Current suspension thoughts on type s vs bilstein vs kw?

[Honcho]

I'm referring to the above.

A lot of info has already been mentioned here. Just my 0.02:

- Bilsteins are very good. No regret. Not harsh unless you go lower than their lower perch (highly advise not to go too low anyway). But no adjustability too.
- The OEM Type S suspension is pricy and with no adjustability at all only for an OEM guy. Can't comment on their ride but generally that's a very, very subjective aspect. Honda couldn't justify to invest a lot of time to dial in the Type S suspension, selling only a few hundreds cars. I'm not saying it's bad but they only cook with water either. There are about 15 years of development between Type S and KW and the development task has changed pretty rapidly as soon as 7-post rig became available.
- KW V3: I've just installed a kit a few days ago.
- What has not been mentioned so far: there are two kits: street and track. I'm referring to the street version.
- No regret either so far but didn't drive it enough.
- Noise: better than the first one I had from them 12 years ago. No unusual noises under normal driving conditions. Just a little bit of slight clunking over very harsh bumps once. Easy to live with.
- The lower compression dialing wheel has been improved over the first version and can be adjusted now with the car sitting on the ground (not comfortable but doable).
- But I'm still looking for the comfort level I had with Bilsteins. Compression is nearly at minimum and rebound is in the middle. But that's just me as my preferences have changed significantly over the years due to some problems with my back. Better a soft car than not driving it at all.
- range of adjustability: the KW V3 is easier to dial in than other systems mentioned here (JRZ or track based ones) just because KW DOES limit the range of adjustability intensionally having in mind that not everybody is an expert knowing how to deal with 4-way adjustable systems. The range is still wide enough. Other systems might offer a wider range which is certainly not needed in a street/fun car.

Your goal: spirited back roads driving (GT3 already as a track tool). My advice: leave the Type S, forget the Bilsteins and whatever has been mentioned so far. Just go straight ahead with a KW V3 street setup. Not know by many: there's some 'pinch of Honda salt' built in them because they took over the 7-post rig from the BAR-Honda F1 team back then.

Maybe Öhlins are an alternative but I'd still have to drive one before I'd decide/judge. You'll find more info on tuning the KW than Öhlins. They're said they need to be rebuilt from time to time. The KW won't last forever either due to their complexity while the Bilsteins will last forever (but do they have too? I'd say no).

Hope this helps with your decision (having in mind that your roads are less perfect than mine). Also having in mind that the stock suspension of my daily Civic Type R (2018) outperforms the NSX by far even with a good suspension and can be adjusted within the cabin. But that has to be expected more than 25 years later, no?

Great advice as usual from Gold. I have to admit I forgot to mention the stock springs on the Bils lower perch. It's great- even for the circuit. Plus you get the Bilstein durability. Not as good as the Type S in my opinion, especially when driven hard, having driven both.

I bought a set of the SOS Sway bars from 2 years ago. I looked on their site to see what diameter they are, but they don't seem to carry them anymore. Are they the same as the old comptech sway bars? I bought them thinking I would go with the KW's, but never got to that step.

On the type S setup, what is the shelf life on something like that. My guess would be that whats available is new old stock, so I'm wondering if they've been sitting for a while, with seal degradation, etc.... Is this an issue? Also I wonder if that shock being made in low quantity will continue to be made when replacement time comes....

Thanks for all the advice.

David

Since it's OEM, it has to be built to OEM standards. So, figure at least 100k miles, just like the "regular" NSX dampers. Plenty of 1999 Zanardi NSXs out there still driving on their original shocks, after all. Availability will always be a concern, since these are limited edition shocks.

 

[goldNSX]

On the type S setup, what is the shelf life on something like that. My guess would be that whats available is new old stock, so I'm wondering if they've been sitting for a while, with seal degradation, etc.... Is this an issue? Also I wonder if that shock being made in low quantity will continue to be made when replacement time comes....

I'd not be concerned about it as you live NOW. Whatever is in 10-20 years is very, very far away (that's why I stated the reason why I installed a KW V3 after nearly two decades on my beloved customized Bilsteins (with Type S springs BTW)). Expect new ones to last around 20 years. Even if they fail sooner than expected you might wish to try another suspension kit. Choose the one you think is best.

