[ Alto Works ] HKS Super Power Flow

Turbo cars can benefit greatly with a well-designed aftermarket air intake, as the stock intake can be, on some cars, a bit restrictive and can limit the additional amount of air necessary for high boost pressures. A higher flow filter, directed to draw air from cooler areas of the engine bay or directly from the front, can help improve power at higher RPMs.

However, there can be several drawbacks with aftermarket intakes, even the best designed ones. Noise is increased, unshielded filters can draw in hot air near the exhaust manifold, and exposed filters can draw in more debris or potentially water. Also importantly, engine tuning can be negatively affected, as the proper balance of air, fuel, and timing is absolutely critical.

Simply dropping in a cone filter does not necessarily improve performance. Many unknowing car owners pull out the stock intake piping, drop in a cone filter, and call it “good.” Stock intakes are designed a certain way for a reason; sometimes extra piping and large, empty Helmholtz chambers are needed and the location of air snorkels are well engineered. Moreover, the Mass Air Flow sensor is placed a certain distance away from the intake throttle body to properly measure air, but sadly, I’ve seen under enough hoods to realize not everyone knows this.

In California and some states in America, the replacement intake must also be certified CARB legal, so options are limited. In Japan, virtually any reasonable intake can be installed and still pass Japanese inspection. Knowing the potential drawbacks of installing an aftermarket intake, I figure the potential benefits still outweigh them and so all my cars have aftermarket intakes installed at the moment, all from highly reputable manufacturers.

Upon inspecting the original intake and filter, I found that it seems actually quite well designed as it is. The intake is piped in from just behind the right headlight, potentially drawing in plenty of fresh air, though sadly the intake piping is slightly small in diameter and has too many sharp bends, potentially decreasing airflow speed and pressure.

The filter design itself seems actually quite good, as the pleated filter offers plenty of surface area to draw air in. I contemplated keeping the original air box and simply altering the intake snorkel to improve airflow. Thankfully the previous owner of this Alto was gracious enough to include an uninstalled HKS Super Power Flow as part of the package, so I neither needed to buy an aftermarket part, nor modify my existing intake.

HKS filters have been criticized in some circles for being ineffectual or even poorly designed, as they say it can allow too much air particulates to enter the intake. Some famous Japanese tuners swear by them, though, and I’ve talked to a few owners who have put many miles (or should I say, kilometers) with the intakes and claim they work well.

Well, why not drop it in and see how it goes?

The mounts it came with were OEM and did not appear to be the mounts HKS originally included, according to their manual, so I had to use some aluminum brackets for a proper fit to avoid hitting the hood or other components in the engine bay.

While there is likely not a huge benefit for a stock-tuned engine, it might open up an ounce of HP if the engine can breathe more. The replacement HKS Super Power Flow intake sound is lovely, the sound of rushing air clearly audible in the cabin, even with windows up. These sounds, combined with the woosh of the recirculating valve, make the car sound lively around 3000 - 6000 RPM.

Along with this installation, I used a super thin .3mm aluminum sheet bent and shaped to block off extra radiant heat from the engine, hopefully encouraging cooler air to be drawn in from around the right headlight. (Although it looks like cardboard from some angles, the brown is actually just an adhesive backing sheet I opted not to remove at this time.)

This heat shield modification is only temporary until I redesign it with a thicker and larger aluminum sheet, which is already in progress. I would also like to use the dummy right inlet to the side of the headlight to potentially force more air directly into the air filter. Let’s see how that goes in the future...

[ Alto Works ] Steering Wheel Modification

Simple modifications that improve the Human-Machine Interface are critical for driving pleasure. Basically, anything that you touch, sit in, and control need to be comfortable. The steering wheel (or “handle” in Japan) is a major component of this, particularly since it connects you and the all-important direction of the vehicle.

I have a particular affinity for Italian-made steering wheels, particularly Nardi over the arguably more common Momo, mostly because I like the feel of a slightly slimmer grip and the very classic look. I personally love the feel of slim-rimmed and small-diameter wheels, having fallen in love with them since I first put one on my Roadster. Nardi has made racing car parts since 1946 and with their heritage tied deeply with Ferrari, they certainly have the right prestige.

