Project Honda Civic Si Part 1: Engine Upgrades And Much Improved Drivability - Honda Tuning Magazine

Sportcar Motion

Loi Song and Sportcar Motion have unofficially become the standard destination for SoCal’s K-series crowd. Whether it’s a mild street setup like mine, or an all-out, hard-core race demon like their supercharged, record-setting ITR, the crew at SCM can make it happen. That doesn’t mean that they don’t do plenty of work on every other type of Honda motor, but the K series is certainly a specialty of theirs.

I contacted Loi about having SCM give me a hand on installing some of the new parts that were piling up in my office. Dealing with just about everything K swap related, not to mention plenty of eighth gens day in and day out, SCM is more than familiar with every square inch of the Si’s engine bay.

Hybrid Racing

If you didn’t know about Hybrid Racing before, you’re no doubt familiar with its name at this point. The company has spent the last few years offering a long, long list of high-quality K-series goods to make your car faster, cleaner, and most importantly, make your life a little easier. When I first introduced the Project Si series, I touched on a few of the quirks that seem to pester the majority of eighth gens on the road. The first being that loud “click” which chimes in every time the clutch pedal is engaged/disengaged. Oh, and that lazy clutch pedal is a bit of a nuisance in its own right. I lived with it for a while, but decided I needed to find some sort of fix, and fast. Talking to Tim Schultz of Hybrid Racing, he mentioned they’d come up with a solution for the problem in a clutch master cylinder upgrade that would not only eliminate the click, but would also improve the car’s lethargic clutch pedal feel. Using an EM1 CMC and a braided stainless line, the Hybrid unit is a direct bolt-on with no need for any modification. The eighth-gen CMC, with its plastic internals, uses a transfer chamber that inherently slows fluid down as you work the clutch, causing mis-shifts and aggravation. The EM1 CMC uses stainless internals and is a direct swap. The clutch feels much more solid and swift, with a slightly lower engagement point that aids in smooth pedal work. And that brings me to the next problem: the shift cables.

To be quite frank, I hate cable shifters. They often feel soggy and unresponsive, both of which I was experiencing. Part of the problem, other than regular wear and tear on any used car, is the fact that Honda relies on quite a bit of plastic with the stock cable system. Hybrid Racing on the other hand, does not. It has put together an entire cable replacement assembly that includes stiffer cables with 6061 aluminum rod ends and metal retainers to really tighten up the shifting. Some on the forums have complained about the price of the Hybrid Racing shift cable upgrade, but I have to disagree. Pricing is a steal in my mind, especially after putting some miles on the Si stirring through the gears. If I were to do this entire project all over again, the Hybrid Racing shift cables and CMC would, without question, be the very first on my list—even before suspension or power parts. Drivability is far more important than power or handling, in my mind.

Drag Cartel, Hybrid Racing, HaSport, Skunk2, and Triad Powderworks

As I’d talked about during the last installment, the engine bay, cowl, and engine position make for some frustrating installation sessions. To make things a little easier, Sportcar Motion dropped the entire motor, which granted more than enough access to swap in a set of Drag Cartel’s new Drop-In-Cams, a freshly powdercoated valve cover, and Skunk2’s low-profile valve cover hardware kit that really cleans up the look of the valve cover. If you’re asking where the valvesprings and retainers are, they’re not needed. Drag Cartel’s Drop-In-Cams work with the stock valvetrain, and I even hit the dyno to see what they could do. (See Part 3 for dyno results.) With the motor dropped, it also granted access to the timing chain tensioner upgrade from Hybrid Racing. Designed from scratch, Hybrid’s tensioner relies on a dual-ratchet design and heat-treated chromoly piston system that actually fits into the timing chain guide tighter than stock, which means you won’t run into alignment and wear issues. It’s a little piece of insurance that everyone should take note of when switching to aftermarket cams, whether they be aggressive or mild, like the DC Drop-Ins.

With the cams and tensioner installed, the motor was set to be bolted back in, but not until the HaSport motor mounts arrived. HaSport had long offered a rear replacement mount for the eighth gen but eventually created an entire mount kit that utilizes the three main mounts: rear, driver side, and passenger side. For a street application, Brian Gillespie of HaSport recommended HaSport’s 62a bushing. This would aid in keeping the engine planted and in transferring torque without causing excessive rattling in the cabin. HaSport does offer a stiffer race application for track cars as well. Like all HaSport mount kits, these were designed using CAD/CAM software, produced in billet aluminum, and the fit and finish are exactly what you’d expect from the industry’s best motor mount supplier—spot-on. Upon initial startup, the mounts can be felt, but as the idle mellows, the vibration is much like that of the stock mounts at stoplights. It’s when you begin slapping through the gears that you really feel them doing their job.

Although the HaSport mounts look great in their polished form, I thought I’d send them, along with a spare RSX valve cover, to Triad Powderworks for a different color. Andrew, owner of Triad, was given the task of coming up with a one-off color. My only direction was that it be some sort of bronze. What he developed was a deep bronze color with a hint of gold that looks stunning when the sun hits it. Smooth coating is something you’ll get from Triad, but the artists there also take the time to clear out any leftover material from the valve cover before returning it to you. It’s a very important step that many aren’t aware of. Bolting a freshly powdercoated valve cover onto your expensive motor with abrasives floating around on the underside is a great way to destroy your pride and joy.