temps

Hey guys, There's some old posts on this but I was wondering how things sat in 2017.

Currently my FC is on Racing Beat springs and Tokico Blues and I think it rides basically perfect - firm but still comfortable, corners flat enough. But the drop is not quite what I'm looking for especially in the rear.

I'm debating either going for Tanabe GF210s on the same Tokico Blues or making the jump to coilovers, but I am worried about spending a bunch of cash to ruin my car.

I had coilovers in a previous car with 600lb/in springs front 400lb/in rear with Tokico Yellows and it just ruined the car for me - way too firm to enjoy driving, and it was so oversprung it actually was dangerous driving it on pavement that wasn't perfectly smooth. Even if I set the shocks to full soft, the ride still sucked because then the car would oscillate over bumps because it was underdamped.

I hear modern coilovers are better but I'm hoping to hear from people who have gone from lowering springs to coilovers, and how the car feels during normal street driving after the change. I am not concerned with ultimate performance as I don't track my car and the street is no place to try and push the limit.

I know with a lower drop I'll need a higher spring rate to keep my rims & tires from mashing into the fenders especially because I'm going with a pretty aggressive fitment, so I can tolerate a moderately firmer ride but if it is going to be nuts even with comfortable valving and custom low spring rates (I would go 5k front / 4k rear on Stance coilovers) I will go with Tanabes instead of coils

Please let me know what spring/strut setup moved from and which coilover you moved to

Thanks!

ZDan

If ride is basically perfect now, and money is an object, you might try keeping the Tokico Blues and get the tanabe springs, if you don't mind the risk that you'll might have to replace the blues with something like KYB AGX which (I think) are more geared to stiffer springs and at least give some damping adjustability.

It looks like Racing Beat springs are ~2.5kg/mm front and ~2.0 kg/mm rear (?). The Tanabe GF210 are 3.1 front, 2.6 rear. That's a kind of big but not huge increase in spring rate, so for sure your damping will be reduced, but the good news is that critical damping only varies with the square root of spring rate, so ~25% stiffer springs only require ~12% more damping to be the same percentage of critical. Or, put another way, going with the stiffer GF210 springs, you will only have ~12% lower damping.

I would try it...

Thing with coilovers is that most will be way stiffer, and also lower-priced ones are pretty much guaranteed to have suck damping, whether it's adjustable or not. I wouldn't go there...

j9fd3s

iTrader: (3)

i agree, if the current combo is good, the tanabe springs aren't going to be a huge change, which is good.

Valkyrie

If you just want the car to look lower, just get some lips, skirts, and bumper extensions.

The car will look lower and you'll get a little less aerodynamic lift without hurting comfort or performance.

Coilovers aren't uncomfortable by default, they just tend to be much, much stiffer than stock springs (two or three times stiffer) because they're designed for performance, not comfort. You could potentially get springs that are just as stiff as stock if you wanted to.

Keep in mind that if you keep lowering the car, it's going to suddenly become less comfortable because you'll have changed suspension geometry so much the arms don't want to move as easily.

Lower = stiffer is not just about keeping the car off the ground or the bump stops. You're also making it stiffer to compensate for the fact that you've changed the suspension geometry (roll center, bump steer). Any suspension will work if you don't let it.

90FC

I've questioned the same thing. I currently have stance coilovers with 8kg/6kg spring rates. When I put the coilovers on my car years ago, my intent was to take the car to the track. Unfortunately, life gets in the way now, so I have less opportunity to make use of the extra ride stiffness.

It doesn't​ ride absolutely horrendous right now, but I wonder how much more I'd enjoy driving it on the street with a softer suspension?

I would like to try a new strut/spring combo similar to your setup, but what holds back is my wheel/tire setup​. I'm running 17x8.5 30mm et wheels with 235 wide tires and it's a tight fit as it is. I'm worried with the stock style springs where they flare out at the bottom will cause clearance issues with my tires. I prefer not to have to run spacers.

LargeOrangeFont

iTrader: (7)

Swap to 7K/5k springs and see how you like it.

You'd likely clear with a stock strut though.

