A discussion on improving ride quality

[NissanGuy]

Originally Posted by Trettiosjuan

I still have some thoughts and wanting feedback on this subject.

So mine is the GT86 version with a front spring rate of only 2,3kg/mm. It's a DD, sometimes driven hard on small bumpy twisty roads.

To improve comfort I have very light 16" wheels with a very compliant tire. They help quite some in harshness and the small road irregularities.
But at say 5-10Hz, the ride is still bad, esp at the front. It's overdamped and just follows the irregularities on the road. Slightly ironical, I think the light wheels made that part worse as the dampers see lower wheel forces and become relatively more firm.
The high damping helps the handling in transition, but in the end the springs are still soft and they bottom out fairly easily, especially on multiple bumps taken quickly on that spirited back road drive.

After reading this forum extensively I realised that rebound damping in the front is stronger than rear despite the much softer front springs. And that contrary to many underdamped cars, a harder spring here could actually work out more comfortable (I tend to very sceptical to such claims but here it could actually be so).

Anyhow, things start to make sense but unfortunately most springs lower the car which I usually don't like - I want bump travel! But I like one of those, the rce yellows. These make sense in light of the damper dynos. And have a chance in improving the above discomfort phenomenon significantly. And also improving handling (I will not elaborate on my understanding of it here as you probably know already). Also the rates and shorter bumps stops suggest they should bottom out later despite the lowering (in commited driving, comfort is less important )

Actually, I think that the 4,5 kg front rate would be a tad too aggressive for the dampers on European roads and tastes, but I'm imagining that the light wheels here certainly make their job easier.

In short, wouldn't have thought I'd ever say so, but now I think that lowering springs really could improve DD comfort and back road handling. That said, anybody have suggestions for spring/perch spacers?

Any holes in my reasoning?

If you want OEM ride height and stiffer front springs, OEM BRZ will do the trick. To me, the BRZ feels much more planted, with much less body roll. The front shocks on BRZ feel, to me, more effective when driving fast, but I find the FRS (which I believe is slightly softer up front than GT86) way more comfortable.

Of course, given how often I seem to agree with ubersuber, my head is apparently wired up differently than the rest of you

[Trettiosjuan]

Originally Posted by NissanGuy

If you want OEM ride height and stiffer front springs, OEM BRZ will do the trick. To me, the BRZ feels much more planted, with much less body roll. The front shocks on BRZ feel, to me, more effective when driving fast, but I find the FRS (which I believe is slightly softer up front than GT86) way more comfortable.

Of course, given how often I seem to agree with ubersuber, my head is apparently wired up differently than the rest of you

This was my first consideration, but the difference from 2,3kg (FRS/GT86) to 2,7kg (BRZ) seemed to small to me. The RCE springs if as adverised seemed like a better option. We'll see as they are on order...

Perception is a b*tch, I even perceive my own car differently on a day to day basis depending on the driving, road, mood etc.

[wparsons]

Originally Posted by NissanGuy

If you want OEM ride height and stiffer front springs, OEM BRZ will do the trick. To me, the BRZ feels much more planted, with much less body roll. The front shocks on BRZ feel, to me, more effective when driving fast, but I find the FRS (which I believe is slightly softer up front than GT86) way more comfortable.

Shocks are the same between FRS, GT86 and BRZ. The only difference is spring rates.

[Racecomp Engineering]

Originally Posted by Trettiosjuan

This was my first consideration, but the difference from 2,3kg (FRS/GT86) to 2,7kg (BRZ) seemed to small to me. The RCE springs if as adverised seemed like a better option. We'll see as they are on order...

Perception is a b*tch, I even perceive my own car differently on a day to day basis depending on the driving, road, mood etc.

Agreed on perception. I'm curious of what you end up thinking of our springs...definitely let me know. Where in Europe are you?

- Andy

[NissanGuy]

Originally Posted by wparsons

Shocks are the same between FRS, GT86 and BRZ. The only difference is spring rates.

One of the better reasons not to trust my impressions haha

[stonenewt]

Originally Posted by wparsons

Shocks are the same between FRS, GT86 and BRZ. The only difference is spring rates.

But if we're agreed that that the stock suspension is over-damped then the higher rate BRZ spring will be a better match for the dampers. If this is the case surely the damping is better on the BRZ?

[Trettiosjuan]

Andy: sure will report back, I'm in Sweden.

BRZ is not as overdamped, but quite some observation of overdamped come from BRZ owners, so the FRS/GT86 is even more so...

[Trettiosjuan]

Ok, as promised, some feedback on the RCE yellow springs.

Short version:
"I have them and I love them".

Long version:
They perform as expected, that is, very good but don't expect miracles.