 

[BATMANs]

I have the KW V3 and really like it for the street. I'm sure Ohlins are better.... but from what I heard it's marginal.

I have SOS SC on a built engine and flex fuel.

on 91 octane I walked a 570Sl gallardo from a freeway roll.

 

[RYU]

My opinion:. Ohlins has been living on their legacy for far too long. Anything short of their top line TTX has been disappointing. I sold them asap when I had them on my S2000 (had the damping range of Tein and rear travel was abysmal where it was constantly on the bumpstops, but the hellaflush low low low crowd loved them for Hot Import nights). Their mountain bike stuff (which I follow very closely) has been prone warranty repairs and notoriously known as needed a "race team" to tune.

I'll easily admit that I have not tried the lower end DFV Ohlins on the NSX, but keep in mind... Aftermarket shops took it upon themselves to spec and develop a setup for the NSX. The damping and setup tune didn't come from Ohlins themselves, props to the local shops for doing this though. No offense to Ohlins owners but their luster has been tarnished in my book.

FYI:. KW Clubsports might get you closer to GT3. If you take the time to understand suspension or have access to a local tuner/driver a higher end damping system totally transforms the car.

 

[mwagner10702]

While not 100% OEM, if I was to keep the stock suspension format (verses coil overs) I would consider a combination of Swift Sport springs and 1997 dampers. The 1997 dampers have higher rebound and compression rates than your OEM 1991 dampers, but lower rates than the Bilsteins (hence better ride than the Bilsteins). The Swift springs are progressive and slight stiffer than OEM and should match up nicely with the slightly higher rate 1997 dampers.


The Swift springs will also lower your car slightly giving it a better appearance.

 

[Honcho]

While not 100% OEM, if I was to keep the stock suspension format (verses coil overs) I would consider a combination of Swift Sport springs and 1997 dampers. The 1997 dampers have higher rebound and compression rates than your OEM 1991 dampers, but lower rates than the Bilsteins (hence better ride than the Bilsteins). The Swift springs are progressive and slight stiffer than OEM and should match up nicely with the slightly higher rate 1997 dampers.


The Swift springs will also lower your car slightly giving it a better appearance.

+1 I always thought the Swift sport springs were a great option for the OEM dampers. They're stiff enough to really wake up the handling, but soft enough not to blow out the shocks. Hard to find these days though...

 

[mwagner10702]

Hard to find these days though...

"In Stock"

https://www.vividracing.com/swift-springs-sport-springs-acura-nsx-9105-p-151455382.html

 

[Procar Specials]

Most of the common suspensions are getting older now, even some of the R suspensions are starting to leak.

I started with the yellow Bilsteins over 20 years ago, than TEIN, tested various KW suspension types, also both NSX-R suspension versions over the years.

Finally it ended last year with a special order from Bilstein/H&R with some own ideas, because support is very important for the next years.
(If an NSX-R damper is starting to leak, there is no chance for a repair, no spare parts available.)

This is my actual suspension, very simple build with some nice features.
Because I sended an NA2R JDM suspension and my old TEIN RE to Bilstein, they could read out the complete configurations.
Also the spring setup is very very simular to the R spec , but the weight of the suspension is only ~ 1/3 from the OEM parts.
dampers are 23x adjustable in compression/rebound.

 

[SakeBomb Garage]

My opinion:. Ohlins has been living on their legacy for far too long. Anything short of their top line TTX has been disappointing. I sold them asap when I had them on my S2000 (had the damping range of Tein and rear travel was abysmal where it was constantly on the bumpstops, but the hellaflush low low low crowd loved them for Hot Import nights). Their mountain bike stuff (which I follow very closely) has been prone warranty repairs and notoriously known as needed a "race team" to tune.

I'll easily admit that I have not tried the lower end DFV Ohlins on the NSX, but keep in mind... Aftermarket shops took it upon themselves to spec and develop a setup for the NSX. The damping and setup tune didn't come from Ohlins themselves, props to the local shops for doing this though. No offense to Ohlins owners but their luster has been tarnished in my book.