Momo and many other companies make good products, undoubtedly, but there is something just right with a Nardi Torino. I will admit, though, I recently switched to a Momo wheel on my NA because I think the wood Momo Indy look complements my classic Roadster (plus) theme. I also got the Momo wheel at a steal, so I couldn’t pass it up. Now I need a wood knob to match. Which looks better to you guys, the Nardi or Momo?

Not all is well with replacing a wheel, however. The main drawback is that, if the car was originally equipped with an airbag, you lose a very important safety aspect in a daily driver car. (Exploding Takata airbags notwithstanding.) If the steering wheel also has some utility buttons, such as those to operate the radio or cruise control, you will lose them, too. But perhaps most importantly, you also have the possibility of the passenger airbag not going off, too, putting a passenger at potential risk.

Of course, some of this can be mitigated. With proper safety gear like a harness, the risk of faceplanting in the steering wheel is lowered. (There are other associated risks with that, but let’s forego that extremely complicated discussion for now.) If you also install a proper airbag resistor, the airbag computer will believe the airbag is still installed, allowing the passenger and other airbags to continue to function properly and remove any airbag error lights in the gauge cluster. The airbag resistor, though, comes at a significant price cost or requires a bit of knowledge to make a DIY resistor. (You’ll need to know exactly the correct ohms resistance the airbag module uses.)

I’ve been using my classic 350mm Nardi wheel for awhile since my first Alto Works and it’s come full circle back on another Alto Works. It has definitely seen better days, but it’s still in good condition; no tears or rips in the high quality leather yet.

To install one, though, is simple, if not costly The steering hub needs to be adapted over to the 6-bolt pattern found on Momo and Nardi wheels, requiring a hub adapter. HKB Sports makes a wide range of inexpensive hub adapters, so finding one is easy. Luckily, this car was not originally equipped with an airbag, therefore it doesn’t necessitate a pricey airbag resistor. The HKB Sports hub was inexpensive at around 2000￥($18 USD) online, though the versions that are offered with airbag defeats are around 6000￥ ($55 USD) and up.

Turn your steering wheel and wheels as 12 o’clock straight as possible and begin. On most cars, to remove the old steering wheel cover or airbag, you have to undo some bolts on the rear of the center / horn. There was none I could find here. It turns out the trick to remove the front panel is to push in and up. I put a bit too much force and ended up bending the metal brackets holding the horn cover. Oh well.

Afterwards, it is a simple matter of undoing the tight nut attaching the wheel to the steering column, wiggling the wheel out, and putting in the new hub. Make sure the top arrow of the hub lines with the top dead center, otherwise, your turn signal cancellations may not work properly. This car had no airbag, so it’s a simple matter of connecting the horn and bolting it all in. For hub adapters with a airbag defeat resistor, you have to make sure they are carefully connected and taped or zip-tied snugly before the wheel is put in, offering enough slack and length for the wheel rotation.

Nice. Now I just need a 30mm hub adapter to get the steering wheel closer to me and I’ll be a happy driver. The feel of the right steering wheel makes the driving experience so much better. Now that the car is feeling better, we can make the car perform better...

Karuizawa Meeting 2017

I had a chance to attend the largest annual Mazda MX-5 Roadster meet in Japan on May 28. (Miatas to us Americans.) Nestled in the mountains of central Japan, Karuizawa is a small, fashionable, and beautiful city in Nagano Prefecture. Though centrally located, the small, local roads make it a slow drive to reach from Tokyo, Osaka, or Fukui, where I am from. Luckily, the weather was absolutely gorgeous that day and I had a wonderful time chasing down local Roadsters on a curvy mountain pass from my hotel.

Coming across the first lot, little convertible cars stretched as far as I could see. Briefly walking the first of the two visible lots, I was mesmerized by the sheer amount of varying combinations of colors, wheels, and kits. Most were tastefully adorned with a few select parts, like a beefy set of wheels, a roll bar, an aftermarket front bumper, and/or lowered to just the right usable height.

To an MX-5 fanatic, this was absolutely heaven. Nearly every car present was meticulously maintained,  despite the early NA6 Roadsters ticking at 27 years old. Here, one could find all generations with crazy conversion kits, rare parts, NB coupes, lovely stock examples, and everything in between.