T.Seuf

I have plans to swap out my 12k/10k coilovers with a set of tein s techs/Bathurst shocks which are progressive (7.8k/5.8k) in the next week or two. I'll comment on my results after a couple test drives.

the 12k/10k coilovers are surprisingly comfortable with stock 16's, but with 18's they are a bit rough...
Having said that I understand I am trying to put more cushion back in my springs to accommodate for less sidewall. We'll see how this turns out.

BLUE TII

iTrader: (9)

I don't remember if my Stance springs were the same length front and back...

But if they are and you want to save some $ you could put the 6Ks in front and get some 4.5Ks for the rear.

temps

I checked most of the aftermarket companies, the lowest Stance coilovers go are 5k/4k. Tein will go 6k/4k and Zeal ($$$) iirc was 5k/4k too. The only ones of those I have much confidence in are Tein and Zeal because they do custom valving... I am not sure if Stance coilovers would be any good with that low of a spring rate. Zeals are extremely expensive... don't think I'm going to go that route.

It kinda seems that soft springs are just for spring/strut setups.

I would not recommend Racing Beat springs. I like the ride but they are too soft for the drop - I had my front fenders rolled this weekend, and my fronts still rub the fender on big bumps. Infrequently, and not much, but still... 16x7 +35mm 225 tire is hardly aggressive. If I do decide to stick with springs/struts I'll have to change to GF210s anyways.

Perfect, look forward to hearing your thoughts. I'm keeping some sidewall on my car so I'll have that much at least to keep things bearable

LargeOrangeFont

iTrader: (7)

I dont think that they are. I think they run 7 inch springs in front and 8 or 9 inch springs in the back.

You can run 7s all around though.

Valkyrie

You can order whatever shock length, damper rate, and spring rate you want.

That's the whole point of coilovers.

LargeOrangeFont

iTrader: (7)

Fortune will build you whatever you want for the car. 7K/5k is probably the lowest you'd want to go in a coilover. If the damping is right, 8k/6k is not bad at all.

BLUE TII

iTrader: (9)

Well, there are assembly line style coilovers where you get what they make (like Tein).

There are companies that will have some leeway on spring rates with special requests and might offer two choices of damping (like Stance).

Then there are companies that will custom build whatever you want.

Some of these are 1 man operations using cheap parts and actually pretty affordable (like FatCat).

Some of these are small operations using the best parts, technology and engineers for race teams and very expensive (like Penske).

And everything in between.

Though I don't understand why you would want to pay coilover price for a smooth riding shock/strut for stockish spring rates when regular performance shocks/struts were developed for exactly that some 30 years ago when the FC was a premium sports car by big manufacturers spending big $

Tokiko, Koni, Bilstein, KYB, Sachs

Hot tip, replace the original bumpstops with new ones if shocks/struts don't come with them while you are putting the suspension back together.

Hot tip, don't buy your "name brand" lowering springs on Ebay where they are probably knock offs.

lOOkatme

iTrader: (19)

if ride is important. make sure you have a flat ride. this means the springs ride frequency is 10-20% stiffer in the rear.

I don't know the motion ratio's for a FC but pick a 1.2hz front and 1.35-1.4HZ rear and this should ride pretty well.

if you want you can get more aggressive and do a 1.5hz front and 1.75hz rear, don't go much above this as it affects ride quality in a big way. its not linear in feel.

Valkyrie

To be fair, I think it's a little absurd to be looking at changing a setup that works well because it doesn't "look" low enough.

I'd just buy the Stances and call it a day, but the car *will* be less comfortable to some extent or another.

Tuning4life

iTrader: (2)

If you really want to start looking at what is comfortable and what is not. Shock dyno's where the low inches per second need to be smooth and transition from compression to damping smoothly as well. the harsher the curve is the harsher the ride.