FYI:. KW Clubsports might get you closer to GT3. If you take the time to understand suspension or have access to a local tuner/driver a higher end damping system totally transforms the car.

I'll be honest the Vanilla S2000 kit has the wrong spring rates and not enough stroke and valving curve leaves a lot to be desired. This is what prompted us to create our own FPSpec long stroke version and valving. We usually physically longer shock cartridges than standards, custom valving curves and spring rates. We have many Racers standing on 1st place podiums on these exact shock sets around the country. We also did a long stroke kit for the ND Miata which took 1st in nationals against S2000's in Auto-X.

Essentially we agree about the Standard DFV kit from a few chassis, have room for improvement. The Ohlins DFV's are like a very fine instrument you can have the most expensive violin but it's not tuned properly it won't perform. The Ohlins DFV are so finally adjustable that we have complete control over the dampening characteristics when we were able to create our own custom damping curves and spring rates.

Ohlins DFV FPSpec


S2000 FPSpec


ND Miata FPSpec

Sakebomb Ohlins GT spring rates are the same 8k/6k as the type r.
Like docjohn said I find the ride a lot better than stock even though the spring rate is much higher because the dampener is much better. The Ohlins DFV dampener became very popular on the BMW/Porsche forums for its ability to handle high spring rates and also be compliant.

I have to admit I wonder how even more comfortable it would be with stock springs.

SakeBomb can custom build you a set based on your application as well.

Hey @Rainman Appreciate you mentioning in here!

We do also make custom spring rates and valving, we understand that everyone has different preferences and needs for their NSX. So, if you would like to hit a different spring rate, absolutely shoot us an email so we can help achieve what you're going for. We've driven on a few different options for the NSX and we really feel that coupled with the NSX suspension Geometry and Ohlins tailored for the NSX. It's one the best we've felt.

 

[stuntman]

Glad [MENTION=20915]RYU[/MENTION] chimed in here- he has a lot of experience with many of the different aftermarket options. I have the R dampers that he dynoed. My own view is that anything beyond single-adjustable shocks is probably going to cause more problems for the average driver than it solves. Unless you are a pro driver and/or have access to telemetry and a chassis engineer, it's going to be hit-or-miss when it comes to your damper setup. Many drivers will end up making their suspension worse. Thus if someone wants to go the adjustable aftermarket route, I steer them to the single-adjustable JRZ product- they're simply fantastic.

True.

Glad [MENTION=20915]RYU[/MENTION]Otherwise, my logic is that Honda spent far more testing time and money on the S and R setups than any aftermarket company could ever do. Those setups were tested for months at the Ring, Suzuka and the Takasu proving ground in Hokkaido using Honda house drivers as well as F1 and Super GT drivers from their works teams. It's gonna be really hard to do better than that.

It's difficult to make a suspension be well rounded for street, track, noise, driveability, balance, etc... than what OEMs can do. But it's easy to make the car handle better and turn faster laps. However, it becomes increasingly more difficult to try to make the suspension better while not sacrificing anything else; without spending a ton of time and $ on R&D.

An supporting piece of evidence is that Dori Dori himself tried to develop a superior suspension to the R and, even then, with a man who has a lot of seat time behind a NSX, Sachs dampers, custom spring rates, etc. they managed...wait for it.... a whopping 0.058 second advantage around Ebisu Circuit over the R suspension. That to me suggests that Honda knew what they were doing. Thus, I say just get the Type S.

That's not really supporting evidence. Tsuchiya was happy that his suspension on his heavier production car (with A/C and radio) was quicker than the "cheated-up" lighter (no A/C or radio) press car that questionably had more power than production cars. In that context, the suspension made up the horsepower difference between the two cars.

In general, I'm not a fan of most Japanese tuner's suspension tuning philosophies, and from the video and images of his coilovers looks like the car is riding on the bumpstops. I don't think it would be too difficult to come up with a better performing and better riding suspension setup than what he did.

