Hi guys,

I have apexi N1 pro coilovers on my FD with 12 kg/mm in front and rear. It's too harsh for the streets around here. I'm looking to replace my current springs or my coilovers. While looking around the forum for the ideal spring rates for my need I realize that not thread exists about spring rates vs comfort.

I thought that a compilation of spring rates vs ride comfort vs performance would be interesting. I know that the tolerance and perspective of everyone is different but it would give an idea.

I posted in this section instead of the suspension section to collect specific data about the FD since the FD seems to run higher spring rates than other gen.

Here is the data needed:
- Coilovers' make and model
- Spring rates
- Area where you live to give an idea of the quality of the streets
- Street/track
- Comfort (x/10)
- Performance (x/10)

So, I'll start:

Coilovers: Apexi N1 pro
Spring rates (f/r): 12/12 kg/mm
Area: Quebec, Canada
Street/track: 99.5%/0.5%
Comfort: 3/10
Performance: 9/10

Feel free to add any interesting informations.

Alex

 

I would like also to see which are good coilovers for comfort

 

Dampening has a huge amount to do with comfort as well. You could have softer springs, but if the dampening is set too high, the car will be less comfortable than the next guy who has stiffer springs with a softer setting for the dampening. To avoid harshness, you may consider choosing coilovers that retain the stock rubber upper shock mounts i.e. coilovers without the pillow ball mounts.

Comfort is highly subjective, and relative to each person's perception of what's comfortable.

It also depends on the person's physique.

For example...

If you have a lot of loose body fat in the abdominal area or if your high estrogen levels have given you man *****, then a shaky front is what you have in store with coilovers. Some guys have so much adipose tissue in their face that their cheeks and multi-chins begin oscillating during freeway undulations. If you're a girl with *****, then an uncomfortable ride and shaky front might be a good type of discomfort that translates into pleasure. If you're a girl with no *****, but with a gut, then your stomach would be the only thing bouncing up and down. If you're a guy, and you have a girl sitting on your lap, then there could be all kinds of things going up and down, which is another example of "good pain" that would be mutually pleasurable to both parties. It that case, stiffer is ALWAYS better.

Hope that helps.

 

Initial set up-
Coilovers: stock R1 springs and GAB Super R
Spring rates (f/r): 4.98/3.54 kg/mm
Area: Northern California, USA
Street/track: 5%/95% auto-x
Comfort: 4/10
Performance: 4/10

Now-
Coilovers: Ohlins DFV
Spring rates (f/r): 11/11 kg/mm
Area: Northern California, USA
Street/track: 20%/80%
Comfort: 7/10
Performance: 9/10

Recap-
The relatively high low speed damping of the GAB Super R work with stock springs to help mitigate body roll in stock class where stock springs are required, but ride very harshly as a result. They are also useful to control the higher spring rate of lowering springs.

Ohlins uses a much higher spring rate with high damping to control it, BUT lets the high spring rate control body roll and has compression and rebound blow off to lessen low speed damping which softens ride quality to better than stock and keeps the tire in contact with the ground.

It rides so much nicer I am driving it on the street a lot more.

 

Example 2 (non FD)

Platform- FC3s RX-7
Coilovers: JIC FLT-A2
Spring rates (f/r): 7/5 kg/mm
Area: Northern California
Street/track: 50%/50%
Comfort: 3/10
Performance: 5/10
Notes- no rear traction, spin 4th gear roll on. Car jumps on any mid corner bump, hard to get out of a corner anything but sideways.
Works great when put on NA FC to help it rotate in auto-x.
-2.75 degrees negative camber available.

Platform- FC3s RX-7
Coilovers: JIC FLT-TAR
Spring rates (f/r): 7/5 kg/mm
Area: Northern California
Street/track: 50%/50%
Comfort: 5/10
Performance: 6/10
Much improved rear traction and comfort from lower damping, barely spin 3rd roll on.
-2.75 degrees negative camber available.

