks BC coils at 8k/8k, with anything else a special order. I just don't understand why this would be the default if the OEM spring rates are different front and rear. I understand there are tons of variables but surely those OEM numbers mean something right?

The motion ratio is different front and rear(Mac Strut vs. Multilink), which changes your effective spring rate. Most of the aftermarket has chosen to use the same rate front and rear. It works so

BC's and 8k. Please don't. Look at ST's, RCE SS1's, Flex A's. There are much better options out there.

[Grady]

My setup now is I have a 2017 PP with Ebach pro springs, 225 MP4s tires, Verus top hats and Ventus 3. Plus other minor changes. On the track my boost seething is low probably 250ish WHP. I daily the car and am satisfied with the ride now. Not sure about the Sach dampers but my experience most factory struts are shit in 30k miles. What would be the better upgrade for performance? I am ok with losing some ride quality. B6’s, Koni, or should I just buy $2k coilovers? I would prefer to keep the top hats and springs I have already purchased. I may run the pilot sport cup 2 tires at one point also. But I will not go to wide tires.

[Scracho]

Hi guys!

I'm on my 4th 86 (Yes 4th) and have played with various suspension setups. I'm in the market for a $1500 street occasional track coilover and all roads have led me to a couple options.

IMO the largest improvement in ride/handling/lap times happen when you go from stock to DECENT coilover setup then from there unless you go to a full on pro setup the lap times aren't improving relative to cost from your decent "entry level" to medium tier coils. Thus the savings can be used for so many other items that will yield a faster, flatter and more enjoyable ride.

So that being said... CSG Tein Flex A OR RCE SS1????

[RToyo86]

@ Racecomp Engineering

Any ideas on when RCE yellows will be available to order?
Looking to order through FT86Motorsports. They're special order which I assume will go directly through you.