- KW V3: I've just installed a kit a few days ago.
- What has not been mentioned so far: there are two kits: street and track. I'm referring to the street version.
- No regret either so far but didn't drive it enough.
- Noise: better than the first one I had from them 12 years ago. No unusual noises under normal driving conditions. Just a little bit of slight clunking over very harsh bumps once. Easy to live with.
- The lower compression dialing wheel has been improved over the first version and can be adjusted now with the car sitting on the ground (not comfortable but doable).
- But I'm still looking for the comfort level I had with Bilsteins. Compression is nearly at minimum and rebound is in the middle. But that's just me as my preferences have changed significantly over the years due to some problems with my back. Better a soft car than not driving it at all.
- range of adjustability: the KW V3 is easier to dial in than other systems mentioned here (JRZ or track based ones) just because KW DOES limit the range of adjustability intensionally having in mind that not everybody is an expert knowing how to deal with 4-way adjustable systems. The range is still wide enough. Other systems might offer a wider range which is certainly not needed in a street/fun car.

That's probably way too soft on compression. Less than the middle compression setting does not do a whole lot. If the ride is not getting better, then you may have another issue like hitting the bump stops, or just needing a softer spring rate, closer to the bilsteins.

What is your ride height (measured from the ground to the bottom of the front and rear jacking tabs)?

KW's are 2-way dampers. Not 4-way.

KW V3 - Since about 2010 or so (I can't remember exactly when) these have become the "go-to" coilover replacement for the NSX. Part of that is because a popular member here promotes them, but also because they are pretty good value. These don't have quite the adjustability range of a higher end damper (e.g. Penske, JRZ imho) but out of the box they are tuned quite well for the car. This will probably get you closest to a 911 GTS. I'm not sure this is really gets you to GT3 level though.

The 991 GTS' front wheel rates are softer than the KW V3 (for the NSX). For a street-only car; the V3's are great.

For more track-focused use, the Clubsport's slightly stiffer rates are better but they simply swapping out the front spring to a 571lb-in rate before installation will give you the same spring rates as the NSX-R (I really like this spring package and will for sure deliver the "GT3" type feel you're looking for). Interestingly enough, the NSX-R rates have the same front wheel rate as the 991 GT3, but a little softer in the rear since the GT3 has a heavy rear-engine and a much larger rear tire.

I'll easily admit that I have not tried the lower end DFV Ohlins on the NSX, but keep in mind... Aftermarket shops took it upon themselves to spec and develop a setup for the NSX. The damping and setup tune didn't come from Ohlins themselves, props to the local shops for doing this though. No offense to Ohlins owners but their luster has been tarnished in my book.

This is often true for many higher-end suspension. Keep in mind that suspension is only as good as it's tuned and supported. If you're interested in a certain brand, it's important to make sure you will have proper support in terms of baseline settings and advice. If a shop does not have much experience or many customers using Brand X dampers on a given car, you might want to reconsider your purchase.

FYI:. KW Clubsports might get you closer to GT3. If you take the time to understand suspension or have access to a local tuner/driver a higher end damping system totally transforms the car.

It sounds like for his given choices, the ClubSports with 571lb front springs will be ideal.

As far as KW settings go, there are a lot of baseline settings and advice here:

http://www.nsxprime.com/forum/showt...Spring-Packages-by-FX-Motorsports-Development

 

[Soundeffects]

How much is this nice coilover system? The KW3 is probably my price range as I can’t justify spending more.

Most of the common suspensions are getting older now, even some of the R suspensions are starting to leak.

I started with the yellow Bilsteins over 20 years ago, than TEIN, tested various KW suspension types, also both NSX-R suspension versions over the years.

Finally it ended last year with a special order from Bilstein/H&R with some own ideas, because support is very important for the next years.
(If an NSX-R damper is starting to leak, there is no chance for a repair, no spare parts available.)

This is my actual suspension, very simple build with some nice features.
Because I sended an NA2R JDM suspension and my old TEIN RE to Bilstein, they could read out the complete configurations.
Also the spring setup is very very simular to the R spec , but the weight of the suspension is only ~ 1/3 from the OEM parts.
dampers are 23x adjustable in compression/rebound.

 

[goldNSX]

That's probably way too soft on compression. Less than the middle compression setting does not do a whole lot. If the ride is not getting better, then you may have another issue like hitting the bump stops, or just needing a softer spring rate, closer to the bilsteins.

What is your ride height (measured from the ground to the bottom of the front and rear jacking tabs)?