Ohlins has a nice smooth low IPS damping and compression, many other shocks are harsh and will feel so.

j9fd3s

iTrader: (3)

if we've learned anything from Ohlins its that the SHOCK has a bigger impact on ride quality than the spring does. get the damping right, and you can run relatively very stiff springs AND have a nice ride.

the springs do control pitch, like l00katme says. also the spring rate dictates how much movement the car will have over a given bump input. imagine a 70's caddy, when it hits a bump the wheel moves a lot. with a stiff spring the wheel doesn't move as much.

a few years ago i had a low mileage stock 87 GXL, and my friend had a GTU's on 8/6 springs with Koni's. the GTU's handled better, of course, but it also rode better.

newer example is maybe my DD miata, and the race car miata. the race car is on Ohlins, and it rides way better than my DD, which came on ebay springs and blown stock shocks.

Valkyrie

I could be wrong, I would think that's mostly because the best shock makers can achieve low friction and stiff low-speed damping (corners and braking) while also having soft high-speed damping.

It's possible that a cheaper shock might have enough damping to handle a given spring rate, but high speed damping ends up being stiff and friction is relatively high.

Good cooling also helps.

My track car FD (10K springs) is MUCH more comfortable than my DD MR-2 (with 5/8K springs), but that's mostly because of the suspension design. That, and it has much lighter steering...

j9fd3s

iTrader: (3)

there are two valves in a shock, the low piston speed valve and the high piston speed valve.

the low speed does the handling, and the high speed does bumps.

it turns out when you get both correct, you can have a good ride and good handling.

for us, we just look at the shock dyno as a whole, and friction isn't measured, just the total output. if you were engineering something, then friction would be separated out, as it matters

lOOkatme

iTrader: (19)

I have tried finding the best shock dyno for the price irrespective of brand name or price or recommendations.

The tire is happiest when the tire is on the ground and the ride is the smoothest for racing or just cruising.

Ohlins and fatcat have really good ways of low forces between 0 and 1 IPS on both compression and rebound which soaks up a lot of little crap. some of the stock shocks do ok as well but have a little sticktion so to speak. some manufacturers have good rebound with horrid compression curves. fortune auto, feal, etc look like this. you want a nice smooth S curve with smooth bends of force, no hard knees or jerks.

This is what tires like and our bodies. Ohlins so far is probably the best. I have looked at the high end shock dyno's and they don't look all that great either. I think Motons actually had a seriously messed up curve from the one I saw.

I put a penske race shock on here...and damn it generates a lot of force quickly, its going to feel pretty rough. What is good is the compression and rebound curve match each other well, that typically is good.

a stock rx8 tokico shock isn't too bad actually for ride and shock dyno.

T.Seuf

Finished pulling my 12/10k monotube coilovers out of the FD last night. Went with Tein S Tech drop springs and a set of Bathurst struts.

While you can lower the spring perch close to 1 inch on the struts, the car currently sits about 25.5-25.75 fender height all around from spring drop alone. This will probably settle a bit. Expected the valving on the Bathurst shocks to be more in line with the 7.8kg/5.8kg springs than stock and they seem to match well, although the dampening is not adjustable.

Since my car is 100% street and only a weekend cruiser, this setup is much more comfortable. It still does a good job of stiffening the suspension compared to stock, eliminates most roll, but absorbs more NVH compared to pillowball coilovers with springs rates that are more suited to track / drift use.
Had to reuse my stock 60k mile top hats since the Bathurst didn't come with any. Some of the rubber was starting to deteriorate, but there is still rubber between springs and perch and springs and body.

May still consider going to 17's from 18's if I can find a set I like, but my rear suspension pillowball bushings should probably be the next priority.

DeaconBlue

iTrader: (31)

I originally had KYB-GR-2 with Eibach springs on the car and thought the ride was fine, but the it was a bit under dampened.

I then went with a set of Stance GT+ coil overs but knew the stock 9K/7K springs were way too stiff for the street, so I installed a set of 400lbs [7.2K] front and 275 lbs [4.9K] rear. I drove the car that way for a 2-3 years and decided that although the handling was phenomenal, the amount of travel for street use was not enough.

So I now have a set of Tokico Illumina and Eibach springs which IMNSHO is be far are the best setup (as far as handling, ride quality and ride height) for use on the street. Just for reference, the car has Racing Beat sway bars, Mazdatrix sway bar link ends, DTSS eliminators, a full complement of poly suspension bushings and Mazda competition mount bushings.