What makes Caymans easier to handle on track

[CB72]

I recently watched a video of a 981 GTS at the Paul Ricard track in the south of France and was amazed by the ease of controlling the car.
https://www.youtube.com/watch?v=pyxtSF63cY4
It just confirms the feedback I got from many Cayman drivers that state that you can easily catch a spin before it happens.
I've never driven one personally but in contrast, I spun or half spun my NSX many times in particular in the wet that did no good to my confidence in the car...
What could be the reasons for this superior road holding?
Mass distribution? Roll center? Center of gravity? Steering feel and response?
Here's my NSX following a Cayman GT4 on a damp track where I feel I'm driving on ice with my Avon ZZR's vs the Cup2's on the Porsche's
https://youtu.be/zYgMhHaazqU

 

[DocL]

First, You were trying to keep up to a car that has superior suspension and computer assistance for the driver. Second, you were on a wet track trying to keep up to a superior car on the track.

Even though the NSX is a fantastic car, it lacks the new technology that Porsche puts into their cars to allow them to out perform your car which was designed and engineered in the late 80’s.

 

[docjohn]

On the plus side trying to keep up can make you a better driver......also try getting a track coach for a few sessions next time out...

 

[RYU]

I was reminded of this driving the FK8 Civic Type R on track. I've asked myself this question in regards to the NSX.

I have a few theories partially supported with anecdotal evidence learned with my NSX.

- modern traction control is part of it
- ability to provide quicker steering inputs whilst slowing down chassis reactions. Using a S2000 quicker steering rack with EPS help me catch things much quicker and it let me go deeper in steering angle because of the power assists. Better damping with the JRZs help control body motions much better.
- anti-compliance or non-compliance suspension also helped especially in the rear. One of my last projects is to swap out old worn bushings in the car.
- bucket seats helps you feel the car rotate around you better
- steering wheel like the Momo NSX-R, though the stock is pretty good in terms of feel too

However, here's my takeaway and one of the reasons I've kept my NSX for so long... Cars that are easy to drive become boring to me very quickly. The CTR was one of them. The NSX makes you earn it and so satisfying when you get it right.

 

[CB72]

I was reminded of this driving the FK8 Civic Type R on track. I've asked myself this question in regards to the NSX.

I have a few theories partially supported with anecdotal evidence learned with my NSX.

- modern traction control is part of it
- ability to provide quicker steering inputs whilst slowing down chassis reactions. Using a S2000 quicker steering rack with EPS help me catch things much quicker and it let me go deeper in steering angle because of the power assists. Better damping with the JRZs help control body motions much better.
- anti-compliance or non-compliance suspension also helped especially in the rear. One of my last projects is to swap out old worn bushings in the car.
- bucket seats helps you feel the car rotate around you better
- steering wheel like the Momo NSX-R, though the stock is pretty good in terms of feel too

However, here's my takeaway and one of the reasons I've kept my NSX for so long... Cars that are easy to drive become boring to me very quickly. The CTR was one of them. The NSX makes you earn it and so satisfying when you get it right.

You are definitely right, modern cars do take some of the fun away but they are fast!
My car is equipped with Recaro bucket seats, Momo style steering wheel and non-compliance bits front and rear from Titanium Dave.
The suspension is from KW V3 clubsport.
In fact, I loose time in two places: at the hairpin at the end of the backstrait as I'm very cautious about using too much throttle with my turbo setup and the NSX-R diff as the rise in power is not linear and correcting the slide negates any time gained.
The other place is just after the finish line at around 120 mph when the track takes a dip while turning right.
I've ridden as a passenger in a 475 hp 991 GT3 and it's really scary when the rear wheels unload.
Here's what happens at 210 km/h in a GT3 RS driven by a professional driver at 1:10"
https://www.youtube.com/watch?v=pI4sjO_R7kc
I could maybe feel more safe with less rebound damping and my APR rear wing?