Platform- FC3s RX-7
Coilovers: Stance XR
Spring rates (f/r): 8/6(+0) kg/mm
Area: Northern California
Street/track: 50%/50%
Comfort: 5/10
Performance: 7/10
reasonable rear traction and good comfort, extended rear stroke/zero rate spring improves rear traction on rough surfaces and dips.
spins 3rd over 5k rpm on roll on.
Zero (0) negative camber available out of box, machined to provide -5.5 deg.

 

Subscribed. Im looking to buy a suspension setup as well and all the info in one place is nice.

 

Thanks for the answer BlueTII.

Need more inputs guys!!

 

JIC probably has the best street/track combo especially the nitrogen charge. I have this set up is pretty active street wise, you can even hear the compression and the rebound of the shocks, and pretty agressive on turns. I havent heard anything on FD set ep of KW v3 but ive heard this is pretty good set up. Any KW set up?

 

Does KW make coilovers for the FD? I have a set of v2's on my other car and absolutely love them, most comfortable coilover setup ive felt.

 

Anyone else wants to share his experience?

 

+1, there are two valves in a damper, a high speed valve for bumps, and a low speed valve for handling, so its possible to have both a good ride and great handling

the spring rate plays a role in ride, but its not as big as the damper

ride comfort is actually measured in watts, although its basically the drivers head movement on a closed course

 

A little late but I'll chime in. JIC FLT A2's 10kg f 8kg r.

Dampening, spring rate and tire sidewall all play a huge and equally important role in ride comfort. Granted a 20kg spring would make anything a rough ride.

The JIC's have 15 settings. I run 7 front 5 rear. Anything over 10 is pretty rough and a setting of 1 makes the car look like a dash board bobble head. IMO an ideal setting for comfort and performance would be:

8kg f
6kg r
6/15 f (with my coil overs)
5/15 r (with my coil overs)
255/40-17 tire (more specifically around a 4in+ sidewall)

Should also note....FD3S

My current setup: 285/30-18 300 tread wear
Comfort 5/10
Performance 6/10

Other tires: 255/40-17 180 tread wear
Comfort 7/10
Performance 7/10

Obviously the 17's are a better ride BUT the 18's are my CCW's and look SOOOOOOOOOO much better :-p

 

Measured in frequency

 

Comfort is subjective and comfort highly depends on the road conditions in your area.

After riding in and owning multiple coilovers, I agree that the 10kg+ spring rates driven on rougher roads are too high of a rate. I own Ohlins DFV and they did a great job of making higher rates comftorable, but I still think if you do very spirited driving on roads that aren't perfectly smooth that they could benefit from a softer spring rate. I have driven ARK coilovers with 12KG springs that came stock and the rates are just harsh. I backed off the spring rate to 8/6 and they are much more comtorable and they stick to the ground soo much better on my spirited runs. They in fact stick better than my ohlins DFV I think (still playing with damping settings). I think the ohlins have great dampers but just too high a rate.

You also need to consider the front/rear split of rates as this changes the handling dynamic of the car. I think a matched front and rear rate isn't bad, I feel like the rear is supported more and does well at high speeds. The split transfers more weight to the rear and grips better. It's more of a preference thing that performance perhaps?

And when you think of stiffness, I think the stock rates are something around 260-280lbs/in front and 198? lbs/in rear.

going to 450/336 (8/6) is a lot stiffer than stock, a 12/12 is 681/681, which is 2.5X stiffer rate in the front and 3.5X stiffer in the rear. I mean that is a ton stiffer.

Overall Softer spring rates give more grip, are more forgiving and ride more comftorable, they really only give up a little in transitions. I think most of us incorrectly view ride stiffness with handling and are more comftorable with quicker transitioning then having the car roll some, but if you think of it, if you were going to catch an egg with your hands, what would you do. you would slowly cradle it when you caught it to prevent breaking the egg. I think suspension with softer rates gives you that slowing down of the car and shocks the tires much less. its also much more forgiving when hitting bumps at high speeds. the breakaway is also so much more forgiving.

 

lOOkatme Comfort is subjective and comfort highly depends on the road conditions in your area.

