top of page

building a badass

 Building a BadAss Part 1 A Watson roadster with a twist

By Tom McGriff Proprietor of mac miller’s garage INDY

Building a BadAss Part 2 “On the Salt”

By Tom McGriff 

 Proprietor of mac miller’s garage INDY

After six weeks of intensive work at the Florida shop, installing plumbing, electrical & hydraulic systems, fuel tank, radiator, engine & driveline, safety stuff, paint & plating and final assembly, the Johnston-Carbone-Wendt roadster is ready for Bonneville.

The high level of preparation and finish of this car is stunning, from its 1959 vintage “Roger Ward”, red & white paint job to its, very cool, Halibrand wheel decals on the flat aluminum aero wheel covers.

The finished weight of the car, without ballast, is 2150 lb. 

RR 590 lb 

LR 590 lb 

RF 485 lb 

LF 485 lb 

Front to rear weight bias F45% R55% 

Right to Left weight bias R50% L50%

For their “starting setup” the team decided to use the same 500 lb/in springs & shock absorbers that were installed when the car left Indy. They set the rear ride height at 3in. and the front ride height at 1in. for some added aero dow nforce.

The Lead Ballast Conundrum 

The main concern of the crew is rear wheel traction. With 400+ HP, 4 in. wide tires and a slick, loose track surface they, definitely, have a legitimate worry, so they decided to locate 300 lb of lead, aft of the rear axle for maximum rear wheel weight. My unreasonable paranoia about front end lift, tells me to put that 300 lb in the nose It is probable that the amount, location and F/R distribution of this ballast is the most important factor for maximizing tire traction under acceleration and stability at top speed. A better understanding of ballast could definitely improve the potential of this car…. I will be thinking a lot more about this.

Painting the car - One detail in final preparation, that is kind of overlooked, but is important is “surface drag”. As the oncoming air rubs along the surfaces of the car, it creates “surface drag”. Much of this drag is generated by protruding or irregular stuff such as bolt heads, Dzus buttons and adjoining bodywork seams. Of course, these things should be as flush with the surface as possible, but also, the paint surface should be as smooth and polished as possible. Some people take this so seriously that they have all of the decals and graphics installed before the final clear coat layers are applied so, even, the thin edges of the decals do not affect the air flowing along the body surface. These same people clear tape over all of the bodywork seams before a run, I think that careful attention to “surface drag” is important.

Bonneville – The Florida team arrived at Bonneville with a great car, great enthusiasm and great expectations. David Johnston and Jerry Carbone are rookies but Bill Wendt is a Bonneville veteran with a “vintage oval track midget” class record to his credit.

A couple of things to consider about Bonneville, besides the vastness of the place and the unusual track surface. * The Salt Flats are over 4200 ft above sea level. This is good and bad. It is good because, aerodynamically, the thin air means less air resistance for better top speed. It is bad because the thin air makes it harder for the engine to “breath” meaning less power. …. Gain a little ….. lose a little….

* Bonneville is a rather tight knit little society and they do not hand out ”free passes” to new teams and new cars. There are definitely protocols and initiations before being allowed on their track surface.

The first order of business is to submit the roadster for technical inspection by the Southern California Timing Association, who sanctions and manages the event.

The car would be scrutinized by “the safety” technoids, the “class rules” technoids, and, I guess, any other SCTA officials who wanted to have a look.

In my opinion, for a new team and new car, the technical inspection is the most important challenge of the entire meet.

During the inspection the roadster was picked at, poked at, examined, dismantled, questioned, commented, measured and eyeballed to the smallest detail.

After two hours, the scrutineers could find no technical concerns with the car and issued the “tech sticker”.

I believe that getting through tech, first time, without any major issues, is the best way for the new car & team to earn the respect of the officials and veteran Bonneville racers. These guys can help you, if they like you.

All three of the team principals intended to drive the car, so, most of the available opportunities to run would be used up with rookie tests and speed qualification runs. They will run the 5 mile short course for speeds under 175 MPH.

During Sunday and Monday runs, both Carbone and Wendt spun the car at just over 140 MPH. Fortunately, with the hard, slick, grainy surface and nothing out there to hit, spins are, normally, just spins and a big thrill for the driver.

These spins were caused by front end aero lift because there was not enough forward ballast. The crew moved 250lb from the rear to the front .

With the revised forward weight distribution, the car was stable and true down the course.

During five days, the team made a total of nine runs, including rookie tests, speed qualifying runs, “the spins” and speed runs of 147.7, 174.9 and181 MPH.

During the 181 run, the engine started to tighten up a bit so they shut it off to avoid damaging the Offenhauser. The problem turned out to be a scuffed piston.