For you Stance or Slammed fans, sadly, very few would have made you tingle. The blue one looks like it is rocking a Project-G bikini top.

Stopping halfway through the second lot, I was puzzled. How could this possibly be the largest MX-5 meet? While it was impressive, where were the booths of manufacturers, the demo cars, the free lunch I was promised? My stomach gurgled, sustained only on rice balls, water, and Monster.

Maybe it was the tiredness of driving so much the past day, but I was certainly not aware of the procession of people passing beyond the trees. And there it was. The main lot.

I had been wasting entirely way too much time on each individual car. It was already noon and I rushed straight to the dealer tents drawing the crowds.

ZOOM Engineering, Barchetta, and Jetstream had so much to offer. My heart raced as I wiped a bit of sweat from my brow. How much could my wallet handle? The cash and carry society made it impossible to overspend.

Here were some of the demo cars that certainly were excellent displays of the company offerings. Garage Vary's ND looks ready to attack the track or local mountain roads alike.

Also in attendance was the 1,000,000th Roadster made, an ND Roadster in Soul Red, adorned with signatures from its travels abroad.

One thing I noted, after walking the lots, was the distinct lack of engine swaps. (Of course, definitely not the V8 LS engines Americans often swap in.) Most of the open hoods had element filters and tower braces and were meticulously clean. Few others had ITBs or forced induction. Closed hoods had no hints of intercooling, so I could only assume the rest were similarly stock. Nonetheless, you could tell these owners appreciated taking care of their car and leaving it as the Mazda engineers had intended.

Some car clubs were out in full force. The two more notable groups were the Nara Gundan Roadsters were adorned with huge stickers and usually some strange theme.

Shin-kai went with full kits, gorgeously blended into the fenders. Absolutely stunning examples.

The love was evident all around. Plenty of homemade DIY modifications and customized parts if you look carefully enough.

See you guys this year. I’ll be there.

www.karuizawa-meeting.com

May 28, 2017

[ Alto Works ] First “Modification” and Wheel Spacers

The car is all well and good so far. Not one day into the ownership of the car, I started making a laundry list of the variety of things must be changed. First was the removal of the extremely heavy and unnecessary audio system. There was an embarrassing tangle of wires and it turns out the rears were not even connected at all, as the positive lead was disconnected. The subwoofer box, as you might surmise, was pretty heavy. I am glad to be rid of it and the rear speakers. The front speakers and head unit will stay, as it has USB / iPhone connectivity so I can listen to my awesome audiobooks. (I’m so exciting that way.)

Here’s one modification that may draw some scorn from car purists: wheel spacers. Cheap, flimsy, aluminum “universal” 5mm spacers not center-bored to the hub, at that. I am well-aware of the potential issues of spacers, of which there are many. Adding width adds additional wear to the bearings and suspension components, changes the handling (for better or worse), and non-hubcentric spacers can potentially upset the car at high speed if they are off-center, creating potential vibrations. Moreover, simple sandwich spacers such as these reduce the amount of thread the lug nuts can tighten over, further reducing safety.

These are more appropriate wheel spacers, as they are specifically drilled for sets of specific patterns and are hubcentric to the diameter of the car. In this case, these are the perfect set for my Swift Sport, at 5x114.3 with a 60.1 center bore. For the Alto, I would need 4x100 with a 54.1 center bore.

At least, I did ensure that it was as centered as possible. What these spacers do is change the look of the wheels. They are now spaced out 5mm toward the outer edges, effectively changing the wheel offset from +45 to +40. I think they look a bit better, since they aren’t as far sunk into the fenders. In the end, knowing the drawbacks, I will leave them on. Keeping the nuts checked and tightened periodically will be a necessity. Further, as I don’t plan on tracking this car, nor drive it particularly long distances, the wear and the potential issue will be minimal, at best (or is it worst?).

I do have the option of going with larger 15mm or 20mm sandwich spacers with studs attached to stance out the car a lot more, which looks like it may also require a fairly aggressive fender roll. But for now, this spacing is adequate. I’d like to go with much wider wheels in the future, like a 13 x 5.5 inch wheel. I suppose 14 inch wheels would be fine too, but I think 55 series tires and 14 inch wheels don’t have enough rubber sidewall for my taste. The look of fat tires is definitely more appropriate to the style, in my opinion. This is an adequate temporary modification to keep my car looking fresh(er).