After riding in and owning multiple coilovers, I agree that the 10kg+ spring rates driven on rougher roads are too high of a rate. I own Ohlins DFV and they did a great job of making higher rates comftorable, but I still think if you do very spirited driving on roads that aren't perfectly smooth that they could benefit from a softer spring rate.

I actually had the opposite problem with my Ohlins. Most the fun local roads are so poorly maintained the Ohlins were bottoming everywhere, so I had to raise my damping way up over what I was racing on to avoid excessive bottoming.

For really rough roads the blow off on highspeed compression is too much on the Ohlins for the HEAVY 49lb wheel/tire I am using because it was set up for stock 39lb wheel/tire.

Finally, I just stopped railing my FD on these terrible terrible roads and switched to the stock suspension/height RX8. But now the 8 is on Ohlins so maybe I need a new beater?

No, luckily I lowered the 8 enough it bottoms on the chassis to road instead of bottoming the shocks!

 

there is a preference part in there. once you get to like 90%, the drivers preference really starts to matter.

to wit: one of our 25 hour drivers is running a specE46 this year, and the guy who built it has it setup really nicely. in the interest of trying to, see what the chassis doe when you make changes, and b making it faster, we lowered the rear ride height.

this is basically a quick way of changing camber and toe.

the car went from well balanced, to being kind of tail happy. it was kind of a handful, but the driver LIKED it. so we raised it up half way, and everyone was happy.

 

actually a better example, is one that uses spring rates to say something about drivers preference for spring rates. they like spring rolls too, but that is a different thread.

anyways, example 2. the Integra. it picks the inside rear wheel up in turns, and so it is VERY picky about the spring rate vs the sway bar rate, a 50lbs difference in spring rate in the back, is the difference between the car working and not.

its a valid example, as the setup on the car is just like the FC, only backwards, because its a honda

 

Think you mean HIGH speed damping here...

Yup, that's exactly why I made the investment in the Ohlins. The ride quality on the street was so intolerable with my old Teins (SS, 9/7 spring rates) that I hated driving the car on streets with any potholes, which is just about any road where I live. Ohlins with 11/11 springs, and now with 13/11 springs = *infinitely* better and more comfortable ride, and with much better low-speed damping for improved handling as well.

 

"Harsh" usually means poor high-speed damping. Stiff spring rates may feel *firm*, but with appropriate damping shouldn't feel "harsh". Maybe the ARK dampers weren't up to the higher spring rates.

Equal spring rates gives much higher wheel rates in back. In cornering this means that the outside rear is being loaded more heavily and the outside front is loaded more lightly. This gives greater front grip and reduced rear grip due to the nonlinear relationship between tire load and tire grip. For a 50/50 car, 50/50 wheel rates is a good place to start, and most very high power/weight modern FR sports cars tend to bias wheel rates more to the front to allow more power to be applied at corner exit. To get 50/50 wheel rates on the FD you want spring rates ~25% stiffer up front. I like a little rear stiffness bias, but equal f/r spring rates gives a bit too much rear bias for the FD, IMO.

Worth noting that natural frequency only goes up with the *square root* of wheel rate. So 4x spring rates only feels 2x as "stiff". But body roll is reduced by a factor of 4 at a given level of cornering g's, and you can transition from max braking to max cornering g's more quickly, and of course left/right transitions more quickly as well. Ultimately it's going to be a compromise and driver preference for a good streetable/trackable setup. For sure a track-only setup is going to have spring rates that are pretty high.

Not really! For reasons described above, softening one end of the car improves grip at that end of the car, but it's because the load reactions are changed. You've eased the cornering load on the outside tire at the softened end of the car which gives it more grip, and increased load at the outside rear at the other end, which takes away grip. You haven't *added* overall grip, you've just changed the front/rear balance of grip.

If you soften both ends the same amount, load reaction in cornering is unchanged and the front/rear balance is unchanged, and you haven't "added" grip at both ends.

All those are much much MUCH more a function of damping than spring rate! Spring rate is barely a factor at all when hitting bumps at high speeds. Damping forces are orders of magnitude higher than spring forces in that situation. How the dampers respond dictates what the car and you will FEEL in that situation, and spring rate is almost irrelevant.