 

[docjohn]

he seems to track out farther and gets on power before you...he may also have bigger and better tires...

 

[TigerNSX]

What could be the reasons for this superior road holding?
Mass distribution? Roll center? Center of gravity? Steering feel and response?

I have a Cayman S, and have tracked both the Cayman and the NSX. I am an intermediate track driver (~30 hours of track time), and not an expert. However, a few observations:

* The Cayman has a shorter wheelbase, and the quicker steering ratio. Together combined, it's much easier for me to react, and correct the car. I find that the NSX (especially '91-'94 with manual steering) requires more efforts to maneuver steering.

* Both cars have stock OEM seats. However, I sit much closer to the ground in the NSX than in the Cayman. I find that my outward visibility/view is much wider and clearer in the NSX than the Cayman. This makes me feel like I am going much faster than when I am in the Cayman even at the same speed. So, mentally, it's much scarier going faster in the NSX (but more fun).

* In fast sharp corners, the Cayman feels much easier to drive quickly. In the long sweeping corners, the NSX feels much more planted than the Cayman.

 

[CB72]

he seems to track out farther and gets on power before you...he may also have bigger and better tires...

Given the power ( 520 hp) and the brakes of the GT3RS he drives the car like a motoGP bike i.e. spend a minimum of time in the corners, get the bike straight and use the power.
I will try that next time if we get access to the track...
The PDK is also a big advantage with shorter gear ratios and lightning speed gear shifts
The tires make also a big difference of course with the latest Michelin Cup 2 R's in dimensions we can only dream off!
The GT4's are more in my league with no PDK, long gear ratios and little mid-range torque:
https://www.youtube.com/watch?v=aHKuHuUlyBo&feature=youtu.be

 

[docjohn]

reading your other thread you need more front end grip/more confidence at turn in ..I would suggest asking Billy (stuntman) for his advice based on your suspension/tire/alignment settings...

 

[Honcho]

reading your other thread you need more front end grip/more confidence at turn in ..I would suggest asking Billy (stuntman) for his advice based on your suspension/tire/alignment settings...

Tagging him. [MENTION=16531]stuntman[/MENTION]

 

[Honcho]

Here's my NSX following a Cayman GT4 on a damp track where I feel I'm driving on ice with my Avon ZZR's vs the Cup2's on the Porsche's
https://youtu.be/zYgMhHaazqU

That's a lovely little circuit- where is it? My wife is French, so maybe I will come visit the next time we are in France.

 

[skafia]

Time to sell the NSX...

 

[CB72]

That's a lovely little circuit- where is it? My wife is French, so maybe I will come visit the next time we are in France.

Here it is :
https://www.super-trackday.com/circuits-automobiles/haute-saintonge.html
It's not a very fast track like Spa in Belgium or the Bugatti in Le Mans but it's quite technical.
I live about a hour and a half away so let me know when you come over!

 

[CB72]

I have a Cayman S, and have tracked both the Cayman and the NSX. I am an intermediate track driver (~30 hours of track time), and not an expert. However, a few observations:

* The Cayman has a shorter wheelbase, and the quicker steering ratio. Together combined, it's much easier for me to react, and correct the car. I find that the NSX (especially '91-'94 with manual steering) requires more efforts to maneuver steering.

* Both cars have stock OEM seats. However, I sit much closer to the ground in the NSX than in the Cayman. I find that my outward visibility/view is much wider and clearer in the NSX than the Cayman. This makes me feel like I am going much faster than when I am in the Cayman even at the same speed. So, mentally, it's much scarier going faster in the NSX (but more fun).

* In fast sharp corners, the Cayman feels much easier to drive quickly. In the long sweeping corners, the NSX feels much more planted than the Cayman.

Thanks for the interesting input.
What Cayman model do you have?

 

[CB72]

Tagging him. [MENTION=16531]stuntman[/MENTION]

My setting is 2.5 mm toe in upfront and 4.1 mm toe in in the rear with 2°25' camber front and 2°30' for the rear.
Tires are Avon ZZR 215/40*17 and 265/35*18.
Ride height at 110 mm front and rear measured from the lift rail running underneath the car.

