Rage Against the Rule Book

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If you’re not too familiar with the Honda Z600, you’re in good company. The odd little front-wheel-drive hatchback was one of Honda’s first forays into the automotive market back in the early ’70s. Call it a toe in the water from a manufacturer who sold its very first car only a few short years earlier.

The Z600’s most noticeable design feature was a funky and thick black rubber molding that surrounded the small, radiused rear window. The black window and narrow grille gave the car a shoe-like appearance—and combined with its very un-American size, the car was more of a joke than a serious attempt by Honda at cracking into the American market.

Mike Haviland also knew little about the Z600, but he didn’t choose to turn one into an autocrosser based on its oddball looks. It was simply the shortest, narrowest car that fit the SCCA autocross rules for the class that he hoped to run.

A moderately successful road racer, Mike built the car simply because he wanted to try his hand at autocross. “Before this, I ran a Yamaha-powered D Sports road racer,” he explains. “I never autocrossed it, but I thought it would be fun.”

Taking Aim

Mike is a “play to win” kind of guy—a trait gained through his other hobby of long-distance running—so he examined the SCCA rulebook carefully for a class in which he could succeed. He hoped to recycle as much of his D Sports Racer as possible, which meant he’d be aiming at one of the Modified autocross classes. He also wanted to pick a class that had a low minimum weight; since he’s a lightweight guy, he felt that would give him an advantage.

“Originally I wanted to run in D Mod,” he explains. “Rules allowed up to a 2-liter engine but only 1400cc with a supercharger. A 1300cc Suzuki Hayabusa engine made 150 horsepower stock but could make big power with a turbo. I knew I could make more power than anyone else in the class because no one was using motorcycle engines.”

At the time, the D Mod minimum weight was 1000 pounds, perfect for the remains of Mike’s 940-pound D Sports racer. SCCA Solo rules also allowed the engine to be set back to the centerline of the wheelbase, and putting the weight of the engine and transmission in the center of the car would help achieve a low polar moment of inertia.

“While this would be very difficult to accomplish with a traditional automotive engine, the compact size and lighter weight of the motorcycle engine and transmission package lends itself to taking advantage of a true mid-engine location,” he explains. “So a second part of my plan was to build a mid-engine chassis that would locate the engine in what was once the passenger seat area.”

A Hayabusa engine and transmission—which weigh approximately 175 pounds together—would offset the weight of the driver and a fuel tank on the driver’s side of the car. The bike drivetrain’s lack of heft would also allow Mike to build an underweight car which he could then ballast up to the minimum for better chassis balance.

“In the end, the car with driver had a side-to-side weight difference in the chassis of only 7 pounds, and I had to add 140 pounds of steel floor pan ballast to hit the then-thousand-pound minimum weight requirement for the class,” he explains.

D Mod rules also allow a complete tube frame chassis as long as the original floor pan is retained. Mike built a wooden mock-up of the complete roll cage and chassis based on the outline of a Honda, and this served as a pattern for the chassis construction.

“My objective in the chassis layout was to keep all the weight centered and as low as possible with the goal of optimizing weight distribution and achieving a very low center of gravity,” he explains. “I incorporated the original D Sports 10-inch rims and brakes in the front, and fabricated a single combined rear brake rotor and chain sprocket, which was centered on a custom-made differential case in the rear.”

Mike is a big fan of Formula SAE competition and tried to adapt as many of its ideas as possible, such as the push-rod suspension layout and use of inexpensive motorcycle rear shocks as suspension units. He also took inspiration from Kurt Bilinski’s Kimini, a radical Honda-powered, Mini-bodied car featured in the November 2006 GRM.

“Kimini was an inspiration, as were the cars that are running in Formula SAE competition right now,” Mike says. “The front suspension was taken from my D Sports Racer, but the rear suspension is all new. Well, the shock placement and control arms are new. The axles and uprights are recycled from the sports racer.”

Based on some preliminarily calculations, Mike figured that he wouldn’t need Kimini’s expensive carbon body. A simple fiberglass body with small flares would work perfectly. As the plan came together, he needed a mold and a floor pan. “I bought a junk Z600 to take the body mold from,” he recalls. “It had dents and stuff, but we Bondoed them up to make it look nice as a mold. The first body was from fiberglass.”

Life Gives You Lemons

Halfway through the build, however, Mike’s plan for world domination—or at least a small part of it—was thwarted by a rule change. The D Mod minimum weights were the first to change, increasing twice during the build. Soon after, the class rules changed again, this time to prohibit motorcycle engines. The cornerstone element of Mike’s Z600 monster was no longer legal.

“The motorcycle engine was a critical part of my package that couldn’t be achieved any other way,” he says. “I was frustrated because the car had been built to the letter of the rules in D Mod, and now it was rendered obsolete by the rule change.”

