If you haven’t heard yet, we’re building our latest project car, the Factory Five Cobra Jet Challenge. We can hardly wait until it’s done, but we have a lot of work to do before the car turns a wheel on pavement.
If you’ve been following the build, you’ll know that we’ve installed the complete front suspension, mounted the rearend in the car, and got about 80-percent of the engine bay cabin metal drilled. Now, It’s time to install our Tilton Engineering goodies, which include their 600-series Pedal Box, 76-series master cylinders, and more. Tilton also sent us a cool little premium billet brake bias adjuster, so we can adjust our front and rear braking force on-the-fly, but that will be installed in a later story when the dash goes into the car.
To get a better feel for the products and to understand how everything works in conjunction, we talked to Tilton Engineering’s President, Jason Wahl.
When all is said and done, our Factory Five Challenge car will weigh anywhere from 2,200 – 2,500 pounds with the driver in place. We wanted to keep the weight to a minimum, so we decided to go with Tilton’s 600-series overhung aluminum pedal assembly (P/N 72-608). Also pictured is their 600-series throttle pedal (P/N 72-615) with the drive-by-wire throttle linkage kit but due to the layout of the Challenge car, we weren’t able to install the throttle pedal. The pedal assembly itself is made from aluminum (the pedals are forged-aluminum), and is engineered to be highly rigid, while keeping the weight down.
The 600-series pedal assembly features a traditional fixed-mount master cylinder location and a balance bar for adjusting front-to-rear brake bias. As we stated in the beginning, we’re going to install Tilton’s premium remote bias adjuster to make adjusting the braking force out on the track a simple task. The lightweight aluminum frame of the pedal assembly features guide “ramps” to reduce balance bar tipping, also to reduce friction and improve brake repeatability. The pedal pivots utilize wave washers to reduce lateral pedal movement, and also oil-impregnated bronze bushings to keep everything operating smoothly.
One thing we really like about Tilton’s 600-series pedal assembly and 600-series throttle pedal is that the foot pads can be adjusted vertically, horizontally, and in angle. All of that adjustability makes it that much more suitable to individual driver preferences. The 600-series pedal assembly also features an adjustable pedal ratio that allows the brake pedal to be tuned to different settings without having to change the master cylinder’s bore size.
To complete the 600-series pedal assembly, we opted for Tilton’s newly-designed 76-series master cylinders and three-chamber plastic reservoir with AN fittings. One of the new features on the 76-series master cylinder is the addition of a top AN-3 outlet port for more flexibility with plumbing, while also retaining the front port to match the function of the recent design. With the added top port, a banjo fitting can also be used. Both outlet ports on the 76-series master cylinder can now be used with standard fittings, eliminating the need to modify or use adapters. These master cylinders are available in seven bore sizes, and Tilton can help you choose the perfect size master cylinder for your application with their sizing questionnaire.
Tilton's Flow Control Valve For Hydraulic Clutches
This little nifty flow control valve might look just like a fitting for fluid to pass through, but it does way more than just that. Tilton’s flow control valve actually allows the clutch to slip slightly during quick engagements to reduce shock loads on the driveline, lowering any chances of losing traction, or damaging any driveline components. Shift times are still quick and pedal feel remains the same. “The smaller the orifice, the greater the restriction and the slower the release bearing will be able to return,” Wahl explained. “Think of it as letting the pedal out slower. We typically recommend that you start with the largest orifice (least restriction) and work your way down. The thought is that it is better to under-restrict than over-restrict, which could cause more heat going into the clutch.” No matter what kind of racing you do, on any certain level, Tilton’s flow control valve is a nifty piece of machinery and a great investment.
The three-chamber reservoir is a good fit for our build because it is made from a fiberglass-reinforced nylon material that stands up well to heat and is also very durable. The reservoir lid even incorporates mesh screens to prevent foreign objects from falling in, as well as two convenient fluid level windows. A two-hole mount makes this reservoir easy to bolt to the firewall/bulkhead.
For our application, Tilton set us up with a 7/8-inch master cylinder for the rear brakes and a 3/4-inch master cylinder for the front brakes. We were curious as to why Tilton set us up with a larger master cylinder for the rear and a slightly smaller unit for the front.