 

[RYU]

Any reason why you're toed-in in the front? Most of us run a bit of toe out with some running 0 toe. It's rare I see toe in settings.

My setting is 2.5 mm toe in upfront and 4.1 mm toe in in the rear with 2°25' camber front and 2°30' for the rear.
Tires are Avon ZZR 215/40*17 and 265/35*18.
Ride height at 110 mm front and rear measured from the lift rail running underneath the car.

 

[CB72]

Any reason why you're toed-in in the front? Most of us run a bit of toe out with some running 0 toe. It's rare I see toe in settings.

With my 17 and 18" wheel combo the car never felt really safe and a local car racer ( Delage Sport in 47300 France) said this is crazy you must have toe in in the front...
He successfully raced BMW's for many years so I accepted his advise thinking that I could always go back to the original setting.
Let me say the car was transformed with a very gradual and linear increase in effort as you turn the steering wheel.
Let's not forget that the original NSX specs were for 15" front wheels.
Now with 17" wheels running semi-slicks no wonder the settings could be different...
Last but not least, I know of at least two guys who incurred total loss of their NSX while driving on straight roads in wet conditions.
One of them was passing a slower a car.

 

[RYU]

[MENTION=19738]CB72[/MENTION] I'm not saying you're wrong. Please use the toe settings you're most comfortable with, but you're going with the opposite of what most of us do here (as a data point)

 

[CB72]

[MENTION=19738]CB72[/MENTION] I'm not saying you're wrong. Please use the toe settings you're most comfortable with, but you're going with the opposite of what most of us do here (as a data point)

No harm done!
I believe [MENTION=32623]Mac[/MENTION]Attack has also tried zero or slight toe in upfront.
It's worth trying believe me.

 

[stuntman]

What could be the reasons for this superior road holding?
Mass distribution? Roll center? Center of gravity? Steering feel and response?

The Cayman has struts front and rear, which is actually a disadvantage, but despite the strut's limitation of a lack of camber gain, the Cayman has a much more consistent roll center and bumpsteer curve compared to a lowered NSX.

Lowered NSXs have a pretty terrible front roll center location, it's too low and migrates significantly. This is why a lot of track and race NSXs use super stiff front springs and swaybars, to minimize the front suspension from moving and the roll center from dropping even more with roll and compression. Because of this, the NSX rotates and snaps when trail-braking (which happens in your video and from the in-car video of many NSXs).

On the rear, lowered NSXs have a really bad camber-gain. With an inch of suspension (compression) travel, the rear camber can gain another -2* of camber. Since you're already at -2*30' that means with just 25mm of travel, you're at well over -4* of camber and not using all of the rear tire. Measuring tire temps with a PROBE type pyrometer will show this. You can improve this by reducing rear static camber and/or stiffening up the rear spring rates.

At stock ride height, the NSX is quite good and predictable, but these geometry issues quickly come up when lowering a car with not stiff enough spring rates. This causes the lack of confidence and inconsistency that makes it difficult for less experienced drivers to feel comfortable with pushing the limits without spinning out.

The bumpsteer of the front and rear of lowered NSXs are usually not good. Getting a bumpsteer kit and properly setting it up will make a big difference. Unfortunately i'm not aware of rear bumpsteer kits. I talked to Carbon6 about making one out of their rear toe link kit. We will see.

What spring rates are you running? I asked you a while back but forgot...

Once i'm done with my dry sump and turbo kit, maybe i'll tackle a front drop spindle that improves the front roll center for lowered NSXs without needing a massive front swaybar, which hurts braking performance and steering feel. But those will likely cost $4K for the set.

Any reason why you're toed-in in the front? Most of us run a bit of toe out with some running 0 toe. It's rare I see toe in settings.

