The Classic Sports Racing Group (CSRG) is excited to welcome Vintage Spec Miata (1990-1997) to all of their events! This is a fun, affordable way to get into vintage racing. If you have any questions regarding prep and presentation, reach out to Rob Fuller: rob@zcargarage.com. Please see below for more information and rules.

 

Why Vintage Spec Miata (VSM)?

Why VSM? It’s a great way to get into vintage racing at an affordable price point. The nice folks at the CSRG have a strict no-contact policy as part of their racing philosophy: this ensures the safest environment for you to race competitively while sharing the track with traditional cars.

 

Lastly, CSRG events are known for their camaraderie and undeniably cool eye-candy. If you want to mix it up with classic race cars of the 60s and 70s in your Spec Miata, this is the ticket.

 

Did we mention it is Fun! See what vintage racing with CSRG is all about in one of our race reports HERE!

 

Fellow Spec-Miata racer Ross L in front of Randy Pobst’s first National Championship-winning Miata (1992). Below, Rob Fuller’s Spec-Miata at the shop:

 

 

CSRG Rules for VSM

 

The first race event is March 15!

 

Register your Vintage Spec Miata for CSRG’s first event, the 2024 David Love Races at Sonoma Raceway March 15-17. Registration details HERE. It will be a blast on Sonoma’s NEWLY PAVED surface with plenty of vintage cars and good times. See you there!

 

We love to see our parts installed and used on client’s cars. Race car driver and Datsun Historian Glenn Chiou is running our Z Car Garage CV Axles in this 1968 Datsun 510 U2.5L Trans-Am race car!

Glenn was preparing to debut his freshly restored 510 for the 2022 Velocity Invitational event at Laguna Seca. A half shaft failure is not something he wanted to worry about while racing so he replaced them with ZCG CV Axles. Glenn installed the set himself with ease:

 

We also provided dyno tuning services to prepare him for the race weekend. The fresh Rebello L18 with Solex/Mikuni 44phh induction and BRE intake made great power.

 

Listen to this 510 make sweet L-Series music on our dyno in the video below. There is also race/paddock action with Glenn behind the wheel:

 

Privateer Spirit

We are happy to report that Glenn successfully raced at the Velocity Invitational event. It’s worth noting like privateers of the period, Glenn builds his race cars, maintains and manages racing efforts himself. Not an easy task so we applaud his passion and work ethic. Glenn builds some beautiful Datsuns and this historically-significant 510 is a shining example.

Photo by Alex Trang

Glenn championed a vintage race group dedicated to the Historic B&C Sedan class and organized a “Celebration of the Two Five Challenge” display at the 2022 Velocity Invitational event. Two of the most iconic cars were present: the ex-Morton #46 BRE Datsun 510 (with Pete Brock below) and ex Kwech #3 Wetson’s Alfa. Yes that is Glenn with the legendary John Morton! Let’s take a look at the history behind Glenn’s Trans-Am 510 before we get into the restoration:

 

The Ex-Finn/Harris U2.5L Datsun 510

 

Glenn has a passion for re-telling the stories of legendary privateer Datsun racers and his penultimate restoration project was this 1968 Ex-Finn/Harris U2.5L Datsun 510, serial number PL510-023047. It is one of very few surviving cars that competed in the SCCA Trans-Am Two-Five Challenge, or more commonly known as the Under 2.5 Liter Series.

 
In 1972, Bob Finn acquired the car from a used car dealership in Santa Barbara, California. The car was sponsored by Bob Nolan Datsun and Chuck’s Shell Service in Santa Maria, California. Competition Street and Rally (CSR) Racing, a shop Finn ran out of Chuck’s Shell Service, prepared the car for competition. It is one of two cars in which an entire package of go-fast parts were purchased from Brock Racing Enterprises in El Segundo, California, as part of their “BRE kit car” program. Mac Tilton, then BRE Crew chief and engineer – later Tilton Engineering, developed the suspension and provided all machine work. Bob Finn and Ron Harris began racing #37 in late 1972.

