Assembling a complex race car like our BlownZ06 Corvette requires careful planning from the front of the car where the supercharger lives, to the rear where the parachutes are deployed. Each area of the car must work with the others to ensure that on race day, everything goes according to plan. In part three of our series on BlownZ06, Tony Mandella of PMR Race Cars takes us through the interior of the car, along with the process of making a C7 Corvette body from multiple carbon fiber parts fit together correctly on a bare chassis.
In our previous build articles, we’ve highlighted the rear section of the car, where the power meets the pavement, and we also looked at the front end where the the steam is made. While both of those areas are of the utmost importance to the car’s performance on the track,, the interior of the car requires a special touch to help tie everything together.
To assist in making the interior whole, PMR used a vast array of parts from the Quarter-Max catalog to get the job done. For stopping BlownZ06, Strange Engineering’s carbon fiber brakes were added to all four corners of the Corvette. To keep the view nice and clear, a full set of windows from Optic Armor were used to finish off the exterior.
Thoughtful Design: The Interior Of BlownZ06
The interior of a race car does more than just serve as the driver’s office — it’s the central nervous system of the car containing a multitude of important parts and systems running through it. Between the doors are critical items like the car’s controls, gauges, dash, electronic systems, and wiring all find a home. Adding all of this to the interior of the car is more than just throwing everything inside so it fits in the roll-cage; a carefully crafted plan must be executed to ensure everything functions properly and works together.
The team at PMR Race Cars has built a wide variety of cars and has learned one thing; the car has to go beyond looking good, it must be functional to ease service times between rounds and each evening after the racing action is complete.
“On this car, like everything else we build, we try to look at what is practical when it comes to servicing the car, in particular when you’re at the race track. It’s an important aspect that requires attention to detail during the entire build so you don’t run into problems when you’re trying to button the car up at the end,” Mandella explains.
The mounting of items like the parachute controls and fire suppression system buttons are areas that need to receive some thought to decide where they’re placed. Putting everything in a location where the driver can reach them, and in a spot where they won’t be accidentally activated when the car is being serviced is key to the build process.
Besides the handles and buttons for safety systems, paying attention to how you plumb them should also be taken into consideration, as Mandella shares.
“All of the different lines you have to run in the car need to be put in areas so that if you have to, let’s say, change a transmission between rounds, the process is easier. You don’t want a fire suppression line running right along a double-frame rail tube, where if you set the transmission down there during the swap you pinch it, so planning around maintenance is important. There are a lot of cars that don’t have this in mind and it might look good, but it can lead to problems.”
Space was a theme and issue for the entire build, cramming five pounds of stuff into a one pound bag applied here for sure when designing the interior. – Tony Mandella
Proper routing goes beyond lines that hold air or fluid; how you wire the car needs to follow the same type of though process. The wiring inside the car needs to be in a place where it can be reached when needed, but is out of the way so it doesn’t become an issue during maintenance.
Mandella goes back to the transmission example in BlownZ06 to illustrate this design concept.
“Since the transmission will be coming out of the passenger side of the car most of the time, we made sure that all the vital electronics and wiring were in a location where they wouldn’t be in the way if the transmission comes out at the track. At the same time, all of the wiring is still easily reachable for the crew when they’re in raceday mode. It doesn’t take away from the function of the car at all, but actually adds to it in a case like this where the design was executed properly.”
PMR tries to incorporate many of the same design checkpoints into their builds to make them as maintenance-friendly as possible. Most of the cars PMR constructs require them to work around the factory floors and other parts, but the freedom provided by constructing BlownZ06 without these hindrances allowed them to open the bag of tricks. However, the size limitations of the Corvette did require Mandella and company to think ahead in where they placed each component.
“Space was a theme and issue for the entire build, cramming five pounds of stuff into a one-pound bag applied here for sure when designing the interior. You have to treat it like a chess game and think a few steps ahead. Starting with the framerails, we had to think about how everything would be affected after that. The double framerails are an example of something that needed to be changed due to other items in the car. We had to modify the design slightly so we would have enough room to get the seat in for the driver to clear the tubing. When you’re in this car things are tight, so everything needs to be put in a smart location,” Mandella says.