I didn't drive it extensively so far but:
- the first KW V3 I had back in 2008 was softer on compression than the one I have now (both street version). Old one: front R6/C9 (rebound 6 clicks from hard, comp. 9 clicks). New one: R10/C12 but still too nervous on fastly driven bad roads. The first one soaked everything up and gave a lot of grip and confidence. Now, I don't dare to drive these roads the same way.
- tires/wheels are the same. 02+.
- the ride height is about the same or two thin fingers between the tire and the fender, so not ultimatively low.
- I've asked them to install a 15 mm rebound to faciliate the install. Did that mess up the characteristic?
- Did they change anything? In between those 12 years they've introduced the clubsport version. Did they firm up the shocks for it? Very wild guess.

 

[Honcho]

How much is this nice coilover system? The KW3 is probably my price range as I can’t justify spending more.

You should contact Detlef at Procar Specials. Apparently he sent a NA2 NSX-R suspension to Bilstein and they mapped the entire damper curve. They then built their own dampers to that spec and added rebound adjustability. This is a holy grail suspension and likely carries a hefty price. Also, Detlef mentioned over on NSXCB that the NSX-R Showa dampers can be rebuilt...

 

[Procar Specials]

You should contact Detlef at Procar Specials. Apparently he sent a NA2 NSX-R suspension to Bilstein and they mapped the entire damper curve. They then built their own dampers to that spec and added rebound adjustability. This is a holy grail suspension and likely carries a hefty price. Also, Detlef mentioned over on NSXCB that the NSX-R Showa dampers can be rebuilt...

Hi, I did that work with Bilstein/H&R Germany in winter 2018/2019.
My goal was to have a unique suspension at my NSX and a troublefree future, means full support for all cases.
All in house and direct contact to the engineer.

They sended me different parts for that project and I decided to add some nice additional features.
Means unibal top hats, cf protection covers for the coilover threads (if height adjustment is done) and special cnc brake line holders, which had to fit with the diameter of the protection covers.
Also special dust boot covers etc....

I already posted a picture which shows the suspension ready for installation and after some setup work was done within 2 months.

I didnt had the intension to offer that suspension, finally because its a suspension into the 4000 Euro plus range, depends on the specs.

P.S.
Showa dampers are repairable, but not localy here in europe (only motorcycles) I had to send them back to japan.......so a huge amount of money is surely necessary.
If you take a look at the dampers, I'm not sure if its worth.
The are nearly 20 years old and their best times are over for sure.

 

[Procar Specials]

here are some of my spare parts....
even superlight titanium screws can be ordered.
The standard Bilstein brake line holders (at the picture right buttom side) are too massive and heavy, so I choose
a special duraluminium version with special screws.

I'm superhappy with the result and proud , that I found MY suspension.
Its no bar stock, maybe also old school, but it fits perfect with the character of the old NSX.

 

[BBVNSX]

From someone with your experience with so many setups, How would you compare KW / NSX-R/ Your new setup?

Weight would be NSX-R -» KW -» New setup (heavier to lighter), but what about handling, street use ect?

I started with the yellow Bilsteins over 20 years ago, than TEIN, tested various KW suspension types, also both NSX-R suspension versions over the years.

 

[Procar Specials]

First of all I have to say honestly that I never have been a big fan from KW.
I know that they build great suspensions for race cars etc, but the suspension for the NSX has a poor build quality IMO.
Nevertheless many people are happy with that, so what can I say.

The NSX-R NA2 suspension (I had them for sale since 2003) is a very good suspension, but 3 issues. Weight, not height adjustable, not damping adjustable.
I liked the handling during different test drives, but finally I removed that suspension again after short time.
In year 2016 I started another try with the same result.

Than I started contact with one of my race buddies from earlier times, which is chief test driver at H&R suspension technology and responsible for all setups finally.
H&R and Bilstein are close together with their facilities and so it was clear that this will be the start of a new projekt.

You have to know that years before I made another Bilstein suspension for the sport auto NSX-R 24h race car, with coilovers etc.
Finally we made 3 suspensions, this one I hold back as Honda finished that project
But this version was a bit overkill for my showcar, nevertheless I sold it to USA.