 

Its first two races were the two final races of the 1972 SCCA Trans-Am Two-Five Challenge season at Laguna Seca and Riverside International Raceway, finishing 15th and 23rd. Unfortunately 1972 would see the end of the Trans Am Two-Five Challenge, but that would not stop Finn and Harris from continuing to race the car. They competed throughout the 1970’s in the SCCA B-Sedan class both regionally and nationally with numerous first place finishes, often beating out factory race teams. While Riverside International Raceway was its home race track, the car could also be seen racing at Willow Springs International Raceway, Laguna Seca Raceway, Sears Point, Portland International Paceway, Ontario Motor Speedway.

  

In that time, Finn and Harris competed against the likes of John Morton, Horst Kwech Harry Theodoracopoulos, Bobby Allison, Walt Mass, Dave Madison, Corky Bell, Norm Balzer, Pat Daily, and many other prominent racers. Bill and Jack Johnston acquired the car in 1979 and would go on to race the car for the next 33 years. Bill Johnston and Steve Dragus shared driving duties, while Jack was the crew chief. Dragus, who was best known for the building engines for Don “The Snake” Prudhomme, prepared the engines. Johnston and Dragus won three regional Cal Club Championships in the 1980’s, and would go on to win the last SCCA GT4 national race at Riverside Raceway before the track closed in 1989. (images and history courtesy of Glenn Chiou)

Restoration

 

The Ex-Finn/Harris Datsun 510 was not always in the orange livery shown above. When Glenn acquired the car several years ago it was red and he ran with this livery at many vintage racing events…until it was time to restore it back to its former glory…

 

Glenn is no stranger to vintage race car restoration. You may have seen Glenn’s FAR Performance 240Z in VIPS Restaurant livery as raced in the 70’s by Loren St. Lawrence. Glenn restored this car himself and it is now back to the Bay Area Datsun Dealers livery as raced by FAR Performance privateer Walt Maas. Glenn also restored the Different Drummer Racing Z raced by Greg Sorrentino. This IMSA GTU Datsun 260Z features our Z Car Garage CV Axles and dyno tuning:

 

The 510 was dissembled for paint and bodywork, using period photos to guide the livery hand-applied by the talented Real Ralph:

 

As usual, Glenn’s painstaking efforts and diligence result in a faithful restoration…where parts are not available he has gone to extraordinary lengths to re-create pieces or use period-correct/surviving parts with archival guidance…shown below: vintage SW oil cooler, BRE remote oil adapter, expansion tank and BRE intake manifold:

 

Glenn assembled the interior with Mil-spec switches & motorsports grade wiring:

 

The fresh Rebello L18 is about to be installed…all done by Glenn himself in his home garage:

 

I was lucky to visit Glenn to see the restoration in-progress and it was simply a feast for the eyes…plated chassis parts, cool bits of history everywhere…plus the BADD 240Z nearby 🙂

 

Datsuns Are Driven!

With the restoration complete, Glenn has been enjoying the Ex-Finn/Harris U2.5L 510 at vintage racing events throughout the year. Follow his racing adventures on Instagram with more photos in the gallery below:

 

Thanks for your support Glenn! Congratulations on the restoration and we love racing with you #racingislife. Learn more about our Z Car Garage CV Axles below:

 

Z Car Garage CV Axles

Our Z Car Garage CV Axles help transmit power to the ground and ensure smoother operation compared to your standard half shafts. These are 100% bolt-in replacing your half-shafts and does not use aluminum adapters commonly found in aftermarket units. We have over 200+ CV axle kits on customer cars and we are stoked with all of the positive feedback.

   

For more information please visit our detailed post our HERE. Below are just a few examples of race cars running out CV Axles:

Race car driver and restoration specialist Jim Froula of Racecraft is running ZCG axles in several of his cars:

Set #246 – installed May 2018 on the “Harry Stewart #52” Datsun 510:

  

Set #247 – installed April 2018 on the 260z

  

Set #248 – installed on Adam Carolla’s “Greg Sorrentino #90” Datsun 510.

  

Supermachine in Tokyo, Japan is running our Z Car Garage Big-Brakes and Z Car Garage CV Axles in their Series Datsun 240Z:

  

Race car driver, restorer and Datsun Historian Glenn Chiou is running our ZCG CV Axles in this IMSA GTU 260z race car!