 

With softer spring rates/damping weight transfer happens more slowly around the car, so driver's who are lagging on inputs do have the benefit of more grip.

You really see this when it starts to rain and even the really "telepathic" drivers could use some more time to put their corrections in. That is when sway bars get disconnected.

Conversely, a driver anticipating corrections has to wait the weight transfer out and then make the correction. The slower the weight transfer happens the bigger the feedback waves are between chassis action and driver correction.

Yes, it feels really good when you nail the initial input and no corrections are necessary. That doesn't happen often in such a dynamic environment.

If you have ever raced a Miata, this is exactly what this chassis is set-up to teach you. You have to "dance" with it, which is a nice way to say you have to wait for it to stop doing its **** before you can get on with doing your **** to make it do the **** you want it to do next.

 

once upon a time we had two drivers sharing 1 car. one driver came from a go kart, and wanted the car to react NOW and the other driver came from an FC, and he wanted something that reacted slower.

so initially we would set everything full stiff for #1 and full soft for #2.

the interesting part? lap times between full soft and full stiff were within .2 seconds up to turn 9, when driver #1 takes a different line and ends up being ~1 seconds faster by the end.

projecting forward 10 years, the sprint car is setup to react fast, and the enduro car is setup to be easier to drive.

 

Yeah, I like something in between.

If the weight transfer is too fast it is easier to shock the contact patch out of grip with a bad/rough input- that is the other side of the coin.

Also, its all relative to the amount of grip/weight transfer the tires are generating.

The 11K Ohlins with 295 Ventus TD race tires is about as soft as you can run with stock swaybars- there is a lot of grip/body roll there!

I felt I had to jack up the damping just to keep off the bumpstops on the high grip clean smooth asphalt and banked turn kart track, it wasn't because I wanted sharper initial response.

---------------------
As far as if I was driving on the street for like a "canyon run"- I just like a comfortable/controlled ride there with super predictable handling. Like what lOOkatme is after.

I don't change the set-up of the car though, just drive slower. When that unpredictable **** does go down the muscle memory kicks in. So far anyways

 

I dunno, the second part does not necessarily follow from the first. If a driver's inputs are lagging, this is less of an issue in a softer-sprung/damped car, but that doesn't mean he is getting more grip. A sensitive driver with quick inputs can always slow them down to suit a slower/softer car.

I'm not saying that "stiffer is always better". But I am saying that the rates we're talking about, ~7kg - 13kg range seen in street/track FDs, that the stiff end of that range is going to be better-suited for track work and should be faster (all else equal).

I got to drive a track-prepped Miata (with a full frame-stiffening cage) at the track last year, and I have to say the thing handled like a go-kart (in a good way)! Stock, the frames are a bit bendy though...

 

I dunno, the second part does not necessarily follow from the first.

Well, stick a novice driver in a capable car with great response like an AP1 S2000 and in another capable chassis with more dull handling like a stock Miata and you will see which one is being driven up to a higher grip level.

I'm not going to waste time arguing my point that drivers with slower inputs can't keep up with cars with very responsive chassis set up as well as cars with less responsive chassis set up and end up driving way under the actual grip limit because of this. We all see that literally every race weekend.

I got to drive a track-prepped Miata (with a full frame-stiffening cage) at the track last year, and I have to say the thing handled like a go-kart (in a good way)! Stock, the frames are a bit bendy though...

Yup, right after I posted that I though I should have said "stock" Miata,

but I didn't edit as I was like "blah, everyone knows what I mean with the almost trademarked stock Miata soft suspension that settles onto the bumpstops."

That is Mazda's Miata character as delivered from NA to ND chassis for better or worse.

 

[QUOTE=ZDan;11934522]

I'm not saying that "stiffer is always better"....[QUOTE]

Stiffer is better until you start to slow down because of it. It does not matter the car or driver, it more depends on the driver's skill and comfort level as j9fd3s pointed out.

On the street or canyons you need something a little more predictable.. you never know what is around the next corner and do not want the car instantly upset by water, gravel, or a swerving to avoid a nomadic indigent or bicyclist.