-Ride: When I read random forum suspension review threads, if the review is longer than the above short version I perhaps a bit too often read "It rides better than stock!" I usually filter that down to "I found one stretch of road where I got the impression it rode better, well hard to really remember, you know, also, considering it's lower (), and such".
No, of course you feel the higher spring rate in compression, car feels firmer in compression on larger obstacles. About twice as firm, really. And there are more vibrations because of the higher spring rates. With that out of the way, they do match the dampers and in rebound it does feel equal or better when there are multiple depression in rapid succession. As such it feels more consistent, the stock suspension could feel quite comfy on some surfaces and then really bite you with the damping on others. So overall, it kind of evens out in the ride department and I prefer the yellows for being more consistent. One good week in, I've already gotten used to them and hardly notice them. Still, if this combo would come on a stock car, the press would call it "stiff" (Yes I realize trackers run rates x-times firmer again, but this is my appreciation). A good stock set-up would have been halfway with slightly stiffer springs, and slightly weaker dampers.

- Performance: the whole car feels more planted. Because it is. Less roll. Now comes a point I must point out I have a slightly uprated rear sway bar, 16mm. The car was quite neutral on that one, less understeer, but I also found the diff worked less consistent as the rear wheels sometimes lost road contact. With the springs I can detect some more understeer, but the rears diff is more consistent and because of the overall upped firmness, it is easier to play with the balance. Overall very pleased here, balance is sweet spot for me and the performance suits my driving (This may balance out differently if you run much stickier rubber than stock, I'm on regular summer tires). I also drive a few narrow bumpy (tree ruts) roads. Quickly. While the car with the yellows is definitely sharper over those harsh bumps, I don't feel I'm riding the bumpstops much more/harder and overall, on such roads the springs have not slowed me down, none the least because the suspension/damping keeps the suspension extended. That said, I do wish there was a black version "regular guy" version of this spring with no or max 10mm drop, than I would have gone faster. Also over speedbumps of which we have many. But I understand that the market is probably too little and honestly, I don't drive such roads too often either and I do like the mild drop visually so...

Concluding:
I like that it works with the stock dampers because a "budget" car should be able to have a good (if not perfect) compromise between ride and handling on OE grade dampers if done right... and these spring do this, by necessity with more weight towards handling, but then it is a sports car after all. Excellent upgrade for the $. And €.

And a picture to close off:

[wparsons]

Originally Posted by stonenewt

But if we're agreed that that the stock suspension is over-damped then the higher rate BRZ spring will be a better match for the dampers. If this is the case surely the damping is better on the BRZ?

BRZ rear rate is lower than FRS rear rate, but BRZ front rate is higher than FRS front rate. If you want the best spring/damper match with stock springs, get BRZ front and FRS rears. The dampers were designed to work with the stiffest OEM rates.

Originally Posted by Trettiosjuan

Andy: sure will report back, I'm in Sweden.

BRZ is not as overdamped, but quite some observation of overdamped come from BRZ owners, so the FRS/GT86 is even more so...

FRS rear feels better, BRZ front feels better on stock springs/shocks.

[Trettiosjuan]

Originally Posted by wparsons

FRS rear feels better, BRZ front feels better on stock springs/shocks.

And on a GT86, the rear rates are reportedly* the softest of them all (3,3 vs 3,5 BRZ vs. 3,8 FRS) so I probably get the greatest overall effect going to the yellows. Good to keep in mind.

*not many souls that drove all of them back to back to make a fair comparison...

[BRZZZZZZZZZZ]

My BRZ on RCE Yellows rides a lot nicer than my WRX on Ohlins coilovers. Both cars corner nearly as flat and have almost zero dive and squat. The BRZ kills the WRX for handling, but that is partially due to the welded diff in the WRX.

[rs999]

Originally Posted by wparsons

BRZ rear rate is lower than FRS rear rate, but BRZ front rate is higher than FRS front rate. If you want the best spring/damper match with stock springs, get BRZ front and FRS rears. The dampers were designed to work with the stiffest OEM rates.



FRS rear feels better, BRZ front feels better on stock springs/shocks.

So wouldn't the easiest way to get the two cars to match up in front rates is to just add a larger front sway to the FR-S leaving everything else the same?

[Trettiosjuan]

No. There is much more to suspension than roll stiffness. Springs and dampers need to play together first, after that one can tweak roll stiffness by adjusting or changing sway bar rates.

[rs999]

Originally Posted by Trettiosjuan

No. There is much more to suspension than roll stiffness. Springs and dampers need to play together first, after that one can tweak roll stiffness by adjusting or changing sway bar rates.

I find the stock springs comfortable and at the perfect height for daily driving. However, I think it is the damping that needs to be corrected to make the ride better, more comfortable, and less likely to bottom out after bumps and other imperfections.

What are your thoughts on front sway, upgraded dampers (biltstein b6 or koni sports), and stock springs? Basically the Strano C spec setup.

I'd like to try the bilsteins but I don't want any harshness, if there were Koni FSD's for this car I think those would be perfect for the setup I just described.