[ Alto Works ] Driving Impressions

Now that the maintenance is out of the way, we can focus on putting the HA11S Alto through some paces and I can give you a more honest review of how it exactly drives by taking it on its first 3-hour road trip to Osaka. First off, the car starts up quickly and smoothly without excessive cranking; good to know the fuel pump, battery, and starter are in good condition. The engine idles and shakes the cabin a bit, somewhat very typical with other unbalanced 3-cylinder engines of this age and mileage. The car accelerates smoothly, with little issues or hesitation between gear shifts.

Power delivery is acceptable, with the turbo spooling up notably around 2500 RPM and trailing off before 6000 RPM. This car only has 63 HP to pull its 670 kg (1477 lbs) listed weight, so it doesn’t pull fast or hard. But it’s not bad at all, actually. The sensation of speed is helped by the relatively low driving position and small roads. If left on “Drive,” the automatic transmission holds the gear until near the redline at around 7000 RPM when the throttle is hammered down. Of course, it chooses to upshift at that point or at the slightest release of the throttle, as to be expected for traditional torque converter boxes. Considering that speeds are legally limited to about 30 km/hr (19 MPH) local roads to 50 km/hr (31 MPH) city roads, this car drives fast enough to be “illegal” within a few seconds.

In comparison to the numerous other kei cars I have driven over the years, this car pulls as well as all of them. While the power-to-weight ratio is less than this Alto, my last HA12S Alto felt a bit peppier, likely due to the 5-speed manual transmission it had. But this is one of the lightest and quickest FWD kei cars that have a plethora of aftermarket support, so it’s perfect as a base car to modify. The small turbo has just enough boost to keep things interesting, but the engine note is harsh when thrashed and the exhaust note is boring. The unknown aftermarket blow-off valve is fun to hear, whooshing and releasing pressure when the throttle is let off. Whenever I get to replacing the exhaust, I’m sure that is when I’ll enjoy this whole experience more.

Unfortunately, the car has a terrible on-center feel, with quite a bit of steering play, quite typical of other kei cars of the 90s. I wish it was a bit crisper and sharper like my last Alto, but it’s far from terrible. The car has a decent feel in slow speed corners, so I took the car out to some curvy roads to see how the car behaves when pushed a bit more. Immediately, I can tell the car does communicate quite a bit through the steering wheel. There is a bit of honestly in an old car that bumps, rattles, and shakes in corners, as every physical sensation is relayed to the driver. Suspension is decently stiff for an older high-mileage car, so I wonder if it has been replaced at some year. It does not bounce, float, or dive on braking or accelerating. The grip, particularly on wet surfaces, is terrible due to the age and quality of the tires, so it has a tendency to understeer. However, the short wheelbase encourages throttle control to rotate the rear and it is quite easy to do so when provoked.

The non-ABS brakes are stiff, necessitating a bit of pressure to push the pedals. While it is better than soft brakes with no feel, as that might indicate air or leaks, hard brakes could indicate a faulty brake booster, though according to a quick preliminary pressure check, it is ok. Maybe it could be problematic rear drums or pistons. No pulsing, noises, or reverberations otherwise.

Speaking of rear drums, sadly the ie and Limited packages have those as standard. Only the RS/Z and R models had rear discs. Of course, it isn’t necessarily a bad thing, as drums are very low maintenance and more than adequate for most non-sport FWD cars.

So how does it feel sitting in the car? The Sports Limited bucket seats are respectable and do a decent job of holding my lower back in place, but I do wish the side and thigh bolstering were a bit more aggressive. The non-adjustable steering wheel has a terrible, truck-like angle, facing more upwards than I would like, considering my typical seating position. The cabin is typically noisy and lacks much sound deadening like many 90s economy cars, so wind and road noise impede in the cabin, compounded by the age and crumbling seals.

The lack of amenities is a charm for me: no automatic folding mirrors, no power mirrors, basic A/C and front speakers, and power windows. That’s all one really needs in a daily-driven project car. Heck, with the rear seat back folded, there is plenty of room for a set of spare tires and tools!

For my steely-eyed readers, you might be able to catch some modifications already in progress on the car. Next week, I'll start to showcase some of those changes.