Rather than totally scrap the almost completed car, Mike appealed to the SCCA. A subsequent rule change allowed the car to run in the B Mod class, the traditional home for open-cockpit sports racers and some formula cars. The car weights are lower and forced induction isn’t allowed, but wings are legal.

Converting the car to B Mod specs required some creative thinking, however. First to go was the stock floor pan and floor ballast. Second was the body shell. Mike was already committed to the Z600 shape, but he scrapped the fiberglass body for a lighter carbon fiber version to get the weight down. He also had to flare the fenders to completely cover the tires, a B Mod requirement.

After four years of part-time work, the completed car was just as Mike envisioned. The frame was light and strong, and the whole package was incredibly compact and efficient. This is a car designed for one thing only: autocross competition. Despite the class change, initial testing has proved that it does have the potential to be competitive.

“Even though rules changes killed most of our advantages, it is a good concept,” Mike reasons. “The engine has particular promise—it puts out 168 horsepower with a bigger-than-stock cam. On our first test run, Tom Berry, a national champion, set the second-fastest time of day.”

Unfortunately that first run killed the engine. The first iteration of the dry sump system didn’t have enough oil capacity, and the engine spun bearings. Mike soldiered on, rebuilding it and taking it for dyno tuning. And during that outing, the coupling on the transmission output shaft came apart.

Mike says the whole experience has been positive, although he did learn a lesson: “There is a risk in using the SCCA Solo rulebook as the basis for a significant race car investment, particularly if the car might take more than two years to construct. I do take some satisfaction in the fact that my car was ruled out of the D Mod class—that tells me that my design concept was definitely on the right track toward having a competitive advantage.”

And while Mike’s Honda might never win an SCCA national trophy—he finds solace in the fact that he can still run the car in the B Mod class—it already has fans thanks to its public debut at last fall’s Japanese Classic Car Show in Southern California.

As for the future, Mike does have one more trick up his sleeve. The Z600 has had such an astounding response from the public that he wants to build a street car based on the same concept. In the works is a N600-based hotrod with a front-mounted, rear-drive Hayabusa engine. If it’s anything like the Z600, the new car should be another show-stopper.

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View comments on the GRM forums
dculberson UltimaDork
2/7/18 3:05 p.m.

I’ve always loved this car. Hard to believe that article was almost 10 years ago I remember it from the magazine so clearly.

iwannarace New Reader
2/7/18 9:00 p.m.

This is the inspiration for my build. I just need to ge the z600 in the garage now...

loosecannon Dork
2/7/18 9:36 p.m.

I had the privilege of seeing this car run once, it looks spectacular. Rumor has it that the car has been sold off in pieces but I cannot confirm this.

freetors Reader
2/7/18 10:02 p.m.

Awesome looking car. Wish I could see it run!

¯\_(ツ)_/¯ UltraDork
2/8/18 6:33 a.m.

In reply to loosecannon :

I feel like I vaguely remember seeing the carbon bodywork for sale several years ago, but cannot confirm that.

759NRNG SuperDork
2/8/18 8:48 a.m.

Is there more of an in depth build on this here(GRM) .......similar to LooseC/NoCones efforts?

81cpcamaro Dork
2/8/18 10:08 a.m.

I've seen it run several times, looks like an absolute blast. It is dang small standing next to it. Fun seeing the driver climb in through the windshield, which was easier than the side window.

T.J. MegaDork
2/8/18 10:33 a.m.

I absolutely drooled over the article when it came out. This is my favorite car of all the cars that have been in the magazine. Just utterly badass. Sad if it has been sold for parts. Even if it was not dominating B-MOD, it was still the coolest thing in the class.

pdmracing New Reader
2/8/18 3:58 p.m.

I had one during gas crisis When they were rationing gas & my ss396 was costing me more than my airman salary.  One day during the Iran crisis we stuffed 4 grown men into one & went of base for one last beer , On the way back @ 55 mph the lite turned red, barking was ok until nada we blew through a 4 lane light how we didn't get killed I never know whe it finally slowed down we got out & teh rotors were glowing bright red.    Another interesting tim was when a German shepard  just cam through the window at a red light. Who was I to say no

On day after many many breakdowns I just left it at the side of some road in VA

eclipse2lancer New Reader
2/8/18 8:02 p.m.
loosecannon said:

I had the privilege of seeing this car run once, it looks spectacular. Rumor has it that the car has been sold off in pieces but I cannot confirm this.

I had the pleasure of competing in BMod at the 2017 Solo National Championships and met Mike. He was there with a new car, a converted NovaBlade (normally an F500 chassis used in FMod), which was being driven by Rich Grupp.

He did confirm this particular build in the article had been sold off for parts. 

Here is a pic of the NovaBlade in grid next to the orange LeGrand I was fortunate to be competing with... which happens to be the old GRM BMod project. The autocross world is a small one.