  

Racer Brad H is running ZCG CV Axles in his IMSA GTU race car:

 
…[read more]

***CARAVAN INFO BELOW***

Join us on Saturday, February 24 for Cars and Coffee at SIM Racers Group in San Jose. Z Car Garage would like to gather a group of vintage cars to attend. Bring out your Datsun, BMW, Alfa or any old-school marque. Stay tuned for caravan details on zcarblog.com Thanks to Classic Sports Racing Group (CSRG) for hosting!

 

Come caravan with us to the event! Meet at Z Car Garage Saturday 2/24 and we will depart at. 8:15am sharp heading to Tully Rd. Friends/family welcome and please contact robATzcargarage.com with any questions. Bring out your Datsuns!

 

 

 

We have the pleasure of continually developing Dirk’s 1973 Datsun 240z to help achieve his vision of a Z car that is adept on the street and track. Improving the driving experience are Z Car Garage Big-Brakes, Z Car Garage CV Axles, Silvia 6-speed transmission and a host of chassis and driveline upgrades. Dirk has been enjoying the Z at open-track days including Laguna Seca and most recently Sonoma Raceway.

Track Day Fun

Let’s hear from Dirk about his journey for optimal chassis settings enabling both spirited street and track driving…

 

DIRK: “Shortly after I first got my Z, I broke the factory open diff on a windy road, and started working on the suspension. It was on stock struts and lowering springs, and the car bottomed out badly under braking while going downhill. So, it went to its first track day with an R180 diff from a Subaru WRX (3.54 Torsen), the factory 4-speed, stock L24, rebuilt stock brakes with high-temp brake fluid, and a set of T3 coilovers with 200# front and 250# rear springs (see that roll)”

 

“After that, I went to 300# and 350# springs to reduce roll and improve overall handling, note much less body roll below”

 

Chassis and Driveline Upgrades

First, there was work to upgrade the steering geometry and suspension. With the car being lowered quite a bit, despite having 1″ RCAs installed, it had a ton of bump steer. Rob installed DP racing adjustable tie rods, removed the front springs, and completely eliminated the bump steer on the alignment rack while moving the suspension through its full range of motion.

New DP Racing tie-rods and in-house alignment:

   

We also refurbished Dirk’s steering rack with fresh parts from our stash:

  

With the Z back in the shop for bodywork we took the opportunity to make more suspension changes. New Koni Race shocks from T3 were installed, which were a much better match for the 300# and 350# spring rates than the Koni Sport shocks they replaced (as Dirk initially ordered the coil overs with lower spring rates, he never replaced the shocks after adjusting the spring rates, and the car always felt underdamped, particularly on the not-adjustable compression stroke):

  

ZCG Big-Brakes and CV Axles

    Dirk visited ZCG and drove “Mrs. Butters”, our 1970 Series 1 240z shop demo car and he was sold on our Z Car Garage Big-Brakes (for small wheels) and Z Car Garage CV Axles! Butters has a way of doing this to our customers 🙂 As fellow S30 owner/racer Glenn C mentioned in his review, on top of braking performance, pedal feel is extremely important and our Big-Brakes deliver. This is a direct result of working with Stoptech to create a totally bolt-in solution requiring no M/C change or additional proportioning valve/adjustments. All fitting behind a 15″ Watanabe or Panasport wheel and retaining factory emergency brake lever! A few details below:

Calipers: Stoptech ST42 4-piston front & rear race calipers (Alum 6061 mil-spec Type III anodized)

Rotors: 280mm x 20.6 with Alum 7075 hats

Pads: Stoptech 309 sport street pads

Blog posts documenting all of our customers running the ZCG Big-Brakes can be found HERE.

A few closer detail shots of the calipers, rotors and hardware:

   

We removed Dirk’s stock brakes and installed our ZCG Big-Brake kit.

 ZCG Big-brakes replacing stock setup up front:

   

At the rear, the factory drum brakes were replaced with our ZCG Big-Brakes. Factory handbrake functionality retained!

