Sunday, December 14, 2014

Enkei GTC 01 Hyper Black track test review

Late in 2013, I explored the option of switching to a wider wheel in the hope to realise more grip from the slight stretch on tyres that many spoke about. After some discussion with S2000 racing drivers, I was told that the gains would probably be much less dramatic than what I hoped they might be but I should consider having a wheel that was both durable and rigid if I planned to continue racing in the events that I regularly partake in. That got me interested in the concept of wheel rigidity and I began searching online which resulted in me coming across this article by Option Magazine below:

In short, the article aimed to emphasize that to some extent, putting up with a bit more weight in the wheel but compensating with much higher wheel rigidity might make a positive performance difference. This piqued my curiosity and I considered how I could enhance my setup in this way. The Enkei RPF1 that I used was pretty strong for the light weight wheels that they were and it felt great to have a light weight wheel with excellent steering response which made the car feel nimble. I did, however, receive feedback that going to wider wheel width in the RPF1 design might increase the chances of more easily damaging the wheel barrel during hard driving. With that point of concern in my mind, I decided that along with going wider in wheel width, I'd have to also go to a stronger wheel and specifically, a wheel that is much stiffer.

But what exactly is stiffness and what would a switch to the stiffer wheel achieve?
Stiffness, as defined on Wikipedia, is the extent that an object resists deformation in response to an applied force. This is not to be confused with strength which indicates the difficulty for an object to break. So having a strong wheel may still result in a wheel that deforms at the application of a force, in this case the forces under cornering and braking, but returns to its original shape thereafter.

Forged wheels would be great as they delivered high material tensile strength and yield strength allowing the wheel to return to its original shape when stretched better than a cast wheel but were prohibitively expensive. Cast wheels by Enkei deliver motorsport grade strength while maintaining reasonable cost so I focused my attention on Enkei's line up to find the stiffest wheel I could get which would be within my budget. After a bit of reading up, I decided to go with the Enkei GTC 01 in Hyper Black for a couple of very compelling reasons:

1. The GTC 01 employs MAT DURA Flow-Forming process that has technology derived from Super GT to allow the wheels to attain competition strength and rigidity.

2. Anti Slip paint on the bead reduces the chance of tire slippage and distortion during the stress of the racing situation.

3. The wheel is heavier than the Enkei RPF1 I was currently running but still relatively reasonable in terms of how much weight is added and to trade off some weight for better performance potential plus enhanced durability is a good compromise in my book.

4. Pricing was very reasonable and I got excellent support from Isaac Tan of YHI Corp on technical aspects of the wheel such as offsets and clearance.

5. What a beautifully designed wheel in a brilliant colour! Those massively curved outward spokes could accommodate some serious big brake kits...*hint* lol!

Here are some pictures of the wheel:

Check out that twin valve setup that was derived from the need to purge air from one valve while filling of nitrogen; a sign of it's motorsports DNA.

Finally they are fitted!

Initial impression of the wheel were that the weight was definitely noticeable as the steering effort required had increased. Fuel consumption and power delivered to the ground did not see any dramatic changes thankfully. Due to wider wheel stance and the increased width, I did have to get a bit of fender adjustment done to prevent rubbing of tyres on the bodywork.

Soon enough it was time to hit the track and so it was that the spanking new wheels made their track debut in the Nov 2013 Time To Attack.

Unfortunately, due to issues with the car, I was not able to perform at my best during the November 2013 Time To Attack but I came away with some pretty good feedback on the tyres. I ran with the same size 255/40/17 Hankook RS3 tyres on RPF1 and with the GTC 01, the generally numb feeling RS3 were now giving me a lot more feedback through the steering. It could possibly be due to the slightly wider wheel width employed but since that increase was only 0.5 inch, I wouldn't attribute that much improvement to such a small change.

The only way to get more understanding of how the wheel helped me would be more track work! And so I did at PG Trackies outing to Johor Circuit...

And more at the 9tro'us Track day at Sepang Circuit...

Oh yes drifting does help validate the increased feedback available LOL!

Although I didn't post any record shattering times at Johor Circuit or Sepang Circuit due to engine and suspension problems, one thing that remained apparent is that the wheels provided plenty of excellent feedback which was critical at braking and cornering. This allowed me to confidently push closer and closer to the limits available with the reassurance that the wheels would not fail at the limit while providing vital "talk" through the steering to let me know what was going on at the contact patch.

Here's a huge thumbs up to Enkei! 

More pics of the car with the GTC 01s at the recent 9tro'us Arena

Let me leave you with a sweet pic by Isaac who snapped a shot while I popped into YHI Advanti Centre for a tyre rotation...

Credits to:
YHI Corp for their support
Isaac Tan for his pic and technical help
Option Magazine for the use of their article
Alan Tay for his picture at PG and 9tro'us Arena
Raedi Yusof for his pic of my drift
Wayn Wong for his pics at Time To Attack
Allen Aznan for his pic at Time To Attack
9tro for the awesome 9tro'us Track Day and 9tro'us Arena events and photos