Tuesday, November 28, 2017

Interior Enhancements; Getting Back to the Track

Interior Enhancements

We did a couple of interesting upgrades to the interior of our WRX over the summer, including a new carbon fiber/leather contoured steering wheel, and a inside-trunk pull handle, plus we tried on another new shift knob. We also installed some new shocks, and got the car back out to the race track in the fall.

We've always coveted some of the fancy Japanese contoured steering wheels, but they are hard to get and very expensive. We finally found a supplier that we liked, with a good quality product at a price point that seemed more reasonable. The wheel has a thicker rim compared to the stock item, and there are shaped portions that fit your thumbs and fingers. The top and bottom are finished in carbon fiber, and the 3-and-9 positions are in leather, perforated for ventilation. The frame is cast aluminum, just like the stock steering wheel.

The wheel installs just like a stock one; we carefully transferred over the stock airbag and spoke covers from our stock wheel. The clock spring, steering angle sensor, and airbag module are delicate and easy to damage, so if you choose to do this upgrade, have a trained mechanic install this part.

We really like the new wheel in the car. The fat rim is easy to grip and feels good. The indentations promote a good proper hand position on the wheel, and they feel comfortable. Plus the new wheel looks great. Several people asked us if it was a factory item.

The integration with the stock steering wheel controls and airbag is seamless. You can't really tell which part is aftermarket and which is original, which is the way we like it.

One tiny annoyance on the 2015+ WRX and STI is the lack of any handle to pull the trunk lid down. Many modern cars have a handle you can grab from the inside to close the trunk. We developed a Mach V trunk handle strap that you can attach to the inside of the trunk lid. This prevents you from getting your hand dirty on the soot and grit that sticks to the back of the trunk, plus you don't have to worry about scratching up the rear of your trunk lid. You can install our trunk pull strap on either the left or right side of the trunk lid; if you install it on the right, as we did, you just have to drill a single hole in the trunk liner. Otherwise, there is no cutting or drilling of the metal trunk. It's a small thing, but it makes us happy.

One last interior modification was to try out another new Raceseng shift knob. This one is called Raceseng Slammology. The -Ology shift knobs are all modular, so you can swap out the Delrin covers to mix and match colors or shapes. The Slammology knob features a full rounded Delrin top. We really like the feel of Delrin in the hand -- it's soft and doesn't get too hot or cold. Plus we love the look -- the smooth Delrin contrasts nicely with the finely-machined stainless steel
peeking out at the bottom of the shift knob.

More Suspension Changes

We had a customer with a 2016 WRX STI that found the stock suspension a little too uncomfortable. We ended up swapping shocks with him, so our WRX got STI shocks. The rear shocks are pretty similar in construction, but the front STI shocks are a fancier inverted monotube design.

The ride with the STI struts is a little bit more nervous in daily use, and you feel small undulations in the road surface more than with the WRX struts. This is something we have experienced before driving the STI, and the struts seem to be a big part of the difference in feel between WRX and STI. But the faster the car goes, the better the STI struts seem to work. At high speeds, even over bumpy surfaces, the STI struts show outstanding road-holding.

Track Testing

We haven't been out to the track with the WRX in a couple of years. The last time out, the car was on stock WRX struts, stock sway bars, our Mach V lowering springs, and Hankook Ventus Evo V12 tires. This time, we had STI struts, the same Mach V springs, our Mach V 22mm rear sway bar, and a set of 265/35R18 Continental ExtremeContact Sport tires on our Mach V Wicked Awesome 18x9.5" wheels. One more difference was that although we were at the same track -- Summit Point Main circuit -- the track was just repaved, so we had brand new fresh tarmac.

Photo by Finish Line Productions
The car performed great. Grip was excellent, with higher cornering speeds at any given part of the track. Chalk that up to the tires. The Continental ExtremeContact Sport offers excellent dry grip, and the grip stayed good as the track sessions went on.

With our Mach V lowering springs (yes, the Mach V springs work and fit perfectly well with the STI struts), our 22mm rear sway bar, and the STI struts, the car felt very neutral. It turned in promptly, with only the slightest hint of understeer on high-speed corner entry. On power exiting corners, the back end would step out just slightly. The whole car felt very planted and easy to control, with no unexpected behavior.

One other modification we made prior to track day was to install some DBA XP650 brake pads. These are a brand new product from DBA. The XP650 compound is specifically recommended for track day use. As promised, the pads held up great, with no fade even after 30-minute track sessions. they worked just fine cold, too, which is unlike some track-oriented pads. On the way to and from the track, they behaved just fine and stopped without squealing or creaking.

The only downside to using these as a street pad is the dust. They put out clouds of black dust. Even on the way to the track, the wheels developed a thin film of brake dust, and after a couple of track sessions there was a distinct plume of black dust down the sides of the car and coating the back bumper. That's par for the course for track brake pads.

We haven't yet decided to stock the DBA pads, but we may offer them in the future. Stay tuned.

Products mentioned in this blog post: