here's transcript of the V-spec preview~
Tuning on this car was done to draw out full potential of the stock parts. This car was designed as Amuse's consept of a Spec-V. We went to Amuse's workshop located at Kisarazu to interview the details.
285/35ZRF20 tyres used on the rear of normal GT-Rs were fitted on the front on the Amuse GT-R to counter understeer. To add downforce at the front a large front spoiler was developed. The rear wing was also enlarged and is made of dry carbon to reduce weight. The front seats were replaced with full bucket seats (Recaro SP-A's) and the rear seats, rear speakers were removed. This resulted in a total of 59.3kgs weight loss, but equipments like air-con and audio were left in. The cat back exhausts were replaced with a light weight titanium system, diameter enlarged 10%. The original Bilstein suspension was left in, but changes were added to lower the ride height.
The weather was fine on testing day, and the car went on its 1st lap to check for problems.
[Keiichi Tsuchiya (pro driver and the Drift King) in the car]
Hmm, the car feels quite good...
So, I'll begin the lap to see how fast she can go.
No problems have emerged, so he goes on his attack lap. Amazingly, the car goes under the targeted time of 1 minute on its check lap at Tsukuba.
[Tsuchiya]
The suspension on this car is awesome.
Wow this is a good car.
I want to teach the Nissan guys about this car's suspension, the way the car handles, how the car turns in and how it settles down... if
I worked at Amuse I'd try to sell this setup to Nissan.
The Amuse GT-R is really easy to handle, its so different from the normal GT-R. Its pliant, safe, and fun to drive.
[Tsuchiya]
So should I go for more laps?
[Amuse]
We still have 1 fresh set of tires
[Tsuchiya]
I have to get used to this car,maybe I'd do a few more laps then switch to the fresh set.
To get accustomed to the Amuse, Tsuchiya takes a few more laps.
[Tsuchiya]
The car understeers a bit..
If the tyres were fresh it'd be better.
Now if I could go full throttle here.. and the last corner, if I take a wider line in and try to accelerate out of the corner in a straight line..
not like what we take on a light-weight car.
Tsuchiya improves his time on this lap, and now its time to use the new tyres.
Its P.M. 2:30 and Tsuchiya goes on his final lap of the day.
[Tsuchiya]
Wow, heavy understeer... the car understeers more then on the used tyres....
Unfortunately no improved lap time on the new tyres.
To see how much horsepower the Amuse GT-R is producing it was dynoed. Amazingly, the car was now producing 585.2ps with only a ECU mod and a cat-back exhaust replacement.
To understand why there was so much increase in horsepower, the car was dynoed with its cats removed with the original ECU . Though this tuning was reckless (on some cars this could produce too much boost and blow the engine), a clean increase in horsepower from low rpms to high rpms was seen.
Looking at the turbo boost pressure revealed that without the cats, the boost pressure rose steeply at low rpms but after 3000rpms the boost was lower than with the cats. This means the ECU monitors and corrects the amount of boost pressure used. Amuse claim that the VR38DETT is a tuneable and reliable engine. The modding of the VR38DETT's ECU enables the engine to use different boost pressures at different rpms.
The Amuse GT-R's boost pressure data shows that during low rpms used most likely during cornering boost pressure is lowered to enhance response, while at high rpms the boost is set to about 1kg/cm2
Last, we'll show a uncut vid of the best lap.
[Tsuchiya]
We were able to go under 1min, but we were faster using used tyres. Track conditions, temps, and maybe the tyre block wobbling on the
new set came into affect and produced more understeer than on the used tyres.
Now if I used a few more new sets and got to understand the Dunlops better, the Dunlops do better if you try to enduce light oversteer, no counter-steering, the lap time could become around 59.5 secs. Next time around, I'd like to aim for that (59.5) time.