    DIRK: “While I liked the feel of the factory brakes (as long as the drums were perfectly adjusted), and they were quite adequate paired up with the original L24, I didn’t dare take the car on track on the tiny solid rotors once I started adding power, first with the Datsun Spirit STR-3 engine. Once ZCG installed the Rebello engine and 6-speed transmission, it was even more obvious that a brake upgrade would be wise…”

 

S15 6-speed transmission

After comparing the Z to his Subaru BRZ on the track, it was clear the Z was better at everything except for shifting gears. Since his engine made a healthy amount of torque, but not enough to warrant a CD009 (350z) transmission, Dirk kept looking for alternatives. He also wanted something with slightly closer gear ratios to better suit the engine’s power band. An S15 Silvia 6-speed seemed like the perfect fit and we installed it back in 2019.

   

The first S15 box had some weak synchros, so Dirk sourced another one that was installed with OE trans fluid, as well as a set of fresh OE motor and trans mounts to help with shifter feel and reduce vibrations in the car.

  

“The S15 transmission fit surprisingly well. ZCG built a custom crossmember to locate it, and the shifter lined up almost perfectly. No transmission tunnel mods were necessary. The modern shifter looked out of place, so ZCG built a custom unit that would look stock, and work with the Datsun competition shift knob. A small 6-speed shift pattern sticker modeled after the one used in the Silvia is the only clue there’s something different going on under this car. And of course the driving experience.”

Making the S15 shifter look factory, we are happy with the result and Dirk’s subtle shift pattern sticker:

   

Our Z Car Garage CV Axles help transmit power to the ground and ensure smoother operation compared to your standard half shafts. We have over 70 CV axle kits on customer cars and we are stoked with all of the positive feedback.

  

Also visible on Dirk’s Z are the excellent adjustable lower control arms from Techno Toy Tuning.

  

DIRK: “The Z has seen a few different tracks. Laguna Seca, Thunderhill in the dry, Sonoma in the dry and the wet. After quite a few street miles on the car with the ZCG big brakes, an 4.11 OS Giken diff, we sorted a few more things with the car. Most notably, we redid the front suspension, and installed a fresh set of Koni race shocks all around the car. These were a much better match for the 300/350 lb/in springs than the Koni sport shocks I originally bought with the coil overs.”

Finally, an opportunity to take the car to the track again came up, and Dirk with the S30, and his friend Joey with his E30 went to Sonoma Raceway:

 

DIRK: “The car was obviously a lot more capable than the last time it visited a track. The driver, however, was a little rusty, so with each session lap times started to come down but there is plenty more left on the table. The brakes were extremely consistent throughout the day, with not a sign of fade. And the whole car performed admirably. The temp gauge was steady right below the middle of the range all day long. I got fuel starvation in turn 11 once, which is somewhat expected with an unmodified set of Mikuni 44 PHHs, but other than that the Z didn’t skip a beat.”

 

We were stoked to see Dirk happy with our Z Car Garage Big-Brakes! Enjoy the video below showing in-car action from Sonoma Raceway, dyno run and more, volume up!

After many more tweaks, different induction setups, spring rate changes, rebuilt stock brakes, and 24K miles of driving including a few track days, Dirk’s Z was inching closer and closer to his vision. The next step in making the car faster would be to put in a more supportive driver’s seat.

3 Liter L-Series Power

Unfortunately, the Datsun Spirit engine developed rod knock which was the impetus for a big drivetrain upgrade. Several other parts of the car where refined as well.

The L28 engine was pulled, sent to Rebello, and built into a 3L powerhouse. Dave bored out the 44PHH venturis to a custom 38.5mm, to hit the perfect compromise between peak power and drivability. We also installed a fresh water pump, alternator, new fan blade, OEM fan clutch and fresh air filters. The beautiful DP Racing oil pan remained. More photos in the gallery below:

  A custom stainless 2.5″ mandrel-bent exhaust mates with a new set of coated Pacesetter headers and Z Story Street muffler (in a search for a reduction in volume while keeping a nice note). Dirk discusses the clutch/flywheel combo below:

  

“The STR-3 already was able to slip the Exedy clutch and we were never fans of the Chromoly steel flywheel. A Jim Wolf Technologies clutch and flywheel combo was installed after first trying a newly developed Kameari single plate street clutch kit, which we both found too loud and racy for this street car. While the JWT pressure plate yielded a different pedal feel that took some getting used too, it was not too heavy and perfectly comfortable to drive in traffic. More importantly, it never slipped under any kind of abuse.”