The XXO/VOT class record, they are shooting for, is 176.5 so the car is fast enough to do the job. With a new car and rookie drivers, it is almost impossible to make a record attempt the first year but they should be well prepared for a serious attempt at their next meet.

The team had a purty good week. They have a great car, had a few thrills, learned a lot about car setup for Bonneville, established some good credibility for themselves and their car, made some valuable new friends among Bonneville officials and veteran Bonneville racers, found some speed by the end of the week and had a great time.

I’m very proud of the team and proud of my first Bonneville car.

A few final comments…….

So? What to do now??? The car is good…. No major changes or redesign is needed.

* The main area of potential development is the “setup”. Now with some Bonneville experience, the team will evaluate their baseline spring rates, shock rates, ride height and front/rear ballast setup for possible improvements.

* It seems that there would be something to be gained with a knowledge of the atmospherics at the Salt Flats, stuff like air density & humidity, barometric pressure, air temp, wind speed & direction. I think I would include one of those little modular weather stations as part of my pit equipment and learn how to interpret it. HA! I’ll bet some of those “salt flats oldtimers” know the perfect time of day and weather conditions for an optimum run.

* The car is equipped with a GPS device, giving “real time” MPH during the run. If this GPS was hooked up to a recorder and superimposed over a course diagram, it could be quite helpful with final drive ratios, etc. I’m sure this would be no problem for some smarter guys than me…… HA! While they’re at it, it would be nice to have some shock travel and ride height sensors.

* With 400 HP, 4” tires and a slick, loose surface, traction and wheel spin is a definite concern, not only off the starting line but, also, at high speed, down the course. With a 2.50 final drive ratio and a mile of acceleration distance before the first timing zone, there is no real urgency for a wheel spinning “burnout”. An orderly departure from the starting line is the responsibility of the driver. The real problem is wheel spin at high speed. At best, it will hurt acceleration and top speed. …… worst, it could cause the car to spin off course. During the past 20 years, there have been a lot of traction control systems tried in all areas of racing. Maybe one of these systems would be useful on a Bonneville car.. ???

After considering all of the above weather stations, data acquisition computers and traction control gizmos, the reality is, sometimes the driver & crew experience, knowledge and intuition is as good as any of these scientific gadgets. The fact is, Bonneville is the only major motorsports event left in the world where a racer can build a car from scratch and drive it by the “seat of his pants”, sometimes at speeds faster than NASCAR, IndyCars and F1.

The Johnston-Carbone-Wendt roadster was built in a small back yard shop with minimal equipment……… not a laboratory, a special factory or a wind tunnel. It was designed and built by experienced racers……… not scientists and engineers. And, it was built from steel, aluminum and fiberglass……. not titanium, magnesium and carbon fiber. By avoiding all of the stuff that has purty much ruined most other top level racing, Bonneville has remained the greatest bastion of genuine “old school” racers, drivers and builders, on the planet. Maybe it should stay that way.

The Johnston-Carbone-Wendt Watson 270 Offy is the latest in a long history of modified Indy cars to run land speed courses. In 1924, Tommy Milton drove a 183c.i. 8cyl. Miller to 151MPH at Muroc Dry Lake in In 1927, Frank Lockhart drove a supercharged 91 c.i. 8cyl Miller to 171MPH at Muroc Dry Lake. In 1928, Wilbur Shaw drove a 151c.i. 4cyl. Miller to 135MPH on the sand at Daytona Beach Fla. In 1930, Shorty Cantlon drove a 183c.i. 4cyl Miller to 145MPH on the Muroc Dry Lake. In 1930, Cliff Woodbury drove a front drive, supercharged 91c.i. 8cyl Miller to 181MPH on the sand at Daytona Beach Fla. In 1932, Wilbur Shaw drove a 220c.i. 4cyl. Miller to 137MPH at the Muroc Dry Lake. In 1940, George Barringer drove the rear engine 4WD Miller to 157.5MPH at the Bonneville Salt Flats. In 1947, Marvin Jenkins tested the supercharged front wheel drive Kurtis NOVI at Muroc Dry Lake before taking it to the 10 mile circular course at the Bonneville Salt Flats, where he ran 179.5 MPH In 2008, the current XXO/VOT class record was set, by the Lattin-Gillette 1959 Kuzma laydown 255c.i. OFFENHAUSER, at 176.5.

It is amazing how different the historically classic America land speed surfaces are. 

Muroc Dry Lake, Cal. dirt surface, 2300ft above sea level. 

Daytona Beach, Fla. sand surface, less than 12ft above sea level 

Bonneville Salt Flats, Utah salt surface, 4200ft above sea level

The Johnston-Carbone-Wendt car is an excellent project and I am very proud of my part in making it happen!

Tom McGriff 

Proprietor of “mac miller’s garage” in INDY

bottom of page