Project S2000: Part 21 – Getting Rid of Squish

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The control of the chassis during all stages of cornering is really where the spherical bearing setup shines. Steering input on turn-in is now much more immediate. Of greater importance is the stability of the car; the car is rock solid stable from turn-in, mid-corner, and corner exit allowing for very precise placement of the car. The steering precision of the car is just phenomenal now. Why is the car now so much better? Before with the stock bushings, the control arms could move relatively to the chassis in yaw changing the angle of the tires relatively to the chassis. This was really evident with the worn left front lower control arm as it was constantly changing angle relatively to the chassis mid-corner upsetting the chassis. Now with the spherical bearings, the arms only articulate in the degrees of freedom they are supposed to with no rotation relative to the yaw of the chassis. Therefore the angles of the tires remain stable relative to the chassis. Lastly, there are no noises to report, just buttery smoothness.

 

We’ll be headed back to the track soon to gather further impressions on our most recent round of modifications.

With the Hasport rear diff mounts, I was not exactly sure what to expect. The one anticipated benefit was improved throttle response. With the stock diff mounts, the initial torque input from hitting the throttle goes towards twisting the differential and deforming the stock mounts. As the new Hasport mounts are magnitudes stiffer restricting movement, there is less time lag in delivering that torque input from the driveshaft to putting power down to the pavement. There are two more benefits though more subtle: the shifting seems to have gotten even better and the rear feels more stable while cornering over bumpy surfaces.

As the rear diff is now much more restricted in movement relative to the chassis, the alignment of the drivetrain stays much straighter. From the transmission, through the driveshaft, to the rear differential, they all stay in better alignment. The Hasport engine mounts made a step improvement in shifting precision and now the Hasport rear diff mounts seem to have added another increment improvement. One side effect, which may be good or bad depending on your point of view, is increased noise due to the rear diff mounts. However, as I already have the Hasport engine mounts which significantly increased noise, the increase in noise due to the diff mounts is very slight. It’s really in the realm of if I’m imagining the noise increase or not. The NT01s are a bit loud too, so those mask any noise increase from the rear diff mounts too.

 

My coworker DK-san was in town visiting from one of our offices in Europe. So, my other coworker VK-san brought out his 997 Porsche 911 Carrera for comparative driving impressions. This was DK-san’s first time driving either car, so it was nice to get his impressions. In his words abbreviated, Project S2000 is the 911 Carrera dialed up a notch. In his words, if he had not driven Project S2000 before the 911, then the 911 would have seemed pretty damn good, but Project S2000 takes it up that next level. The suspension and steering response, braking feel and power, noise, shifter feel… so I think I’m heading in the right direction in targeting the feel philosophy of a GT3RS.

VK-san took his turn in the S2000 and says it feels like a go-kart relative to his 911. He wishes he could get the shifter and braking feel of Project S2000 in his 911. Thanks to the Hasport mounts and StopTech brakes for those. While the 911 has stronger acceleration, the sheer cornering grip allowed by the suspension modifications and Nitto NT01s handily surpasses his 911. Granted, it’s not exactly fair comparing the NT01s vs street tires, but all of the suspension modifications from the KW Clubsports to the new spherical bearing kit from BlackTrax Performance to the chassis bracing have transformed Project S2000 into a very precise handling machine with insane grip levels. VK-san also really liked the response of the lighter AP1 flywheel as it made rev-matching on the downshifts a joy. I have a fair amount of seat time behind VK-san’s 911 and my two major knocks against it are the shifter feel and brakes.

The throws are a bit on the long side and there is a lack of positive feedback when you slide the shifter into the gates. I’d call the feel as halfway between the S2000 and a Lotus Elise (which is to say very poor). As for the brakes, I think the brakes just need a different pad compound as they feel very wooden; there’s really not any initial bite. But man… that steering feel… the steering is not as precise as Project S2000 currently sits with the spherical bearing suspension setup, but the weight and feedback through the steering wheel is legendary Porsche. I get it now. Of course, the engine has way more torque and power. Maybe someday, I’ll get around to adding a big dose of power to Project S2000 as the handling grip can handle a lot more power.

Next up is some track testing at Buttonwillow on December 21st with SpeedVentures. Swing by and say hi if you’re there!

 

Sources

S2000 Pro Competition Spherical Bearing Suspension Set (Blacktrax)

Hasport

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