 

[Procar Specials]

Now back to the question NSX-R to my Bilstein/H&R

NSX-R NA2 suspension has 6,4 + 6,4 + 8,3 + 8,3 kg, so total weight is 29,4 kg (64,8 lb)
My suspension has 3,6 + 3,6 + 3,6 + 3,6 kg, so total weight is 14,4 kg (31,7 lb)

Over 50 % lighter, simular damping curve, simular spring rates (rear +8 kg) and 23x adjustable compression/rebound
I prefer a softer damper setup.

Theses days, there are so many suspensions at the market, but I doubt that the most fits well with the NSX.
Where I know?

BTW...this one which I tested too (KW competition, the ultraexpensive one)


And this one

 

[Procar Specials]

Also this one.....which are still one of my favourites
Still have them with the Procar 60mm spring system.
This is the lightest setup of suspension for NSX ever build.

 

[Procar Specials]

My first coilover suspension which I build was an stock Bilstein B8 1663+1665 damper, made for NSX with the 2 milled grooves.
It was year 2001 and I build this for Marc Johnson from Dali Racing.

Early and later versions....
long time ago....20 years now.....we were pioneers.....

 

[stuntman]

I didn't drive it extensively so far but:
- the first KW V3 I had back in 2008 was softer on compression than the one I have now (both street version). Old one: front R6/C9 (rebound 6 clicks from hard, comp. 9 clicks). New one: R10/C12 but still too nervous on fastly driven bad roads. The first one soaked everything up and gave a lot of grip and confidence. Now, I don't dare to drive these roads the same way.
- tires/wheels are the same. 02+.
- the ride height is about the same or two thin fingers between the tire and the fender, so not ultimatively low.
- I've asked them to install a 15 mm rebound to faciliate the install. Did that mess up the characteristic?
- Did they change anything? In between those 12 years they've introduced the clubsport version. Did they firm up the shocks for it? Very wild guess.

I don't think anything was changed over the years.

- Are the wheels and tires the same model or the EXACT same tires themselves (that are 12 years old)?
- Do you have the same alignment?
- What is a "15mm rebound" ?
- While not ideal, Can you park the car on a flat surface and measure the distance from the ground to the bottom of the (front and rear) jacking tabs? -do it on both sides and report back.

Now back to the question NSX-R to my Bilstein/H&R

NSX-R NA2 suspension has 6,4 + 6,4 + 8,3 + 8,3 kg, so total weight is 29,4 kg (64,8 lb)
My suspension has 3,6 + 3,6 + 3,6 + 3,6 kg, so total weight is 14,4 kg (31,7 lb)

Over 50 % lighter, simular damping curve, simular spring rates (rear +8 kg) and 23x adjustable compression/rebound
I prefer a softer damper setup.

So the dampers are single-adjustable? (compression and rebound is tied together)?

 

[goldNSX]

- Are the wheels and tires the same model or the EXACT same tires themselves (that are 12 years old)?
- Do you have the same alignment?
- What is a "15mm rebound" ?
- While not ideal, Can you park the car on a flat surface and measure the distance from the ground to the bottom of the (front and rear) jacking tabs? -do it on both sides and report back.

2008/2020
- same rims 17/17 OEM
- tires same size, 215+255/40/17, 2008 Bridgestone which are prone for a stiff sidewall, 2020 Goodyear with a medium stiff sidewall
- same alignment
- a 15 mm rebound limits the shock travel while fully expanded and is installed within the shock (on my special request while they build them on demand anyway). Shorter struts can be mounted easier (as we all know) and there's still plenty of travel left (like a rally car). Could justify even 20 mm without any compromise.
- will do, out of my mind roughly around 11 cm front and rear. I normally measure the distance between the fender (without the plastic wheel well) and the center of the wheel caps: front 33 cm, rear 35 cm.
- maybe the most change is on my side in these 12 years.