The clutch hydraulics were replaced to work with new alumimum flywheel/JWT HD clutch combo:

   

We installed a ZCG-built 4.11 OS Giken limited-slip differential in the R180 along with a custom aluminum driveshaft:

   

Dyno Tuning

The previous L28 made 202hp/194tq at the wheels with Rob’s tuning. Now with the fresh 3L it baselined at 245hp/226tq with more area under the curve:

Rob tuned the car further on the chassis dyno, setting it up with a very lean idle at Dirk’s request (to minimize gasoline fumes at idle). With A/F optimized and Nismo Mikuni carbs massaged, Rob unlocked another 20hp yielding a stout 265hp/232tq to the wheels:

 

With gains of 62hp/37tq at the wheels over the L28, Dirk is very happy with the new 3L:

“While the Datsun Spirit engine had a very peppy mid-range and made more delicious induction noises, there’s no argument that the more powerful Rebello engine elevated the car to the next level of performance and fun. The entire setup worked incredibly well together, and we hit an impressive 265hp at the rear wheels, or 60hp more than the engine made in its previous iteration, putting it in the 100hp/liter ballpark at the crank. Not bad for a dinosaur engine on California pump gas!”

Datsun 510, 620 and Z car love

Dirk bought his first Datsun in 2014, a 1970 510, to learn how to work on cars himself. After learning more about the history of Datsun, and the significance of both the 510 and the 240Z in establishing Japanese cars in the American market, he knew he had to own a Z as well.

  

A year later, the right Z showed up on eBay in Texas, a 1973 in silver gray. After pouring over the photos and talking to the seller, Dirk bought the car sight unseen. The idea was to have a nice Z to enjoy and drive, while continuing to work on the (sometimes not) rolling restoration of his 510. The car was lovingly restored by a dad and his children and in mostly stock condition. Dirk also has Datsun 620 work truck complete with dual-Mikuni’s:

   

Dirk shares his experience working with us:

“Collaborating closely with Rob and ZCG has elevated the optimization process. Rob will frequently talk me out of a bad idea, or into a good one (like the OS Giken LSD). Sometimes I talk him into a bad idea and it turns out to work really well, like the S15 gearbox. The most fun is when we brainstorm stuff together like turning the catch can setup into an improvised simple PCV system, eliminating all hints of oil fumes from the car while running.”

 

Enjoying the Ride

Dirk’s been driving his Z-car pretty much every day since the latest upgrades, and it’s been working phenomenally well:

“The drivetrain + brakes make it as happy to accelerate as it is to stop, and with the quick, closely spaced shifts and eager engine, it’s fun to do a casual grocery run, and to drive quickly. With the electrical systems and all fumes well under control, it’s truly a car you can do anything with, and probably more reliable than my BMW.”

 

We loved to see Dirk driving his Z on rallies and fun runs this year. Most recently we joined fellow Japanese vintage car owners on the Tokyo Calling event hosted by Breakfast Club Rally:

  

Dirk also joined us for a New Year’s Day drive through our favorite Bay Area Backroads:

  

We enjoyed working with you Dirk and it was rewarding to help improve your Z.

“Some say good is the enemy of great, but that’s true if you think you’re done. I don’t see my Z car less as a “build” that’s done. I’m always developing it, just like continually developing a race car (e.g. my Lemons car, http://instagram.com/bittersc243) to stay competitive. In this case the competition is merely for making the Z into the most fun driving experience I can imagine, and the journey of continuous refinement and improvement is a big part of the fun for me.”

  

Farewell, Dirk!

 

We helped Dirk prepare both the 510 and Z for overseas shipment to the Netherlands. Stay tuned for a feature on Dirk’s Datsun 510, it’s a really neat little Dime with a screaming L-Series. Thanks for your support Dirk and LONG LIVE THE Z!

Join us on Saturday, February 24 for Cars and Coffee at SIM Racers Group in San Jose. Z Car Garage would like to gather a group of vintage cars to attend. Bring out your Datsun, BMW, Alfa or any old-school marque. Stay tuned for caravan details on zcarblog.com Thanks to Classic Sports Racing Group (CSRG) for hosting!