Project NSX: Part 13 – Track Testing Yokohama A052 Tires and Swift Springs

“One Lap Billy” Tests the Yokohama A052


With the new Swift springs and Yokohama ADVAN A052 tires, we were able to improve our NSX’s best lap time by an impressive 2.95 seconds, turning a 1:56.04 lap.  This lap improvement was despite having a smaller 215-width front tire (vs 235) and producing probably around 15whp less than the last lap time, due to installing a very restrictive stock muffler and stock intake manifold, vs the ported manifold that’s worth over 11whp alone.

This may unofficially be the fastest naturally-aspirated, OEM-aero NSX or S2000 lap time to ever be turned on 200-treadwear street tires.  If you know of a NA-car with OEM aero that turned a faster time, please post in the comments below.

Yokhama A052 265/35-18 Rear Tire NSX post trackThe Rear tire wear was quite minimal.  The wear across the tire was excellent, showing that the decision to run less rear camber (-1.9*) is not causing excessive tire roll over, and it actually made more rear grip.  There is a little wear at the edge of all the tread blocks, which is normal from track use.  Overall, the rear tires looked great.

Yokohama A052 215/40-17 NSX post trackThe front tire wear also looked excellent across the tire and at the tread blocks.

MotoIQ Project NSX sunsetWith the day over, we were extremely pleased with the performance of the Yokohama A052 tire, and the handling and balance improvements of the new Swift Springs.  There’s a reason the A052 has set so many records over the last 5 years, and it’s easy to see why.  It’s a fantastic and highly-capable tire.  Our NSX is now faster than ever, and the handling and performance bar has been raised further.  Stay tuned for the next installment of Project NSX!








  1. That NSX looks fantastic. Why did you go back to the restrictive stock intake manifold and muffler?

    A052’s will be my top choice for when go for new tires for my track NC, thanks to your review.

  2. The car looks so right with 17s and 18s vs the larger wheel set. You mention the roll center debacle, but I can’t imagine there’s not correction kits made for the NSX. Have you looked into them?

    Like James asked above, why go back to stock exhaust setup? Was the previous setup just too loud?

    1. I’ll be track testing 17/18 vs 18/19 soon.

      There are not any roll center correction options out there. Which is why I’ll be developing a billet upright to fix this in addition to the dry sump I designed that retains air conditioning.

      The stock muffler was to make the car tolerable until the turbo goes on since the previous exhaust was pretty much straight-piped. The stock manifold was due to the gutted and ported one being modified for a drive by wire throttle which will go on soon.

  3. How disruptive to the drivability of the car would it be to simply make both the front and rear rims sizes 18″? I know the NSX has always been designed with staggered sizes and widths of tires. Would it even be possible to standardize them?

      1. Can you explain/educate on your driving style a little please? Going into turn 1 you say “a little bit of entry neutrality” and from what I can observe you did that by turning in sharply and then quickly reducing steering angle. Is to counter the understeer you would have gotten if you turned in more smoothly? And what were you doing with you feet when you did the sharp turn in?

      2. started watching your Senna vid, you said the same thing about entry neutrality for turn 1 but didn’t do the sharp turn in then dial back. Can you explain what you mean by “entry neutrality” too? I mean the words are kinda self explanatory, but I’m hoping I can learn something I didn’t think of…

        1. Hi Bob. “neutrality” is when there is little to no steering input as the car is cornering, before the point where the car oversteers and requires counter-steer (steering in the opposite direction of the turn).

          To answer your question about what I’m doing with my feet: Half of steering a car through a corner is done with the steering wheel. The other half of steering a car is with your feet – weight transfer from the application of throttle and brake. The NSX has a slower steering rack and the suspension geometry causes the car to turn more as the car is trail-braking. This causes excess rotation, which is why the car rotates and requires less steering after turn-in (“neutrality”). The Senna on the other hand, uses electronics to apply more braking force to the inside rear tire to help turn the car. This sophisticated system, combined with a quicker steering ratio, does not need as an aggressive steering input for turn-in. But as the system works, the car rotates more than the steering input and also gets ‘neutral’, requiring very little steering INTO the corner. However on exit, when the car understeers, you’ll see more steering input.

    1. Longer springs will lower the spring perch height and will interfere with clearance to the tire.

      The rear corner weights of the car are ~900lbs. A ~450lb spring will compress 2″ at ride height. Since there is more than 2″ of droop travel in these dampers, longer springs will still become loose and flop around at full droop travel, which is what helper springs prevent by keeping load on the springs at all times. In short, longer springs won’t solve anything and will cause more problems.

  4. Not sure why it’s so hard to weigh stuff before you change it. When you spend money on a part, it’s kinda nice to know that you are getting some kind of improvement.

    Call me an engineer, but I always weigh components, and usually break out the calipers to get specs. It’s actually really fun to geek out on this stuff.

    Having said that, I really appreciate the write up.

    1. If you read Part 4 where we cover the CE28’s, they are 17×8” +38 front and 18×9.5” +40 rear CE28s to weigh in at 15lbs and 17lbs respectively.

      A052 tires in 215/40-17 front and 265/35-18 rear come in at 19 & 24lbs respectively.

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