If there is an emergency situation on the track, the last thing the driver needs to be doing is hunting for fire suppression buttons or other safety measures.
Even with some of the strict class rules for BlownZ06 that pertain to the use of framerails and wheelbase, one area of the rulebook that isn’t as strict is the interior. Since a stock-appearing dash isn’t a requirement, the team at PMR decided to not put one in the car at all. This allows for more space inside the cockpit and makes it easier to access the wiring wiring behind the unit should there be any need to make repairs. It also gave PMR the freedom to place the FuelTech FT600 (with integrated digital dash) in a convenient location that the driver can see without having to adjust his seating position.
“Every driver is a little different on how they want items placed inside the car, so that’s the first we look at when designing a layout. James was actually really open to our ideas and thoughts based on our experience, and that helped in the sense we didn’t have to make any big changes for things to fit while still being practical. It can be a simple process but turn complex quickly if the driver has some big changes they want done. We still have to make sure the driver doesn’t put things where they can’t reach it easily. Most guys don’t think worst-case scenario, so we have to put the idea in their head and make them realize they might have to find something if the car is upside down and on fire,” Mandella explains.
Finishing Parts For BlownZ06
There’s no doubt that it takes a lot of hardware to complete a car like this. Different systems in the car require their own supporting parts and pieces to complete them and each one has to be mounted in the cabin. There are also additional chassis parts and controls that are unique to the interior of the Corvette.
With the majority of the chassis complete, PMR moved inside the car to add the final piece, the Quarter-Max driveshaft tunnel. This is a safety requirement for any car of this caliber and helps to keep the driveshaft from turning loose on the driver in case of a failur. The kit comes with a chrome-moly plate that’s already rolled into two separate halves and two tubes you can use as the driveshaft safety loops. Also included are all the tabs, pins, and other hardware needed to make it a removable unit.
Mandella found the Quarter-Max Drive Shaft Tunnel Kit to be exactly what the doctor ordered, which helped his team to finish the car’s construction within the tight timeframe they had to do so.
“This kit is very complete and it saved us a lot of time over fabricating one ourselves. All of the necessary parts to satisfy the safety requirements were in the kit from the start. It was nice that we didn’t have to waste time to fabricate something ourselves, and the installation was very easy when we finished building it.”
To keep BlownZ06 legal in the power department, a master disconnect switch needed to be added to the battery. Quarter-Max offers a complete kit, which includes everything needed to get the switch mounted, including the hardware, battery tray, tabs, and switch itself. This allowed PMR to mount the batteries and switch where they needed for the best possible weight distribution.
“The bracket Quarter-Max provides has multiple locating pin spots to keep the switch in place and is adjustable to fit our need. It has a really good feel and provides plenty of adjustment to rotate the switch to the correct position while you’re trying to orient it for installation. We used our own rod that we made out of billet aluminum to fit the car a little better, and for where we mounted it to create a push/pull-style switch,” Mandella explains.
Since the boost controller requires CO2 to function properly, a bottle must be mounted inside the car to provide the gas. A bottle holder kit from Quarter-Max was ordered to keep the larger CO2 bottle in place each time BlownZ06 makes a trip down the track. PMR used the pre-fabricated base included in the kit to mount the bottle vertically and then attached it to the rollcage with the aircraft-style clamp that was included in the kit.
Pedals And Braking For BlownZ06
The pedal assembly of a racecar is a simple idea that can require some creative problem-solving based on how the rest of the car has been fabricated. For the throttle pedal, an off-the-shelf part will usually get the job done, but with the space limitations of BlownZ06’s floorboards that wasn’t going to be an option. PMR wanted to design the throttle pedal around the car itself — not design the car around the pedal — so they had to get creative to make it fit. Some trimming and other processes needed to be done to get the loud-pedal to find its home on the floor of the Corvette.
For the brake pedal, PMR was able to use a standard Quarter-Max floor-mounted unit. Like the throttle pedal, a custom set of brackets had to be fabricated to get the brake pedal to fit. All of this was done in the name of space to get a custom fit and ensure there were no issues getting the linkages for each pedal to work as desired.
When designing the braking system for a build, PMR always makes sure it can handle more than what is expected. Going that extra mile is important so the driver is kept safe and the car will function as intended.