Some more observations:
Back in 2008 I could set the KW V3 to the comfort level of a Mercedes but the rear felt a little bit floaty then.
2020 no floatiness even with the softest compression setting. It's definitely more agile. When set at the stiffer end it results in much more (undesired) movement of the car, the car gets a little 'shaky', at least for me as I do like a suspension which soaks up most of the harsh irregularities, at least on the street. Not sure (and guessing) if I'm trying to solve a highspeed problem with the low-speed adjustment. But still, the car feels responsive, even in the softest setting. I can live with it I think but I'd have favored the ability to go even softer for some trips. Kind of 'pea under the mattress' problem. All I can say is that there must have changed something. I even have a shock dyno of them from back in 2008 but don't feel like doing one again before the next winter.

Bilstein: I had them before with a custom valving, soft at low speed, medium at middle and quite high at high speeds and they were a blast to drive over harsh roads, esp. when driven very fast. Very, very predictable, high level of grip too. So Bilsteins with the right valving are a very good choice.

 

[stuntman]

2008/2020
- same rims 17/17 OEM
- tires same size, 215+255/40/17, 2008 Bridgestone which are prone for a stiff sidewall, 2020 Goodyear with a medium stiff sidewall

Tires can vary GREATLY in terms of feel, performance, grip, size, etc.. A good read:
https://motoiq.com/how-to-properly-select-and-size-tires-for-performance/

- a 15 mm rebound limits the shock travel while fully expanded and is installed within the shock (on my special request while they build them on demand anyway). Shorter struts can be mounted easier (as we all know) and there's still plenty of travel left (like a rally car). Could justify even 20 mm without any compromise.

Who builds them on demand? Who did the customization (shop and person you worked with)?

Why did you do this? Just for ease of installation?

- will do, out of my mind roughly around 11 cm front and rear. I normally measure the distance between the fender (without the plastic wheel well) and the center of the wheel caps: front 33 cm, rear 35 cm.

That's 4.3" and also from your photos, the car isn't slammed.

Some more observations:
Back in 2008 I could set the KW V3 to the comfort level of a Mercedes but the rear felt a little bit floaty then.
2020 no floatiness even with the softest compression setting. It's definitely more agile. When set at the stiffer end it results in much more (undesired) movement of the car, the car gets a little 'shaky', at least for me as I do like a suspension which soaks up most of the harsh irregularities, at least on the street. Not sure (and guessing) if I'm trying to solve a highspeed problem with the low-speed adjustment. But still, the car feels responsive, even in the softest setting. I can live with it I think but I'd have favored the ability to go even softer for some trips. Kind of 'pea under the mattress' problem. All I can say is that there must have changed something. I even have a shock dyno of them from back in 2008 but don't feel like doing one again before the next winter.

Reducing rebound & droop travel can absolutely affect ride quality. Depending on who did what, and how, its possible things were changed that can explain the differences in handling and ride quality. Stiffening the LS compression does affect HS.

 

[Honcho]

Who builds them on demand? Who did the customization (shop and person you worked with)?

Gold will answer I'm sure, but I believe he had Bilstein do this directly. Their support to European customers is much better than here in the states. I was going down this road earlier on my S Zero project and it was just too hard being in the US. If I lived in Germany, I would have done what Gold and Detlef did too- a custom single adjustable Bilstein coilover built specifically for the NSX suspension geometry. There you have access to the entire library of Bilstein shocks and Bilstein themselves are willing to design and build and valve them to any spec you give them, as well as matching them to any OEM damper you wish. They did it for Detlef too. I'm jealous!

I suppose here in the states you could have a quality shop like Performance Shock Inc do the same thing with Penske or Koni dampers, but I'm not sure they could achieve the same fidelity as a major OEM like Bilstein, who can literally engineer and manufacture every single component of the system. Anyway, when my NSX-R suspension finally dies, I'll have to revisit the issue: rebuild OEM or build a "modern" system like Detlef?

 

[Procar Specials]

So the dampers are single-adjustable? (compression and rebound is tied together)?

Yes, so all is very easy to adjust.
7/23 from soft is my favourite setup, but I do use 25mm sway bays, which makes it stiffer as is is.
Also the tires, Bridgestone RE070 (JDM NSX-R NA2 tire) makes it stiffer as it is.
The most important thing is that the rebound travel is very long, so it can be used on a track like Nordschleife.
Wheels always on the road, thats the secret.

I had suspension here 4 way adjustable, but you will need an engineer to adjust that right.

you can see the rebound here