My car currently has toe-in at the front. It improves turn-in and 'on-center' response, but increases rut-wandering and can make the car more 'darty'. Ideal toe depends on a lot of factors. I usually default to 0-toe.

 

[CB72]

The Cayman has struts front and rear, which is actually a disadvantage, but despite the strut's limitation of a lack of camber gain, the Cayman has a much more consistent roll center and bumpsteer curve compared to a lowered NSX.

Lowered NSXs have a pretty terrible front roll center location, it's too low and migrates significantly. This is why a lot of track and race NSXs use super stiff front springs and swaybars, to minimize the front suspension from moving and the roll center from dropping even more with roll and compression. Because of this, the NSX rotates and snaps when trail-braking (which happens in your video and from the in-car video of many NSXs).

On the rear, lowered NSXs have a really bad camber-gain. With an inch of suspension (compression) travel, the rear camber can gain another -2* of camber. Since you're already at -2*30' that means with just 25mm of travel, you're at well over -4* of camber and not using all of the rear tire. Measuring tire temps with a PROBE type pyrometer will show this. You can improve this by reducing rear static camber and/or stiffening up the rear spring rates.

At stock ride height, the NSX is quite good and predictable, but these geometry issues quickly come up when lowering a car with not stiff enough spring rates. This causes the lack of confidence and inconsistency that makes it difficult for less experienced drivers to feel comfortable with pushing the limits without spinning out.

The bumpsteer of the front and rear of lowered NSXs are usually not good. Getting a bumpsteer kit and properly setting it up will make a big difference. Unfortunately i'm not aware of rear bumpsteer kits. I talked to Carbon6 about making one out of their rear toe link kit. We will see.

What spring rates are you running? I asked you a while back but forgot...

Once i'm done with my dry sump and turbo kit, maybe i'll tackle a front drop spindle that improves the front roll center for lowered NSXs without needing a massive front swaybar, which hurts braking performance and steering feel. But those will likely cost $4K for the set.


My car currently has toe-in at the front. It improves turn-in and 'on-center' response, but increases rut-wandering and can make the car more 'darty'. Ideal toe depends on a lot of factors. I usually default to 0-toe.

Hi Billy,
Many thanks for this valuable input!
I believe the KW V3 clubsport are rated at 8 kg/mm at both ends.
If I increased the front to 10 kg/mm it would replicate the NSX-R 2002 setup.
Why not have the front drop spindles fabricated in steel at least for a first try?
Many years ago, I drove a Swiss racing NSX that had a unique suspension setup and I believe they used steel?
Last but not least my car's height is at 110 mm ( measured from the lift rails), is that really low?
John

PS: These guys might be of help?
https://honeddevelopments.com/product-category/suspension-geometry-tuning/

 

[stuntman]

Hi Billy,
Many thanks for this valuable input!
I believe the KW V3 clubsport are rated at 8 kg/mm at both ends.
If I increased the front to 10 kg/mm it would replicate the NSX-R 2002 setup.
Why not have the front drop spindles fabricated in steel at least for a first try?
Many years ago, I drove a Swiss racing NSX that had a unique suspension setup and I believe they used steel?
Last but not least my car's height is at 110 mm ( measured from the lift rails), is that really low?
John

Your car is lower than the NSX-R and probably needs higher rates. Tsuchiya ran 9/14, and I don't really like that setup direction, because it does not address the front roll center dropping.
NSX-R is 10/8, but for a track-focused car like yours, i'd probably try a 12/10. Jim Cozzolino ran 13-14 front with a 10 rear for the longest time.
It's good to see that you have a Dali 22mm front bar but what rear bar do you have?
They could be fabbed out of steel. I'll probably go down the path of CNC aluminum since I don't have a good fab guy anymore and they are a bit more complex to make than most spindles.
You're pretty low from a geometry standpoint, but a common height for NSXs.

 

[RYU]

The Cayman has struts front and rear, which is actually a disadvantage, but despite the strut's limitation of a lack of camber gain, the Cayman has a much more consistent roll center and bumpsteer curve compared to a lowered NSX.