“Since the braking system is so powerful on this car, you have to make sure everything is designed correctly. For example, the master cylinder has to be mounted properly and can’t allow flexing to occur, so when you’re on the brakes, you don’t lose braking power or have mounts that fail. The brake rod needs to push perfectly in-line with the master cylinder to avoid issues and that needs to be addressed when you’re mounting the pedal,” Mandella explains.
The backbone of the braking system on BlownZ06 is a full carbon-fiber setup from Strange Engineering. In a previous article about the chassis of BlownZ06, we talked with JC Cascio from Strange to get all of the details on the brakes and how PMR routed all of the lines.
According to Mandella, the Strange brakes are exactly what’s needed on a car like BlownZ06.
“With the carbon-fiber brake kit from Strange, you’re getting a great quality part. The carbon-fiber brakes are best for getting a fast car to stop and respond. They have a different feel from steel brakes and help remove a ton of weight from the car overall. So you’re going to make the car go faster by removing rotating weight with a set of brakes like these.”
Mounting The Body And Windows For BlownZ06
Mounting the body of BlownZ06 was like a giant automotive puzzle, and the corner pieces they started with were the factory framerails and door surrounds. PMR had to research the dimensions of a stock Corvette to know where the framerails needed to be placed to build the car. After the framerails were in the proper location, they could attach the surrounds and make sure they had the dimensions right to mount the rest of the body. A series of Clecos were then used to help hold the body in place until it could be mounted in a more permanent fashion.
Making sure the body is mounted properly goes beyond the car looking good — it has to remain in place at speed.
“The components that we used are so lightweight, and the big thing is making sure there are enough attachment points to the body that they don’t try to rip off at 200 mph. We added a lot of surface plates to the Clecos so they could hold the body on where we wanted. Another thing we were looking for as we went along were vibration areas and weak points on the body. This is done so you can tie everything together and the body can be strong enough to deal with the air trying to grab it at speed,” Mandella says.
The components that we used are so light and the big thing is making sure there are enough attachment points to the body that they don’t try to rip off at 200 mph. -Tony Mandella
The process of fitting the body together on BlownZ06 is very similar to building a model car, but with bigger parts that are made of expensive composite materials. All of the body panels have more material than needed when they come out of the mold so they can be trimmed up to fit the car as needed. It’s a slow process for the shop, but the extra material allows them to make the body fit exactly how they want it based on the build.
Mandella explains the process of getting all the parts to fit properly onto BlownZ06’s chassis. from Skinny Kid Race Cars on BlownZ06.
“The framerails and door surrounds tied into the rest of the body as they slide over each other, and that helped us figure out where everything else got placed. They are pretty secure in that design, and the lips all overlap to make a flat mounting surface with nothing to catch the wind on all the body panels. The door surrounds attached to the rear quarter panel, and then they attach to the roof, and that attached to the deck lid, then the rear tail section.”
After the body was in place the final step to make the car whole was to install the Optic Armor windows. With the polycarbonate windows, you have to make sure you have smooth transitions so the air doesn’t have a lip to grab. This falls right in line with the body mounting process — smooth transitions with no gaps and a tight fit.
To mount the windows, PMR used the Quarter-Max window mounting kit. This kit has the chrome-moly tubing and tabs to build the frames for the door windows in the car. It also includes tabs that can be used for windshields, but since the windshield on the C7 is so large, a few extra had to be purchased.
Mandella and his team made quick work of getting the Optic Armor windows installed on the Corvette.
“The Optic Armor windows just fit so well with their design and and fitment. For the rear window, there wasn’t one available for the C7 yet, so we used one of Optic Armor’s blank pieces that had a similar curve and got it to fit in place. The rest of the windows were simple because the frame was already there in the door and the windows fit right in. The front windshield is a bit unique, so we had to come up with the frame mount on the bottom to match the curve of the window. The Optic Armor pre-molded unit made things easier since it fit right the first time.”
The journey of building a car like BlownZ06 has been an exciting one for all involved. Creating a car like this requires a solid game plan from the start to not only ensure a smooth build, but a final product that will be able to win on the track. Tony and his team at PMR Race Cars built a piece of functional racing art that we hope will be as fast as it looks.