“Smaller master cylinders generate more line pressure (for the same amount of input force),” Wahl explained. “Since most road race cars see the front brakes doing approximately 70% of the work, the larger front calipers and rotors alone are not enough to properly bias the car. Thus we have to feed more pressure to the front (via a smaller master cylinder) and less pressure to the rear (via a larger master cylinder).”
For those that have never installed an aftermarket pedal assembly into their vehicle, it can seem a little intimidating, but if you have a good idea of how the system works, you should have no problem. Lucky for us, our car is a little less than half-way assembled, so we had a blank canvas and a reasonable amount of space to work with.
Being that the pedal box has a rear mount in addition to the main bracket, we slid the rear mount onto the master cylinder mounts of the pedal assembly and marked where we need to drill for the two holes on the 3/4-inch tubes that will finish securing our pedal box to the chassis. After drilling the holes and fastening the hardware, we were ready to install our throttle pedal and master cylinders.
Lokar’s Billet Coyote Throttle Pedal
Unfortunately, we had some spacing complications come up with Tilton’s 600-series throttle pedal during installation, so we decided to go with Lokar‘s drive-by-wire electronic throttle pedal (JEGS P/N 625-XDBW-6004). Lokar’s throttle pedal utilizes a non-contact hall effect sensor and is able to be programmed to optimize electrical output for a virtually instant throttle response with no lag whatsoever. Also, since Lokar’s throttle pedal is a direct bolt-in application for the 2011+ Mustangs, it will work perfectly with the room we have in our footwell. Another plus is the fact that we don’t have to modify anything for it to fit. All we needed to do was make a simple bracket to mount the pedal where we wanted and the pedal assembly has two mounting nuts in the back of the housing.
“The OE pedal is designed to look good and be comfortable in one application only….the car it came out of,” explained Brian Downard of Lokar. “Once you remove that and try to fit it in another foot well it starts to look big, clunky, and quite frankly may not be very comfortable in a Roadster pick up, Factory Five Cobra, or a 68 Mustang. Not to mention, “the look” or style, you may need three different styles of pedals for these three applications to fit the style and the usage of those very different cars. With the Lokar Drive-By-Wire we have given the car owner the ability to choose the pedal that will fit the application and style they want to convey in the interior of the car.”
To install the 76-series master cylinder, we placed a jam nut on the threaded shaft and placed the unit on the master cylinder mounts. From there, we turned the threaded shaft into the threaded mount on the brake pedal. Next, we simply secured the master cylinder to the pedal assembly with locknuts and repeated the same steps for our other 76-series master cylinders. Since there weren’t any provisions for Tilton’s three-chamber reservoir on our sheetmetal for the firewall, we decided to take matters into our own hands and mount it dead center behind the engine, on the firewall, of course. The reservoir itself has two mounting holes, so we utilized those for a simple installation.
Fittings with Fragola
When building a car from scratch we try to encourage the customer to use all AN style fittings. – Jeff Stacy, Fragola
Fragola makes about every different type of fitting you could imagine in both aluminum and steel. We utilized their straight bulkheads, bulkhead tees, bulkhead 90s, tube nuts, tube sleeves, and more. “When building a car from scratch we try to encourage the customer to use all AN style fittings,” says Jeff Stacy of Fragola. “It makes the installation much cleaner and easier. When the project starts out using a real car we will adapt AN style fittings to the OE inverted flare style fittings that come stock on production cars.”
When the question came up about soft versus hard lines, Stacy mentioned, “Remember that plumbing a car with the smallest line will give you the best pedal feel and pressure. We do not recommend plumbing the entire car with soft line. Plumbing with hard line to each wheel and then using soft line to the caliper works the best.”
AEM Brake Pressure Switches
Installation of Tilton’s 600-series pedal box was a breeze, especially because our car is still in the process of being assembled. Overall, the quality, fit, and finish of the 600-series pedal box is great, and it helps that there is a lot of adjustability for the driver. We definitely can’t wait to test out Tilton’s 600-series pedal box, three-chamber reservoir, premium bias adjuster, and 76-series master cylinders out on the track!