Lowered NSXs have a pretty terrible front roll center location, it's too low and migrates significantly. This is why a lot of track and race NSXs use super stiff front springs and swaybars, to minimize the front suspension from moving and the roll center from dropping even more with roll and compression. Because of this, the NSX rotates and snaps when trail-braking (which happens in your video and from the in-car video of many NSXs).

On the rear, lowered NSXs have a really bad camber-gain. With an inch of suspension (compression) travel, the rear camber can gain another -2* of camber. Since you're already at -2*30' that means with just 25mm of travel, you're at well over -4* of camber and not using all of the rear tire. Measuring tire temps with a PROBE type pyrometer will show this. You can improve this by reducing rear static camber and/or stiffening up the rear spring rates.

At stock ride height, the NSX is quite good and predictable, but these geometry issues quickly come up when lowering a car with not stiff enough spring rates. This causes the lack of confidence and inconsistency that makes it difficult for less experienced drivers to feel comfortable with pushing the limits without spinning out.

The bumpsteer of the front and rear of lowered NSXs are usually not good. Getting a bumpsteer kit and properly setting it up will make a big difference. Unfortunately i'm not aware of rear bumpsteer kits. I talked to Carbon6 about making one out of their rear toe link kit. We will see.

What spring rates are you running? I asked you a while back but forgot...

Once i'm done with my dry sump and turbo kit, maybe i'll tackle a front drop spindle that improves the front roll center for lowered NSXs without needing a massive front swaybar, which hurts braking performance and steering feel. But those will likely cost $4K for the set.


My car currently has toe-in at the front. It improves turn-in and 'on-center' response, but increases rut-wandering and can make the car more 'darty'. Ideal toe depends on a lot of factors. I usually default to 0-toe.

That's a great explanation. Thanks for sharing that. I do have a text where you recommended a slight toe out in the front. Perhaps that was unique to my setup or perhaps the preference has changed? In any case, I'm pretty close to zero toe myself but about <1mm of total toe out as I dial in the feel of the S2K rack. I have not tried going past zero into Toe-in but worth a try someday. With my car feeling fairly neutral I've stopped tinkering.. the only tinkering is the idiot behind the wheel that needs a bunch of driver mods.

I'm not a fast driver but I can echo the fact that every time I raise my car it continues to drive better though I'm starting to notice more body roll.

Hopefully the NSX front knuckle project comes to fruition!

 

[asylum]

First tires can make a huge difference. Seconds per lap. Especially if you can not get them at the right temp, which is trickier on the wet. Especially with "race" or high performance" tires that tend to have a thinner ideal temperature of operation area. And to do this, you must have the right suspension and sway bar settings which are probably too hard if they give you satisfaction on the dry.

 

[simonasaur]

The way the nsx feels to me mimics its shape, as a wedge the weight is so apparent right behind you. it initiates turn in so well, and the mass behind you seems to help the car rotate into corners. Up to 7/10ths this is a huge advantage and makes it feel like its on rails, and that you're in total control of the car. But when you exceed that limit, or get near it, it becomes an experts level driving car very quickly. I haven't driven the gt4, but I spent a few days with the cayman R. While they're both mid engine cars, I wouldn't say they felt similar at all. The cayman is just so easy to drive fast, its suspension feels like its filled with the most expensive rubber. That being said, ill take the NSX 10 times out of 10. The feedback is like a seeing a band in person at a small venue with great sound, vs hearing the cd from another room.

It appears to me from the 1st video, you are braking later than the cayman coming into corners. At around 1;40 you can see this as you begin to gain some ground in the turn but then have to lift to correct, meanwhile he's taken the "slow in fast out" approach, and begins to pull away. its possible working on your style to better match the cars strengths could gain you that pace you're after.

Please take my comment as it was intended, to help, not to criticize your driving. I admire anyone who takes their NSX to the racetrack.