Suspension Tips, for those who want to lower this car.

[amayzlin]

Thank you very much for this post. I recently purchased a 2013 FR-S with Five Axis Edition Kit. It includes the Body Kit, 19" wheels and Tein High Tech Lowering Springs (but factory OEM suspension).

http://www.fivead.net/edition-vehicl...cion-fr-s.html

I am not a professional or a racer, just an enthusiast, and I have to say that the ride is awesome. It has exceptional looks, it's fast, handles great - I am very happy with it. However, when I go over bumps, I hear knocking sounds from the front and rear wheels. I took the car to the mechanic, and he said that the sounds are the result of the lowering springs + OEM suspension/struts, and nothing can be done about the sounds until the proper suspension to support the lowering springs is installed. There's also a chance that the car is lower than by 0.9 (as specified in specs of the Tein Springs) What would you suggest I do? Do I just live with the noise, install different springs or get an aftermarket suspension kit? What type of suspension would you recommend?

Thanks in advance!

[Racecomp Engineering]

Knocking sounds are bad and you should not hear them with properly installed springs. Check everything over and make sure nothing is loose.

- Andy

[amayzlin]

Originally Posted by Racecomp Engineering

Knocking sounds are bad and you should not hear them with properly installed springs. Check everything over and make sure nothing is loose.

- Andy

Thanks for your response, Andy! What are possible examples of installing the springs IMproperly? Do silencer rubbers contribute to elimination of these sounds cause I don't think they came with the springs.

Thanks...

[Racecomp Engineering]

Check top nuts and make sure they are tight. Are you sure you're hearing it in the front and rear? Is it a loud clunk that you are hearing that sounds like something is loose?

I don't sell Tein springs but I thought that they did come with coil wrap.

- Andy

[amayzlin]

Originally Posted by Racecomp Engineering

Check top nuts and make sure they are tight. Are you sure you're hearing it in the front and rear? Is it a loud clunk that you are hearing that sounds like something is loose?

I don't sell Tein springs but I thought that they did come with coil wrap.

- Andy

Yeah, I'm pretty sure it's the front and rear. The sound is more like a knock - doesn't give an impression that something is loose. Could it be that the coils are hitting each other or the springs have sagged? It was mentioned to me that the car is dropped lower than spring specifications state.

[Racecomp Engineering]

Hard to say without looking at it.

[SurfAndSand]

"thud" is hitting bump stops? :p

"clunking" shifting/loose parts?

[Howardwei]

Originally Posted by Moto-P

Increasing, or changing tires sizes both in width and diameter has consequences that change many different variables, and simply raising the contact patch should not be taken lightly or be treated as a fix-all solution. Increased tire contact patch also means less ability for the tires to reach proper temperature, and reduced grip over loose surface as rain and snow, and even dirt.

I think to keep the inherent balance of power and handling of the FRS/BRZ, the tire size change should be minimal, regardless of going with 16", 17" or 18" to keep the same diameter, and relatively small widths. 225's and 235 width should be plenty for a light FRS, to be fun and agile as universal car. Going beyond this only if there is a specific purpose in various field of REAL racing.

Hi,
Thank you so much for the elaboration. I am going to purchase a set of Te 37sl black in 18x9.5 square set up or 18x9.5 rear and 8.5 front. I was told doing 9.5 in front need a camber so i don't want to mess with that at all. But I do want to have my car lower to compensate for the aesthetic look that it would come with the wheels. My objective is to lower it by 1 inch. Would I need anything else besides a new set of spring from Cusco? I dont wanna lose the ability to oversteer easily like the stock one. I have a BRZ by the way. As far as tire is concern I want to do 255/35 in the back and 235 in the front. I am new ot thise so My set up is probably not sophisticated. I originally intended to do 255 all around.

Thank you so much!

Howard

[Hachiroku14]

how about the gc top mounts which can extend "play" of the struts? 2" rear 1" front correct me if im wrong. So will lowering with a good coilover with these top mounts still retain the performance the coilover was trying to achieve with a slightly lower car than most? say 1-2" MORE? Or will my next problem besides rubbing will be the center axis being out of spec? Thanks for the input!!!

[Racecomp Engineering]

Originally Posted by Hachiroku14

how about the gc top mounts which can extend "play" of the struts? 2" rear 1" front correct me if im wrong. So will lowering with a good coilover with these top mounts still retain the performance the coilover was trying to achieve with a slightly lower car than most? say 1-2" MORE? Or will my next problem besides rubbing will be the center axis being out of spec? Thanks for the input!!!

Lowering type top mounts help with bump travel but not geometry. The travel is more important but not the full story.

- Andy

[maksfrs]

I have my car maybe an inch and a half dropped - fully soft on the 30 way dampening BC Coilovers - couldn't complain at all. and gap is smaller, but no difficulties even during rough Canadian winter. But for the summer/track time, I will for sure invest into good grip street/race rubbers.

[Moto-P]

Originally Posted by troek

would you recomend a progressive spring or a linear spring for the track?

Progressive is fine, as long as you're not tuning a car for a very precise setting for a very particular driver/track/tire combination.

[Moto-P]

Originally Posted by SurfAndSand

Thanks for posting your thoughts. I wonder how MOTO can chime in on this - supposedly lowering the vehicle with stock wheels/tires will worsen response. Possibly you haven't explored the true limit of the vehicle - and this makes sense, since you were testing on the street.

RSR's Down-Sus or any near-compatible OEM replacement style lowering springs of mild nature is fine for visual aesthetics. It will not alter the suspension too much since the harder rate they are designed with is only for reducing the suspension travel when things are lowered on stock shocks. Since lowering a car on stock OEM shocks, will effectively reduce the working stroke range of the suspension, we simply need slightly stiffer springs to make it work in that shorter range of motion.

Will it improve handling? Well yes and no. It will improve the driver "feel" of the car since the initial response for feedback is more immediate. However in real-term performance, it isn't going to change very significantly and we do tend to lose a little in the comfort department since we are not touching the character of the shocks, and simply changing a spring out will cause a very slight mis-match. So thnk of spring upgrade as a sacrifice in slight comfort and gain in visual appeal, but not really up or down on the performance aspects. True "UP"grade doesn't happen with small and individual parts changes, but more drastic and complete make-over with combination of higher grade mono-tube shocks wrapped with coil-over piston/case adjustable (as in RSR Sports-i) and some links and arms to recalibrate the entire car at the new specifications and going where parts list constraint couldn't do with $25,000 limit on sticker price initially.

[Jose_Timberlake]

Originally Posted by samsam5886

To me it's not about the wheel gap... it's about the wheel being concentric with the fender! And the FR-S/BRZ does that quite well, so IMO the FR-S/BRZ isn't too high at all. The ride height is perfect. In fact, lowering the car will ruin the already concentric wheel/fender look from the side. Who else agrees with me on this? There's no need to worry about scraping your car either as a bonus! And besides, the car's center of gravity is already low enough.

Truly appreciate you saying this! I've been back & forth on whether or not I should/need to add lowering springs to my FR-S but just couldn't shake the fact that the current factory setup feels perfect right out the box. As you pointed out, I also feel the ride height is perfect, despite there being a slight wheel/fender gap, it really is concentric.