-Will Lahee



iwannarace New Reader
2/9/18 1:06 p.m.
eclipse2lancer said:
loosecannon said:

I had the privilege of seeing this car run once, it looks spectacular. Rumor has it that the car has been sold off in pieces but I cannot confirm this.


He did confirm this particular build in the article had been sold off for parts. 

That is tragic.

David S. Wallens
David S. Wallens Editorial Director
2/9/18 1:16 p.m.

Yeah, we met up with the owners/builders at Solo Nats this year. Sad to hear that the "Honda" is gone. Pretty sure they said that they still have the body, though....

6/14/18 1:41 p.m.

"Bitten by the rulebook " sounds familiar.  As a Lt stationed in France in the early 1960s, I had a 998cc WSM Sprite coupe built in London to run as a surefire contender in the under-1-liter GT class on The Continent.  Lengthy delays in construction meant that I was unhappily shipped back to CONUS before the Sprite was finished.  So much for my dreams of FIA European glory!  SCCA rules were of course completely different from those in France, and I ended up way over my head in CProd; she would've been a decent FProd or GProd runner.  Years later, I think she finally ended up in EProd long after I'd sold her.  Lesson learned:  those murky crystal balls will get you every time!  (otoh, I did get a lotta practice in watching my mirrors!)

6/14/18 1:54 p.m.

I had the distinct honor of driving that little beast at the Spring Nationals in Lincoln in 2012.  Something that doesn't come through in the photos in the article is the true size perspective.  At 6-2 and 200 lbs.  I was considerably larger than Mike and had to climb in through the windshield.  When sitting in the driver seat (or more accurately, sitting atop the side bolsters) I felt and looked like a bear riding a tricycle.  I remember being off the pace in BM, but that was due to my incredibly awkward driving position and rustiness.  The car's performance capability was amazing.  Something else that doesn't come through in the article is that Mike and his wife are two of the nicest people you'll ever meet despite being certifiably crazy.  The article does mention "long distance running," but it doesn't mention that they are both world-class ultra-marathoners.  Yeah... competing in 50 and 100-mile races through the desert where you go through 2-3 pairs of shoes in one race.  Uh huh.  Certifiable.  But also just world-class nice folks.  –Bob Tunnell     PS. Also pretty cool is that same weekend Patty got to drive Del Long's EM Jeep, pictured in the photo above under the More Like This heading  That was a great weekend for both of us!

Joe Gearin
Joe Gearin Associate Publisher
6/14/18 2:00 p.m.

^^^ Thanks for posting Bob!  Always good to hear a first-person account.


And as far as "the nicest people you'll ever meet"   you and Patty certainly would know.  Takes one to know one and all that!     

HoserRacing HalfDork
6/14/18 2:04 p.m.

I know someone with a Honda 600 they're looking to sell if anyone is interested in recreating the beast devil

pheller PowerDork
6/14/18 6:28 p.m.

I'm not overly familiar with the rulebook, but how much of this vehicle was original, if anything? 

Was the D-Mod rulebook at the time just allowing you to create any chassis as long as fit under an original body shape? 

BHPBob New Reader
6/18/18 6:03 p.m.

In reply to pheller :

In answer to your first question... none that I'm aware of.  Which is not all that uncommon in DM and EM.

The rules say, "...the shape of the body must remain recognizable as that of the approved make and model."  Additionally the floor pan length must match the original and the width must match or exceed that of the original.  There are some allowances for wheelbase deviation from the original although they come with weight penalties so most stick with the OE wheelbase.  But there is no requirement for any original parts to be used.

ojannen Reader
6/18/18 9:04 p.m.

In reply to pheller :

Normally in D-Mod/E-Mod, you have to pick a body shell that fits the wheelbase you want.  The rules are open enough that you most cars end up with a tube frame, driver on the left, engine on the right, suspension in the front, live axle in the rear.  That is why you end up with things like the Jeep.  The original car had an 80" wheelbase and that happens to be the minimum wheelbase for the class.

D-Mod changed about 5 years ago, while the Honda was being built.  Motorcycle engines were outlawed and the minimum weight was increased by 200 or 300 lbs.  I believe that combination of changes made the Honda obsolete.  The engine pushed it into B-Mod where it was oversized and overweight.


7/14/18 10:37 p.m.

So this guy builds the coolest car in the free world and then sells it off for parts? WTH?

But... The molds still exist, right??? Where do I send my money to get one?


Knurled. MegaDork
7/14/18 11:22 p.m.
twofoot said:

So this guy builds the coolest car in the free world and then sells it off for parts? WTH?


Even when the article was written, the car was rendered obsolete during its build due to rule changes.


One of my favorite cars ever featured in GRM.  But it's still a motorsports-only car, and what happens to them when their class moves on?  Autocross is too esoteric for cars to wind up in museums, and I don't know if vintage autocross would ever really catch on.

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